Incidental detection of urinary tract abnormalities with skeletal scintigraphy.

Urinary tract abnormalities are detected as incidental findings in 15% of skeletal scintigraphic studies. Several scintigraphic patterns denote these abnormalities. Bilateral diffuse increased uptake is found in patients who have undergone chemotherapy and those with hyperparathyroidism, hypercalcemia, and sickle cell disease. Bilateral diffuse decreased uptake occurs in patients with end-stage renal disease, extensive metastatic disease to the bone, and various hematologic disorders. Focal increased activity is associated with postoperative changes and effects from radiation therapy. Focal decreased uptake is caused by space-occupying lesions such as abscesses, cysts, and neoplasms. Abnormal size, shape, and position associated with abnormalities of the kidney and bladder can also be seen. Although these scintigraphic patterns are seldom suggestive of a definitive diagnosis, they are highly specific for urinary tract disease.