Relationship between the Carotid Plaque T1 Relaxation Time and the Plaque-to-Muscle Signal Intensity Ratio on
Ayumu Eto1, Yoshimasa Kinoshita1, Yoshihisa Matsumoto1
1Department of Neurosurgery, Fukuoka University Chikushi Hospital, Chikushino, Japan.
Background:
Black-blood magnetic resonance imaging (BB-MRI) is useful for the characterization and assessment of carotid artery plaques. The plaque-to-muscle signal intensity (SI) ratio (plaque/muscle ratio [PMR]) is used widely to evaluate plaques. However, the correlation between the PMR and the T1 relaxation time needs to be determined. We measured the T1 relaxation time of carotid plaques using T1 mapping and compared the results with the PMR on BB-MRI scans.
Methods:
Between April 2014 and July 2015, 20 patients with carotid artery stenosis were treated by carotid artery stenting. All patients underwent preoperative magnetic resonance plaque imaging. The ratio of the plaque SI to the sternocleidomastoid muscle was calculated on T1-weighted BB-MRI scans. T1 mapping was performed in the region where the vessel was narrowest using the inversion recovery technique. The T1 relaxation time was recorded to determine whether there was a correlation with the PMR.
Results:
The plaque T1 value was 577.3 ± 143.2 milliseconds; the PMR value obtained on BB-MRI scans was 1.23 ± .27. There was a statistically significant decrease in the T1 value as the PMR increased (P < .0001).
Conclusions:
As the T1 relaxation time was well correlated with the PMR on BB-MRI scans, the evaluation of vulnerable plaques using the PMR was reliable and convenient.
Insights
Black-blood MRI plaque-to-muscle ratio (PMR) correlates with T1 relaxation time. This finding supports the reliability of using PMR for assessing vulnerable carotid artery plaques.
Area of Science:
- Cardiovascular Imaging
- Medical Physics
Background:
- Black-blood MRI (BB-MRI) is crucial for characterizing carotid artery plaques.
- The plaque-to-muscle signal intensity ratio (PMR) is a common metric for plaque evaluation.
- The relationship between PMR and T1 relaxation time in carotid plaques requires elucidation.
Purpose of the Study:
- To determine the correlation between T1 relaxation time and the plaque-to-muscle ratio (PMR) in carotid artery plaques.
- To validate the utility of PMR in assessing plaque vulnerability using T1 mapping.
Main Methods:
- Twenty patients with carotid artery stenosis undergoing stenting were included.
- Preoperative magnetic resonance plaque imaging was performed using T1-weighted BB-MRI.
- T1 mapping and plaque/muscle ratio (PMR) measurements were conducted in the narrowest vessel region.
Main Results:
- A statistically significant inverse correlation was observed between T1 relaxation time and PMR (P < .0001).
- The mean plaque T1 value was 577.3 ± 143.2 ms, and the mean PMR was 1.23 ± 0.27.
Conclusions:
- T1 relaxation time is significantly correlated with the PMR derived from BB-MRI scans.
- PMR serves as a reliable and convenient method for evaluating vulnerable carotid artery plaques.
Related Concept Videos
01:24Magnetic Resonance Imaging
01:21Imaging Studies for Cardiovascular System IV: CMRI