|Patient: 78 year old female|
|History: 78-year-old woman with left foot pain for the past month. Radiographs obtained at the patient's primary care physician's office were reportedly negative for fracture.|
|Findings: Three phase bone scintigraphy of the lower extremities was obtained. There is increased uptake of radiotracer within the distal left third metatarsal on both the immediate and delayed phase imaging. |
Radiographs of the left foot demonstrate sclerosis and flattening of the third metatarsal head, consistent with avascular necrosis (Freiberg's infraction.)
When combined with the radigraphs of the feet, these findings are consistent with the diagnosis of avascular necrosis.
|Diagnosis: Osteonecrosis of the 3rd metatarsal head (Freiberg's Infarction).|
General Discussion: Avascular necrosis is usually post-traumatic in etiology, though it can also be due to the use of steroids or vascular disease. When performed early, bone sintigraphy demonstrates decreased activity in the affected region. This is followed by increased activity during the hyperemic repair phase days to weeks later.|
The sensitivity for detection of avascular necrosis on bone scan is greater than conventional radiographs due to the detection of increased blood flow and osteoblastic activity. Limitations to bone scintigraphy include decreased specificity. In the case of early AVN, MR is more sensitive than bone scintigraphy and thus more widely used.
|Specific Discussion: Freiberg's Infarction is avascular necrosis of the metatarsal head. It most commonly affects the 2nd and 3rd metatarsal heads, with the second being the more commonly involved. It is thought to be post-traumatic, and has been associated with the use of high-heeled footwear. It is 3-4 times more commen in women than men.|
Mettler, FA, Guiberteau, MJ. Essentials of Nuclear Medicine Imgaing, 5th ed. Philadelphia, Saunders, 2006.
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Case Number: 99396Owner(s): Keith Fischer and Shane InoueLast Updated: 12-15-2010 The reader is fully responsible for confirming the accuracy of this content.
The reader is fully responsible for confirming the accuracy of this content.