Abstract
Background and Aims
The Renal Resistive Index (RRI) measured in intrarenal arteries is considered a marker of cardiovascular damage, and its value can express the amount of renal perfusion. However, some experimental investigations don’t confirm this association. Moreover, in recent works, End Diastolic Velocity (EDV) was used as a better than RRI marker of kidney damage. The study aimed to investigate relations between different ultrasound Renal Doppler parameters (RRI, acceleration (ACC), acceleration time (ACT), and EDV) with the Renal Blood Flow (RBF) estimated in contrast-enhanced computed tomography (CE-MDCT).
Method
In 25 patients (14F, 11M; age 58.9 ±19.0; eGFR 56,9 ±27.4 mL/min/1.73m2) with hypertension and suspected renal artery stenosis, ultrasound Color Doppler examination of intrarenal segmental arteries (GE Logiq P6) was performed. Then CE-MDCT (GE Discovery 750 HD) of renal arteries with RBF assessment was completed. Renal Doppler parameters (RRI, ACC, ACT, and EDV) and RBF were evaluated for each kidney separately. Finally, 31 kidneys without a narrowing of supplying arteries were considered for statistics.
Results
Mean values of intrarenal Doppler parameters were calculated: RRI = 0.699 ±0.113; ACC = 7.41 ±2.75 [m/s2]; ACT = 35.8 ±8.4 [ms]; EDV = 13.68 ±8.41 [cm/s]. CE-MDCT RBF = 218.04 ±71.92 [ml/s/100g]. Only RRI and EDV correlated significantly with RBF (r = -0.544; p=0.002 and r=0.428; p=0.018, respectively). The retrograde multivariable regression analysis included all investigated ultrasound renal Doppler parameters showed an independent association only between RRI and RBF (b = -0.544; R2 = 0.27, p < 0.002).
Conclusion
Only Renal Resistive Index measured in intrarenal segmental arteries is independently related to the Renal Blood Flow from investigated ultrasound renal Doppler parameters. Although End Diastolic Velocity is positively correlated with RBF, this association is not superior to Renal Resistive Index.