الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The wrist joint is considered the most complex articulation in the human body. The small size of the anatomic structures, the diversity of disorders that can cause symptoms, and the high rate of asymptomatic findings are some of the factors that contribute to the difficulty of diagnosis and management in this region. MR imaging has been used in the evaluation of a wide spectrum of this joint disorder, its multiplanar capabilities and refined tissue contrast allow detailed assessment of osseous and soft tissue pathology. The small ligaments of the wrist including the scapho-lunate interosseous ligament can be challenging to assess at conventional wrist MRI, especially given their complex anatomy. Magnetic resonance arthrography (MRA) has become the preferred modality for imaging patients with internal derangement of the wrist, which include lesions of the triangular fibrocartilage complex (TFCC), scapholunate and lunotriquetral ligaments. The triangular fibrocartilage complex consists of the triangular fibrocartilage proper (articular disk), the dorsal and palmar radioulnar ligaments, the ulnocarpal meniscal homologue, the dorsal and palmar ulnocarpal ligaments, the sheath of the extensor carpi ulnaris tendon, and the capsule of the DRUJ. Injury to this ligamentous complex is responsible for many cases of ulnar wrist pain. The SLL and LTL are the most important intrinsic carpal ligaments for maintaining carpal stability. Furthermore, the dorsal portions of the SLL ligament and the volar part of the LTL are essential for the stabilization of the wrist because they are the intrinsic ligaments most often injured in cases of instability. The aim of this study was to assess the value of conventional MRI in detecting the etiology of wrist pain and also to assess the diagnostic value of direct MR arthrography compared to conventional MR imaging in assessment of lesions affecting the triangular fibrocartilage and intrinsic ligaments of the wrist joint. The sixty patients included in this study, presented clinically with chronic refractory unexplained wrist pain. MRI was done for all patients and MRA (with mid carpal & radio carpal injection of a diluted mixture of gadolinium, iodinated contrast media, local anesthetic and saline) was done for patients with suspected TFC and/or ligamentous injury. MRI was excellent in diagnosing kienbock disease even in the early stages when wrist X-ray was normal. Ganglion cysts were easily detected by MRI, appearing hypointense in T1WI and hyperintense in T2WI and STIR images. MRI is very helpful in detecting scaphoid fractures. Mild ischemia of the proximal pole appears homogenously hyperintense in T2WI while moderate to severe ischemia appears heterogeneously hyperintense in T2WI. AVN appears hypointense in all pulse sequences. Axial images can easily detect swollen median nerve with hyperintense signal in T2WI which is diagnostic of carpal tunnel syndrome. Tenosynovitis is better assessed in axial T2WI where the affected tendon appears surrounded by hyperintense signal and the tendon itself may appear swollen and edematous. The performance of MRI was fair in the diagnosis of complete tears, but partial tears of the scapholunate ligament and even more so the lunotriquetral ligament were frequently overlooked. Poor sensitivity of MRI was also found for TFCC tears. MRA (MR arthrography) combines the advantages of conventional MR imaging and arthrography by improving the visualization of small intra-articular abnormalities. MR arthrography is an excellent technique for determining the site and extent of pathologic lesions of the TFCC, and the intrinsic ligaments. It is useful in the evaluation of patients who have refractory pain, or instability syndromes of the wrist.