MRI Diagnosis of Spontaneous Osteonecrosis of the Knee :A Report of 15 Cases / 实用放射学杂志

ABSTRACT

Objective To explore the clinical and MRI features of spontaneous osteonecrosis of the knee(SONK).Methods 15 patients with SONK diagnosed by clinic and imaging were collected.All of cases were examined by MRI,of them 5 cases underwent CT scan and 3 cases underwent radiographic examinations.Results The subchondral lesions were seen in all cases on MRI and the lesions located in the femoral condyle weight-bearing zone in 14 cases.The subchondral "fracture cleft"sign was found in 2 cases;the subchondral long T1 and short T2 linear abnormal signal intensity surrounding with bone marrow edema were shown by MRI in 3 cases of them.The subchondral focal lesions were slight long T1 and long T2 signal intensity in 10 cases.The subchondral lesion were showed clearly only in 2 cases of 5 cases with CT scan,and only 1 case of 3 cases with plain X-ray examinations.Conclusion MRI is more sensitive than CT and radiography in showing the lesions of SONK.The SONK can be diagnosed based on the clinical and MRI features.