What question did this study set out to answer?

This research aims to evaluate right ventricular myocardial blood volume using ultrafast power Doppler imaging and histopathological correlation.

February 28, 2026Open Access

Ultrafast power Doppler imaging for RV myocardial perfusion assessment: histopathologic correlation and in vivo comparison – a pilot study

Key Result

Ultrafast power Doppler imaging showed significantly lower mid-diastolic RV myocardial blood volume in RV pressure overload rats (5.3% vs. 7.8%, p<0.05) and humans (3.1% vs. 4.8%, p=0.03), correlating

Key Points

This research aims to evaluate right ventricular myocardial blood volume using ultrafast power Doppler imaging and histopathological correlation.
Twelve rats were randomized into pulmonary artery banding and control groups.
UPD-derived fractional moving blood volume was measured in the RV lateral wall after six weeks.
Capillary density was quantified through immunostaining, evaluating its relationship with acFMBV in rats and humans.
Mid-diastolic acFMBV in PAB rats was 5.3% ± 0.9%, significantly lower than 7.8% ± 1.2% in controls (p<0.05).
Capillary density showed a strong correlation with acFMBV (r=0.78, p<0.01).
In humans, mid-diastolic acFMBV was 4.8% ± 0.7% in patients compared to 3.1% ± 2.3% in healthy volunteers (p=0.03).

Structured PICO

Does ultrafast power Doppler (UPD)-derived acFMBV accurately quantify right ventricular myocardial blood volume compared to histological capillary density in the setting of RV pressure overload?

Population

12 rats (sex ratio 1/1) and 14 humans (7 healthy volunteers and 7 age-matched patients with right ventricular pressure overload)

Intervention

Ultrafast power Doppler (UPD) imaging to measure attenuation-compensated fractional moving blood volume (acFMBV)

Comparator

Sham controls (for rats) and healthy volunteers (for humans); histopathological capillary density via CD31 immunostaining as a reference standard

Outcome

Mid-diastolic acFMBV and its correlation with capillary densitysurrogate

Ultrafast power Doppler imaging provides a feasible, non-invasive method to quantify right ventricular myocardial blood volume that correlates well with histological capillary density in both rodent models and human patients.

Main Result

Absolute Event Rate: 0% vs 0%

Abstract

Abstract Background Myocardial vascular remodeling is a key feature in various diseases associated with right ventricular (RV) pressure overload but its non-invasive assessment remains challenging. The new technique attenuation-compensated fractional moving blood volume (acFMBV) based on ultrafast power Doppler (UPD) was developed for myocardial blood volume quantification, linked to RV remodeling and capillary density, but not validated in vivo. Objectives To quantify RV myocardial blood volume across the cardiac cycle using UPD in rodent models, with histopathological validation, and assess its feasibility in human patients. Methods Twelve rats (sex ratio 1/1) were randomized to pulmonary artery banding (PAB) (n=6) or sham controls (n=6). After six weeks, UPD-derived acFMBV was measured in the RV lateral wall, representing myocardial blood volume. Capillary density was quantified via CD31 immunostaining, and its correlation with mid-diastolic acFMBV was evaluated. UPD was also applied in 7 healthy human volunteers and 7 age-matched patients with RV pressure overload. Results Mid-diastolic acFMBV in PAB rats was significantly lower than in controls (5.3% ± 0.9% vs. 7.8% ± 1.2%, p0.05), correlating with reduced capillary density (r=0.78, p0.01). In humans, mid-diastolic acFMBV was also lower in RV pressure overload patients compared to healthy volunteers (4.8% ±0.7% vs. 3.1% ±2.3%, respectively, p = 0.03). Conclusion In this pilot study, UPD-based acFMBV correlates with histological capillary density, supporting its potential as a reliable, non-invasive tool for quantifying RV myocardial blood volume in clinical settings. These observations will need to be confirmed in studies with larger sample sizes.