Renal ptosis, otherwise known as nephroptosis or “floating kidney,” is a condition of abnormal descent of the kidney, often asymptomatic with controversy over its clinical and therapeutic significance. The aberrant location of renal and renal collecting system activity associated with this condition may serve as a diagnostic pitfall in PET/CT interpretation. We report a case of dynamic renal ptosis demonstrated on 18F-FDG PET/CT, identified as right kidney migration from an ectopic location on attenuation correction CT images, obtained immediately after upright positioning, to the right renal fossa on subsequent PET images, obtained after approximately 10 min of supine positioning.
From the Nuclear Medicine Service, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, MD.
Received for publication September 18, 2018; revision accepted December 16, 2018.
Conflicts of interest and sources of funding: none declared.
The views expressed in this article are those of the author(s) and do not reflect the official policy of the Department of the Navy, Department of Defense, or U.S. Government.
Correspondence to: Justin Taylor, MD, Department of Radiology, Walter Reed National Military Medical Center, 4494 North Palmer Road | Building 9 | Floor 1, Bethesda, MD 20889. E-mail: firstname.lastname@example.org.