Richard S. Breiman

Risk of Injury to Adjacent Organs with Lower-pole Fluoroscopically Guided Percutaneous Nephrostomy: Evaluation with Prone, Supine, and Multiplanar Reformatted CT

PURPOSE To assess the risk of injury to organs near the kidney during lower-pole fluoroscopically guided percutaneous nephrostomy by evaluation of prone, supine, and multiplanar reformatted computed tomography (CT). MATERIALS AND METHODS Eighty-three patients who underwent prone and supine CT examinations were identified retrospectively. The expected path of nephrostomy tube placement to the lower-pole calyx was simulated on prone and supine axial images and multiplanar CT reformations. Intervening organs along this path were considered at risk for injury and were recorded for each kidney (N = 166). RESULTS The risk of organ injury as determined on multiplanar reformatted prone images (n = 5) and supine images (n = 0) was significantly less (P < .05) than determined on axial prone images (n = 25) or supine images (n = 10). The colon was the only organ identified to be at risk for injury during the simulated lower-pole percutaneous nephrostomy placement; spleen and liver were not seen along the nephrostomy path on axial or multiplanar reformatted images. CONCLUSION Lower-pole fluoroscopically guided percutaneous nephrostomy carries a low risk of visceral injury, and the risk of injury is overestimated by evaluation of axial CT images alone compared with oblique parasagittal reformations.

Evaluation of diffuse liver steatosis by ultrasound, computed tomography, and magnetic resonance imaging: which modality is best?

PURPOSE To compare ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) determination of diffuse liver steatosis. MATERIALS AND METHODS Quantification of liver steatosis on ultrasound, CT, and MRI was correlated with histopathology in 67 patients. RESULTS Opposed-phase MRI demonstrated the highest correlation with steatosis (0.68 and 0.69, P<.01; intraclass correlation coefficient, 0.93). Spearmans correlation (and intraclass correlation) coefficients were lowest for ultrasound [0.54, 0.33 (0.40)] and enhanced CT [0.33, 0.39 (0.97)]. CONCLUSION Opposed-phase MRI demonstrated best overall performance for determining steatosis.

CT-Pathologic Correlations in Hodgkin's Disease and Non-Hodgkin's Lymphoma

In order to assess its potential uses in the staging and treatment planning of lymphoma, CT was performed in 27 newly diagnosed, previously untreated patients with Hodgkins disease or non-Hodgkins lymphoma; 18 staging laparotomies provided pathologic correlations. CT detected and defined disease in areas not well evaluated by conventional techniques (high para-aortic, mesenteric, splenic hilar nodes). CT interpretation of splenic size and weight correlated well with splenic weight confirmed at pathology. Nodules were identified in several spleens containing foci of lymphoma.

Problems and pitfalls in the evaluation of thoracic aortic dissection by computed tomography

Several conditions can lead to cither false positive or false negative diagnoses of aortic dissection by computed tomography (CT) with intravenous administration of contrast medium. Insufficient contrast enhancement may cause intimal flaps to be missed, leading to a false negative diagnosis. False positive diagnoses result when extraaortic structures (e.g. mediastinal veins. pericardium, thickened pleura, and lung) are mistaken for false channels in the aorta. Superimposition of structures in thick CT slices may cause intimal calcifications to appear displaced. Streak artifacts across the descending aorta can resemble double aortic channels or intimal flaps. Fusiform aneurysms with thrombus are often hard to distinguish from thrombosed dissections by CT as well as by aortography.

Comparison of traditional methods with 3D computer models in the instruction of hepatobiliary anatomy

This study was designed to determine whether an interactive three‐dimensional presentation depicting liver and biliary anatomy is more effective for teaching medical students than a traditional textbook format presentation of the same material. Forty‐six medical students volunteered for participation in this study. Baseline demographic information, spatial ability, and knowledge of relevant anatomy were measured. Participants were randomized into two groups and presented with a computer‐based interactive learning module comprised of animations and still images to highlight various anatomical structures (3D group), or a computer‐based text document containing the same images and text without animation or interactive features (2D group). Following each teaching module, students completed a satisfaction survey and nine‐item anatomic knowledge post‐test. The 3D group scored higher on the post‐test than the 2D group, with a mean score of 74% and 64%, respectively; however, when baseline differences in pretest scores were accounted for, this difference was not statistically significant (P = 0.33). Spatial ability did not statistically significantly correlate with post‐test scores for the 3D group or the 2D group. In the post‐test satisfaction survey the 3D group expressed a statistically significantly higher overall satisfaction rating compared to students in the 2D control group (4.5 versus 3.7 out of 5, P = 0.02). While the interactive 3D multimedia module received higher satisfaction ratings from students, it neither enhanced nor inhibited learning of complex hepatobiliary anatomy compared to an informationally equivalent traditional textbook style approach. Anat Sci Educ 4: 84–91, 2011.

CT and MRI of Congenital Anomalies of the Seminal Vesicles

OBJECTIVE The purpose of this article is to provide a current review of the spectrum of CT and MRI findings seen in common congenital anomalies of the seminal vesicles. CONCLUSION CT and MRI can both accurately show renal and seminal vesicle anomalies. Seminal vesicle anomalies often occur concurrently with renal and vasal defects. MRI is a better tool for accurately defining anatomic relationships when one is planning to excise a seminal vesicle cyst or if one is considering a difficult differential diagnosis.

Accuracy of Plain Abdominal Radiographs in the Detection of Retained Surgical Needles in the Peritoneal Cavity

Objective:To determine the accuracy of plain abdominal radiographs in the detection of retained surgical needles of varying size in the peritoneal cavity. Summary Background Data:Accidental retention of surgical foreign bodies in the peritoneal cavity is estimated to occur once in every 1000 to 1500 abdominal operations and early prevention and identification of retained foreign bodies is increasingly important because of mounting public awareness. Most of the existing literature on the imaging detection of surgical foreign bodies has focused on retained sponges, even though retained needles may account for up to 50% of such objects and the true accuracy of plain abdominal radiographs in the detection of retained needles is not well established. Methods:Eight plain radiographs were obtained of a 41 kg pig cadaver after placement of a total of 39 surgical needles of varying size (4–77 mm in length) in a randomized selection of the 9 segments of the peritoneal cavity. Five radiologists independently reviewed the radiographs and indicated the location of all suspected retained needles. Analyses were performed using the known site and size of placed needles as the standard of reference. Results:In total for all readers, 195 needles were detectable in 360 abdominal segments. The overall mean accuracy, sensitivity, and specificity for plain radiographs in the detection of retained surgical needles were 74% (267 of 360), 69% (135 of 195), and 80% (132 of 165), respectively. Sensitivity for needles 25 mm or more in length was significantly (P < 0.0001) higher than that for needles of 11 to 24 mm or 10 mm or less, with respective values of 99% (69 of 70), 84% (46 of 55), and 29% (20 of 70). Readers demonstrated moderate interobserver agreement, with a multireader κ value of 0.60. Conclusions:Abdominal radiographs have high sensitivity and interobserver agreement in the detection of retained surgical needles over 10 mm in length, but smaller needles are detected with significantly lower sensitivity and the utility of plain abdominal radiographs in this setting is more debatable.

Computed tomography of corpus luteal cysts

Objective: To describe the computed tomography (CT) features of corpus luteal cysts. Methods: We retrospectively identified 10 patients with a diagnosis of corpus luteal cysts established by ultrasound who had also undergone contemporaneous CT. A single attending radiologist, without knowledge of other clinical or radiologic findings, recorded the morphologic features of the cysts based on the CT images. Results: The corpus luteal cyst seen at sonography was visible at CT in all 10 patients. All cysts were unilocular, with a mean density of 25 HU (range, 12 to 45). The mean maximum axial cyst diameter was 2.2 cm (range, 1.4 to 2.9). The mean cyst wall thickness was 3 mm (range, 2 to 4). All cyst walls were crenulated. Cyst wall enhancement was hyperdense in 6 cases, isodense in 3 cases, and hypodense in 1 case. Free fluid was seen in 9 of 10 patients. Conclusions: At CT, corpus luteal cysts are typically less than 3 cm in diameter and are characterized by a thick, crenulated, or hyperdense wall. Recognition of these CT findings should prevent misinterpretation or inappropriate management.

Atypical cases of gallstone ileus evaluated with multidetector computed tomography

Objective: To describe the multidetector computed tomography (CT) findings in 3 patients with atypical gallstone ileus. Methods: We retrospectively evaluated computed radiography and CT images from three cases of surgically proven gallstone ileus. Two radiologists evaluated by consensus all images for the presence of ectopic gallstone, small bowel obstruction, intrahepatic pneumobilia, cholecystic pneumobilia. One author recorded whether diagnosis of gallstone ileus was made prospectively on radiologic reports and correlated findings to pathology. Results: All cases of gallstone ileus were atypical in that one patient had porcelain gallbladder, one had recurrent pyogenic cholangitis, and one was only 35 years of age. Prospective clinical diagnosis of gallstone ileus was made in only 1 patient at computed radiography and all 3 patients at CT. Retrospectively, small bowel obstruction and cholecystic pneumobilia were identified retrospectively in all 3 patients at both computed radiography and MDCT, and an ectopic gallstone, intrahepatic pneumobilia, and choledochoduodenal fistula was seen in 2, 1, and 0 patients at computed radiography and 3, 2, and 3 patients at CT respectively. Conclusion: Multidetector CT is an accurate means to diagnose gallstone ileus, even in patients with atypical features. In particular, multidetector CT is useful for identifying the ectopic gallstone at the transition point between dilated and decompressed bowel.

Evaluation of Potential Outcome Predictors in Type II Endoleak: A Retrospective Study With CT Angiography Feature Analysis

OBJECTIVE The purpose of this study is to investigate which CT features of type II endoleaks following abdominal aortic aneurysm (AAA) endoluminal stent-graft repair can be used to predict clinical outcome. MATERIALS AND METHODS We retrospectively identified 59 patients with type II endoleak after endovascular repair of an AAA with CT of the abdomen and pelvis. Patients were stratified into two groups: those who did (n = 23) and those who did not (n = 35) require reintervention. CT characteristics of type II endoleaks were recorded and correlated with the clinical outcome. RESULTS The CT features showing the strongest association with the clinical outcome were the transverse diameter of the endoleak cavity (mean, 1.13 cm in the nonreintervention group vs 1.85 cm in the reintervention group; p = 0.007) and the maximum diameter of the vessel communicating with the endoleak (0.34 vs 0.40 cm; p = 0.046). The transverse diameter of the endoleak cavity on arterial phase imaging had the greatest predictive capability, with an area under the receiver operating characteristic curve of 0.74. A transverse diameter greater than 1.42 cm had a positive predictive value of 0.71 and a negative predictive value of 0.82. The anteroposterior diameter, location, and heterogeneity of the endoleak cavity and the number of patent communicating vessels did not correlate well with clinical outcome. The correlation between endoleak cavity measurements and clinical outcome was independent of the aneurysm size. CONCLUSION There are identifiable CT features associated with the clinical outcome of patients with type II endoleak that have moderate predictive capabilities.