Related Experiment Videos
Quantification of carotid blood flow velocity using MR phase mapping
1Institute of Diagnostic Radiology, Heinrich Heine University, Düsseldorf, Germany.
Journal of Computer Assisted Tomography
|September 1, 1994
Summary
Phase mapping (PM) accurately quantifies carotid blood flow velocity and pulsatility, comparing well with Doppler ultrasonography for extracranial carotid disease assessment. This MR technique provides valuable hemodynamic insights, except in cases of high-grade stenosis.
Area of Science:
- Medical Imaging
- Cardiovascular Imaging
- Hemodynamics
Background:
- Carotid blood flow velocity (CBFV) and pulsatility are crucial indicators of cerebrovascular health.
- Accurate quantification of CBFV is essential for diagnosing and managing extracranial carotid disease.
- Existing methods like Doppler ultrasonography have limitations in certain scenarios.
Purpose of the Study:
- To evaluate the feasibility of a two-dimensional phase-sensitive magnetic resonance (MR) technique, phase mapping (PM), for quantifying CBFV and pulsatility.
- To assess the accuracy of PM in normal subjects and patients with extracranial carotid disease.
- To compare PM measurements with established Doppler ultrasonography techniques.
Main Methods:
- Phase mapping (PM) was used to measure systolic peak, minimum diastolic, and mean CBFV, along with pulsatility index.
- Measurements were performed in the common carotid arteries (CCAs) of 22 normal subjects and 32 patients, and in the internal carotid arteries (ICAs) of 25 patients.
- Data obtained via PM were compared with independent measurements from pulsed-wave Doppler ultrasonography.
Main Results:
- Strong correlations were observed between PM and Doppler ultrasonography for systolic peak CBFV in both CCA (r=0.91) and ICA (r≥0.82).
- Good correlations were also found for mean CBFV (r≥0.79) and minimum diastolic CBFV (r≥0.75) in the CCA.
- High between-method correlations for velocity waveforms were noted in the CCA (r=0.90 for normals, r≥0.88 for patients), with slightly lower correlations for the ICA (r≥0.75).
Conclusions:
- Phase mapping (PM) demonstrates strong agreement with Doppler ultrasonography for quantifying carotid blood flow velocity and pulsatility.
- PM is a feasible MR technique for providing quantitative hemodynamic information in patients with extracranial carotid artery disease.
- PM's utility may be limited in assessing ICA stenosis distal to high-grade obstructive lesions due to lower agreement in these specific cases.