Bone scintigraphy and densitometry in children with osteopetrosis.

Bone scintigraphy and dual x-ray absorptiometry were performed in 18 children (8 males, 10 females) with clinical and radiologic diagnoses of osteopetrosis in order to demonstrate the scintigraphic features of this rare disorder and to measure the bone mineral density. Their mean age was 9 years (range, 3-16 years). Bone scintigraphy demonstrated characteristic features of a widened metaphysis of all long bones that showed increased tracer uptake, particularly in the distal femur and proximal tibia. Dual x-ray absorptiometry of the lumbar spine, three femoral sites, and total body showed a marked increase in bone mineral density. The mean values for bone density of the lumbar spine and greater trochanter were markedly elevated than were other sites. Compared with a normal group matched for age and gender, the increase in bone mineral density was 181% for the lumbar spine and 193% for the greater trochanter. The authors concluded that bone imaging and bone densitometry are useful in establishing the diagnosis of osteopetrosis by demonstrating increase tracer uptake in the widened metaphysis and increased bone density. Bone densitometry may be of prognostic value in follow-up, especially in monitoring the response to therapy.