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Published on: August 17, 2022
Noninvasive assessment of coronary vasodilation using magnetic resonance angiography
Masahiro Terashima1, Craig H Meyer, Brian G Keeffe
1Division of Cardiovascular Medicine, Stanford University, Stanford, CA 94305, USA.
Insights
Coronary magnetic resonance angiography (MRA) noninvasively measures coronary artery vasodilation after nitroglycerin. This technique shows promise for studying coronary vasomotor function.
Area of Science:
- Cardiovascular Imaging
- Noninvasive Diagnostic Techniques
Background:
- Coronary vasodilation is crucial for coronary circulation.
- Invasive coronary angiography has been used to study epicardial coronary vasodilation.
- Coronary magnetic resonance angiography (MRA) offers a potential noninvasive alternative for assessing coronary artery size changes.
Purpose of the Study:
- To investigate the utility of coronary MRA for assessing human epicardial coronary artery vasodilation.
- To evaluate coronary MRA as a noninvasive method for measuring changes in coronary artery diameter.
Main Methods:
- High-resolution multi-slice spiral coronary MRA was performed on 32 subjects (12 patients, 20 healthy controls) before and after sublingual nitroglycerin (NTG).
- Quantitative analysis of coronary vasodilation was conducted on cross-sectional images of the right coronary artery (RCA).
- Time-course analysis of vasodilation and signal-to-noise ratio were assessed post-NTG.
Main Results:
- Coronary MRA revealed a 23% increase in RCA cross-sectional area post-NTG (p <0.0001).
- Significant vasodilation was observed between 3 and 15 minutes after NTG administration.
- MRA measurements demonstrated low interobserver variability (< or =5%) and strong correlation with X-ray angiography (r=0.98).
- Vasodilation magnitude correlated with baseline area and age.
- A 31% improvement in coronary signal-to-noise ratio was noted post-NTG (p = 0.002).
Conclusions:
- Nitroglycerin-enhanced coronary MRA effectively measures noninvasive coronary artery vasodilation.
- Coronary MRA is a promising noninvasive technique for evaluating coronary vasomotor function.
Objectives:
The purpose of this study was to investigate the use of coronary magnetic resonance angiography (MRA) for assessing human epicardial coronary artery vasodilation.
Background:
Coronary vasodilation plays a vital role in the human coronary circulation. Previous studies of epicardial coronary vasodilation have used invasive coronary angiography. Coronary MRA may provide an alternative noninvasive method to directly assess changes in coronary size.
Methods:
Thirty-two subjects were studied: 12 patients (age 55 +/- 18 years) and 20 healthy subjects (age 34 +/- 4 years). High-resolution multi-slice spiral coronary MRA (in-plane resolution of 0.52 to 0.75 mm) was performed before and after sublingual nitroglycerin (NTG). Quantitative analysis of coronary vasodilation was performed on cross-sectional images of the right coronary artery (RCA). A time-course analysis of coronary vasodilation was performed in a subset of eight subjects for 30 min after NTG. Signal-to-noise ratio was also measured on the in-plane RCA images.
Results:
Coronary MRA demonstrated a 23% increase in cross-sectional area after NTG (16.9 +/- 7.8 mm2 to 20.8 +/- 8.9 mm2, p <0.0001), with significant vasodilation between 3 and 15 min after NTG on time-course analysis. The MRA measurements had low interobserver variability (< or =5%) and good correlation with X-ray angiography (r=0.98). The magnitude of vasodilation correlated with baseline cross-sectional area (r=0.52, p=0.03) and age (r=0.40, p=0.019). Post-NTG images also demonstrated a 31% improvement in coronary signal-to-noise ratio (p = 0.002).
Conclusions:
Nitroglycerin-enhanced coronary MRA can noninvasively measure coronary artery vasodilation and is a promising noninvasive technique to study coronary vasomotor function.
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