COMPARISON OF HIGH-FIELD (1.5 T) AND LOW- FIELD (0.2 T) MR-IMAGING FOR THE RELIABILITY OF MENISCAL DIAGNOSIS

The aim of this study was to evaluate the reliability of a low field s trength MRI unit (0.2 T; Esaote, Biomedica) and a high field strength MRI unit (1.5 T; Siemens) in detecting meniscal lesions. Twenty patien ts were investigated on a 0.2-T low-field MRI unit and a 1.5-T high-fi eld MRI unit for meniscal lesions. Evaluation was performed of four me niscal compartments (anterior and posterior medial and lateral meniscu s), for a total of 80 observations. The reliability of diagnosis was r anked qualitatively on a three-point scale. Investigations of the high -field MRI unit revealed a meniscal tear in 6 patients and ruled out a tear in 14 patients. Evaluation of individual meniscal compartments r evealed diagnosis with high confidence in 58 observations and with mod erate confidence in 22 observations. Investigations of the low-field M RI unit revealed a meniscal tear in 5 patients and ruled out tears in 15 patients. Evaluation of individual meniscal compartments revealed d iagnosis with high confidence in 39 observations, with moderate confid ence in 38 observations, and with low confidence in 3 observations. Th e diagnosis in high-and low-field images was identical in 98.7 % of ca ses; in one patient observations from the high-field unit changed the therapeutic management. Diagnostic reliability was significantly highe r with highfield strength MR imaging. Low field strength MR imaging sh ows comparatively high diagnostic accuracy for meniscal lesions compar ed to high field strength imaging; however, we demonstrated a signific antly higher confidence in diagnosis with high-field MR imaging.