Assessment of renal congestion in a rat model with congestive heart failure using superb microvascular imaging

Figures

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  Fig. 1. Measurement of IRPI. The left panel presents a long-axis view of the right kidney as visualized using SMI. The blue, yellow, and green circles respectively represent ROI for interlobular, interlobar, and both vessels. The right panel depicts a graph with the area ratio on the vertical axis and time on the horizontal axis. The area ratio, which is determined by dividing the number of blood flow pixels displayed on SMI by the number of pixels in the ROI, varies with pulsation. ROI region of interest, SMI superb microvascular imaging

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  Fig. 2. Renal interstitial edema. These panels show pathological images of Masson's trichrome-stained kidneys of a control subject. The left panel shows the right kidney stained with Masson's trichrome. The right panel is a higher magnification image of the boxed area in the left panel. Upper panels are raw Masson's trichrome staining (a). Middle panels show renal parenchyma in red using QuPath (b). The lower panels show the areas with edema in light blue (c)

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  Fig. 3. CVP and renal congestion. These panels show the central venous pressure (a) and renal congestion parameters RMP (b), TTP in cortex (c), TTP in medulla (d), and renal edema (e). Error bar means standard error. Differences between the two groups were evaluated using Mann–Whitney test. CVP central venous pressure, HF heart failure, RMP renal medullary pressure, TTP time to peak.

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  Fig. 4. IRPI. A comparison of IRPI between control and HF groups is shown. The ROI was set in interlobular (a), interlobar (b) and interlobular and interlobar artery and vein (c). HF heart failure, IRPI intrarenal perfusion index, ROI region of interest, SMI superb microvascular imaging. Error bar means standard error. Differences between the two groups were evaluated using Mann–Whitney test. HF heart failure, IRPI intrarenal perfusion index, ROI region of interest, SMI superb microvascular imaging

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  Fig. 5. Correlation between pulse Doppler parameters and IRPI. These panels demonstrate the correlation between IRPI and pulse Doppler parameters, including VII (a) and RI (b). IRPI intrarenal perfusion index, RI superb microvascular index, VII venous impedance index

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  Fig. 6. Relationship between IRPI and CVP, RMP, TTP in medulla, and renal edema. Owing to the non-normal distribution of CVP (a), RMP (b), TTP in the medulla (c), and renal edematous area (d), natural logarithmic transformations were employed to meet the requirements for normality in the analysis. CVP central venous pressure, IRPI intrarenal perfusion index, RMP renal medullary pressure, TTP time to peak