Arterial flow volume measurement using signal intensity gradient versus phase contrast

Area of Science:

• Medical Imaging
• Cardiovascular Research
• Neuroimaging

Background:

• Accurate measurement of cerebral blood flow is vital for diagnosing and managing cerebrovascular diseases.
• Time-of-flight magnetic resonance angiography (TOF-MRA) is a common technique, but its ability to quantify flow volume needs validation.
• Signal intensity gradient (SIG) offers a potential method for flow volume calculation within TOF-MRA.

Purpose of the Study:

• To compare blood flow volumes measured by SIG in TOF-MRA with those obtained by two-dimensional phase-contrast MR (PC-MR).
• To assess the correlation and agreement between SIG volume and PC-MR flow volumes in experimental setups and human subjects.
• To evaluate the clinical applicability of SIG volume from TOF-MRA for assessing cerebral blood flow.

Main Methods:

• Experimental study using four varying-sized tubes to measure flow volumes with both PC-MR and TOF-MRA.
• Prospective cross-sectional study involving healthy human participants, examining internal carotid and vertebral arteries.
• Statistical analysis included Pearson's correlation coefficients, coefficients of determination (R²), and Bland-Altman plots to assess agreement.

Main Results:

• In tubal experiments (n=80), flow volumes showed a high correlation (r=0.98, R²=0.96, p<0.001) between TOF-MRA SIG volume and PC-MR.
• In human studies, 50 internal carotid and 49 vertebral arteries were analyzed.
• Cerebral artery flow volumes demonstrated a strong correlation (r=0.93, R²=0.87, p<0.001) between the two methods.

Conclusions:

• Calculated SIG volumes from TOF-MRA are highly correlated with blood flow volumes measured by PC-MR.
• The SIG method provides a reliable approach for quantifying blood flow in extracranial cerebral arteries.
• This finding supports the use of TOF-MRA with SIG calculation for improved cerebrovascular assessment.