MRI OF THE HYALINE KNEE-JOINT CARTILAGE - ANIMAL EXPERIMENTAL AND CLINICAL-STUDIES

The value of MR imaging for the detection of hyaline cartilage lesions using 2-D spin-echo and 3-D gradient-echo imaging was evaluated in an animal experiment in 10 dogs and in a clinical study in 30 patients. MR imaging findings were compared with histopathological and arthrosco py findings, respectively. Using MRI neither grade I nor grade II hyal ine cartilage lesions were detectable. In the animal experiments 77 % of grade III lesions and all the grade IV lesions were seen. However, in the clinical study only about the half of grade III and IV lesions were detected. 3-D gradient-echo MR imaging was superior to 2-D spin-e cho imaging (p < 0.001), while 3-D FLASH and 3-D FISP did not differ s ignificantly in the detection rate (p < 0.34). 3-D gradient-echo MR im aging seems to be the best method for the delineation of high grade ca rtilage lesions. However, early stages of cartilage degeneration are i nvisible even with this imaging modality.