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Objective: The purpose of this study is to determine the diagnostic performance of MRI and MR arthrography for depicting ligamentum teres lesions., Materials and Methods: A literature search was performed. Original studies reporting the diagnostic accuracy of MRI examinations for the depiction of ligamentum teres lesions were included., Results: Eight studies entailing 1456 MRI examinations were included (frequency of median ligamentum teres injury, 25.9%; interquartile range, 14.1-45.3%). Two studies reported the results of unenhanced MRI examinations, and their diagnostic performance could not be estimated. Sensitivity, specificity, and diagnostic odds ratio (DOR) of all MRI examinations were 64.7%, 86.9%, and 12.2, respectively, whereas the sensitivity, specificity, and DOR of MR arthrography examinations were 82.2%, 88.6%, and 35.9, respectively. The heterogeneity (I 2 ) for all MRI and MR arthrography examinations was 92.3% and 88.2%, respectively. Five blinded MR arthrography studies with 643 MR arthrography examinations found an appropriate threshold effect for summary ROC construction (AUC, 0.95). The summary estimate of these studies yielded a sensitivity of 87.8%, a specificity of 91%, and DOR of 73.1. The heterogeneity (I 2 ) for this group was 64.3%. In patients with low pretest probability (25%), MR arthrography enabled the exclusion of ligamentum teres lesion (postprobability for a negative result, 4%; negative likelihood ratio, 0.13)., Conclusion: MR arthrography can depict ligamentum teres lesions with high accuracy. However, its diagnostic performance for differentiating various types of ligamentum teres lesions (partial, complete ligamentum teres tears, and hypertrophic ligamentum teres), as well as the diagnostic performance of unenhanced MRI for the depiction of ligamentum teres lesions, is yet to be determined because of the paucity of reported data in the literature.

Objective: The objective of our study was to determine the prevalence of honorary authorship in articles published in the American Journal of Roentgenology (AJR) and to evaluate the factors that might influence the perception of honorary authorship., Materials and Methods: Corresponding authors of 1333 Original Research articles published in AJR between 2003 and 2010 were invited by e-mail to complete a Web-based, self-administered survey. Univariable analysis of sample proportions was performed using the chi-square test. Multivariable logistic regression models were used to assess the independent factors that were associated with the probability of honorary authorship., Results: Responses were received from authors of 490 articles (36.8% response rate). Most respondents were aware of the authorship guidelines proposed by the International Committee of Medical Journal Editors (n = 399, 81.4%) and the issue of honorary authorship (n = 353, 72.0%). Authorship was most commonly decided by the first author (n = 256, 52.2%). One hundred twenty-one authors (24.7%) perceived that one or more coauthors listed for the respective article did not make sufficient contributions. Factors most strongly associated with honorary authorship included a work environment where a senior department member was automatically listed (odds ratio [OR], 1.33), the suggestion that an honorary author should be included (OR, 5.96), and the perception that a coauthor performed only a single nonauthor task (i.e., reviewing the manuscript: OR, 1.54)., Conclusion: A substantial proportion of articles had evidence of honorary authorship. The rate of honorary authors was higher among authors who worked in an environment where senior members were routinely added to all manuscripts submitted for publication, authors who perceived that a coauthor listed had only reviewed the manuscript, and authors who reported that someone suggested they should include an honorary author.

Objective: Nonelderly patients presenting with knee pain often have patellofemoral maltracking or impingement abnormalities. There is a relative paucity of literature on the incidence and significance of impingement-related edema of the superolateral aspect of Hoffa's (infrapatellar) fat pad in these cases. Our study was designed to systematically evaluate the correlation of superolateral Hoffa's fat pad edema with various anatomic parameters of trochlear morphology and patellar alignment., Materials and Methods: We evaluated 50 knee MRI examinations in 47 patients for the presence of edema in superolateral Hoffa's fat pad and associated anatomic abnormalities of the patellofemoral joint., Results: Of the 50 examinations, 25 (50%) showed superolateral Hoffa's fat pad edema, and statistically significant differences were seen between those with and without edema with respect to sex (6/22 men vs 19/28 women) and patellar tendon patellar-length ratio (1.3 ± 0.16 and 1.1 ± 0.12 for those with and without edema, respectively)., Conclusion: The findings in our study suggest that edema in superolateral Hoffa's fat pad may be an important indicator of underlying patellofemoral maltracking or impingement in younger, symptomatic patients.

Objective: Given the complexity of medical knowledge and intermittent nature of clinical learning, technology can be helpful for information management. DexNote is a freely accessible application that allows users to develop structured notes, enabling rapid access to previously encountered material and incorporation of new information. Sample notes with approximately 22,000 entries are described., Conclusion: Using an upward and downward branching organizational structure, DexNote makes the highly connected nature of medical information an integral part of the knowledge database.

Objective: The purpose of this study was to evaluate interpretative performance with different MDCT reconstruction parameters in adult patients with suspected appendicitis., Materials and Methods: MDCT scans of 212 adult patients obtained in an emergency department with a 64-MDCT scanner were prospectively collected. Acquisition technique included 24 x 1.2 mm detector configuration and IV contrast administration with or without oral contrast administration. Data sets were reconstructed with three techniques: 5 x 5 mm, 3 x 3 mm, and 2 x 1 mm (section thickness x interval). Each of the 212 sets of images (grouped by reconstruction technique) was reviewed retrospectively using axial sections by two independent readers blinded to diagnosis. Medical record review was conducted to identify patients with appendicitis. Visualization of the appendix, confidence in visualization, confidence for presence or absence of specific CT findings, diagnostic accuracy, and diagnostic confidence were compared across reconstruction techniques. Data were analyzed with simple and ordinal logistic regression with adjustment for multiple observations derived from each patient and for reader differences., Results: Progressively thinner reconstruction section thickness was associated with a significant increase in the rate of visualization of the appendix (p < 0.001 for 5 x 5 vs 3 x 3; p = 0.03 for 3 x 3 vs 2 x 1), visualization confidence (p < 0.001 for 5 x 5 vs 3 x 3 and 3 x 3 vs 2 x 1), and confidence for presence or absence of findings. Seventeen subjects (8%) had appendicitis. Correctness of diagnosis was not significantly associated with reconstruction method. However, for correctly diagnosed cases interpreted as normal, impression confidence increased with progressively thinner section thickness (p < 0.001 for 5 x 5 vs 3 x 3 and 3 x 3 vs 2 x 1)., Conclusion: In this investigation of contrast-enhanced MDCT of the appendix, visual ization of the appendix and confidence in interpretation of axial images progressively improved with use of thinner reconstruction sections.

Objective: The purpose of this study was to evaluate the current practice of patient preparation for 64-MDCT angiography (CTA) of the coronary arteries., Materials and Methods: Sites in the United States that perform 64-MDCT coronary angiography were surveyed by mail in 2006. Information requested included physician specialty; experience level; details about patient preparation, including the use, dose, route, and timing of premedication; and acceptable heart rate and rhythm. A total of 142 surveys were analyzed, with comparison of parameters across specialties (radiology, cardiology, or shared) and experience levels., Results: All facets of the study (premedication, data acquisition, cardiac interpretation) are performed exclusively by radiologists in 49% of sites and by cardiologists in 14%. All sites administer beta-blockers. Target heart rate was reported as < or = 65 beats per minute (bpm) by 89% of responders. Despite most centers aiming for a heart rate of < or = 65 bpm, the maximum allowable heart rate is > 65 bpm in 80% of centers. Patients with arrhythmia are scanned in at least 25% of sites. Most sites (84%) administer nitroglycerin. Significant differences between specialties were noted for experience levels, timing and route of beta-blocker administration, and for target heart rate. The likelihood of scanning in the setting of arrhythmia and beta-blocker timing correlated with experience levels., Conclusion: These 64-MDCT coronary artery data from 2006 reveal consensus for a range of patient preparation parameters. Use of beta-blockers and nitroglycerin is routine, and the target heart rate is usually < or = 65 bpm. However, differences were noted for beta-blocker protocols and acceptable heart rate and rhythm, and some differences in practice are associated with experience level and specialty.

Objective: The purpose of our study was to determine the feasibility and value of proton MR spectroscopy at 3 T for characterizing musculoskeletal tumors., Subjects and Methods: At 3 T, 18 patients with musculoskeletal lesions (four histologically proven to be malignant, 14 proven benign histologically or at clinical follow-up) underwent 23 MR spectroscopy studies, 20 with a single-voxel technique and three with a multivoxel technique. Seventeen patients were imaged with a surface coil and six with a body coil. Choline signal (3.2 ppm) was measured in each voxel and expressed relative to background noise as signal-to-noise ratio (SNR). Choline SNRs of malignant tumors and benign lesions were compared., Results: Diagnostic spectra were obtained in 20 of 23 lesions. For malignant lesions (osteosarcoma with two MR spectroscopy sites, metastasis, grade 1 sarcoma), choline SNRs were 5.2 and 4.2 (performed with body coil) and 4.8 and 18.7 (performed with surface coil), respectively. For benign lesions (neurofibroma, two stress reactions, bone cyst, hemangioma, lipoma, Baker cyst), choline SNR was 6.3 (with surface coil), 5.5 (with surface coil), and not detected for five cases. Seven postoperative patients with myocutaneous flaps showed either the typical spectrum of muscle or negligible choline. Only a water peak existed in a bone cyst and a significant lipid peak in a lipoma. Choline SNRs were different for malignant and benign lesions (11.7 vs 2.3, p = 0.04, as performed with a surface coil)., Conclusion: At 3 T, both single-voxel and multivoxel MR spectroscopy are feasible. Proton MR spectroscopy is a potential noninvasive tool for characterizing lesion composition and malignant activity.

Objective: The purpose of our study was to evaluate factors predictive of the presence of invasive carcinoma associated with intraductal papillary mucinous neoplasm (IPMN) of the pancreas on MDCT., Materials and Methods: Preoperative MDCT of 36 consecutive patients (23 men, 13 women; mean age, 66.6 years) who had undergone surgical resection and had a pathologic diagnosis of IPMN were retrospectively assessed. CT was performed with a 4-MDCT scanner with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Arterial and venous phase images were acquired at 25 and 50-60 sec from the start of IV contrast administration. Type of ductal involvement, location, tumor size in branch duct type and combined type lesions, caliber of the main pancreatic duct, caliber of the common bile duct or common hepatic duct, and solid appearance of the lesion were assessed on CT and correlated with pathologic findings for invasive carcinoma., Results: Pathologic analysis revealed carcinoma in situ in seven patients (19%) and invasive carcinoma in 15 patients (42%) arising from the IPMN. With invasive carcinoma, the size of the tumor in branch duct type and combined type, and the caliber of the main pancreatic duct were significantly larger compared with the lesions without invasive carcinoma (4.7 +/- 1.7 cm vs 2.6 +/- 1.4 cm [p = 0.0007] and 9.3 +/- 5.5 mm vs 4.6 +/- 4.1 mm [p = 0.006], respectively). A solid mass (p < 0.001), dilatation of the common bile duct or common hepatic duct (> or = 15 mm), and the presence of a stent (p = 0.0004) were correlated with the presence of associated invasive carcinoma., Conclusion: MDCT helped to predict invasive carcinoma associated with IPMN.

Objective: The objectives of our study were to define CT and MRI features that distinguish pathologic fractures from stress fractures and to compare the performance of CT and MRI with radiography., Materials and Methods: Two reviewers retrospectively reviewed 45 MR images, 37 CT scans, and 43 radiographs in 59 patients (30 biopsy-proven pathologic fractures and 29 stress fractures followed to resolution). The features observed on MRI were abnormal bone marrow (well-defined, ill-defined); intracortical, periosteal, or muscle T1 or T2 signal; endosteal scalloping; and a soft-tissue mass. The features seen on CT were marrow abnormality and character (well-defined, ill-defined, permeative, moth-eaten), endosteal scalloping, periosteal reaction (benign, aggressive), and a soft-tissue mass. Reviewers rated their confidence for diagnosing a pathologic fracture on a 1-3 scale (< 50%, 50-95%, > 95% sure, respectively) with each technique. Performance of each technique was defined by reviewer accuracy and area under the receiver operating characteristic curve (Az); the frequency with which the MRI and CT features were associated with pathologic and stress fractures was calculated., Results: For both reviewers, accuracy for differentiating pathologic from stress fractures was highest on MRI (accuracy/Az: reviewer 1, 98%/0.97; reviewer 2, 93%/0.99); CT (reviewer 1, 88%/0.83; reviewer 2, 82%/0.90) was less accurate than radiography (reviewer 1, 94%/0.98; reviewer 2, 88%/0.96). On MRI, pathologic fractures compared with stress fractures exhibited well-defined T1 marrow signal (83% vs 7%, respectively; p < 0.001), endosteal scalloping (58% vs 0%, p < 0.001), muscle signal (83% vs 48%, p = 0.026), and a soft-tissue mass (67% vs 0%, p < 0.001). On CT, pathologic fractures compared with stress fractures exhibited marrow abnormality (84% vs 17%, respectively; p = 0.001), endosteal scalloping (44% vs 0%, p = 0.006), and aggressive periosteal reaction (36% vs 0%, p = 0.04)., Conclusion: MRI is useful for distinguishing pathologic from stress fractures, especially after inconclusive radiographic findings. Specifically, pathologic fractures exhibit well-defined T1 marrow alterations, endosteal scalloping, and adjacent soft-tissue abnormalities.

Objective: Our aim was to develop a simple, low-cost, Internet-based application for radiology order-entry, reporting, and workflow management during off-hours., Conclusion: The system was quickly accepted by users both within and outside the radiology department, and it required very modest resources to develop, deploy, and support. In a busy on-call setting at a high-volume academic institution, the system described was effective in obtaining more thorough patient histories from referring physicians, reducing the number of telephone calls required, and documenting more rigorously the communication between radiologists and clinical services. These benefits allow the generation of more informative and timely radiology reports.

Objective: We sought to summarize systematically the published evidence describing the accuracy of contrast-enhanced helical CT for diagnosing pulmonary embolism., Materials and Methods: We selected all systematic reviews published before December 2003 that evaluated the accuracy of CT angiography for the diagnosis of pulmonary embolism. We also selected all prospective studies from the same time period in the primary literature in which all subjects underwent both CT and conventional angiography, the latter being considered the reference standard. Articles were identified through a computerized MEDLINE search and by other means. The quality and content of each article were evaluated independently by pairs of researchers., Results: Six systematic reviews and eight primary studies were selected. The combined sensitivities of CT for detecting pulmonary embolism ranged from 66% to 93% across the systematic reviews and the combined specificities ranged from 89% to 97%. Only one of the reviews reported a combined sensitivity of greater than 90%. Among the eight primary studies, the sensitivities ranged from 45% to 100% and specificities ranged from 78% to 100%. Only three of the eight primary studies reported a sensitivity greater than 90%. None of the primary studies used scanners with four or more detectors., Conclusion: A systematic literature review revealed a wide range of reported sensitivities, only a minority of which exceeded 90%. Pooled estimates of sensitivity and specificity reported by systematic literature reviews should be interpreted with caution because of potential selection bias and heterogeneity in the reviewed studies. Accuracy studies of recent generations of MDCT scanners are not yet available despite the current dissemination of this technology.

Objective: We sought to examine the incidence of complications and change in pulmonary artery pressure in patients with pulmonary hypertension who were undergoing pulmonary angiography., Materials and Methods: A retrospective review was performed for all patients who underwent pulmonary angiography over a 10-year period at a single institution. Patients with moderate pulmonary hypertension (pulmonary artery pressure, 30-59 mm Hg) and severe pulmonary hypertension (pulmonary artery pressure, >/= 60 mm Hg) served as the study population. Demographic data, clinical indication, pre- and postcontrast pulmonary artery pressure measurements, type of pulmonary hypertension, contrast agent volume, complications, and American Society of Anesthesiologists (ASA) classification were recorded for all patients and compared., Results: Two hundred two of 612 patients who underwent pulmonary angiography had pulmonary hypertension. Moderate pulmonary hypertension was present in 155 patients (77%) and severe pulmonary hypertension, in 47 patients (23%). Three (2.0%) of four complications were fatal. The complication rate was higher in patients with severe pulmonary hypertension compared with patients with moderate pulmonary hypertension but not statistically significant (6.3% vs 0.6%, p = 0.63). Patients with complications had a higher mean ASA score than those without complications (4.0 vs 3.0, p = 0.03). Patients with lung transplants had the greatest increase in pulmonary artery pressure after pulmonary angiography compared with all other clinical indications (16.75 +/- 12.97 mm Hg vs 5.46 +/- 6.86 mm Hg, p = 0.003)., Conclusion: The complication rate of pulmonary angiography in patients with pulmonary hypertension is low. However, in severely ill patients with acute pulmonary hypertension, pulmonary angiography should be undertaken with extreme caution.

Objective: The objective of this study was to determine whether an artificial neural network, a new data analysis method, offers increased performance over conventional logistic regression in predicting the presence of a pulmonary embolism for patients in a well-known data set., Materials and Methods: Data from the 1064 patients who received an angiographically based diagnosis of pulmonary embolism in the Prospective Investigation of Pulmonary Embolism Diagnosis study were encoded using a previously described method. The 21 input variables represented abnormalities identified on each patient's ventilation-perfusion scan and chest radiograph. Two methods-an artificial neural network with one hidden layer and a multivariate logistic regression-were compared for accuracy in predicting the presence or absence of pulmonary embolism on subsequent pulmonary arteriography., Results: No significant difference was observed between the two methods. Areas under the receiver operating characteristic curves +/- standard deviation were 0.78 +/- 0.02 for the artificial neural network model and 0.79 +/- 0.02 for the logistic regression model. Furthermore, use of these two methods resulted in no more diagnostic accuracy than did the use of a simple threshold model based only on the number of subsegmental perfusion defects, which was the dominant input variable., Conclusion: In the study population, the usefulness of data from ventilation-perfusion scans as predictors of the presence of a pulmonary embolism was similar for the three analytic methods, a finding that reinforces the importance of making comparisons to simpler or more established methods when performing studies involving complex analytic models, such as artificial neural networks.

Unlabelled: OBJECTIVE.:The aim of this study was to determine the sensitivity, specificity, and accuracy of CT in the diagnosis of small-bowel obstruction in children., Materials and Methods: The CT scans of 30 children with surgically proven small-bowel obstruction, 22 children with ileus, and 29 children who served as controls were retrospectively reviewed by two of four interpreters who were unaware of the children's final diagnoses. Causes of obstruction in the patients included 19 adhesions, six cases of volvulus, five intussusceptions, four strictures, and two cases each of internal hernia and abscess. Eight obstructions had multiple causes. The CT scans were evaluated for the presence of small-bowel obstruction using a scale with five degrees of confidence. In cases of discrepancy of more than one level of certainty, a third interpreter was consulted. Criteria for small-bowel obstruction included a discrepancy in caliber between the proximal dilated and the more distal small bowels or generalized small-bowel dilatation (>2.5 cm) in the presence of a collapsed colon. An interpreter's rating that an obstruction was either present or probable was considered a positive finding; a rating indicating that the interpreter was not sure whether an obstruction was present or believed that an obstruction was not probable or saw normal anatomic structures was considered a negative finding for small-bowel obstruction. The cause and level of obstruction also were recorded., Results: There were 26 true-positive (87%) and four false-negative (13%) interpretations for small-bowel obstruction. Among the interpretations of scans of patients with ileus, 68% were true-negative and 32% were false-positive interpretations for small-bowel obstruction. Among the control group, there were no false-positive readings. Sensitivity of CT was 87%, specificity was 86%, and accuracy was 86%. In the scans of children 2 years and younger, CT had a sensitivity of 100% and specificity of 0%. Of the patients with surgically confirmed levels of obstruction, the correct level of obstruction was described by both interpreters in 12 (86%) of 14 scans. The causes of obstruction were correctly identified in 14 (47%) of 30 scans., Conclusion: CT is both sensitive and specific for use in diagnosing small-bowel obstruction in children, especially in children older than 2 years.

Objective: We determined the relative value of teleradiology and radiology resident coverage of the emergency department by measuring and comparing the effects of physician specialty, training level, and image display method on accuracy of radiograph interpretation., Materials and Methods: A sample of four faculty emergency medicine physicians, four emergency medicine residents, four faculty radiologists, and four radiology residents participated in our study. Each physician interpreted 120 radiographs, approximately half containing a clinically important index finding. Radiographs were interpreted using the original films and high-resolution digital monitors. Accuracy of radiograph interpretation was measured as the area under the physicians' receiver operating characteristic (ROC) curves., Results: The area under the ROC curve was 0.15 (95% confidence interval [CI], 0.10-0.20) greater for radiologists than for emergency medicine physicians, 0.07 (95% CI, 0.02-0.12) greater for faculty than for residents, and 0.07 (95% CI, 0.02-0.12) greater for films than for video monitors. Using these results, we estimated that teleradiology coverage by faculty radiologists would add 0.09 (95% CI, 0.03-0.15) to the area under the ROC curve for radiograph interpretation by emergency medicine faculty alone, and radiology resident coverage would add 0.08 (95% CI, 0.02-0.14) to this area., Conclusion: We observed significant differences between the interpretation of radiographs on film and on digital monitors. However, we observed differences of equal or greater magnitude associated with the training level and physician specialty of each observer. In evaluating teleradiology services, observer characteristics must be considered in addition to the quality of image display.

Objective: The purpose of this study was to determine whether CT can be used to distinguish serous cystadenomas from mucinous cystadenomas or cystadenocarcinomas of the pancreas and play an enhanced role in patient triage and treatment., Materials and Methods: A blinded retrospective analysis of CT scans from 50 patients with pathologically proven primary cystic pancreatic neoplasms was performed independently by three radiologists. Using classic CT criteria as reported in the literature, each tumor was categorized as definitely serous, mucinous, or indeterminate. Tumor location, size, presence of calcification, and size of largest cyst were recorded. Data for each reviewer were analyzed independently. Consensus data were then subjected to multivariate logistic regression analysis., Results: The ability of our reviewers to diagnose serous neoplasms ranged from 23% to 41%. Eight mucinous neoplasms were mistaken for serous tumors by two of the three reviewers. When consensus between at least two of the three reviewers was used for diagnosis, 27% of serous neoplasms were correctly diagnosed and all of the mucinous tumors were correctly identified as uncertain or mucinous, yielding the same clinical end point. For multivariate logistic regression analysis, a cyst smaller than 2 cm had a statistically significant association (p = 0.005) with serous tumors, and the presence of peripheral tumoral calcification had a statistically significant association (p = 0.01) with mucinous tumors., Conclusion: There is significant variability in the CT appearance of serous and mucinous neoplasms of the pancreas, making CT an insensitive tool for differentiating these tumors. All tumors with peripheral calcifications were identified as mucinous neoplasms.

Objective: The purpose of this study was to evaluate the accuracy of CT angiography with volume rendering for quantifying vascular stenoses in vitro., Materials and Methods: Vascular models with three degrees of stenosis (33%, 67%, and 83%) were imaged at three orientations to the axial plane (parallel, perpendicular, or 45 degrees ) using helical CT with 2-mm collimation and two pitches (1 or 2), two reconstruction intervals (1 or 2 mm), and two scan times (.75 or 1 sec). Diameter and percentage of stenosis were measured from volume renderings using full width at half maximum. Images were measured in two planes whenever resolution varied with direction. Statistical analysis was performed using analysis of variance., Results: Mean absolute error of the measured percentage of stenosis was 7% (range, 0-27%). The actual percentage of stenosis and vessel orientation had the most significant effects on accuracy (p < .001). The measured percentage of stenosis was significantly less accurate with phantoms parallel to the axial plane than with other orientations (p < .001). Mean absolute error in the measured percentage of stenosis was 4% when the parallel-to-the-axial-plane orientation was excluded. Overlapping (1-mm) reconstructions were significantly more accurate than 2-mm reconstructions (p < .05) and direction of measurement significantly affected accuracy (p < .05), but these effects were secondary., Conclusion: CT angiography with volume rendering can accurately quantify vascular stenoses, but it is less accurate for vessels in the axial plane. With 2-mm collimation, vessel characteristics have greater effects on accuracy than do acquisition parameters.

SCRIBE is an automated radiology reporting system that uses the HyperCard environment on Macintosh computers. Radiologic findings and anatomic terms are presented in graphic form, and the appropriate terms are selected by using a trackball or touch-sensitive video screen. Additional lists of more specific terms and differential diagnoses can be requested by the user for abnormal findings. The system is suited to the reporting of plain films and is being used in the emergency room of a large academic radiology department. Advantages of the system include low cost, operational familiarity to Macintosh users, and elimination of transcription costs. Finished reports are immediately available in both printed and electronic forms.