Measurement of cerebral blood flow using phase contrast magnetic resonance imaging and duplex ultrasonography

Abstract

Phase contrast magnetic resonance imaging (PC-MRI) and color-coded duplex ultrasonography (CDUS) are commonly used for measuring cerebral blood flow in the internal carotid (ICA) and vertebral arteries. However, agreement between the two methods has been controversial. Recent development of high spatial and temporal resolution blood vessel wall edge-detection and wall-tracking methods with CDUS increased the accuracy and reliability of blood vessel diameter, hence cerebral blood flow measurement. The aim of this study was to compare the improved CDUS method with 3 T PC-MRI for cerebral blood flow measurements. We found that cerebral blood flow velocity measured in the ICA was lower using PC-MRI than CDUS (left ICA: PC-MRI, 18.0 AE 4.2 vs. CDUS, 25.6 AE 8.6 cm/s; right ICA: PC-MRI, 18.5 AE 4.8 vs. CDUS, 26.6 AE 6.7 cm/s, both p < 0.01). However, ICA diameters measured using PC-MRI were larger (left ICA: PC-MRI, 4.7 AE 0.50 vs. CDUS, 4.1 AE 0.46 mm; right ICA: PC-MRI, 4.5 AE 0.49 vs. CDUS, 4.0 AE 0.45 mm, both p < 0.01). Cerebral blood flow velocity measured in the left vertebral artery with PC-MRI was also lower than CDUS, but no differences in vertebral artery diameter were observed between the methods. Dynamic changes and/ or intrinsic physiological fluctuations may have caused these differences in vessel diameter and velocity measurements between the methods. However, estimation of volumetric cerebral blood flow was similar and correlated between the methods despite the presence of large individual differences. These findings support the use of CDUS for cerebral blood flow measurements in the ICA and vertebral artery.

Cerebral blood flow in normal aging adults: cardiovascular determinants, clinical implications, and aerobic fitness

“…In such cases, an alternative method may be phase-contrast MRI combined with the time-of-flight angiography. In our previous study, we found that colorcoded duplex ultrasonography and phase-contrast MRI have the similar estimations of volumetric CBF measured from the internal and vertebral arteries (Khan et al 2017).…”

“…In our previous study, we found that color‐coded duplex ultrasonography and phase‐contrast MRI have the similar estimations of volumetric CBF measured from the internal and vertebral arteries (Khan et al . ).…”

Vertebral Artery Diameter and Flow: Nature or Nurture

“…The main limitation of our study is the lack of confirmation with MR imaging that has a higher specificity and sensitivity for VA diameter measurement . However, B‐mode ultrasound was performed by the same expert professional sonographers in order to visualize the VA according to their best knowledge.…”

“…However, B‐mode ultrasound was performed by the same expert professional sonographers in order to visualize the VA according to their best knowledge. Moreover, evidence supports the use of Color Doppler ultrasound for cerebral blood flow velocity measurements in the VA against MRI, which is not the case for VA diameter measurement . On the other hand, flow velocities are also influenced by systemic (eg, blood pressure, heart rate, heart failure, hematocrit values, etc) and local (eg, coiling, kinking, and external constriction) factors beyond the degree of stenosis, which can change the vertebral flow velocities as well.…”

Metabolic and vascular risk factors are associated with reduced cerebral blood flow and poorer midlife memory performance

“…Notably, the mean of the PLS-defined regional CBF values was not associated with memory performance. Our choice of the upper velocity cut-off that was comparable to previous work (Khan et al, 2017), but could have introduced some bias in the phase contrast CBF quantification. Another possibility is the potential of ceiling effects in the CBF or RAVLT measures, as this group included cognitively intact 50-year-old adults.…”