Gall bladder activity on technetium99m-ethylenedicysteine renogram masquerading as ectopic kidney

Abstract

99mTc-EC (Technetium-99m-ethylenedicysteine) is a renal tubular imaging agent introduced as an alternative to 99mTc-MAG3 (Technetium-99m-mercaptoacetyltriglycine) (1). This radiopharmaceutical can be easily labeled at room temperature and has high radiochemical purity and long stability for at least 8 h. Within 1 h 70% of 99mTc-EC is excreted in the urine (2). 99mTc-EC provides the same Scintigraphic information as 99mTc-MAG3. The Hepato biliary excretion of 99mTc-EC is very low and usually does not affect image interpretation on routine imaging, the possibility of visualization of the gall bladder should be kept in mind while reporting the 99mTc-EC renogram (1). We present a case of 99mTc-EC renogram, a suspected case of hypoplastic/ectopic right kidney, to look for ectopic kidney. In this case, there was unexpected visualization of gallbladder in delayed images. We herewith present this case, so that physician should be careful while reporting 99mTc-EC renogram, as there may be chances for gall bladder to be masquerading as Ectopic kidney.

Pelvic Renal Ectopia: Unusual Position Abnormality

“…Renal ectopia is different from nephroptosis: the latter is an abnormal location acquired after renal ascension to its natural position. Nephroptosis is due to increased kidney movement in the retroperitoneal space, and is usually observed in obese patients after rapid weight loss; its irrigation is originated in the lumbar aorta, and the ureter has a normal length [12,13]. In the present case, CTU raised concern for nephroptosis and a supernumerary kidney; however, a contrasted CTU confirmed the definitive diagnosis of left renal ectopia of pelvic location -an unusual finding which led to this case report.…”

Clinical Significance of Hepatobiliary Localization of Tc-99m EC in Diuretic Renography

“…When kidneys are functioning normally, the hepatic uptake might not be readily noticeable due to the strong emission originating from the kidneys. 6,[17][18][19][20] Administering probenecid before LLEC administration hampers the excretion of LLEC through the kidneys, leading to a decrease in the excretion of the tracer through urine. This alteration is accompanied by a more noticeable visualization of EC within the liver and a slower clearance from the bloodstream.…”

“…When kidneys are functioning normally, the hepatic uptake might not be readily noticeable due to the strong emission originating from the kidneys. 6 17 18 19 20 …”