Blood flow resistance in lesion vessels and normal host vessels evaluated by pulsed Doppler ultrasound

Abstract

Blood flow rate in the microcirculation is proportional to the arteriole-venule pressure difference and inversely proportional to the blood flow resistance (BFR). Generally, the BFR studies to date have focused on using invasive methods and were carried out in non-physiological conditions. Moreover, few studies have been concerned with the relationships of BFR between the tumor vessels and the normal host vessels. The present study investigated the BFR in malignant lesion vessels, benign lesion vessels and normal host vessels in physiological conditions using pulsed Doppler ultrasound as a tool and the thyroid as a model, A total of 133 patients with thyroid nodules were included in the study. The results revealed that most of the BFR parameters were higher in malignant lesion vessels than in benign lesion vessels (P=0.001-0.029), as well as lower in normal host vessels than in malignant or benign lesion vessels (P=0.000-0.017); Low to moderate significant positive correlations of BFR between benign lesion vessels and normal host vessels were also found (r=0.358-0.480, P=0.000 for all). Finally and interestingly, low negative correlations between the malignant nodule sizes and some of the BFR parameters were revealed, though these correlations were not statistically significant (r=-0.205--0.261, P=0.108-0.211). Our results suggested that pulsed Doppler ultrasound could be successfully used to measure BFR in physiological conditions and to reveal the BFR relationship between lesion vessels and normal host vessels, as well as the relationship between the lesion sizes and the BFR.