Femoral head avascular necrosis: correlation of MR imaging, radiographic staging, radionuclide imaging, and clinical findings.

Abstract

To better correlate the appearance of avascular necrosis (AVN) of the femoral head on magnetic resonance (MR) images with the stage of disease, MR images of 56 proved AVN lesions were compared with staging from corresponding radiographs (n = 56), Tc-99m scans (n = 41), and grade of symptoms (n = 28). Fractures complicating AVN were seen in 28 (50%) of 56 radiographs (radiographic stages III-V). With long repetition (TR) and echo delay (TE) times, a characteristic "double line sign" consisting of high signal intensity inside a low-intensity peripheral rim was seen in 45 lesions (80%). The central region within the rim was isointense with marrow fat on both short and long TR and TE images in 20 (71%) of 28 lesions uncomplicated by fracture (stages I-II) but in only four (14%) of 28 stage III-V lesions (P less than .001). Symptoms were least severe in lesions isointense with fat and most severe in lesions with low-signal central regions at short and long TRs and TEs. The peripheral double line sign on long TR/TE images may add specificity to the diagnosis of AVN by MR imaging. A chronologic pattern of central MR signal features is presented which may allow staging of AVN by MR imaging.

MRI Evaluation of Aseptic Osteonecrosis in Children over the Course of Hyperbaric Oxygen Therapy

“…As a non-invasive diagnostic method with excellent soft-tissue contrast, MRI is the method of choice in evaluating bone marrow. In correspondence with the classification by Mitchell et al, AON shows typical findings in MR dependent on its respective stage in time [12].…”

Magnetic resonance imaging of bone marrow in oncology, Part 2

“…Osteonecrosis/AVN is localized within the radiation portal and usually is diagnosed years after RT; typical locations include the mandible, clavicle, humeral head, rib, and femur. On MRI, the presence of high signal intensity inside a low-intensity peripheral rim on T2-weighted images (the "double line" sign) is specific for the diagnosis of AVN [27].…”

Bone marrow necrosis in bone marrow transplantation: the role of MR imaging

“…1,3 MR imaging is being increasingly used in bone marrow imaging 6 due to its capability of evaluating large areas of bone marrow compared with bone marrow biopsies. Although the utility of MR imaging in the diagnosis of femoral head avascular necrosis is well-established, 8,9 little is known about the MR features of BMN in haematological malignancies.…”