Purpose: The accurate preoperative evaluation of impingement syndrome and rotator cuff lesions, as well as the confirmation of the clinical and operative findings.

Material-Method: 281 patients with clinical findings of impingement syndrome and/or lesions of the rotator cuff were evaluated with MRI.

Results: The following MRI diagnoses were made: tendons’ lesions 306 (degeneration 138, complete rupture 116, partial rupture 52), impingement 196. The following RC lesions were in association with impingement syndrome: degenerative changes 106, complete rupture 101, incomplete rupture 48. The above mentioned tendon lesions were in many patients in all forms of degeneration (mixed). The dimention of all complete ruptures were measured on the MRI (116). In 93 patients of them operation followed. The MRI findings were confirmed in all patients except three (the operative findings showed 8,10,15 mms larger tears in comparison with the MRI measurements, 2, 4.5 and 5 months post-MRI examination respectively). Comparing the clinical and MRI findings we found agreement in 83.54%, unclear clinical diagnosis in 5.06%, partial agreement in 8.86% and disagreement in 2.53%.

Conclusions: MRI is an excellent method in evaluating the rotator cuff lesions and those of the impingement syndrome as well as the extend and degree of muscle atrophy. More important though is the accurate evaluation of the extend and quality of RC lesions, which are closely related to the result of surgical intervention.