Comparison of magnetization transfer‐preparation and T2‐preparation for dark‐blood delayed‐enhancement imaging

• Published in: NMR in biomedicine Vol. 33; no. 11; pp. e4396 - n/a
• Main Authors: Jenista, Elizabeth R., Wendell, David C., Kim, Han W., Rehwald, Wolfgang G., Chen, Enn‐Ling, Darty, Stephen N., Smith, Logan R., Azevedo, Clerio F., Parker, Michele A., Kim, Raymond J.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01-11-2020
• Subjects: Atria; Atrium; Biological products; Blood; cardiovascular imaging; Conspicuity; Gadolinium; Image acquisition; Magnetization; magnetization transfer; myocardial viability; Myocardium; Ventricle; magnetization transfer; myocardial viability; cardiovascular imaging
• ISSN: 0952-3480; 1099-1492
• DOI: 10.1002/nbm.4396

Recently developed dark‐blood techniques such as Flow‐Independent Dark‐blood DeLayed Enhancement (FIDDLE) allow simultaneous visualization of tissue contrast‐enhancement and blood‐pool suppression. Critical to FIDDLE is the magnetization preparation, which accentuates differences between myocardium and blood‐pool. Here, we compared magnetization transfer (MT)‐preparation and T2‐preparation for use with FIDDLE. Variants of FIDDLE were developed with MT‐ or T2‐preparation modules and tested in 35 patients (11 at 1.5 T, 24 at 3 T). Images were acquired with each FIDDLE variant in an interleaved fashion 10 minutes after gadolinium administration with otherwise identical acquisition parameters. Images were visually and quantitatively assessed for artifacts and differences in right ventricle to left ventricle (RV‐to‐LV) blood‐pool suppression. Bright artifacts, reflecting incomplete blood‐pool suppression, were frequently observed in the left atrium with T2‐preparation FIDDLE at 1.5 and 3 T (82% and up to 100% of patients, respectively). MT‐preparation FIDDLE resulted in fewer patients with artifacts (0% at 1.5 T, 22% at 3 T; P < .01). Left atrial blood‐pool signal was significantly more homogeneous with MT‐preparation than with T2‐preparation at 1.5 and 3 T (P < .001 for all comparisons). Visibly different RV‐to‐LV blood‐pool suppression was observed with T2‐preparation in 36% of patients at 1.5 T and up to 94% at 3 T. In these patients, RV blood‐pool signal was elevated, reducing the conspicuity of the myocardial‐RV blood‐pool border. Conversely, there were no visible differences in RV‐to‐LV blood‐pool suppression with MT‐preparation. Quantitative assessment of differences in blood‐pool suppression and blood‐pool artifacts was consistent with visual analyses. We conclude that for dark blood–blood delayed‐enhancement imaging of the heart, MT‐preparation results in fewer bright blood‐pool artifacts and more uniform blood‐pool suppression than T2‐preparation.
A fundamental component of the cardiac MRI examination is delayed contrast‐enhancement imaging, which is crucial for delineating infarcted from normal myocardium. Unfortunately, infarcted myocardium immediately adjacent to the left ventricle cavity may be hidden if there is poor contrast between hyper‐enhanced myocardium and bright blood‐pool. In this study, we compared magnetization transfer (MT)‐preparation and T2‐preparation modules for use with dark‐blood delayed‐enhancement, and found that MT‐preparation resulted in fewer blood‐pool artifacts (red and blue arrows).