Avascular necrosis of the femoral head: early MRI detection and radiological correlation.
Magnetic Resonance Imaging (MRI) and conventional radiographs were compared in 49 hips with Avascular Necrosis (AVN). MRI detected AVN in 25% of the hips during the preradiological stage of the disease. Both MRI and conventional radiographs accurately detected AVN in the remaining 75% of hips. Correlation between the patterns observed with the two techniques reflected the underlying histopathologic events. The reactive interface between infarcted bone and viable bone could be identified on MRI as a low signal intensity (SI) band. On conventional radiographs the reactive interface appeared as a sclerotic band. The adjacent hyperemic zone was seen on MRI as a high SI band and as a lucent zone on the plain films. Variations of this pattern occurred as related to the extend and duration of AVN and to the individual's ability to mount a healing response. Minor degrees of collapse of the femoral head were better identified with plain radiographs but MRI demonstrated small areas of hyperintensity probably corresponding to early subchondral fractures.
Beltran
J
J
Department of Radiology, Ohio State University Hospitals, Columbus 43210.
Burk
J M
JM
Herman
L J
LJ
Clark
R N
RN
Zuelzer
W A
WA
Freedy
M R
MR
Simon
S
S
D005271:Femur Head Necrosis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D011859:Radiography; D013997:Time Factors