Correlation Diagnostic Contribution of SPECT/CT Imaging to 99mTc-DTPA Dynamic Scintigraphy in Patients with Different Renal Pathologies

Abstract

Introduction: Dynamic renal scintigraphy with 99mTechnetium diethylenetriaminepentaacetic acid (99mTc-DTPA) is a widely performed imaging method to evaluate kidney function of patients with various renal pathologies. However the one-stop-shop combination with subsequent SPECT/CT imaging is a rarely discussed topic. Objective: The aim of the study was to evaluate the diagnostic benefits of SPECT/CT imaging to 99mTc-DTPA dynamic renal scintigraphy. Materials and Methods: A group of 32 patients (21 females and 11 males) who underwent dy- namic nephroscintigraphy with subsequent SPECT/CT was retrospectively studied. A dose of 185MBq (5mCi) 99mTc-DTPA was intravenously applied. A low-dose non-contrast CT protocol was used for attenuation correction and anatomical correlation. Results: Impaired relative renal function in various degrees of left kidney was detected in 18 patients (56%) and of right kidney in 14 patients (44%). SPECT/CT imaging identified the particular cause for the renal dysfunction in the analyzed subjects. The hybrid imaging demonstrated urolithiasis in 11 patients, postoperative ureteral strictures in 5 patients, diagnosed urological cancer in 4 patients and external compression of ureter in 2 patients as a possible obstructive cause. Congenital renal anomalies were the identified causes of impaired renal function in 10 patients – hypoplastic kidney in 4 patients, duplex kidney in 2 patients, multiple cortical cysts in 2 patients, aberrant vessel obstructing the pyeloureteral segment in 1 patient and horseshoe kidney in 1 patient. Conclusion: Dynamic renal scintigraphy combined with SPECT/CT is a very useful clinical tool, by providing not only functional but also anatomical information of the urinary tract, especially in the evaluation of obstructive uropathies and congenital renal abnormalities, that has the potential to change clinical management.