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Published on: August 17, 2022
Combined respiratory and cardiac triggering improves blood pool contrast-enhanced pediatric cardiovascular MRI
Shreyas S Vasanawala1, Frandics P Chan, Beverley Newman
1Department of Radiology, Stanford University School of Medicine, Lucile Packard Children's Hospital, 725 Welch Road, Room 1679, Stanford, CA 94305-5913, USA. vasanawala@stanford.edu
Insights
This study introduces a new cardiac MRI technique that combines respiratory and ECG triggering. This method significantly improves image quality and anatomical detail in pediatric cardiovascular MRA scans.
Area of Science:
- Cardiovascular Imaging
- Medical Physics
- Pediatric Radiology
Background:
- Contrast-enhanced cardiac MRI (magnetic resonance angiography) is prone to motion artifacts.
- Current methods often necessitate breath-holding, which is challenging for pediatric patients.
Purpose of the Study:
- To develop and evaluate a novel blood pool contrast-enhanced MRA technique.
- This method integrates simultaneous respiratory and electrocardiogram (ECG) triggering.
Main Methods:
- A gradient echo sequence was modified for combined triggering on a 1.5-T scanner.
- Twenty-three pediatric patients with heart disease underwent both triggered and non-triggered MRA using gadofosveset.
- Radiologists assessed image quality and anatomical structure delineation in a blinded, randomized comparison.
Main Results:
- Triggered MRA sequences consistently received higher scores for all anatomical structures.
- Direct comparisons showed a significant preference for triggered images in delineating cardiac structures.
- The improvements in image quality and delineation were statistically significant.
Conclusions:
- Combined cardiac and respiratory triggering, utilizing a blood pool contrast agent, enhances anatomical structure delineation in pediatric cardiovascular MRA.
- This advanced technique offers improved diagnostic accuracy for congenital and acquired heart conditions in children.
Background:
Contrast-enhanced cardiac MRA suffers from cardiac motion artifacts and often requires a breath-hold.
Objective:
This work develops and evaluates a blood pool contrast-enhanced combined respiratory- and ECG-triggered MRA method.
Materials And Methods:
An SPGR sequence was modified to enable combined cardiac and respiratory triggering on a 1.5-T scanner. Twenty-three consecutive children referred for pediatric heart disease receiving gadofosveset were recruited in HIPAA-compliant fashion with IRB approval and informed consent. Children underwent standard non-triggered contrast-enhanced MRA with or without suspended respiration. Additionally, a free-breathing-triggered MRA was acquired. Triggered and non-triggered studies were presented in blinded random order independently to two radiologists twice. Anatomical structure delineation was graded for each triggered and non-triggered acquisition and the visual quality on triggered MRA was compared directly to that on non-triggered MRA.
Results:
Triggered images received higher scores from each radiologist for all anatomical structures on each of the two reading sessions (Wilcoxon rank sum test, P < 0.05). In direct comparison, triggered images were preferred over non-triggered images for delineating cardiac structures, with most comparisons reaching statistical significance (binomial test, P < 0.05).
Conclusion:
Combined cardiac and respiratory triggering, enabled by a blood pool contrast agent, improves delineation of most anatomical structures in pediatric cardiovascular MRA.
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