Because avascular necrosis (AVN) of femoral head occurs primary in young adults and is frequently bilateral, the goal of treatment is to preserve rather than to replace the femoral head. The early diagnosis of avascular necrosis of the femoral
head
must
be stressed. But, it is difficult because the radiologic change usually appears after some progerssion of the disease process. To explore the ability of Magnetic Resonance Imaging (MRI) in the diagnosis of AVN of the femoral head, during the
period
from
May, 1991 to July, 1992, we compared 116 cases of MRI proven AVN from 71 patients with radiographs and radionuclide scans (n=104) and clinical symptoms.
@ES The following results were obtained.
@EN 1. The number of patients according to etiologic factors were alcoholic 36(50.7%), idiopathic 23 (32.4%), steroid 10 (14.1%) and traumatic 2 (2.8%).
2. According to the Steinberg's radiologic classfication, there were 18 cases (16%) of stage I, 25 cases (22%) of stage II, 22cases (19%) of stage III. 42 cases (36%) of stage IV and 9 cases (7%) of stage V.
3. There was 12.5% of false negative bone scanning findings.
4. According to the classification suggested by Mitchell, the lesions were divided into 4 classes (MR) class A ; 39 cases (34%), class B ; 8 cases (7%), class C ; 14 cases (12%) and class D ; 55 cases (47%).
The characteristic double-line sign was seen in 75 cases (65%).
5. Most of the lesions corresponded to rentgenographic early stage were MRI class A (isointensity with and the lesions with rentgenographic late stage were MRI class D (isointensity with fibrous tissues).
6. Most of the hips which had no or mild symptom were MRI class A and the hips with severe pain were MRI calss D.
7. Most of the cases with Grade 3 synovial fluid were MRI class D.
8. The Pathologic intertrochanteric bone marrow finding was seen in 29.3% which was suspected as bone infarction or edematous change.
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