Focal Decreased Renal Uptake
Focal areas of decreased renal uptake are generally caused by space-occupying lesions which destroy or replace normal renal parenchyma, such as abscesses, cysts , primary, and metastatic neoplasms. Irregularity of the renal contour may be seen with infarcts or scarring from chronic pyelonephritis. Iatrogenic focal decreased uptake is seen after partial nephrectomies.
Bone scintigram (posterior view) shows a large area of decreased uptake in the upper pole of the left kidney, a finding that corresponds to a large renal cyst seen on CT scan (B).
Renal Cyst
Bone scintigram (posterior view) shows a large area of decreased radionuclide uptake in the lower pole of the right kidney, a finding that corresponds to a large cyst on the longitudinal view of the right renal sonogram (B).
(A) Bone scintigram (posterior view) in a patient with renal cell carcinoma shows a large area of decreased uptake in the lower pole of the left kidney, a finding that corresponds to a large mass seen on the CT scan (B). On the bone scan there is also decreased uptake in the lower pole of the right kidney (arrow) which corresponds to a cyst seen on CT. The focal area of increased radiotracer uptake in the lower thoracic spine probably represents metastatic disease.
Renal cell carcinoma.
The bone scintigram (A) shows a focal photopenic region in the lower pole of the right kidney, which corresponds to a large mass seen on CT scan (B).
Bone scintigram (posterior view) in a patient with non-Hodgkin's lymphoma shows enlarge kidneys bilaterally with multiple areas of diminished radiotracer uptake, a finding that corresponds to multiple low-attenuation masses seen on CT scan (B).
Anterior view (A) of a bone scan shows a photopenic area in the superior pole of the right kidney (arrow), the posterior view (B) is normal, US image (C) demonstrate a large shadowing gallstone. Attenuation from calcified gallstone causes the photopenic area in the kidney.