Utility of Intraprocedural Contrast-Enhanced CT in Ablation of Renal Masses.

OBJECTIVE. The purpose of this study was to evaluate the efficacy of radiofrequency ablation (RFA) of renal masses comparing a group who did not undergo intraprocedural CT and a group who did. MATERIALS AND METHODS. A retrospective review included 45 consecutively registered patients who underwent RFA of renal masses. If an adequate biopsy specimen was not obtained or follow-up was inadequate, the patient was eliminated from review from calculation of primary technical efficacy. The inclusion criterion was having undergone RFA with two cooled-tip electrodes. Baseline demographics (age, body mass index, and sex), renal mass characteristics (diameter, side, location, position, morphologic features, type of mass, and grade), technical details (repositioning and hydrodissection), and complications were evaluated. Follow-up images were evaluated to determine the presence of recurrence at the ablation site in the two groups. RESULTS. Among the 45 patients who underwent RFA, 13 did not undergo intraprocedural CT and 32 intraprocedural did. Thirty-five patients met the criteria for follow-up and positive biopsy results. For calculation of recurrence, 10 patients were in the group who did not and 25 were in group who did undergo intraprocedural contrast-enhanced CT. No correlation was found between baseline demographics, renal mass characteristics, and technical results of the two groups. There was an 89% overall technical efficacy rate with a 96% primary technical efficacy rate in the group who underwent intraprocedural CT compared with a 70% rate in the group who did not undergo intraprocedural CT. Negative correlation was found between the groups with respect to technical efficacy rate at p < 0.05. CONCLUSION. Intraprocedural contrast-enhanced CT yields important information about completeness of ablation during the procedure, allowing probe repositioning and thus better therapeutic effect.

Impact of Patient and Procedure-Related Factors on Radiation Exposure from Uterine Artery Embolization.

PURPOSE: To determine the range of radiation dose metrics for uterine artery embolization and the impact of patient and procedure factors on those measures. MATERIALS AND METHODS: Procedure records of 515 uterine embolization procedures were reviewed and various metrics recorded, including patient demographics, body mass index (BMI), radiation exposure measures and procedure-related details. Descriptive statistics were used to summarize the measures, and appropriate parametric and nonparametric tests were used to compare and assess the correlation between the measures and the cumulative dose (CD), dose area product and fluoroscopy time (FT). Multivariable regression analysis was used to assess the impact of individual factors on the measures of radiation dose. RESULTS: The strongest correlation among the measures compared were between CD and BMI (r = 0.70), while the correlation between BMI and FT was weak (r = 0.23). Dose was higher for those procedures done with aortography and those who had TAGM as the embolic agent. Multivariable analysis demonstrated an increase of 7.4% in CD for each increase in BMI, 5.9% for each increase in cm uterine length. FT was impacted to a lesser extent, with an increase of 2.8% per unit BMI. Increasing procedure time had a greater impact on FT (r = 0.56) than on CD (r = 0.33). CONCLUSION: Among the measured variables, BMI had the greatest impact on CD and has a substantial impact on the risk of radiation-induced skin injury, even without prolonged FT.

Incidentally Detected Focal Fundal Gallbladder Wall Thickening at Contrast-Enhanced Computed Tomography: Prevalence and Computed Tomography Features of Malignancy.

OBJECTIVE: The aim of this study was to determine the prevalence and computed tomography (CT) features of malignancy in incidental focal fundal gallbladder wall thickening. METHODS: Patients with incidental focal fundal gallbladder wall thickening on CT were included if they had an ultrasound or magnetic resonance imaging diagnostic of the etiology (n = 19), stability on CT for 1 year (n = 84), or pathological correlation (n = 13). Morphologies were classified as type 1 (nodular/pinched intramural low attenuation), type 2 (intramural low attenuation), type 3 (homogeneous enhancement), type 4 (nodular/pinched homogeneous enhancement), type 5 (intramural cystic spaces), or type 6 (hyperenhancing/heterogeneous enhancement). RESULTS: One hundred sixteen patients had the following morphologies: type 1 (n = 57), type 2 (n = 10), type 3 (n = 6), type 4 (n = 19), type 5 (n = 14), and type 6 (n = 10). Four cases (3.4%; 95% confidence interval, 0.9%-8.6%) of malignancy were identified (type 6 in 3 and type 3 in 1). CONCLUSIONS: Incidental focal fundal gallbladder wall thickening is usually benign. Computed tomography features help distinguish benign from malignant etiologies.

Portal Vein Thrombosis: Imaging the Spectrum of Disease With an Emphasis on MRI Features.

OBJECTIVE: The purpose of this article is to review the classic and uncommon imaging findings of portal vein thrombosis (PVT) (acute, chronic, congenital, and septic thrombus) as visualized on multiple modalities, with an emphasis on MRI findings. Additional aims are to understand the imaging of obliterative portal venopathy and its clinical significance, appreciate morphologic changes of the biliary system that may accompany PVT, and recognize changes in liver enhancement patterns seen with PVT related to the hepatic arterial buffer response. The review also addresses morphologic changes of the liver that may occur after PVT, including nodular regenerative hyperplasia, central hepatic hypertrophy, and peripheral fibrosis that may stimulate cirrhosis, as well as the importance of portal vein mapping and the diagnostic findings and clinical significance of tumor within the portal vein in the liver transplant population. CONCLUSION: PVT may be a complication of liver cirrhosis, but it may also occur as a primary vascular disorder without liver disease. PVT can result in portal hypertension and may present with variceal bleeding or hypersplenism. Radiologists should be familiar with the imaging of PVT in patients of various ages and in different clinical scenarios. PVT can influence hepatic perfusion, the shape of the bile ducts, and liver architecture. Bland PVT and tumor-related PVT have major implications for hepatic transplant.