Measurement of effective renal plasma flow using model analysis of dynamic CT in the preoperative evaluation of the renal transplant donors

Yumi Kataoka; Hitoshi Nishio; Ryo Matsukiyo; Ryoichi Kato; Midori Hasegawa; Takashi Kenmochi; Ryoichi Shiroki; Hiroshi Toyama; Takashi Ichihara; Shigeki Kobayashi

doi:10.20407/fmj.2018-017

Measurement of effective renal plasma flow using model analysis of dynamic CT in the preoperative evaluation of the renal transplant donors

Fujita Med J. 2020;6(3):73-80. doi: 10.20407/fmj.2018-017. Epub 2020 Feb 11.

Authors

Affiliations

¹ Faculty of Medical Quantum Science, Fujita Health University Graduate School of Health Sciences, Toyoake, Aichi, Japan.
² Department of Radiology, Fujita Health University Hospital, Toyoake, Aichi, Japan.
³ Department of Nephrology, Fujita Health University, School of Medicine, Toyoake, Aichi, Japan.
⁴ Department of Organ Transplant Surgery, Fujita Health University, School of Medicine, Toyoake, Aichi, Japan.
⁵ Department of Urology, Fujita Health University, School of Medicine, Toyoake, Aichi, Japan.
⁶ Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Aichi, Japan.
⁷ Department of Artifical Intelligence in Medical Imaging Development, Fujita Health University, School of Medicine, Toyoake, Aichi, Japan.
⁸ Faculty of Radiological Technology, Fujita Health University, School of Medical Sciences, Toyoake, Aichi, Japan.

Abstract

Objectives: Renal scintigraphy is widely used to evaluate residual function of a transplanted kidney from the donor. Dynamic computed tomography (CT) imaging can evaluate both kidney morphology and regional renal function. The aim of this study was to develop an imaging protocol and a calculation method using dynamic CT for assessing the effective renal plasma flow (ERPF) by model analysis, and to evaluate the validity of the obtained ERPF values.

Methods: Preoperative dynamic CT examination with a low radiation dose exposure system was performed for 25 renal transplant donors, and ERPF was calculated from the obtained images (CT-ERPF). To calculate CT-ERPF, we set the region of interest (ROI) in the renal cortex using automatic ROI-setting software developed in our laboratory. We compared the processing time with automatic and manual ROI settings. To evaluate the validity of CT-ERPF, we examined the correlation of age with CT-ERPF and compared with reported ERPF values. We also compared the uptake rates of technetium-99m-dimercaptosuccinic acid and CT-ERPF in terms of the right-to-left ratio.

Results: There was good agreement of CT-ERPF assessed using automatic and manual ROIs. CT-ERPF was negatively correlated with age and showed values below the reference ERPF range in 21 cases. The right-to-left ratio of CT-ERPF showed a significant correlation with that of technetium-99m-dimercaptosuccinic acid.

Conclusions: Using our method, CT-ERPF was a useful indicator for preoperative evaluation of donor's renal function.

Keywords: Dynamic CT; Effective renal plasma flow; Low radiation dose CT.