0.2-tesla magnetic resonance imaging of internal lesions of the knee joint: a prospective arthroscopically controlled clinical study

The results of magnetic resonance imaging (MRI) were compared with those of arthroscopy in a prospective series of 244 patients. A dedicated system fo r MRI of limbs and peripheral joints - the 0,2-T Artoscan (Esaote, Italy)- was used for imaging knee joint lesions. T1-weighted spin-echo sagittal ima ges, T2-weighted gradient-echo coronal images, and axial views for lesions of the femoropatellar joint were acquired. Paraxial sagittal and oblique co ronal views were obtained for imaging of the cruciate ligaments. This proto col allowed excellent visualization of the cruciate ligaments and medial an d lateral meniscus in almost all patients. Compared with arthroscopy perfor med within 48 h after imaging, the sensitivity, specificity, and accuracy w ere respectively 93%, 97%, and 95% for tears of the medial meniscus; 82%, 9 6%, and 93% for tears of the lateral meniscus; 100%, 100%, and 100% for tea rs of the posterior cruciate ligament; 98%, 98%, and 97% for tears of the a nterior cruciate ligament; and 72%, 100%, and 92% for full-thickness articu lar cartilage lesions. The examination can be performed within 30-45 min at lower cost than diagnostic arthroscopy. MRI with a 0.2-T magnet is a safe and valuable adjunct to the clinical examination of the knee and an aid to efficient preoperative planning.