Additional Value of SPECT/CT Imaging to $${}^{\rm 99m}$$Tc-DTPA Dynamic Renal Scintigraphy in the Diagnosis of Patients with Different Nephro-urological Conditions

Abstract

Dynamic renal scintigraphy with ^99m Technetium diethylenetriaminepentaacetic acid (99mTc-DTPA) is a generally used imaging technique for evaluating renal function of patients with various nephro-urological conditions. However, the application of SPECT/CT is not regularly performed as a part of the study. The aim of the study was to evaluate the added value of SPECT/CT imaging to dynamic renal scintigraphy with ^99m Tc-DTPA. Thirty-eight patients – 23 females (60.5%) and 15 males (39.5%), aged 16–83 years (mean: 55.4, standard deviation: 18.76) underwent dynamic nephroscintigraphy with subsequent SPECT/CT. The CT scan was performed with a low dose protocol. A dose of 185 MBq (5 mCi) ^99m Tc-DTPA was administered intravenously. Our analysis demonstrated impaired relative renal function in various degrees of left kidney in 21 patients (55.3%) and of right kidney in 17 patients (44.7%). SPECT/CT maging revealed the specific cause, responsible for the renal dysfunction in the cases. The hybrid imaging demonstrated calculosis in 11 patients, urological cancer in 6 patients, postoperative strictures of ureter in five patients, external compression of ureter from ovarian cyst in one patient and compression of ureter due to nephroptosis in one patient as a possible obstructive cause. In 14 patients congenital renal anomalies were the identified causes of impaired renal function – hypoplastic kidney in five patients, duplex kidney in three patients, multiple cortical cysts in three patients, aberrant vessel obstructing the pyelo-ureteral segment in two patients and horseshoe kidney in one patient. The combination of conventional ^99m Tc-DTPA dynamic renal scintigraphy with subsequent SPECT/CT could provide not only functional but also anatomical information of the urinary tract, especially in the valuation of obstructive uropathies and congenital renal abnormalities that can change the clinical management.