UNLABELLED: OBJECTIVE.:The purpose of this article is to analyze the MR anatomy and variable imaging characteristics of the thumb in asymptomatic volunteers. SUBJECTS AND METHODS: MRI of the thumb was obtained in 34 asymptomatic volunteers (mean age, 33.9 ± 9.2 years). Two radiologists independently assessed visibility and signal intensity (SI) and thickness of the following structures of the metacarpophalangeal and interphalangeal joints: proper and accessory radial and ulnar collateral ligaments, volar and dorsal plates, adductor pollicis aponeurosis, and annular pulleys. The presence and size of a synovial recess at the base of all plates was assessed. RESULTS: On intermediate-weighted fat-saturated images, the ulnar collateral ligament of the metacarpophalangeal joint (reader 1, 79%; reader 2, 62%) and the adductor pollicis aponeurosis (reader 1, 50%; reader 2, 82%) commonly had a striated appearance. The radial collateral ligament of both joints was mainly of low SI (metacarpophalangeal joint, 53% for reader 1 and 85% for reader 2; interphalangeal joint, 59% for reader 1 and 82% for reader 2). All four pulleys were visible in each volunteer. An intermediate SI was observed in almost all pulleys, whereas the variable annular pulley had predominantly a low SI (reader 1, 50%; reader 2, 74%). The ulnar collateral ligament of the metacarpophalangeal joint is typically less than 3 mm thick, and the radial collateral ligament is less than 2 mm thick. A full-thickness synovial recess at the base of the dorsal plate of the metacarpophalangeal joint was seen in almost all volunteers (reader 1, 97%; reader 2, 100%). CONCLUSION: The ligaments and pulleys of the thumb show considerable variability on MRI in healthy volunteers. The ulnar collateral ligament of the metacarpophalangeal joint is typically striated and less than 3 mm thick. A full-thickness synovial recess at the base of the dorsal plate of the metacarpophalangeal joint is a normal finding and should not be misdiagnosed as a tear.
UNLABELLED: OBJECTIVE.:The purpose of this article is to analyze the MR anatomy and variable imaging characteristics of the thumb in asymptomatic volunteers. SUBJECTS AND METHODS: MRI of the thumb was obtained in 34 asymptomatic volunteers (mean age, 33.9 ± 9.2 years). Two radiologists independently assessed visibility and signal intensity (SI) and thickness of the following structures of the metacarpophalangeal and interphalangeal joints: proper and accessory radial and ulnar collateral ligaments, volar and dorsal plates, adductor pollicis aponeurosis, and annular pulleys. The presence and size of a synovial recess at the base of all plates was assessed. RESULTS: On intermediate-weighted fat-saturated images, the ulnar collateral ligament of the metacarpophalangeal joint (reader 1, 79%; reader 2, 62%) and the adductor pollicis aponeurosis (reader 1, 50%; reader 2, 82%) commonly had a striated appearance. The radial collateral ligament of both joints was mainly of low SI (metacarpophalangeal joint, 53% for reader 1 and 85% for reader 2; interphalangeal joint, 59% for reader 1 and 82% for reader 2). All four pulleys were visible in each volunteer. An intermediate SI was observed in almost all pulleys, whereas the variable annular pulley had predominantly a low SI (reader 1, 50%; reader 2, 74%). The ulnar collateral ligament of the metacarpophalangeal joint is typically less than 3 mm thick, and the radial collateral ligament is less than 2 mm thick. A full-thickness synovial recess at the base of the dorsal plate of the metacarpophalangeal joint was seen in almost all volunteers (reader 1, 97%; reader 2, 100%). CONCLUSION: The ligaments and pulleys of the thumb show considerable variability on MRI in healthy volunteers. The ulnar collateral ligament of the metacarpophalangeal joint is typically striated and less than 3 mm thick. A full-thickness synovial recess at the base of the dorsal plate of the metacarpophalangeal joint is a normal finding and should not be misdiagnosed as a tear.
Authors: Christoph A Agten; Andrea B Rosskopf; Maciej Jonczy; Florian Brunner; Christian W A Pfirrmann; Florian M Buck Journal: Skeletal Radiol Date: 2017-11-06 Impact factor: 2.199