title: Accuracy of MRI-based Diagnoses for Distal Upper Extremity Soft Tissue Masses.
abstract: To determine the accuracy of the pre-operative MRI-based diagnosis of soft tissue masses in the forearm, wrist, and hand, the records of 144 patients who underwent an MRI followed by excision of a soft tissue mass in the forearm, wrist, or hand were reviewed. The MRI-based diagnosis was compared to the histological diagnosis, which was considered the gold standard. The sensitivity, specificity, positive predictive value, and negative predictive value of the MRI-based diagnosis were calculated. A multivariate regression analysis was performed.While the accuracy of the MRI-based diagnosis varied widely, there was an overall sensitivity of 75 %. The most accurate diagnosis was an MRI-based diagnosis of ganglion cyst, which had a sensitivity of 94.7 % and a specificity of 94.4 %. Of particular concern was that the MRI-based diagnosis of a malignancy was only 66.7 % sensitive, with a positive predictive value of 44.4 %. On multivariate regression analysis, there was a trend towards improved accuracy in the wrist when compared to the finger, although this did not reach statistical significance.While pre-operative MRI remains a valuable tool for the evaluation of soft tissue masses in the distal upper extremity, caution is warranted when basing the diagnosis on MRI evidence alone.
  
  
  METHODS
  Level IV/Diagnostic.
authors.affiliation: Andrews Sports Medicine and Orthopaedic Center, 805 St. Vincent's Drive, Ste. 100, Birmingham, AL 35205 USA.
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: McKeon
authors.affiliation: Vanderbilt School of Medicine, 1161 21st Avenue South, Ste. T1217, Nashville, TN 37232 USA.
authors.forename: Brian T
authors.initials: BT
authors.lastname: Wright
authors.affiliation: Vanderbilt Orthopaedic Institute, Vanderbilt University Medical Center, 1215 21st Avenue South, Ste. 3200, Nashville, TN 37232 USA.
authors.forename: Donald H
authors.initials: DH
authors.lastname: Lee
keywords: Benign tumor; Imaging; MRI; Malignant tumor; Upper extremity