OBJECTIVE. The objective of our study was to compare the detectability and distinguishability of simulated soft-tissue opacities of 50 variants of an anthropomorphic breast phantom in mammograms acquired with a digital direct flat-panel detector versus an analog system; we also compared the image settings "analog film," "digital film," and "digital monitor."

MATERIALS AND METHODS. The studies were performed on digital (Lorad Selenia) and analog (Mammomat 3) mammography systems. Four hundred fifty silicone cubes devised with different randomly distributed columns, holes, or both columns and holes (diameter, 3–7 mm; height, 0.5–4.0 mm) were used as test bodies. One experimental series was performed with a silicone scatter body and one with a silicone and an anthropomorphic ground-meat scatter body. All x-rays were obtained at identical settings and exposures. Four radiologists rated the films and monitor-displayed images independently of each other in randomized order on a standardized electronic questionnaire.

RESULTS. The digital monitor technique generally scored better than digital film viewing and analog readings. The McNemar test for multiple paired comparisons mostly yielded a p value of < 0.0005. The smallest volume category counted as the most valid test scenario for all raters, where the percentage of correct positive findings ranged between 30% and 58% (analog technique), 43% and 68% (digital film viewing), and 55% and 66% (monitor viewing). The corresponding accuracy rates were 77–93%, 75–95%, and 81–85%, respectively, with kappa values of 0.2–0.5 (analog) and 0.3–0.6 (digital) for comparing the gold standard with raters' evaluations.

CONCLUSION. Digital flat-panel mammography is superior to the analog screen-film method for the detection of simulated opacities.

OBJECTIVE. The objective of our study was to describe the imaging features of polyacrylamide gel breast implants in women with and those without complications from mammoplasty.

CONCLUSION. Although polyacrylamide gel implants may mimic conventional implants on both sonography and MRI in women who do not have complications from mammoplasty, polyacrylamide gel implants have some distinguishing features. The imaging appearance of polyacrylamide gel implants is related to the technique of injection and whether there are any associated complications. The implants are usually in a retroglandular location. Mammography, sonography, and MRI can be used to evaluate short-term complications, although MRI appears to be the most sensitive. Common short-term complications include extravasation of polyacrylamide gel and secondary infection, which may be related to lactation. The long-term complications of polyacrylamide gel mammoplasty are unknown. Knowledge of the appearances of polyacrylamide gel implants in women with and those without complications from mammoplasty is useful in the radiologic evaluation of such patients.

OBJECTIVE. The purpose of our study is to review the accuracy of our method of non-imaging-guided anterior glenohumeral gadolinium contrast injection targeting the rotator interval in 100 consecutive patients.

MATERIALS AND METHODS. One hundred consecutive community-referred patients at our MRI facility underwent non-imaging-guided glenohumeral contrast injection targeting the rotator interval, with no patients excluded on the basis of expected diagnosis. The studies were then retrospectively reviewed for accuracy of injection based on patient factors and diagnosis.

RESULTS. This method was 99% accurate in our study, regardless of diagnosis.

CONCLUSION. The relative ease, efficiency, reproducibility, and accuracy of this method of non-imaging-guided anterior glenohumeral injection make it the method of choice at our institution, and we believe this technique merits consideration for more widespread utilization.

OBJECTIVE. The purpose of our study was to report the results of screening CT colonography (CTC) in an asymptomatic average-risk Asian population.

MATERIALS AND METHODS. In 2005 and 2006, 1,015 Korean adults (609 men and 406 women; mean age, 51 years) underwent screening CTC using a 16-MDCT scanner and an automated CO₂ delivery system. During the study period, the protocols were changed to use less vigorous purgation and lower radiation doses; fecal tagging (n = 890) and primary 3D interpretation (n = 966) were generally used. CTC results were categorized as C0, inadequate; C1, no significant polyp; C2, one or two 6- to 9-mm polyps; C3, polyps ≥ 10 mm or ≥ three 6- to 9-mm polyps; and C4, mass. Patients with positive CTC results were referred to gastroenterologists for follow-up or management planning.

RESULTS. Categories C0–C4 were assigned to 21 (2.1%), 916 (90.2%), 54 (5.3%), 23 (2.3%), and one (0.1%) patients, respectively. Fifty-four patients with C4 (n = 1), C3 (n = 20), or C2 (n = 33) underwent subsequent optical colonoscopy: complete (n = 53) and incomplete (n = 1). Per-patient positive predictive values (PPVs) for categories C3–C4 and C2–C4 were 90% (18/20) and 74% (39/53), respectively. Per-polyp PPVs at 10- and 6-mm thresholds were 92% (22/24) and 69% (45/65), respectively. The diagnostic yield for advanced neoplasm was 1.5% (15/1,015).

CONCLUSION. Our results seem comparable to Western experiences, showing that a successful screening CTC program can be reproduced in an Asian population.

OBJECTIVE. The purpose of this study was to determine whether injection of hemostatic agents directly into an injury site under the guidance of contrast-enhanced sonography can effectively control hemorrhage due to hepatic trauma.

MATERIALS AND METHODS. Fifteen mixed-breed dogs 2–3 years old and weighing 17–20 kg were anesthetized with intramuscular pentobarbital sodium (30 mg/kg). A special impacting device was used to induce hepatic trauma with a mean force of 5.3 ± 0.3 kN. Twelve of the 15 dogs had hepatic injuries with a grade of 3–4 or 4. The 12 dogs were divided into treatment and control groups. In the treatment group, hemocoagulase atrox (1 Klobusitzky unit) and -cyanoacrylate (1 mL) were administered by transcutaneous injection into the injury site and the bleeding site, respectively, under the guidance of contrast-enhanced sonography. The control group received injections of 0.9% normal saline solution.

RESULTS. After injection into the treatment group, no active bleeding was observed at the liver injury site. In the control group, evidence of active bleeding was present on contrast-enhanced sonograms. Laparotomy of the treatment group showed that hepatic injuries had been covered and adhered by clots and the glue membrane of the hemostatic agents and that free intraperitoneal blood volume was significantly less than in the control group (p < 0.001). Bleeding did not stop in the control group.

CONCLUSION. In dogs, transcutaneous local injection of hemostatic agents can effectively reduce blood loss due to severe liver trauma. Because it is simple, convenient, and effective, the technique may be an alternative for bedside and battlefield management of hepatic hemorrhage due to trauma.

OBJECTIVE. The purpose of this study was to evaluate the usefulness of low-dose MDCT for radiologic monitoring of patients who have undergone placement of bronchial stents for airway bypass.

SUBJECTS AND METHODS. In a prospective study, seven patients underwent MDCT according to a low-dose protocol (40 mAs, 120 kVp) before and after stent placement. The positions of the stents in the segmental bronchi were analyzed and compared with the bronchoscopic findings, which were reference standard. Patency versus lack of patency of stents was classified with five levels of confidence, and a definitive diagnosis was assigned to each stent. Prediction of stent dislodgment, follow-up findings, and complications occurring during the observation period were recorded. Consensus reading was performed by two radiologists. Statistical analysis was conducted by receiver operating characteristic analysis or four-field table.

RESULTS. Seven patients underwent implantation of 37 stents (mean, 5 ± 2 [SD] stents per patient; range, 2–8 stents). The area under the curve for differentiating patent from occluded stents was 0.995 with resulting sensitivity and specificity of 86.5% and 98.1%. The correct diagnosis of patency was established with MDCT for all but one stent (sensitivity, 94.7%; specificity, 100%). Sensitivity and specificity for prediction of dislodgment were 80% and 91%. Five stents were not identified during inspection bronchoscopy but were found in a regular position at MDCT. Three instances of minor bleeding and one of pneumothorax resolved spontaneously. The mean effective dose of the scan was 1.3 ± 0.6 mSv.

CONCLUSION. Low-dose MDCT is feasible for radiologic monitoring after airway bypass procedure.

OBJECTIVE. Limited coverage of the brain in the z-axis has been a drawback of perfusion CT. The purpose of this study was to evaluate the usefulness of perfusion CT with extended coverage in the z-axis for the assessment of acute stroke in an emergent clinical setting.

MATERIALS AND METHODS. Fifty-eight patients who underwent 80-mm-coverage perfusion CT within 24 hours after stroke onset were included. Perfusion CT was performed using a 64-MDCT unit equipped with 40-mm-wide detector and the toggling table technique. Lesion detection by perfusion CT was analyzed using follow-up diffusion-weighted imaging and MR angiography as the reference standards. More conventional 20-mm-coverage perfusion CT was simulated by extracting data obtained at the basal ganglia level for comparison with 80-mm-coverage perfusion CT.

RESULTS. Fifty-one patients had acute infarctions and seven patients did not. For 80-mm-coverage perfusion CT, perfusion abnormality was detected in 42 of 51 patients (sensitivity, 82.4%; and specificity, 85.7%). When patients with small artery disease (small acute infarctions in the basal ganglia, thalamus, corona radiata, and pons) were excluded, sensitivity increased to 92.3%. As compared with 80-mm-coverage perfusion CT, 20-mm-coverage perfusion CT missed nine acute infarctions located above or below the level of the basal ganglia (p = 0.0039).

CONCLUSION. Perfusion CT with 80-mm-coverage was found to be useful as an initial imaging method in acute ischemic stroke, although it had low sensitivity for detecting small acute infarctions. In particular, this technique provided higher lesion detection than 20-mm-coverage perfusion CT.

OBJECTIVE. Renal volumetry is an essential part of split renal function assessment in MR urography. The aim of this study was to assess the accuracy and repeatability of a 3D segmentation algorithm based on the belief functions theory for calculating renal volumes from MR images.

MATERIALS AND METHODS. The true volumes of 20 animal kidneys of various sizes were obtained by fluid displacement. Each kidney was examined using two different MR units. Three-dimensional proton density–weighted acquisitions with an incremental slice thickness were performed. The MR volume was then measured with a segmentation algorithm based on the belief functions theory. Two independent observers performed all segmentations twice. Accuracy, intraobserver variability, and interobserver variability were evaluated by the Bland-Altman method. The number and type of manual corrections were recorded as well as the entire processing time.

RESULTS. The mean renal volume estimated by fluid displacement was 114 mL (range, 38–224 mL). With regard to the renal volumes obtained from assessments of adjacent axial MR images, the maximal SDs of the difference were 2.2 mL (accuracy), 0.6 mL (intraobserver variability), and 1.8 mL (interobserver variability). Segmentation of axial slices provided better accuracy and reproducibility than coronal slices. Overlapped coronal slices yielded poor results because of the partial volume effect. The mean processing time including optional manual modifications was less than 75 seconds.

CONCLUSION. The belief functions theory can be considered an accurate and reproducible mathematic method to assess renal volume from MR adjacent images.

OBJECTIVE. The purpose of this pictorial essay is to illustrate several clinical situations in which SPECT/CT can be effectively applied in nuclear radiology practice.

CONCLUSION. SPECT/CT has recently emerged as a valuable adjunct to standard techniques in clinical nuclear radiology. This technique provides significantly improved scintigraphic localization and characterization of disease, increasingly important in this era of minimally invasive surgery and targeted radiotherapy.

OBJECTIVE. The purpose of this study was in vitro sonographic–pathologic correlation of findings in dissected axillary lymph nodes from breast cancer patients undergoing axillary lymph node dissection and classification of the sonographic appearance of the nodes on the basis of cortical morphologic features to facilitate early recognition of metastatic disease.

MATERIALS AND METHODS. High-resolution sonography was used for in vitro examination of 171 lymph nodes from 19 axillae in 18 patients with unknown nodal status who underwent axillary lymph node dissection for early infiltrating breast cancer. The images were evaluated by two blinded observers, and discordant readings were referred to a third blinded observer. Each lymph node was classified as one of types 1–6 according to cortical morphologic features. Types 1–4 were considered benign, ranging from hyperechoic with no visible cortex to thickened generalized hypoechoic cortical lobulation. Type 5 (focal hypoechoic cortical lobulation) and type 6 (hypoechoic node with absent hilum) nodes were considered metastatic. The reference standard for metastatic disease was histopathologic evaluation of sectioned nodes by a single pathologist blinded to sonographic findings. Largest nodal diameter also was measured.

RESULTS. Interobserver agreement was 77% for classification of nodal morphology (types 1–6) and 88% for characterization of a node as benign or malignant. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of cortical shape in prediction of metastatic involvement of axillary nodes were 77%, 80%, 36%, 96%, and 80%. Type 4 nodes had the most false-negative findings (four of 36). Node size ranged from 0.2 to 3.8 cm, and subcentimeter nodes of all types were detected.

CONCLUSION. In breast cancer, axillary lymph nodes can be classified according to cortical morphologic features. Predominantly hyperechoic nodes (types 1–3) can be considered benign. Generalized cortical lobulation (type 4) is uncommonly a false-negative finding, but metastasis, if present, is invariably detected at sentinel node mapping. The presence of asymmetric focal hypoechoic cortical lobulation (type 5) or a completely hypoechoic node (type 6) should serve as a guideline for universal performance of fine-needle aspiration for preoperative staging of breast cancer. This classification, when verified with larger samples, may serve as a useful clinical guideline if proven with results of in vivo studies.

OBJECTIVE. The purpose of this study was to evaluate the applicability of the current BI-RADS for sonography to the assessment of synchronous breast nodules other than the primary malignant tumor in patients with breast cancer.

MATERIALS AND METHODS. One hundred eighty-nine synchronous nodules in 147 breast cancer patients were surgically excised after localization, and 412 synchronous nodules in 191 patients were observed or biopsied or excised without localization. Among a total of 601 synchronous nodules, 372 nodules were ipsilateral and 229 were contralateral to a primary malignant tumor. Two radiologists retrospectively reviewed sonograms of these nodules and determined the sonographic BI-RADS category without clinical information or pathologic results. For each nodule, the preoperative BI-RADS category and pathologic or follow-up results were compared.

RESULTS. Four hundred eighty-two nodules were classified category 3; 112 nodules, category 4; and seven nodules, category 5. Fifty-five (11.4%) of the category 3 nodules and 57 (47.9%) of the category 4 and 5 nodules were confirmed malignant. Thirty-six (21.2%) of 170 category 3 synchronous nodules in the same quadrant as the primary tumor were confirmed malignant, as were 12 (9.8%) of 122 nodules in a different quadrant and eight (4.2%) of 190 nodules in the contralateral breast.

CONCLUSION. For assessment of synchronous nodules in breast cancer patients, application of conventional screening sonographic BI-RADS categories may not account for possible increased risk of malignancy in synchronous nodules, especially those in the same quadrant of the breast as the index malignant tumor.

OBJECTIVE. The purpose of this study was to assess the role of sonography in the diagnosis and management of palpable solid breast masses in adolescents and to correlate the sonographic findings with the histopathologic findings and clinical outcome.

MATERIALS AND METHODS. A retrospective study was conducted with the breast sonograms of 20 adolescent girls 13–19 years old who presented with palpable breast masses found to be solid at breast sonography. The Stavros sonographic criteria were used to assess the benignity or malignancy of solid breast masses. All sonographic findings were correlated with histopathologic or clinical follow-up findings.

RESULTS. Sonography showed 21 solid masses in 20 patients (one patient had bilateral solid breast masses). All but six solid masses were presumed benign according to the Stavros sonographic criteria. All solid masses were proved benign at histopathologic or clinical follow-up examination.

CONCLUSION. Sonography was not useful for predicting the histologic diagnosis of all solid benign breast masses in adolescent patients. The Stavros sonographic criteria, however, were useful for predicting benignity in 65% of the breast masses on which histopathologic examination was performed. Tissue biopsy may be performed on solid breast masses that do not meet the criteria for benign masses according to the Stavros sonographic criteria.

OBJECTIVE. The purpose of our study was to determine the efficacy of contrast-enhanced CT in detecting a thickened endometrium. We used transvaginal sonography as the reference standard.

MATERIALS AND METHODS. Between March 2005 and January 2007, data from 259 patients (mean age, 47 years; age range, 18–90 years) who underwent transvaginal sonography and contrast-enhanced CT of the pelvis were analyzed retrospectively. The endometrium was quantitatively measured in millimeters on sonography. On CT it was qualitatively categorized as normal, thickened, indeterminate, or not visualized and compared with the sonography findings and original radiology reports. When the endometrium was indeterminate (thickened or triangular in shape on axial images), sagittal reconstructions were performed for final categorization. Two reviewers evaluated the CT scans and sonograms jointly with differences resolved by consensus. Kappa, Wilcoxon's rank sum test, and intraclass correlation statistics were derived.

RESULTS. The overall sensitivity and specificity of CT in detecting the thickened endometrium was 53.1% and 93.5%, respectively, relative to transvaginal sonography. The positive and negative predictive values were 66.7% and 89.1%, respectively. Kappa, the statistical measure of agreement between CT and sonography data, was 0.5049. All cases of a triangular endometrium were normal in size on sagittal reconstruction images.

CONCLUSION. Routine pelvic CT correctly identifies a normal endometrium in most patients. Sagittal reconstruction images are helpful to further evaluate the endometrium on CT in cases with a prominent or triangular endometrium because these are often related to uterine version. CT is relatively insensitive in detecting the thickened endometrium but better able to identify gross rather than subtle thickening, which must be further characterized by transvaginal sonography.

OBJECTIVE. This study aimed to evaluate the utility of MDCT in planning abdominal perforator surgery for breast reconstruction in patients who have undergone mastectomy.

SUBJECTS AND METHODS. One hundred twenty-six consecutive patients scheduled for postmastectomy breast reconstruction using deep inferior epigastric perforator flaps underwent MDCT. The images were evaluated to identify, characterize, and map the dominant musculocutaneous perforator vessels of the deep inferior epigastric artery. In the first 36 patients, we compared the intraoperative findings with the preoperative MDCT findings. In the latter 90 patients, the dominant perforator vessels were directly selected on the basis of MDCT findings.

RESULTS. We found an exact correlation between the intraoperative and radiologic findings in the first 36 cases. In the following 90 cases, the average operating time saved per patient was 1 hour 40 minutes and there was a significant reduction in postsurgical complications. The preoperative evaluation by MDCT confirmed the wide range of variability in the vascular anatomy of the abdominal wall previously described in anatomic studies.

CONCLUSION. MDCT provides valuable information before surgery about the arterial anatomy of the inferior abdominal wall. It enables accurate identification of the most suitable dominant perforator vessel and makes surgical perforator flap procedures for breast reconstruction faster and safer.

OBJECTIVE. Polyacrylamide gel injection mammoplasty has recently been used for breast augmentation. However, many complications have been reported including complications that in some patients resulted in the need for mastectomy. This article reviews the MRI appearances of various complications of polyacrylamide gel injection mammoplasty including breast asymmetry; intramammary or extramammary gel displacement, including intrathoracic extension; and glandular atrophy, inflammation, and infection resulting in mastectomy.

CONCLUSION. Because poly acrylamide gel has a high water content, we found that sagittal and axial T2-weighted are the best sequences to use to detect complications.

OBJECTIVE. The purpose of this article is to describe and illustrate the variety of common morphologic features, enhancement patterns, and kinetics of pure ductal carcinoma in situ (DCIS) on dynamic contrast-enhanced MRI of the breast, using the American College of Radiology BI-RADS lexicon.

CONCLUSION. Breast MRI plays an important role in the detection of DCIS, which most often appears as nonmass clumped enhancement, in a ductal or segmental distribution, with variable enhancement kinetics.

OBJECTIVE. Papillary lesions of the breast are a heterogeneous group of lesions that are difficult to diagnose as benign or malignant. The purpose of this article is to review clinical presentation, imaging features, and pathologic correlation of papillary lesions of the breast and to discuss the prognosis and management of these lesions.

CONCLUSION. Recognition of the variety of benign and malignant papillary lesions of the breast will facilitate diagnosis and proper management.

OBJECTIVE. This study was designed to investigate whether the use of MR diskography would result in improved reader confidence over the use of CT diskography alone for evaluating foraminal impingement causing lumbar radiculopathy.

SUBJECTS AND METHODS. Sixteen disk levels in 14 consecutive patients with suspected foraminal impingement causing lumbar radiculopathy were prospectively included in the study. A mixture of diluted gadodiamide and iodinated contrast material was injected at each disk level. After diskography, a CT scan (CT diskography) and T1-weighted fat-suppressed MR image (MR diskography) were obtained. Two spine radiologists and an orthopedic spine surgeon independently scored CT diskography and MR diskography for foraminal evaluation on a 3-point scale: 1, low confidence; 2, moderate confidence; and 3, high confidence. Each reader also assessed whether MR diskography showed an additional benefit over CT diskography with regard to the depiction of foraminal abnormalities only. Another radiologist reviewed conventional MR images focused on disk height and morphology.

RESULTS. The reviewers' confidence scores for MR diskography were superior to those for CT diskography (reader 1, p = 0.00008; reader 2, p = 0.0008; reader 3, p = 0.0015) (p < 0.05). MR diskography was considered beneficial in 13 of 16 disk levels (reader 1), 14 of 16 (reader 2), and 14 of 16 (reader 3). MR diskography increased the confidence scores for the detection of foraminal impingement, especially in cases of severe disk degeneration, but did not show additional benefits in cases of an extensive vacuum in the disk or large disk extrusion.

CONCLUSION. Simultaneous MR diskography and CT diskography with a mixture of gadodiamide and iodinated contrast material may be beneficial for evaluating foraminal impingement causing lumbar radiculopathy.

OBJECTIVE. The purpose of this study was to analyze the sonographic appearance of a large series of pathologically proven ganglia.

MATERIALS AND METHODS. A computer search of sonography and pathology reports for hand and wrist ganglia was performed. All sonography reports and images were reviewed for ganglion size, location, presence of a neck, echogenicity, acoustic enhancement, locules, color Doppler flow, margins, wall thickness, and calcifications and to determine if the ganglion was palpable or collapsed. All pathology reports were reviewed for histologic features that were then correlated with the sonographic images. Ganglia were categorized into three groups: simple, complex cystic, and solid-appearing.

RESULTS. Of 60 ganglia, 34 were complex, 91% of which were located within the dorsal or volar wrist; 97% had well-defined margins; 76%, locules; 68%, acoustic enhancement; 47%, a thick wall; 15%, internal reflectors; and 12%, blood flow. Of the 23 simple ganglia, 11 involved the extensor or flexor tendon sheath, 73% of which were simple. Complex ganglia had a larger mean volume than simple. Three ganglia were solid-appearing. A visible neck was seen in 25% of ganglia.

CONCLUSION. Most ganglia are complex rather than simple on sonography. Complex ganglia are larger than simple ganglia; located within the dorsal or volar wrist; and usually have well-defined margins, thick walls, locules, and acoustic enhancement. A small percentage have blood flow and internal reflectors. Simple ganglia are smaller and can occur within the volar or dorsal wrist, or flexor tendon sheath. Most flexor tendon sheath ganglia are simple rather than complex. Solid-appearing ganglia, although unusual, may mimic a benign neoplasm or synovitis.

OBJECTIVE. The purpose of this study was to investigate the in vivo morphologic and elastic parameters of trabecular bone with high-resolution 3-T MRI in a healthy reference population.

SUBJECTS AND METHODS. A series of wrist MR images were acquired with high-spatial-resolution (180 µm) isotropic voxels from 40 subjects without reported bone disease. After image postprocessing, the bone volume-to-total volume ratio, trabecular thickness, trabecular separation, and trabecular number were calculated in the morphologic analysis. Trabecular bone was mechanically simulated using the finite-element method to calculate the apparent elastic modulus parameter. The relationship between morphologic and mechanical parameters was studied. The influence of the analyzed bone volume was also investigated.

RESULTS. Statistically significant sex influences were found on the bone volume-to-total volume ratio (p = 0.003), trabecular thickness (p = 0.02), and apparent elastic modulus (p = 0.01); these parameters were lower in women. However, trends were found only on trabecular separation (p = 0.06) and trabecular number (p = 0.07). Age had no statistically significant influence in any morphologic (bone volume-to-total volume ratio, r = –0.24, p = 0.13; trabecular thickness, r = –0.03, p = 0.88; trabecular separation, r = 0.12, p = 0.47; and trabecular number, r = –0.23, p = 0.16) or elastic (apparent elastic modulus, r = –0.18, p = 0.26) parameter. A statistically significant relationship between apparent elastic modulus and the square of bone volume-to-total volume ratio was found (r = 0.968, p < 0.001). This association was not seen (r = 0.185, p = 0.25) and apparent elastic modulus results were considerably different (p < 0.001) if the volume of analyzed bone was reduced.

CONCLUSION. We found that bone volume-to-total volume ratio, trabecular thickness, and apparent elastic modulus are parameters significantly influenced by sex. Apparent elastic modulus results show a relationship with bone volume-to-total volume ratio. Trabecular bone volume should be maximized for an appropriate mechanical analysis.

OBJECTIVE. Posterolateral rotatory instability of the elbow is a diagnosis largely made by clinical examination; no relevant radiographic signs have been reported. We have seen four patients with an osseous defect and detachment of a fragment of bone in the posterolateral margin of the capitellum. These patients had chronic posterolateral rotatory instability of the elbow.

CONCLUSION. An osseous defect of the posterolateral corner of the capitellum is an uncommon finding that in each instance was associated with chronic posterolateral rotatory instability of the elbow. We termed this lesion the "Osborne-Cotterill lesion." We report our findings in these patients; when this lesion is diagnosed, clinicians should consider posterolateral rotatory instability.

OBJECTIVE. The purpose of this article is to present the cases of four consecutive patients with preoperative MR diagnosis of humeral avulsion of the glenohumeral ligament (HAGL) who had no evidence of HAGL at arthroscopy.

CONCLUSION. These four cases suggest that the diagnosis of HAGL should be reserved for arthroscopy and illustrate the difficulty in distinguishing HAGL from other abnormalities of the inferior glenohumeral ligament complex with MRI. Thus, MRI findings classically associated with HAGL should be more broadly described as defects of the inferior glenohumeral ligament complex. This terminology more accurately describes the abnormalities of the inferior glenohumeral ligament complex that may be depicted by MRI.

OBJECTIVE. This article will review the current role of MDCT and 3D imaging in the diagnosis and management of adults with enteroenteric intussusception.

CONCLUSION. Because of significant advancements in CT along with its increasing use, detection of enteroenteric intussusceptions by CT has increased. These findings are sometimes in asymptomatic patients, often transient, and without an identifiable lead point. This has complicated the management of adult patients with intussusception because not every patient with intussusception may need surgery.

OBJECTIVE. The purpose of this study was to examine the relation between the CT whirl sign and outcome among patients with a clinical and radiologic diagnosis of small-bowel obstruction (SBO).

MATERIALS AND METHODS. The cases of 453 patients who underwent abdominal CT because of clinical suspicion of SBO were reviewed retrospectively. Patients with a radiologic diagnosis of SBO were included. Management with surgery or medical therapy was correlated with the presence of the whirl sign and other radiologic findings. Statistical calculations were performed to determine the value of the whirl sign in predicting the type of management needed for SBO.

RESULTS. According to CT criteria, 194 patients received a diagnosis of SBO and were included in the study. The whirl sign was identified on the CT scans of 40 of the 194 patients. Thirty-two of the 40 patients had SBO necessitating surgery, for a positive predictive value of 80%; 133 of 154 patients did not need surgery, for a negative predictive value of 86%. Fifty-three of 194 patients either underwent surgery or died of SBO during conservative therapy. The whirl sign was present on the CT scans of 32 of the 53 patients, for a sensitivity of 60%. One hundred thirty-three of 141 patients did not need surgery and did not have a whirl sign, for a specificity of 94%. The odds ratio for the whirl sign in predicting the presence of SBO necessitating surgery was 25.3 (95% CI, 10.3–62.3).

CONCLUSION. A patient with the whirl sign on CT is 25.3 times as likely as a patient without the sign to have SBO necessitating surgery. The results suggest an important role of the whirl sign in assessment of treatment options for patients with clinical and radiologic signs of SBO.

OBJECTIVE. This study was designed to quantify and characterize the air-containing thoracic esophagus on CT to help diagnose diseases and facilitate correlation with lung diseases that may be associated with aspiration.

SUBJECTS AND METHODS. The maximal air-containing esophageal lumina on each section of standard CT scans of 110 subjects were measured. These subjects came from a cohort of 10,132 self-reported healthy individuals who underwent CT for measurement of coronary artery calcium. Measurements were interpolated to account for variation in the length of the thoraces.

RESULTS. Greater than 60% of the esophageal segments contained no air. On average the maximum air column was 10.5 (SD, 5.0) mm. Only 7.9% of the lumina were > 10 mm. Only 2% were > 15 mm, and only 0.2% were > 20 mm. The average number of lumina > 10 mm as a proportion of the entire esophageal length was 8% (14%). The average size at the carina was 2.6 (4.1) mm. In the upper 30% and from 61% to 75% down the length of the esophagus, < 5% of the lumina were > 10 mm. Less than 3% of subjects had air in the lowest two sections, indicating that the normal lower esophageal sphincter was closed.

CONCLUSION. Esophageal air of > 10 mm should be considered abnormal in all segments except between the cardiac ventricles and lower esophageal sphincter. In this area, > 15 mm should be considered abnormal. An air–fluid level is abnormal.

OBJECTIVE. The objective of this study was to compare the diagnostic accuracy of tumor staging in patients with advanced esophageal cancer based on contrast-enhanced CT findings alone with that based on a combination of CT and double-contrast esophagography and to evaluate the relevance of tumor stage to survival rate.

MATERIALS AND METHODS. In 94 patients who underwent surgery as the primary treatment for esophageal cancer and had a diagnosis of postoperative T stage 3 (pT3) or pT4 disease based on pathologic examination, T stage was evaluated using CT alone and using a combination of CT and double-contrast esophagography. The diagnostic criterion for T4 disease using CT alone was tumor strongly displacing or deforming adjacent organs. The diagnostic criterion for T4 disease using the combined method was tumor displacing or deforming adjacent organs in the direction that corresponded to the direction of the location of the tumor or the deepest ulcer as diagnosed by barium esophagography. Concordance of T staging based on imaging with postoperative T staging based on pathology results, the gold standard, and survival rate were assessed for CT alone and for the combined method.

RESULTS. The concordance rate with postoperative T staging pathology results was 78% for CT alone and 84% for CT and double-contrast esophagography combined, with a significant difference between the two diagnostic methods. For patients with a diagnosis of T3 and those with a diagnosis of T4 using CT alone, the 3-year survival rate was 42% and 26%, respectively, with no significant difference between the two. For patients with a diagnosis of T3 and those with a diagnosis of T4 using the combined method, the 3-year survival rate was 42% and 21%, respectively, with a significant difference between the two.

CONCLUSION. The diagnostic performance of contrast-enhanced CT and double-contrast esophagography combined in staging advanced esophageal tumors is better than that of CT alone and thus has potential for estimating prognosis.

OBJECTIVE. The purpose of this study was to determine the frequency and appearance of esophageal wall thickening on CT scans in a series of patients with findings of diffuse esophageal spasm on barium studies.

CONCLUSION. CT revealed marked esophageal wall thickening in seven (21%) of 33 patients who had findings of diffuse esophageal spasm on barium studies. CT showed significantly greater esophageal wall thickening in the lower thoracic esophagus 5 cm above the gastroesophageal junction than in the upper thoracic esophagus at the level of the aortic arch or in the midthoracic esophagus at the level of the carina (p < 0.01). This esophageal wall thickening corresponded to the presence of multiple strong nonperistaltic contractions in the lower thoracic esophagus on barium studies. Our findings suggest that diffuse esophageal spasm should be included in the differential diagnosis when CT shows smooth circumferential wall thickening in the lower half of the thoracic esophagus, particularly in elderly patients with dysphagia or chest pain.

OBJECTIVE. The objective of our study was to determine the diagnostic value of analyzing the pattern of gallbladder wall enhancement on MDCT to characterize diffuse gallbladder wall thickening as benign or malignant.

MATERIALS AND METHODS. MDCT scans obtained during the portal venous phase in 78 patients with gallbladder wall thickening caused by various pathologic conditions were retrospectively reviewed by two blinded observers. The CT features of benign and malignant gallbladder wall thickening were compared by means of univariate and multivariate analyses. The study cases were then divided into five patterns according to enhancement pattern. Using these five patterns, two radiologists reviewed the MDCT images and recorded their diagnostic confidence for differentiating benign versus malignant cause on a 5-point scale. The diagnostic performance of CT was evaluated by each observer using a receiver operating characteristic curve analysis.

RESULTS. The thicknesses of the inner and outer layers ("thick" enhancing inner layer ≥ 2.6 mm, "thin" outer layer ≤ 3.4 mm), strong enhancement of the inner wall, and irregular contour of the affected wall were significant predictors for a malignant cause of gallbladder wall thickening (p < 0.001). The two-layer pattern with a strongly enhancing thick inner layer and weakly enhancing or nonenhancing outer layer and the one-layer pattern with a heterogeneously enhancing thick layer were patterns that were significantly associated with gallbladder cancer (p < 0.05). When we consider those two enhancing patterns as a sign of malignancy, the diagnostic accuracy of MDCT was 89.1% and 87.6% for the two observers, respectively.

CONCLUSION. Analyzing the enhancement pattern of a thickened gallbladder wall on MDCT is helpful in differentiating gallbladder cancer from benign inflammatory diseases.

OBJECTIVE. The purpose of this study is to estimate the optimal time delay before the initiation of arterial phase scanning for detection of hypervascular hepatocellular carcinoma (HCC) on 16-MDCT when a rapid bolus injection of contrast medium is administered.

SUBJECTS AND METHODS. In this prospective study, 25 patients (19 men and six women; mean age, 63.5 years; age range, 50–81 years) with pathologically confirmed HCC were included. Dynamic 16-MDCT imaging was performed in cine mode using 70 mL of nonionic iodinated contrast medium (300 mg I/mL) at an injection rate of 7 mL/s. Four consecutive 5-mm-thick slices at the maximum diameter of the HCC were selected as the region of interest. Time–attenuation curves were generated by region of interest drawn on the aorta, tumor, and liver. Qualitative assessments of conspicuity for contrast medium wash-in, peak, and wash-out of aorta and tumor were performed.

RESULTS. There were 108 arterial phase enhancing lesions (mean [±SD], 4.9 ± 2.4 cm; range, 0.7–12.9 cm) in the 25 patients. The maximum Hounsfield value of aorta, tumor, and background liver parenchyma were 463.8 ± 98 HU, 106.5 ± 19 HU, and 98.3 ± 14 HU, respectively. At the time of onset of peak tumor enhancement, the difference between tumor density and background liver density was 38.2 ± 19 HU. The time–attenuation curve showed that the mean times of contrast enhancement start, peak, and end were 9.2 ± 2.7 seconds, 19.4 ± 2.1 seconds, and 38 ± 13.5 seconds, respectively, for the aorta, and 15.5 ± 2.6 seconds, 26.3 ± 2.9 seconds, and 57.7 ± 14.4 seconds, respectively, for 25 pathologically confirmed hepatocellular carcinomas. Qualitatively, the mean times of contrast enhancement wash-in, peak, and washout were 10.2 ± 2.8 seconds, 19.9 ± 3 seconds, and 39.9 ± 9.2 seconds, respectively for the aorta, and 18 ± 4.2 seconds, 27 ± 3 seconds, and 55.7 ± 21 seconds, respectively, for tumor. There were no differences between quantitative and qualitative measurements of wash-in and peak time for the aorta (p = 0.00017, p = 0.00016) and tumor (p = 0.00163, p = 0.00040).

CONCLUSION. When using 70 mL of 300 mg I/mL of contrast medium with an injection rate of 7 mL/s in 16-MDCT scanning, the optimal time to initiate scanning for HCC is 26.3 ± 2.9 seconds (range, 24.0–34.5 seconds) after contrast medium administration.

OBJECTIVE. The purpose of this study was to evaluate the imaging features of intrahepatic biliary intraductal papillary-mucinous neoplasm manifesting only as dilatation of the lobar or segmental bile ducts without a visible mass to determine whether this type of cholangiocarcinoma can be recognized on the basis of distinct imaging features.

CONCLUSION. Intrahepatic biliary intraductal papillary-mucinous neoplasm can spread along the mucosa without forming a mass and can produce a large amount of mucin. Severe dilatation of the lobar or segmental intrahepatic bile ducts with crowding and severe atrophy of the hepatic parenchyma are helpful imaging findings.

OBJECTIVE. The purpose of this article is to illustrate the radiologic features of various biliary and nonbiliary complications after laparoscopic cholecystectomy.

CONCLUSION. Various complications should be considered in patients who do not make an uneventful postoperative recovery after laparoscopic cholecystectomy. Sonography is the easiest and most noninvasive method for screening for such complications. MR cholangiography is most effective in showing biliary complications and CT, for the evaluation of nonbiliary complications. Endoscopic retrograde cholangiography enables not only detailed biliary estimation but also biliary decompression.

OBJECTIVE. In radiofrequency ablation of lesions that require probe repositioning, distinguishing between treated and untreated regions can be difficult. We describe a method of using existing CT equipment to summate images of a current probe placement with those of earlier placements or scans of transiently enhancing targets.

CONCLUSION. Summation of CT scans during radiofrequency ablation involving multiple probe placements is feasible and results in a better appreciation of probe positioning relative to the target lesion.

OBJECTIVE. The purpose of this article is to describe the imaging findings after laparoscopic cholecystectomy, including the normal postoperative findings and the typical appearances of major complications. The relative merits of the imaging techniques available are discussed.

CONCLUSION. Laparoscopic cholecystectomy is a commonly performed surgical procedure and radiologists are often called on to identify or rule out postoperative complications. In such cases, the correct diagnosis is crucial in optimizing patient management.

OBJECTIVE. Current generation MDCT technology facilitates identification of small, nonenhancing lesions in the pancreas. The objective of this study was to determine the prevalence of findings of unsuspected pancreatic cysts on 16-MDCT in a population of adult outpatients imaged for disease unrelated to the pancreas.

MATERIALS AND METHODS. Contrast-enhanced MDCT scans of the abdomen were reviewed from 2,832 consecutive examinations to identify pancreatic cysts. Patients with a history of pancreatic lesions or predisposing factors for pancreatic disease or who were referred for pancreatic CT were excluded.

RESULTS. A total of 73 patients had pancreatic cysts, representing a prevalence of 2.6 per 100 patients (95% CI, 2.0–3.2). Cysts ranged in size from 2 to 38 mm (mean, 8.9 mm) and were solitary in 85% of cases. Analysis of demographic information showed a strong correlation between pancreatic cysts and age, with no cysts identified among patients under 40 years and a prevalence of 8.7 per 100 (95% CI, 4.6–12.9) in individuals from 80 to 89 years. After controlling for age, cysts were more common in individuals of the Asian race than all other race categories, with an odds ratio of 3.57 (95% CI, 1.05–12.13). There was no difference by sex in the prevalence of cysts (p = 0.527); however, cysts were on average 3.6 mm larger (p = 0.014) in men than women.

CONCLUSION. In this outpatient population, the prevalence of unsuspected pancreatic cysts identified on 16-MDCT was 2.6%. Cyst presence strongly correlated with increasing age and the Asian race.

OBJECTIVE. The purpose of this study was to evaluate the clinical significance of endoleaks detected on combined arterial and delayed contrast-enhanced follow-up CT examinations of patients who have undergone endovascular aneurysm repair of abdominal aortic aneurysm.

MATERIALS AND METHODS. One hundred forty-four patients underwent periodic follow-up CT examinations 12–72 months after abdominal aortic aneurysm repair. The CT protocol consisted of an unenhanced scan and contrast-enhanced scans in the arterial and 90-second delayed phases. The endoleaks detected on dual-phase CT scans were evaluated in association with the outcome (therapeutic intervention or endoleak resolution).

RESULTS. The 144 patients underwent 728 CT examinations with a mean follow-up period of 35.5 ± 14.5 months. Fifty endoleaks were detected in 50 (34.7%) of the patients. Eight endoleaks were detected in the arterial phase only, eight in the delayed phase only, and 34 in both phases. Intervention was performed to manage 16 endoleaks detected in both phases. CT showed that three endoleaks were stable (two in the arterial phase only and one in both phases) and that 31 had resolved completely (six in the arterial phase only, eight in the delayed phase only, and 17 in both phases). This finding represents a higher frequency of resolution of endoleaks detected in one phase only than in both phases (Fisher's exact test, p = 0.006).

CONCLUSION. Endoleaks detected only in the delayed phase of CT had resolved spontaneously without intervention. Therefore, we can consider eliminating the delayed phase of acquisition to minimize radiation exposure.

OBJECTIVE. The objective of our study was to illustrate various CT findings of peritoneal mesotheliomas, to review their clinicopathologic features, and to discuss the differential diagnoses.

CONCLUSION. The clinicopathologic features of peritoneal mesotheliomas vary among the subtypes such as malignant mesotheliomas, cystic mesotheliomas, and well-differentiated papillary mesotheliomas, and accordingly, there is a spectrum of CT appearances.

OBJECTIVE. Visceral artery aneurysms are uncommon, but they are clinically important because of the high incidence of rupture and life-threatening hemorrhage. Visceral artery aneurysms in patients with vascular anatomic variations are extremely rare, but detecting these variations is significant in this setting to determine the best treatment strategy; therefore, a thorough assessment of the aneurysm and of the vascular anatomy before treatment is paramount.

CONCLUSION. Three-dimensional contrast-enhanced MR angiography is a noninvasive technique for the diagnosis and display of visceral artery aneurysms. It can provide 3D anatomic information that is needed for surgery or embolization.

OBJECTIVE. Pulmonary tuberculosis (TB) is a common worldwide infection and a medical and social problem causing high mortality and morbidity, especially in developing countries. The traditional imaging concept of primary and reactivation TB has been recently challenged, and radiologic features depend on the level of host immunity rather than the elapsed time after the infection. We aimed to elaborate the new concept of the diagnosis and treatment of pulmonary TB, to review the characteristic imaging findings of various forms of pulmonary TB, and to assess the role of CT in the diagnosis and management of pulmonary TB.

CONCLUSION. Fast and more accurate TB testing such as bacterial DNA fingerprinting and whole-blood interferon- assay has been developed. Miliary or disseminated primary pattern or atypical manifestations of pulmonary TB are common in patients with impaired immunity. CT plays an important role in the detection of TB in patients in whom the chest radiograph is normal or inconclusive, in the determination of disease activity, in the detection of complication, and in the management of TB by providing a roadmap for surgical treatment planning. PET scans using ¹⁸F-FDG or ¹¹C-choline can sometimes help differentiate tuberculous granuloma from lung malignancy.

OBJECTIVE. The vibration response imaging device that we studied (VRIxp) records the intensity and location of lung sounds during a cycle of breathing. The goals of this study were to describe the characteristic features and quantitative lung data recorded by the VRIxp device from healthy asymptomatic subjects.

SUBJECTS AND METHODS. Breath sounds (frequency range, 150–250 Hz) recorded from the backs of 151 healthy asymptomatic subjects (96 nonsmokers and 55 smokers) by the VRIxp device were mapped to create a sequence of 2D images. Three raters interpreted and scored the images for predefined static and dynamic features. In addition, quantitative lung data were analyzed for characteristic regional distributions.

RESULTS. The readers of the images had good inter- and intrarater agreement. Image development in 93% of the evaluations showed an inspiratory and expiratory phase with a progressive and regressive stage that developed bilaterally in a vertical and synchronized manner. Characteristic image features of the maximum energy frame included a smooth, rounded, uninterrupted contour and a planar distribution, area size, and intensity that had right–left symmetry. Quantitative lung data expressed as percentages of the total (100%) vibration energy were normally distributed with mean values (± SD) of 55% ± 6% for the left lung and 45% ± 6% for the right lung. Most of the subjects with images, quantitative lung data, or both lacking these typical features were cigarette smokers or had a history of smoking (p < 0.05).

CONCLUSION. Breath sounds in healthy asymptomatic subjects can be recorded and displayed in a dynamic series of images that have predictable and characteristic features recognizable and complemented by quantitative lung data. Identification and description of these characteristic image features in this study will facilitate future studies of vibration imaging in specific pulmonary diseases.

OBJECTIVE. The purpose of this article is to review the CT appearance of postoperative morphology and complications after surgical correction of congenital heart anomalies.

CONCLUSION. Echocardiography is typically the initial imaging technique used for congenital heart disease; however, some thoracic regions are beyond the imaging scope of echocardiography, particularly after surgical revision. This article shows, through a series of illustrative cases, the usefulness of 64-MDCT in these patients.

OBJECTIVE. The objective of our study was to use MRI to analyze the topographic localization of myocardial lesions and their relationship to plasma brain natriuretic peptide (BNP) levels and several cardiac function parameters in patients with cardiac sarcoidosis.

MATERIALS AND METHODS. Delayed contrast-enhanced MRI was performed in 40 patients with sarcoidosis (11 cardiac, 29 extracardiac cases). Using a 29-segment model of the left ventricle (LV), the extent of myocardial hyperenhancement was visually scored (0 = no hyperenhancement, 1 = 1–25%, 2 = 26–50%, 3 = 51–75%, 4 = 76–100% hyperenhancement) and was compared with plasma BNP level and several parameters of cardiac function.

RESULTS. Ten of the 11 patients with cardiac sarcoidosis showed myocardial hyperenhancement, whereas none of the 29 patients without cardiac sarcoidosis did. In patients with cardiac sarcoidosis, hyperenhancement was significantly more extensive in basal short axis slices than in apical short axis slices (p < 0.0005). Myocardial hyperenhancement was significantly more frequent in subepicardial layers than in subendocardial layers. The global extent of myocardial hyperenhancement was significantly correlated with plasma BNP levels and the LV end-diastolic volume index and was negatively correlated with the LV ejection fraction.

CONCLUSION. In patients with cardiac sarcoidosis, myocardial lesions detected on delayed contrast-enhanced MRI were predominantly localized in the basal and subepicardial myocardium. The extent of myocardial lesions may be related to LV dysfunction and plasma BNP level in patients with cardiac sarcoidosis.

OBJECTIVE. The purpose of this study was to determine whether a dedicated coronary CT protocol provides adequate contrast enhancement and artifact-free depiction of coronary, pulmonary, and aortic circulation.

MATERIALS AND METHODS. Dedicated coronary 64-MDCT data sets of 50 patients (27 men; mean age, 54 ± 12.4 years) consecutively admitted from the emergency department with suspected acute coronary syndrome were analyzed. Two independent observers graded overall coronary arterial image quality and qualitative and quantitative contrast opacification, motion, and streak artifacts within the pulmonary arteries and aorta.

RESULTS. Coronary image quality was excellent in 48 patients (96%) and moderate in two patients (4%). Eleven left main and 22 left upper lobar pulmonary arteries were not visualized. Qualitative evaluation showed pulmonary arterial tree opacification to be excellent except for the right and left lower lateral and posterior segmental branches (52–54% rate of poor opacification). Quantitative evaluation showed four central (8%), six lobar (8%), and 206 segmental (29%) branches had poor contrast opacification (< 200 HU). Nineteen right upper lobar arteries (38%) were slightly and one was severely affected by streak artifact. At the segmental pulmonary artery level, marked differences in contrast enhancement were detected between the upper (292 ± 72 HU) and both the middle (249 ± 85 HU) and the lower lobes (248 ± 76 HU) (p < 0.01). Mean aortic opacification was 300 ± 34 HU with excellent contrast homogeneity without severe motion or streak artifacts.

CONCLUSION. In the evaluation of patients presenting to the emergency department with suspected acute coronary syndrome, a dedicated coronary CT protocol enables excellent assessment of the coronary arteries and proximal ascending aorta but does not depict the pulmonary vasculature well enough for exclusion of pulmonary embolism.

OBJECTIVE. The purpose of this study was to compare the frequency of detection of pulmonary nodules on cardiac CT scans acquired with a limited field of view with the frequency of detection at full field of view.

CONCLUSION. Viewing of cardiac CT scans obtained only at a limited field of view can result in missing more than 67% of nodules larger than 1 cm and more than 80% of nodules smaller than 1 cm.

OBJECTIVE. We explored the potential for patients with proven venous thromboembolism or pulmonary embolism (PE) to have occult malignancies detected during the same CT examination. To verify this, we compared the presence of occult malignancies identified on pulmonary artery CT angiography (CTA) and CT venography (CTV) when venous thromboembolism (VTE) was present.

SUBJECTS AND METHODS. Pulmonary artery CTA combined with CTV was performed on a 16-MDCT scanner on 186 adult patients suspected of having pulmonary embolism without any known malignancies. CTV was performed from the diaphragm to the knee 180 seconds after CTA. Two radiologists evaluated the presence of VTE, that is PE or deep venous thrombosis (DVT), and tumor lesions on both examinations in consensus. The malignant nature of the possibly identified tumors was confirmed by pathologic examination.

RESULTS. VTE was found in 49 patients (26%). Malignant tumors were detected in 24 patients (13%). Eleven patients with malignant tumors had VTE (46% of patients with malignant tumors; 22% with VTE and 6% of all patients). There was correlation with presence of malignancies between both and DVT and DVT associated with PE but not between presence of malignancies and PE only. Patients with DVT and those with DVT associated with PE had a risk ratio of 3.2 and 3.3, respectively, for having a malignant tumor discovered simultaneously.

CONCLUSION. A high number of malignant tumors can be incidentally discovered on pulmonary artery CTA, even more so with additional CTV. Radiologists should scrutinize scans to pick up unknown malignancies, especially in patients with identified VTE.

OBJECTIVE. MRI at 3 T, which has a higher signal-to-noise ratio than 1.5-T MRI, is potentially more sensitive and specific at delineating epileptogenic lesions and may influence management of refractory epilepsy. The purposes of the current study were to compare image quality of 3-T MRI with that of 1.5-T MRI in the evaluation of epilepsy and, in cases of focal epilepsy, to compare the two field strengths in terms of lesion detection and characterization.

MATERIALS AND METHODS. Retrospective review was performed on 50 sets of MR images of 25 patients who underwent both 3-T and 1.5-T brain imaging with a dedicated epilepsy protocol, including fast spin-echo T2-weighted, coronal FLAIR, coronal fast multiplanar inversion recovery, and 3D spoiled gradient-recalled echo pulse sequences. Parameters assessed were distortion and artifact, lesion conspicuity, gray–white matter differentiation, and motion. Each pulse sequence was graded on a 4-point scale. Reviewers performed qualitative assessments of the site of abnormality and the most likely diagnosis.

RESULTS. MRI at 3 T outperformed MRI at 1.5 T in all four parameters and was statistically superior (p < 0.05) to 1.5-T MRI in all categories except motion. On 3-T MRI, lesions were detected in 65 of 74 cases compared with 55 of 74 cases at 1.5 T (p = 0.0364), and lesions were accurately characterized in 63 of 74 cases compared with 51 of 74 cases at 1.5 T (p = 0.0194). The odds ratios showed identification of a focal epileptogenic lesion with 3-T MRI 2.57 times as likely as identification with 1.5-T MRI and accurate characterization of lesions 2.66 times as likely as characterization with 1.5-T MRI.

CONCLUSION. In evaluation of epilepsy, MRI at 3 T performed better than 1.5-T MRI in image quality, detection of structural lesions, and characterization of lesions. High-field-strength imaging should be considered for patients with intractable epilepsy and normal or equivocal findings on 1.5-T MRI.

OBJECTIVE. The purpose of this study was to review the imaging features of congenital variants of and pathologic conditions affecting the brachiocephalic vein.

CONCLUSION. CT and MRI are excellent for visualizing developmental anomalies and mediastinal tumors that involve the brachiocephalic vein. Although they affect this vein less commonly than do developmental anomalies and tumors, trauma, aneurysm formation, stenosis related to dialysis or other conditions, and various complications related to central venous catheters do occur, and familiarity with the imaging findings is helpful for diagnosis.

OBJECTIVE. Parathyroid adenomas cause hypercalcemia and are culprits in the development of renal stone disease. With serum assays available, early detection of parathyroid tumors is possible. We performed this retrospective review to determine whether the prevalence of nephrocalcinosis and nephrolithiasis is still increased in patients with primary hyperparathyroidism compared with those not affected by the disorder in view of the early detection of parathyroid adenomas.

MATERIALS AND METHODS. We retrospectively reviewed the renal sonograms of 271 patients with surgically proven primary hyperparathyroidism. All patients had undergone renal imaging within 6 months before parathyroid surgery. Our control group consisted of 500 age-matched subjects who had right upper quadrant sonograms obtained for various reasons.

RESULTS. Nineteen (7.0%) of the 271 patients with primary hyperparathyroidism had renal stones, and eight (1.6%) of the 500 subjects in the control group had stones. Pearson's chi-square analysis showed that this difference in prevalence is significant (p < 0.0001).

CONCLUSION. Our results showed a fourfold increased prevalence of asymptomatic renal stone disease in patients with surgically proven primary hyperparathyroidism compared with subjects not affected by the disorder. The National Institutes of Health consensus conference on asymptomatic primary hyperparathyroidism recommended that patients with renal stone disease undergo parathyroid surgery. These patients should undergo surgery even if they have minimal or no elevation of the total serum calcium value and no other metabolic manifestations of hyperparathyroidism. The finding of nephrocalcinosis or nephrolithiasis is, therefore, a significant finding in evaluating patients for parathyroid surgery. Routine imaging of the kidneys is necessary when primary hyperparathyroidism is documented.

OBJECTIVE. The purpose of this study was to evaluate the accuracy of CT in the diagnosis of chronic infiltrative lung disease in children.

MATERIALS AND METHODS. Fifty-nine patients selected over a 14-year period (29 girls, 30 boys; mean age, 6 ± 4.9 years; range, 2 months–18 years) had nine disorders. CT scans were evaluated independently by two experienced chest radiologists, who were unaware of pathologic or clinical data. The radiologists recorded specific CT findings of infiltrative lung disease and were asked to give the most likely diagnosis and up to two differential diagnoses. Descriptive statistic analysis was followed by logistic regression analysis for each elementary lesion on the grid of abnormalities.

RESULTS. A correct first-choice diagnosis was made in 38% of CT observations. The correct diagnosis was among the three main choices in 59% of CT observations. Pulmonary alveolar proteinosis (n = 18) was most frequently correctly diagnosed; it was the first-choice diagnosis 47% of the time and among the three main choices 72% of the time. The correct first-choice diagnosis of idiopathic pulmonary fibrosis (n = 16) was made 43% of the time; of hypersensitivity pneumonitis (n = 4), 37% of the time; of sarcoidosis (n = 7), 28% of the time; of idiopathic pulmonary hemosiderosis (n = 6), 16% of the time; and of connective tissue diseases (n = 5), 10% of the time. All single cases of pulmonary fibrosis with calcification, lymphangiectasia, and Langerhans' cell histiocytosis were correctly diagnosed.

CONCLUSION. Our results showed there are limitations to diagnosing chronic infiltrative lung disease in children on the basis of CT data alone. We suppose that these differences are explained by the technical difficulties of high-resolution CT in children, the insufficient number of cases of and data on high-resolution CT of children, and the heterogeneity of lesions of a given cause.

OBJECTIVE. The aim of this essay is to describe the imaging features of marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type throughout various organs.

CONCLUSION. Awareness of the expected locations of MALT lymphoma combined with knowledge of the incidence and imaging findings leads to accurate diagnosis of lesions suspicious for this disorder and helps to differentiate this disease from other abnormalities.

Cerebrospinal fluid (CSF) leak occurs when there is an osseous and dural defect at the skull base, with direct communication of the subarachnoid space to the extracranial space, usually a paranasal sinus. Recognition of the leak site and source and appropriate treatment are necessary to avoid rhinorrhea or otorrhea, low-pressure headaches, and meningitis, known complications of CSF leak. The imaging evaluation has evolved over the past several decades. Description of current techniques available to direct treatment options, including multidetector thin-section computed tomography, and imaging recommendations are presented.

© RSNA, 2008

In the presence of joint space narrowing, it is important to differentiate inflammatory from degenerative conditions. The presence of osteophytes, bone sclerosis, and subchondral cysts and the absence of inflammatory features such as erosions suggest osteoarthritis. Typical osteoarthritis involves specific joints at a particular patient age. When osteoarthritis involves an atypical joint, occurs at an early age, or has an unusual radiographic appearance, then other causes for cartilage destruction should be considered, such as trauma, crystal deposition, neuropathic joint, and hemophilia. There are several types of arthritis, such as juvenile chronic arthritis and gouty arthritis, that may have a variable appearance compared with that of other common inflammatory arthritides.

© RSNA, 2008

Despite recent advances in prehospital care, multidetector computed tomographic (CT) technology, and rapid definitive therapy, trauma to the aorta continues to be a substantial source of morbidity and mortality in patients with blunt trauma. The imaging evaluation of acute aortic injuries has undergone radical change over the past decade, mostly due to the advent of multidetector CT. Regardless of recent technologic advances, imaging of the aorta in the trauma setting remains a multimodality imaging practice, and thus broad knowledge by the radiologist is essential. Likewise, the therapy for acute aortic injuries has changed substantially. Though open surgical repair continues to be the mainstay of therapy, percutaneous endovascular repair is becoming commonplace in many trauma centers. Here, the historical and current status of imaging and therapy of acute traumatic aortic injuries will be reviewed.

© RSNA, 2008

Purpose: To test the hypothesis that premedication with acetaminophen, ibuprofen, and/or 4% lidocaine gel would decrease discomfort and improve satisfaction with screening mammography in women who expect a higher level of discomfort.

Materials and Methods: In this HIPAA-compliant, institutional review board–approved, prospective, double-blinded, placebo-controlled clinical trial, 418 women aged 32–89 years who expected substantial discomfort with screening mammography were randomly divided to receive premedication with acetaminophen, ibuprofen, and/or 4% lidocaine gel. Subjects provided informed written consent. The primary outcome was discomfort. Secondary outcomes were satisfaction and plans for future mammography on the basis of discomfort. Subjects completed structured questionnaires with visual analog scales to measure discomfort and satisfaction. A generalized linear mixed-models framework was used to assess the effect of medications on discomfort during mammography, and satisfaction with technologist and machine combinations was included as a random effect. The "plans for mammography next year" outcome was modeled by using a binary distribution and logit link function.

Results: Discomfort was significantly lower in the lidocaine gel group (P = .01). Satisfaction was significantly negatively correlated with discomfort (P < .001). Satisfaction and whether or not the subject had delayed her mammography because of fear of discomfort had significant effects on plans to undergo mammography next year (P < .001 for both). There were significant differences in discomfort between different combinations of technologists and machines.

Conclusion: Premedication with 4% lidocaine gel significantly reduced discomfort during screening mammography, and reduced discomfort may improve the likelihood of future mammographic screening and early detection of breast cancer.

© RSNA, 2008

Purpose: To evaluate the use, final outcome, and positive biopsy rate of American College of Radiology ultrasonographic (US) Breast Imaging Reporting and Data System (BI-RADS) categories 3, 4, and 5 recommended for breast masses.

Materials and Methods: At US, consecutive masses, palpable and nonpalpable, categorized as BI-RADS 3, 4, and 5 between January 1, 2003, and December 31, 2004, were retrospectively reviewed with institutional review board approval. Medical records provided imaging and histologic information.

Results: After patients lost to follow-up were excluded, the study population was 767 patients with 926 masses (476 palpable, 450 nonpalpable). In BI-RADS 3 masses (n = 356), imaging follow-up of 252 masses documented stability for 6–24 months. Aspiration of 24 masses revealed cysts. Biopsy in 80 masses revealed three malignancies, all of which were diagnosed within 6 months of the index examination, were smaller than 1 cm, and were node negative (negative predictive value = 99.2%). In BI-RADS 4 masses (n = 524), aspiration results indicated 35 cysts; biopsy in 455 revealed 85 malignancies (positive predictive value [PPV] = 16.2%). Imaging follow-up only in 34 revealed no cancers 2 and more years later. Among BI-RADS 5 masses (n = 46), 43 were malignant and three benign (PPV = 93.4%).

Conclusion: Inconsistent use of BI-RADS category 3 occurred in 14.0% of cases when biopsy was recommended. Although biopsy was performed in almost equal numbers of palpable and nonpalpable masses, only 11% of palpable BI-RADS 3 and 4 masses were malignant, as compared with 22% of nonpalpable masses. Strict adherence to lexicon characteristics of probably benign lesions should improve specificity.

© RSNA, 2008

Purpose: The purpose of this study was to compare ventricular volumes in patients with congenital heart disease measured by using (a) a cardiac gated sequence, (b) a standard real-time sequence, and (c) a radial real-time k-space and time (k-t) sensitivity encoding (SENSE) sequence.

Materials and Methods: The local research ethics committee approved this study, and written consent was obtained from all participants. Of 40 patients with congenital heart disease, ventricular volumes were measured by using the three sequences. Global image quality and motion fidelity were scored and compared with a Wilcoxon signed rank test. Image contrast, edge sharpness, and summed perimeters (the total length of the endocardial tracings for a given ventricle at systole and diastole) were quantified and compared by using paired t tests. Ventricular volumes were compared with paired t tests, Bland-Altman analysis, and correlation coefficients.

Results: Global image quality, motion fidelity, image contrast, edge sharpness, and summed perimeters were all greater for radial real-time k-t SENSE imaging compared with standard real-time imaging (P < .05). However, the gated acquisitions were significantly superior to radial real-time k-t SENSE (P < .05). For cardiac gated versus radial k-t real-time acquisitions, there was no difference between right ventricular (RV) volumes and ejection fraction (EF) (P > .15). There was a small difference in left ventricular (LV) end-diastolic volume (EDV) and thus, LV stroke volume and EF (P < .05). For cardiac gated versus standard real-time acquisitions, both RV and LV EDV and thus, stroke volume and EF were significantly lower (P < .05).

Conclusion: Ventricular volumes and function can be accurately quantified by using radial k-t SENSE real-time imaging.

© RSNA, 2008

Purpose: To determine the optimal width and timing of the electrocardiographic (ECG) pulsing window within the cardiac cycle in relation to heart rate (HR), image quality, and radiation exposure in patients who are suspected of having coronary artery disease.

Materials and Methods: The institutional review board approved the study, and all patients gave informed consent. Dual-source computed tomography (CT) was performed in 301 patients (mean HR, 70.1 beats per minute ± 13.3 [standard deviation]; range, 43–112 beats per minute) by using a wide ECG pulsing window (25%–70% of the R-R interval). Data sets were reconstructed in 5% steps from 20%–75% of R-R interval. Image quality was assessed by two observers on a per-segment level and was classified as good or impaired. High-quality data sets were those in which each segment was of good quality. The width and timing of the image reconstruction window was calculated. On the basis of these findings, an optimal HR-dependent ECG pulsing protocol was designed, and the potential dose-saving effect on effective dose (in millisieverts) was calculated.

Results: At low HR (≤65 beats per minute), high-quality data sets were obtained during end diastole (ED); at high HR (≥80 beats per minute), they were obtained during end systole (ES); and at intermediate HR (66–79 beats per minute), they were obtained during both ES and ED. Optimal ECG pulsing windows for low, intermediate, and high HR were at 60%–76%, 30%–77%, and 31%–47% of the R-R interval, respectively, and with these levels, the effective dose was decreased at low HR from 18.7 to 6.8 mSv, at intermediate HR from 14.7 to 13.4 mSv, and at high HR from 11.3 to 4.2 mSv.

Conclusion: With optimal ECG pulsing, radiation exposure to patients, particularly those with low or high HR, can be reduced with preservation of image quality.

© RSNA, 2008

Purpose: To retrospectively determine the benchmark incidence of nephrogenic systemic fibrosis (NSF) related to the confirmed use of different gadolinium chelate contrast agents at four U.S. university tertiary care centers.

Materials and Methods: Institutional review board approval was obtained for this HIPAA-compliant multi-institutional study; the requirement for informed patient consent was waived. Patients who had a diagnosis of NSF between January 2000 and December 2006 were identified at four tertiary care centers with renal transplant and dialysis services. A standard checklist was used to acquire reliable data from the four centers. The diagnosis of NSF was confirmed histopathologically in all patients. The association of NSF development with gadolinium chelate contrast agent administration in each patient was assessed. The type and cumulative dose of contrast agent administered to each patient with NSF were determined at each center by using the standard checklist. The benchmark incidence of NSF was determined and expressed as the ratio of the number of patients with NSF who had undergone gadolinium chelate–enhanced magnetic resonance (MR) imaging, relative to the total number of patients who underwent gadolinium chelate–enhanced MR imaging at each tertiary care center. Benchmark incidences of NSF were compared among the four centers by using Fisher exact tests.

Results: Gadodiamide was used at University of North Carolina at Chapel Hill (center A) and Emory University (center B), and gadopentetate dimeglumine was used at Wake Forest University (center C) and Thomas Jefferson University (center D) during the study period. Twenty-three patients at center A, nine patients at center B, three patients at center C, and one patient at center D had NSF and had undergone gadolinium chelate–enhanced MR imaging. The incidence of NSF was one in 2913 patients who underwent gadodiamide-enhanced MR examinations and one in 44 224 patients who underwent gadopentetate dimeglumine–enhanced MR examinations.

Conclusion: The benchmark incidence of NSF was much greater at the two centers where gadodiamide was used than at the two centers where gadopentetate dimeglumine was used.

© RSNA, 2008

Purpose: To determine the incidence and associated risk factors of nephrogenic systemic fibrosis (NSF) in patients who undergo gadolinium-based contrast agent (GBCA)-enhanced magnetic resonance (MR) imaging.

Materials and Methods: Institutional review board approval was obtained for retrospective review of the medical records from two hospitals to identify all cases of biopsy-confirmed NSF and all patients administered a GBCA from January 1, 1997, to June 30, 2007. Informed patient consent was not required. The incidence of NSF was calculated for patients who received a standard dose of GBCA, patients who received a high dose, and subgroups of patients with renal impairment.

Results: Fifteen patients developed NSF after gadolinium-enhanced MR imaging. All of them had an estimated glomerular filtration rate (eGFR) lower than 30 mL/min, and 11 had acute renal failure or acute deterioration of chronic renal failure. The incidence of NSF after gadolinium-enhanced MR imaging without screening for renal function was zero of 74 124 patients with the standard dose of GBCA and 15 (0.17%) of 8997 patients with the high dose (P < .001). The NSF incidence associated with a high dose of GBCA increased to 0.4% in patients in a chronic hemodialysis program and to 8.8% in those who had an eGFR lower than 15 mL/min but were not undergoing hemodialysis (P < .001). The NSF incidence in the patients with acute renal failure who received a high dose when their creatinine level was increasing was 19% (11 of 58 patients) when hemodialysis was delayed for longer than 2 days. More patients with NSF had proinflammatory events, and compared with patients without NSF, these patients had lower pH, younger age, lower eGFR, elevated serum phosphorus levels, and a longer delay between GBCA injection and hemodialysis.

Conclusion: For patients with an eGFR lower than 15 mL/min, hemodialysis helped to prevent NSF. For patients with an eGFR lower than 30 mL/min who received a high dose of GBCA, acute renal failure, delayed hemodialysis after contrast agent injection, proinflammatory events, and hyperphosphatemia were associated with increased risk of NSF.

© RSNA, 2008

Purpose: To determine the quality of reporting of diagnostic accuracy studies before and after the Standards for Reporting of Diagnostic Accuracy (STARD) statement publication and to determine whether there is a difference in the quality of reporting by comparing STARD (endorsing) and non-STARD (nonendorsing) journals.

Materials and Methods: Diagnostic accuracy studies were identified by hand searching six STARD and six non-STARD journals for 2001, 2002, 2004, and 2005. Diagnostic accuracy studies (n = 240) were assessed by using a checklist of 13 of 25 STARD items. The change in the mean total score on the modified STARD checklist was evaluated with analysis of covariance. The change in proportion of times that each individual STARD item was reported before and after STARD statement publication was evaluated (² tests for linear trend).

Results: With mean total score as dependent factor, analysis of covariance showed that the interaction between the two independent factors (STARD or non-STARD journal and year of publication) was not significant (F = 0.664, df = 3, partial ² = 0.009, P = .58). Additionally, the frequency with which individual items on the STARD checklist were reported before and after STARD statement publication has remained relatively constant, with little difference between STARD and non-STARD journals.

Conclusion: After publication of the STARD statement in 2003, the quality of reporting of diagnostic accuracy studies remained similar to pre–STARD statement publication levels, and there was no meaningful difference (ie, one additional item on the checklist of 13 of 25 STARD items being reported) in the quality of reporting between those journals that published the STARD statement and those that did not.

© RSNA, 2008

Purpose: To develop and evaluate a method based on ultrashort echo-time radial magnetic resonance (MR) imaging to quantify bone water (BW) concentration as a new metric of bone quality in human cortical bone in vivo.

Materials and Methods: Human subject studies were institutional review board approved and HIPAA compliant; informed consent was obtained. Cortical BW concentration was determined with custom-designed MR imaging sequences at 3.0 T and was validated in sheep and human cortical bone by using exchange of native water with deuterium oxide (D₂O). The submillisecond T2* of BW requires correction for relaxation losses during the radiofrequency pulse. BW was measured at the tibial midshaft in healthy pre- and postmenopausal women (mean age, 34.6 and 69.4 years, respectively; n = 5 in each group) and in patients receiving maintenance hemodialysis (mean age, 51.8 years; n = 6) and was compared with bone mineral density (BMD) at the same site at peripheral quantitative computed tomography, as well as with BMD of the lumbar spine and hip at dual x-ray absorptiometry. Data were analyzed by using the Pearson correlation coefficient and two-sided t tests as appropriate.

Results: Excellent agreement was obtained ex vivo between the water displaced by using D₂O exchange and water measured with respect to a reference sample (r² = 0.99, P < .001). In vivo, BW in the postmenopausal group was greater by 65% (28.7% ± 1.3 [standard deviation] vs 17.4% ± 2.2, P < .001) than in the premenopausal group, and patients with renal osteodystrophy had higher BW (41.4% ± 9.6) than the premenopausal group by 135% (P < .001) and the postmenopausal group by 43% (P = .02). BMD showed an opposite behavior, with much smaller group differences. Because the majority of BW is in the pore system of cortical bone, this parameter provides a surrogate measure for cortical porosity.

Conclusion: A new MR imaging–based method for quantifying BW noninvasively has been demonstrated.

© RSNA, 2008

Purpose: To demonstrate the feasibility of using proton magnetic resonance (MR) imaging to noninvasively detect extravascular and luminal fluid in a murine model of allergen-induced airway inflammation.

Materials and Methods: The Basel Veterinary Authority approved this experiment. Actively sensitized female Balb/c mice received ovalbumin or saline and underwent MR imaging (a) once 24 hours after the fourth administration of ovalbumin or saline (n = 25) or (b) several times between and after ovalbumin or saline administrations (n = 22) to determine the volume of fluid signal induced by an allergen. Images were acquired in spontaneously breathing animals, without cardiac or respiratory gating. Signal detected with a gradient-echo sequence was compared with bronchoalveolar lavage (BAL) fluid parameters and with perivascular and peribronchial edema and mucus observed at histologic analysis.

Results: Up to 24 hours after the fourth administration of ovalbumin, intense and continuous fluid signals (volume, 40–50 µL) were detected in proximal lung regions. At 72 hours after the fourth administration of ovalbumin, remaining signals (21.1 µL ± 3.8) had a discontinuous texture. The number of eosinophils in the BAL fluid at 24 and 72 hours and their activation were higher in mice that received ovalbumin than in those that received saline. Histologic analysis revealed edema and secreted mucus in the early phase, whereas only mucus was encountered in the late phase.

Conclusion: These findings suggest that the main component of the early response was plasma leakage (edema), while the main component of the late response was secreted mucus. With the technique validated, the basis for pharmacologic studies in this murine model of lung inflammation with use of MR imaging as a noninvasive readout was provided.

© RSNA, 2008

Purpose: To measure the early therapeutic response to a novel apoptosis-inducing antibody, TRA-8, by using diffusion-weighted magnetic resonance (MR) imaging in a mouse breast cancer model.

Materials and Methods: Animal experiments had institutional animal care and use committee approval. Four groups of nude mice bearing luciferase-positive breast tumors (four to five mice with eight to 10 tumors per group) were injected intravenously with 0 mg (group 1), 0.025 mg (group 2), 0.100 mg (group 3), or 0.200 mg (group 4) of TRA-8 on days 0 and 3. Diffusion-weighted imaging, anatomic MR imaging, and bioluminescence imaging were performed on days 0, 3, and 6 before dosing. Averaged apparent diffusion coefficients (ADCs) for both whole tumor volume and a 1-mm peripheral tumor shell were calculated and were compared with tumor volume and living tumor cell changes. After imaging at day 6, proliferating and apoptotic cell densities were measured with Ki67 and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling, or TUNEL, staining, respectively, and were compared with cleaved caspase-3 density.

Results: The ADC increase at day 3 was dependent on TRA-8 dose level, averaging 6% ± 3 (standard error of mean), 19% ± 4, 14% ± 4, and 34% ± 7 in the whole tumor volume and 1% ± 2, 9% ± 5, 13% ± 5, and 30% ± 8 in the outer 1-mm tumor shell only for groups 1, 2, 3, and 4, respectively. The ADC increase in group 4 was significantly higher (P = .0008 and P = .0189 for whole tumor volume and peripheral region, respectively) than that in group 1 on day 3, whereas tumor size did not significantly differ. At day 3, the dose-dependent ADC increases were linearly proportional to apoptotic cell and cleaved caspase-3 densities and were inversely proportional to the density of cells showing Ki67 expression.

Conclusion: Diffusion-weighted imaging enabled measurement of early breast tumor response to TRA-8 treatment, prior to detectable tumor shrinkage, providing an effective mechanism to noninvasively monitor TRA-8 efficacy.

Supplemental material: http://radiology.rsnajnls.org/cgi/content/full/248/3/844/DC1

© RSNA, 2008

Purpose: To determine exemplarily the amount of DNA damage and the repair kinetics after interventional radiologic procedures by using visualization of foci of the phosphorylated form of the H2AX histone variant (H2AX) to quantify DNA double-strand breaks (DSBs) at percutaneous transluminal angioplasty (PTA) of the lower limb arteries.

Materials and Methods: After local ethics committee approval and written informed consent were obtained, five patients (two women, three men; mean age, 64.4 years; age range, 45–76 years) scheduled for computed tomography (CT) and 20 patients (six women, 14 men; mean age, 68.5 years; age range, 53–85 years) scheduled for PTA of lower limb arteries were prospectively entered into the study. Blood samples were taken before the first exposure to ionizing radiation and 5 minutes, 1 hour, 6 hours, and 24 hours after the last exposure. Additional samples were taken from the irradiated limb (femoral vein) of three patients who underwent PTA—before the first radiation exposure, 5 and 10 minutes after the first exposure, and 5 minutes after the last exposure. Lymphocytes were isolated, fixed, and stained with anti-H2AX antibody, and H2AX focus yields were determined with fluorescence microscopy. Data were analyzed with linear regression and two-sample F tests.

Results: Mean increase in number of H2AX foci after CT (7.78 per 1 Gy · cm) depended linearly on dose-length product (r = 0.997). Number of foci reached background levels within 24 hours. Mean numbers of H2AX foci per cell increased by factors of 4.08–20.67 in blood samples taken 5 minutes after PTA compared with mean numbers of foci before PTA. Mean radiation dose increase, 6.56/(10 Gy · cm²), depended linearly on dose-area product (r = 0.993). Maximal focus yield in cells taken directly from the irradiated limb was higher than that in cells from the systemic circulation (by mean factor of 1.46). Data showed compromised DSB repair capacity after PTA (P < .05). Mean number of foci at 24 hours (0.07 focus per cell) was significantly higher than mean number of foci in cell background (0.04 focus per cell, P < .05).

Conclusion: H2AX focus formation can be used to determine in vivo induction of DNA DSBs after PTA. DSB repair capacity is compromised in patients who undergo PTA of lower limb arteries.

© RSNA, 2008

Purpose: To prospectively evaluate the learning curves and reading times of inexperienced readers who used the virtual dissection reading method for retrospective computed tomographic (CT) colonography data sets, with and without concurrent computer-aided detection (CAD).

Materials and Methods: An Institutional Review Board approved this study; informed consent was waived. Four radiologists without experience in CT colonography evaluated 100 optical colonoscopy–proved data sets of 100 patients (49 men, 51 women; mean age, 59 years ± 13 [standard deviation]; range, 21–85 years) by using the virtual dissection reading method. Two readers used concurrent CAD. Data sets were read during five consecutive 1-day sessions (20 data sets per session). Polyp detection and false-positive rates, receiver operating characteristics (ROCs), and reading times were calculated for individual, CAD group, and non-CAD group readings. Diagnostic values were compared by calculating the 95% confidence intervals (CIs) around the relative risk. Areas under ROC curves (AUCs) (Hanley and McNeil for paired analysis and z statistics for unpaired analysis) and reading times (Wilcoxon signed rank test) were compared across the sessions, within each session and for the whole study.

Results: The range of detection rates was 79 of 111 (.71 [95% CI: .61, .79]) to 91 of 111 (.82 [95% CI: .73, .88]). The range of false-positive rates was 17 of 111 (.15 [95% CI: .09, .23]) to 22 of 111 (.20 [95% CI: .12, .28]). All readers' AUCs rose from session 1 to session 4; this rise was significant (P < .05) for the non-CAD group. Only during session 1 was the CAD group AUC (.83) higher than the non-CAD group AUC (.54) (P < .05). Comparison of CAD and non-CAD reading times showed no significant difference for the whole study or during each session (P > .05).

Conclusion: The virtual dissection reading technique allows short learning curves, which may be improved by the concurrent use of CAD, without significant effect on average reading time.

© RSNA, 2008

Purpose: To describe the appearance, prevalence, and possible associations of colonic wall redundancy in patients with cystic fibrosis (CF).

Materials and Methods: The institutional review board approved this HIPAA-compliant study. Abdominal computed tomographic (CT) images of 38 consecutive patients with CF and a control group of 38 consecutive potential renal donors were retrospectively identified. Three readers independently recorded presence and location of colonic wall redundancy and wall thickness of the ascending, transverse, and descending colon. Interobserver agreement for colonic wall redundancy was determined with the statistic. Colonic wall thicknesses were compared between patient groups with the Student t test. Proportions of adult and pediatric patients with and those without colonic wall redundancy and prevalence of specific gene mutations were compared between groups with the Fisher exact test. CT findings were compared with radiologic reports and clinical records.

Results: Each reviewer found colonic wall redundancy in 11 of 28 adults with CF but in none of the children with CF (P < .05 for each reviewer). There was excellent interobserver agreement for identification of colonic wall redundancy ( = 0.91, P < .001). Mean thickness of the wall of the ascending colon was significantly greater in patients with CF who had colonic wall redundancy (4.0 mm) than in those without this finding (1.8 mm, P < .05) or in control patients (1.2 mm, P < .05). Among adult patients with CF, F508 mutation was the predominant mutant allele in 10 of 13 patients with normal colons at CT, whereas more uncommon non-F508 mutations were seen in seven of 10 patients with colonic wall redundancy (P < .05). Asymptomatic colonic wall redundancy at CT was prospectively misinterpreted as acute colonic disease in five adult patients.

Conclusion: Proximal colonic wall redundancy is seen frequently in adults with CF and may be more common in those with non-F508 CFTR gene mutations. This finding provides a starting point for further investigation of the molecular basis of colonic phenotype in CF.

© RSNA, 2008

Purpose: To evaluate the capabilities of multisection computed tomography (CT) in determining the likelihood of invasiveness of intraductal papillary mucinous neoplasm (IPMN).

Materials and Methods: The institutional review board approved this research and waived informed consent from the patients. Two radiologists blinded to the pathologic assessment of malignancy or parenchymal invasion of IPMN retrospectively evaluated CT images of 61 consecutive surgically resected tumors (26 adenomas, 15 noninvasive carcinomas, and 20 invasive carcinomas) in patients who underwent multiphase contrast material–enhanced CT with 0.5- or 1-mm collimation. The findings were statistically analyzed by using univariate and multivariate analyses, with the optimal cutoff levels of each continuous parameter determined by generating receiver operating characteristic curves.

Results: The following findings showed significant differences among the three groups: maximum diameter of the main pancreatic duct (MPD), size (length of major axis) of the largest mural nodule in the MPD or in any associated cystic lesion, abnormal attenuating area in the surrounding parenchyma, calcification in the lesion, protrusion of the MPD into the ampulla of Vater, and bile duct dilatation. An MPD diameter of 6 mm or larger, a mural nodule of 3 mm or larger, and an abnormal attenuating area were independently predictive of malignancy. A mural nodule of 6.3 mm or larger in the MPD and an abnormal attenuating area were independently predictive of parenchymal invasion. According to these criteria, the sensitivity, specificity, and accuracy for identifying malignancy were 83%, 81%, and 82% and for identifying parenchymal invasion were 90%, 88%, and 89%, respectively.

Conclusion: Multisection CT is useful for distinguishing among adenoma, noninvasive carcinoma, and invasive carcinoma in patients with IPMN.

© RSNA, 2008

Purpose: To characterize the utility of abdominal radiography for nontrauma emergency patients in a single-institution setting.

Materials and Methods: Following approval from the Director of Professional Services, a retrospective review of radiography and of patient records was conducted for patients who presented to a nontrauma emergency department over a period of 6 months and who were imaged by using abdominal radiography. Only the first radiograph per patient was used for analysis. The interpretations were sorted as normal, nonspecific, or abnormal. The patients' medical records were reviewed to determine whether further imaging was performed (computed tomography, ultrasonography, or upper gastrointestinal imaging) and results were compared with abdominal radiography. Chart reviews were conducted to identify patients in whom abdominal radiography alone influenced treatment.

Results: In 874 patients, interpretation of abdominal radiography was normal in 34% (n = 300), nonspecific in 46% (n = 406), and abnormal in 19% (n = 168). Further imaging was performed for 50% (436) of all patients. Of 300 patients whose abdominal radiography results were normal, 42% (n = 125) had follow-up imaging; 72% (n = 90) of these showed abnormal, 78% (165 of 212) showed nonspecific, and 87% (86 of 99) showed abnormal findings. Of 438 patients who did not undergo follow-up imaging, 75% (n = 327) were discharged. For all indications other than catheter placement, abdominal radiography helped confirm the suspected diagnosis in 2%–8% of cases. In 37 (4%) of 874 patients, abdominal radiography was possibly helpful in changing patient treatment without a follow-up study.

Conclusion: Abdominal radiography is often requested; however, its results contribute to patient treatment in a small percentage of cases. With the exception of catheter placement, if a patient requires investigation beyond clinical history, physical examination, and lab results, the emergency physician should be encouraged to request more definitive imaging.

© RSNA, 2008

Purpose: To evaluate the ability of the apparent diffusion coefficient (ADC) to help predict response to chemotherapy in patients with colorectal and gastric hepatic metastases.

Materials and Methods: Institutional review board approval was obtained; all patients provided informed consent. Standard magnetic resonance (MR) imaging and diffusion-weighted (DW) MR imaging were performed before and 3, 7, and 42 days after initiating chemotherapy for 87 hepatic metastases in 23 colorectal and gastric cancer patients (16 men, seven women; mean age, 55.7 years; range, 33–71 years). Lesions were classified as either responding or nonresponding, according to changes in size at the end of therapy. Linear mixed-effects modeling was applied to analyze change in ADCs and size following treatment. The Pearson correlation test was calculated be