Avner Yoez Yemin MD, Presenter: Nothing to Disclose

Ronald Steven Adler MD, PhD, Abstract Co-Author: Nothing to Disclose

Jenny T. Bencardino MD, Abstract Co-Author: Nothing to Disclose

Soterios Gyftopoulos MD, Abstract Co-Author: Nothing to Disclose

John S. O'Donnell MD, Abstract Co-Author: Nothing to Disclose

Neil Pravin Shah MD, Abstract Co-Author: Nothing to Disclose

James S. Babb PhD, Abstract Co-Author: Nothing to Disclose

Tyson Martin, Abstract Co-Author: Nothing to Disclose

To determine whether needle approach has clinically relevant impact on diagnostic accuracy and confidence of shoulder MRA.

A retrospective database search for consecutive shoulder MRAs with surgical correlation within 6 months was performed in a year timeframe. Exclusion criteria included prior surgery and technically limited study. The study group was categorized into two subgroups (anterior and posterior approach) based on needle technique. The MRAs were de-identified and randomized. Four musculoskeletal radiologists measured the following variables independently and blinded to needle approach: capsular distension, extravasation, SLAP, Bankart/variant, reversed Bankart/variant, and SGHL/MGHL/IGHLs tears. For each variable the diagnostic confidence was graded from 0 to 5. Sensitivity, specificity, accuracy, NPV and PPV were calculated for each diagnosis as well as kappa coefficients for inter-observer agreement, logistic regression for correlated data and exact Wilcoxon signed rank tests.

31MRAs were included, 14 were performed using anterior approach (F:2 ; M:13 ; mean age 33.1 (range:15-59). 17 were performed using a posterior approach (F:1; M:16 ; mean age 37.7 (range: 21-62). In the anterior approach group, Ss/Sp/accuracy/NPV/PPV (%) were as follows: SLAP 54.5/75/58.9/31/88.9 and Bankart/variant 75/80.6/78.6/85.3/68.2. In the posterior approach group, Ss/Sp/accuracy/NPV/PPV (%) were as follows: SLAP 60.7/80.0/72.1/74.4/68 and Bankart/variant 100/63.5/72.1/100/45.7. When comparing anterior (A) to posterior (P) approach in regards to specificity for detection (A%/P%/P-value) of IGHL tear: 73.2/82.8/0.346; MGHL tear 89.3/85.3/0.527; SGHL tear 85.7/88.2/0.618; Reverse Bankart 83.9/77.9/0.588. Inter-reader agreement in terms of detection was moderate for the anterior approach (Kappa: 0.4 - 0.6) and moderate to substantial for the posterior approach (Kappa: 0.4 - 0.7). There was no statistically significant difference for reader confidence scores.

Our findings demonstrate a statistically significant improvement in NPV for evaluation of Bankart lesions and SLAP tears using a posterior approach and moderate agreement (kappa>0.4) for both approaches in terms of the detection of any one attribute.

Posterior needle approach for MRA of the shoulder has a greater negative predictive value for both Bankart lesions and SLAP tears when compared to an anterior approach.

Yemin, A, Adler, R, Bencardino, J, Gyftopoulos, S, O'Donnell, J, Shah, N, Babb, J, Martin, T, MR Arthrography (MRA) of the Shoulder: Does Approach Really Impact Diagnostic Accuracy and Confidence?.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13017354.html