OBJECTIVE. The purpose of this study was to describe the most reliable measurement procedure for acoustic radiation force impulse technology and to define the normal wave velocity values in a healthy liver.SUBJECTS AND METHODS. Twenty healthy volunteers underwent acoustic radiation force impulse imaging tissue quantification and were enrolled in this prospective study. All patients were examined by two independent operators at the same time. Twenty-four measurements per subject were obtained. Intraoperator and interoperator evaluations were performed. Statistical comparison of all mean data was performed with Student's t test. A value of p < 0.05 was considered significant. A comparative analysis was performed, and interclass correlation coefficients were calculated.RESULTS. The operators obtained 960 measurements. A statistically significant difference was found between the mean shear wave velocity values obtained by one operator deep in the right lobe of the liver and the values obtained on the surface ...

Objective This study aimed to assess the feasibility, safety, and efficacy of radiofrequency ablation (RFA) of pancreatic neuroendocrine tumors (PNETs). Methods We performed RFA on 10 patients (7 women) aged 38 to 75 years with histologically diagnosed PNETs (secreting in 3 cases) who could not or would not undergo surgical resection. Tumor nodules (diameter, 0.9-2.9 cm; mean [SD], 1.6 [0.5] cm) were located in the head (n = 7) or body (n = 3) of the pancreas. Ultrasound-guided RFA was performed percutaneously (n = 7), endoscopically (n = 1), or intraoperatively (n = 2) using commercially available equipment. Complete ablation was defined as absence of enhancing tissue at the tumor site on contrast-enhanced imaging studies and normalization of previously elevated serum hormone levels. Results Complete ablation was achieved with 1 (n = 9) or 2 (n = 1) RFA procedures. All neuroendocrine syndromes regressed within 24 hours of treatment. No recurrences were observed during follow-up (range, 12–60 months; median [SD], 34 [14] months). No deaths occurred. Major complications included acute pancreatitis in 3 patients, 2 of whom developed pancreatic fluid collections that were successfully managed with ultrasound-guided drainage and endoscopy. Conclusions Radiofrequency ablation is a feasible, safe, and effective option for patients with small PNETs who cannot or do not want to undergo surgical resection.

OBJECTIVE. The objective of our study was to evaluate the MDCT features of incidentally detected neuroendocrine tumors (NETs) of the pancreas, identify features that can predict tumor biology or aggressiveness and long-term outcome, and determine the incidence of “nonbenign” behavior. MATERIALS AND METHODS. In this retrospective study, 60 histologically verified pancreatic NETs incidentally detected with contrast-enhanced MDCT were included. Various MDCT features such as size, morphology, enhancement, and presence of calcifications were evaluated and were correlated with tumor biology on histopathology. The sensitivity, specificity, predictive values, and accuracy were calculated for MDCT features in predicting nonbenign biology and risk of recurrence. RESULTS. A total of 32 of 60 (53%) NETs were nonbenign: most were large (mean, 29.1 mm) with a solid or complex pattern. NET size of 3 cm or larger yielded a positive predictive value of 61% for nonbenign tumors and 100% when calcification was present. In 1...