title: Renal vascular perfusion index in a canine model.
abstract: Decreased renal perfusion plays an important role in the progression toward renal failure. In this study, a novel measure was proposed to quantify renal perfusion using canine model. Serial renal vascular images at different vascular areas including the whole vascular tree, interlobar, arcuate and interlobular vessels were captured. Image processing software was designed to analyze the changes of power Doppler intensity of colored pixels within regions-of-interest (ROI). For a given ROI, the power Doppler vascular index (PDVI) was found to fluctuate with the cardiac cycle. It was also noted that the power Doppler signals generated by arterial vessels have different fluctuating waveforms and different phase compared with the signal derived from venous vessels. A power Doppler correlation-map was developed to differentiate the arteries and veins in the ROI. Using the serial power Doppler images and the derived flow direction information, the interlobular perfusion can be strongly quantified. The renal vascular perfusion index (RVPI) defined as the ratio of PDVI(max) versus PDVI(min) was significantly higher in the interlobular vessel areas than three other areas for seven healthy dogs. The RVPI resembles the systolic/diastolic (S/D) ratio that commonly reflects arterial hemodynamics. RVPI and power Doppler correlation-map reveal more "dynamic" sense of vascular perfusion and provide a novel approach for the examination of renal function in clinical practice.
authors.affiliation: Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan.
authors.forename: Yio-Wha
authors.initials: YW
authors.lastname: Shau
authors.forename: Sun-Hua
authors.initials: SH
authors.lastname: Pao
authors.forename: Nai-Kuan
authors.initials: NK
authors.lastname: Chou
authors.forename: King-Jen
authors.initials: KJ
authors.lastname: Chang
authors.forename: Jeou-Jong
authors.initials: JJ
authors.lastname: Shyu
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D004285:Dogs; D007091:Image Processing, Computer-Assisted; D007668:Kidney / Q000000981:diagnostic imaging*; D007677:Kidney Function Tests; D023421:Models, Animal; D010477:Perfusion; D012077:Renal Artery / Q000000981:diagnostic imaging; D012079:Renal Circulation / Q000502:physiology*; D012082:Renal Veins / Q000000981:diagnostic imaging; D018615:Ultrasonography, Doppler, Color / Q000379:methods*