Middleton, William D.

Abstract Percutaneous core-needle biopsy (PCNB) plays a growing and essential role in many medical specialties. Proper and effective use of various PCNB devices requires basic understanding of how they function. Current literature lacks a detailed overview and illustration of needle function and design differences, a potentially valuable reference for users ranging from early trainees to experts who are less familiar with certain devices. This pictorial aims to provide such an overview, using diagrams and magnified photographs to illustrate the intricate components of these devices. Following a brief historical review of biopsy needle technology for context, we emphasize distinctions in design between 2 major classes of PCNB devices (side- and end-cutting devices), focusing on practical implications for how each device is most effectively used. We believe a nuanced understanding of biopsy device function sheds light on certain lingering ambiguities in biopsy practice, such as the optimal needle gauge in organ biopsy, the benefits and risks associated with coaxial technique, the impact of needle selection and technique on bleeding, and the risk of unsuccessful sampling. In a subsequent pictorial, we will draw on the concepts presented here to illustrate examples of biopsy needle failure and how unrecognized needle failure can be an important and often preventable cause of increased biopsy risk and lower tissue yield.

Abstract An important sonographic sign of cholecystitis is stone impaction in the gallbladder neck. Demonstration of stone mobility excludes impaction. The purpose of this study is to analyze the orientation of the gallbladder on computed tomography and determine the patient position most likely to facilitate stone mobility. ImageJ processing software was used to determine the x (transverse), y (anterior-posterior), and z (craniocaudal) coordinates for the gallbladder neck and fundus in 544 consecutive computed tomography examinations. The differences in the fundal and neck coordinates were used to determine the likelihood of moving a stone from the neck to the fundus for the left and right lateral decubitus positions (x coordinates), the prone position (y coordinates), and the upright position (z coordinates). The coordinate with the largest difference was considered to predict the position most likely to facilitate stone motion. The difference in position of the fundus and neck was greatest in the y-, z-, and x-axis in 232 (42.6%), 194 (35.7%), and 118 (21.7%) of patients, respectively. For body mass index (BMI) less than 25 kg/m2, the difference was greatest in the z-axis (59.8%). For BMI greater than 25 kg/m2, the difference was greatest in the y-axis (47.1%). Based on their relative location, the optimal position to facilitate gallstone mobility from the gallbladder neck to fundus was most often prone (especially in high BMI patients), followed by upright (especially in low BMI patients), followed by right lateral decubitus. The left lateral decubitus position was never optimal.

ObjectiveTo analyze and classify arterial supply and venous drainage of postcatheterization femoral arteriovenous fistulas (AVFs).MethodsA review of extremity Doppler reports identified 77 femoral AVFs in 75 patients. Doppler exams were reviewed retrospectively. Fistulas were classified as above or below the common femoral artery bifurcation and subclassified based on the location of arterial inflow and venous outflow.ResultsArterial inflow originated above the femoral bifurcation in 32 cases. The communication was between the common femoral artery and the superficial circumflex iliac vein in 25 of 32 cases and between a branch of the common femoral or external iliac artery and the common femoral or external iliac vein in 4 of 32 cases. In 3 of 32 cases, AVFs arose from the common femoral artery, but the venous outflow was not determined. Arterial inflow originated from the superficial femoral artery in 23 cases. Venous outflow originated from the common femoral vein in 10 of 23 cases, the femoral vein in 7 of 23 cases, and the lateral circumflex femoral vein in 6 of 23 cases. Arterial inflow originated from the deep femoral artery in 12 cases. Venous outflow originated from the common femoral vein in 6 of 12 cases and from the lateral circumflex femoral vein 6 of 12 cases. In 8 cases, the AVF originated below the bifurcation, but the arterial inflow was not classified. In 2 cases, it was impossible to determine if the AVF originated above or below the bifurcation.ConclusionsIatrogenic femoral AVFs arise above the femoral bifurcation more often than previously recognized. Classification based on the arterial inflow and venous outflow provides a straightforward means of describing these fistulas.