EFFECT OF FIELD-OF-VIEW ON MR DIAGNOSIS OF ROTATOR CUFF TEARS

Purpose. To determine the effect of decreasing the field of view (FOV) on the accuracy of MR for diagnosing rotator cuff tears. Material and methods. One hundred shoulder MR scans with surgical correlation were evaluated for the presence or absence of a cuff tear. The sensitivity and specificity of MR relative to the surgical results were determine d for the 59 patients scanned with a 24-cm FOV, and the 41 patients sc anned with an 18-cm FOV. All other imaging parameters including acquis ition time were identical, The sensitivity and specificity of the two groups were compared using a t-test.Results. The specificity of MR for diagnosing a rotator cuff tear improved from 0.65 for the 24-cm FOV g roup to 0.89 for the 18-cm FOV group (P=0.04). The sensitivity changed from 0.91 to 0.96 (P=0.25). Conclusion. Reducing the FOV from 24 cm t o 18 cm results in a statistically significant improvement in specific ity of MR for diagnosing rotator cuff tears.