Assessment of the rotator cuff and glenoid labrum using an extremity MR system: MR results compared to surgical findings from a multi‐center study

Abstract

Purpose: To conduct a multi-center assessment of the use of a 0.2-T, extremity MR system (E-scan; General Electric Lunar Corp. and Esaote, Genoa, Italy) for identifying tears of the rotator cuff and glenoid labrum. Materials and Methods:A retrospective study was performed involving 160 patients (age range, 15-84 years old) from five facilities in the United States, comparing shoulder MR imaging to surgical findings. MR imaging of the shoulder was conducted as follows: shoulder coil; T1-weighted spin echo, coronal-oblique and axial images; short Tau inversion recovery (STIR), coronal-oblique images and axial images; and T2-weighted spin echo, coronal-oblique and sagittal-oblique images. The MR examinations were interpreted in an independent, prospective manner by two radiologists with extensive musculoskeletal MRI experience. Arthroscopic (N ϭ 103) or open surgical (N ϭ 57) procedures were performed within a mean of 53 days after MR imaging.Results: Surgical findings demonstrated rotator cuff tears in 131 patients and labral tears in 60 patients. For the rotator cuff, the sensitivity, specificity, positive predictive value, and negative predictive value were 90%, 93%, 98%, and 68%, respectively. For the labrum, the sensitivity, specificity, positive predictive value, and negative predictive value were 55%, 100%, 100%, and 82%, respectively. Conclusions:There was good agreement when MR results obtained using the extremity MR system were compared to surgical findings for identifying rotator cuff tears, while the sensitivity of MR imaging for determining labral tears was relatively poor. Nevertheless, these findings were comparable to those reported in the peer-reviewed literature for MR systems operating at mid-, and high-field-strengths. MAGNETIC RESONANCE (MR) IMAGING is regarded as a useful and accurate technique for diagnosing shoulder disorders, including rotator cuff disease and lesions of the glenoid labrum (1-16). MR imaging of the shoulder has been predominantly performed by using wholebody MR systems operating at high-field-strengths (1.0 -1.5 Tesla) or, more recently, utilizing low-fieldstrength (0.2-0.35 Tesla) scanners (1-16). In 2001, Shellock et al (3) studied the diagnostic capabilities of an extremity MR system for identifying shoulder pathology. This investigation compared MR examinations to surgical findings in 47 patients and reported good agreement with regard to determining tears of the rotator cuff and glenoid labrum. In fact, the diagnostic performance of the extremity MR system was reported to compare favorably to that of whole-body, mid-and high-field-strength MR scanners for a variety of musculoskeletal applications (17,18).Performing MR examinations of the shoulder using the extremity MR system offers distinct advantages over conventional MR systems, including reduced start-up costs, more convenient siting and installation, lower maintenance fees, and greater patient comfort and safety (17,18). Importantly, these advantageous features permit the extremity MR system to be readily utilized...

Mri Evaluation in Suspected Cases of Rotator Cuff/ Labral Tears on Low Field Mri System

“…In the study by Zlatkin et al (2004) for the rotator cuff tears, where the sensitivity, specificity, positive predictive value, and negative predictive value were 90%, 93%, 98%, and 68% respectively, our study shows comparative results. [4] In a similar study by Shellock et al (2001), [2] to detect lesions of the rotator cuff and glenoid labrum in 47 patients using a 0.2 T scanner, for the rotator cuff tears (combined full thickness and partial thickness), the sensitivity, specificity, positive predictive value, and negative predictive value were 89%, 100%, 100%, and 90% respectively, again revealing good correlation to our study.…”

“…[2,4,5,6] 2. Partial thickness tears: 3 Different types according to the portion of the tendon that is abnormal:…”

“…[4,5,6] 3. Tendinosis: Histological changes of Rotator Cuff tendons, most commonly mucoid degeneration and fibro-cartilaginous metaplasia, appear as moderately increased focal irregular or diffuse intermediate intra-substance signal intensity on T1-and T2-weighted images.…”

“…In practice, it can occasionally be difficult to distinguish between severe tendinosis and a partial thickness tear; sometimes both possibilities must be considered. [2,4,5] 4. Humeral head Cysts: Humeral head "cysts," foci of fluid signal intensity in the bone marrow of the greater tuberosity near the Rotator Cuff insertions.…”

Imaging of Rotator Cuff Pathology - Is Ultrasound as Good as Mri

“…The accuracy of ultrasound in experienced hands was found to be as good as that of MRI. (18) The MRI has shorter learning curve; it should be used secondarily and in selective cases because it provides more information about extent of tendons and has lower risk of artifacts. Due to the cost difference between the two procedures, our study clearly shows that ultrasound is more cost-effective test to use for identification of rotator cuff tears.…”