Evaluation of intense renal parenchymal activity ("hot kidneys") on bone scintigraphy

Area of Science:

• Nuclear medicine
• Radiology
• Nephrology

Background:

• Bone scintigraphy is a nuclear medicine imaging technique.
• Renal parenchymal activity on bone scintigraphy is typically a normal finding, but intense activity can indicate pathology.
• Abnormalities of the urinary tract are occasionally detected on bone scintigraphy.

Purpose of the Study:

• To review bone scintigrams for urinary tract abnormalities.
• To identify causes of intense renal parenchymal activity on bone scintigraphy.
• To report previously undocumented associations with medications.

Main Methods:

• Retrospective review of 600 bone scintigrams performed over 12 months.
• Identification of cases with abnormalities of the urinary tract.
• Detailed analysis of six cases exhibiting intense renal parenchymal activity.

Main Results:

• Thirty-six of 600 scintigrams showed urinary tract abnormalities.
• Six cases demonstrated intense renal parenchymal activity ("hot kidneys").
• Two "hot kidney" cases were associated with mitoxantrone, one with calcitonin, and two with hypercalcemia/radiotherapy; one case was idiopathic.

Conclusions:

• Intense renal parenchymal activity on bone scintigraphy is rare.
• New associations between "hot kidneys" and mitoxantrone and calcitonin treatments are reported.
• Further investigation is warranted for idiopathic cases and medication-related findings.