Poor Tc-99m dimercaptosuccinic acid uptake, re-evaluation with Tc-99m MAG3 scintigraphy in Lowe syndrome
A 13-year-old boy who had Lowe syndrome that was known since newborn, admitted to our clinic from another hospital to take a DMSA kidney scan. His serum electrolytes were, urea: 33 mg/dL (normal 8.4-38.4), creatinine: 0.91 mg/dL (normal 0.84-1.25), Na: 139 mmol/L (normal 135-150), K: 4.3 mmol/L (normal 3.5-5), Cl:109 mmol/L (normal 96-110). In his venous gas analyzes, pH: 7.35 (normal 7.31-7.41), HCO3 content: 20.7 mmol/L (normal 24-28), pCO2:38.4 mmHg (normal 41-51). In DMSA scan [], there was a huge high-grade radioactivity accumulation in anterior to the left kidney and extends through the pelvis. The left kidney can be hardly seen in the posterior images because of the radioactivity accumulation that belongs to the urinary bladder. Both kidneys accumulated the activity low grade. In left posterior oblique images, the left kidney is seen when the attenuation goes away. We took an ultrasonography (USG) image and confirmed the huge activity accumulation was the urinary bladder. In his CT, the anatomical details were better. Furthermore, dilated ureter may be seen like deviated neurogenic bladder. However, there was no ureter abnormality in USG or CT. We took Tc-99m MAG3 scintigraphy in 10 days. The concentration functions of the radioactivity of both kidneys were normal, as expected and seen in patients with renal tubular acidosis and renal tubular dysfunction in the literature. However, it was shown in Lowe syndrome for the first time as we know.