Bone scintigraphy equipped with a pinhole collimator for diagnosis of avascular necrosis of the femoral head.

The objective was to compare the sensitivities for diagnosis of avascular necrosis of the femoral head of bone scintigraphy equipped with a pinhole collimator and with an high resolution parallel collimator. Bone scintigraphy equipped with a pinhole collimator and with an high resolution parallel collimator were performed in 16 patients with bilateral (n=7) or unilateral (n=9) avascular necrosis of the femoral head. Bone scintigraphy equipped with a pinhole collimator documented a photopenic defect in 78.3% of the necrotic hips, while bone scintigraphy equipped with an high resolution parallel collimator documented a defect in 47.8%. There was no false-positive diagnosis of avascular necrosis of the femoral head on either bone scintigraphy equipped with a pinhole or with an high resolution parallel collimator. In conclusion, bone scintigraphy equipped with a pinhole collimator has a greater sensitivity for diagnosis of avascular necrosis of the femoral head than bone scintigraphy equipped with an high resolution parallel collimator.