Diagnostic accuracy of filtration fraction assessed by dynamic 99mTc-diethylenetriaminepentaacetic acid renal scintigraphy after angiotensin-converting enzyme inhibition for the diagnosis of renovascular hypertension

Objectives: To explore the diagnostic accuracy of qualitative and quantitative filtration fraction assessed by dynamic 99mTc-diethylenetriaminepentaacetic acid renal scintigraphy (99mTc-DTPA) after administration of angiotensin-converting enzyme inhibitor (ACEI) for the diagnosis of renovascular hypertension. Methods: Our hospital database of children or adults (≥ 10 years) who underwent 99mTc-DTPA captopril renal scintigraphy with a clinical suspicion of renovascular hypertension from March 2007 to December 2017 were retrospectively reviewed. Patients with high or low probability for renovascular hypertension were enrolled. Qualitative evaluation of the relative filtration fraction (RFF) of the affected kidney was conducted by comparing visual assessment of radioactivity of the affected kidney relative to that of the contralateral kidney during the first 60 second and the 2- to 3-minutes respectively. Quantitative evaluation of the relative filtration fraction of the affected kidney was obtained as dividing the relative glomerular filtration by the relative plasma flow. Results: A total of 15 patients whose scintigraphic findings with high probability for renovascular hypertension and 158 patents with low probability was finally included. Of fifteen patients with high probability of renovascular hypertension, twelve patients showed abnormal qualitative RFF, and sensitivity of qualitative RFF was 80.0% (95% CI, 51.9-95.7). The qualitative RFF was normal in 152 of 158 patients with low probability of renovascular hypertension, and specificity was 96.2% (95% CI, 91.9-98.6). RFF was lower in patients high probability than in those with low probability (0.79 ± 0.15 vs. 1.02 ± 0.11, P