Avascular necrosis

Case contributed by Melbourne Uni Radiology Masters


Pain in hips and knees.

Patient Data

Age: 48-year-old
Gender: Female
Nuclear medicine

Tc 99m MDP bone scan

NM Isotope Bone Scan.

Focal and discreet areas of increased isotope activity are noted in both femoral heads and in the region of the tibial plateau on  both sides

The renal transplant is visualised in the right iliac fossa and the bladder contains isotope.

In a renal transplant patient the findings are in keeping with avascular necrosis

Case Discussion

Avascular osteonecrosis (AVN) is a serious osseous complication after renal transplantation. Bone scintigraphy and MRI are both useful in the detection of early osteonecrosis after renal transplantation. 

Bone scintigraphy is quite sensitive (~85%) and is the second option after MRI. It is a choice when multiple sites of involvement must be assessed in patients with risk factors. The findings are different accordingly to the time of the scan:

  • early disease: often represented by a cold area likely representing the vascular interruption
  • late disease: may show a "doughnut sign": a cold spot with surrounding high uptake ring (surrounding hyperaemia and adjacent synovitis)
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Case information

rID: 38530
Published: 19th Nov 2015
Last edited: 23rd Dec 2016
Tags: rmh, hennessy
Inclusion in quiz mode: Included

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