Reverse double inversion‐recovery: Improving motion robustness of cardiac T₂‐weighted dark‐blood turbo spin‐echo sequence

Abstract

Background Cardiac dark-blood turbo spin-echo (TSE) imaging is sensitive to through-plane motion, resulting in myocardial signal reduction. Purpose To propose and validate reverse double inversion-recovery (RDIR)—a dark-blood preparation with improved motion robustness for the cardiac dark-blood TSE sequence. Study Type Prospective. Population Healthy volunteers (n=10) and patients (n=20) Field Strength 1.5T (healthy volunteers) and 3T (patients) Assessment Compared to double inversion recovery (DIR), RDIR swaps the two inversion pulses in time and places the slice-selective 180° in late-diastole of the previous cardiac cycle to minimize slice mis-registration. RDIR and DIR were performed in the same left-ventricular basal short-axis slice. Healthy subjects were imaged with two preparation slice-thicknesses, 110% and 200%, while patients were imaged using a 200% slice-thickness only. Images were assessed quantitatively, by measuring the myocardial signal heterogeneity and the extent of dropout, and also qualitatively on a 5-point scale. Statistical Tests Quantitative and qualitative data were assessed with Student’s t-test and Wilcoxon signed-rank test, respectively. Results In healthy subjects, RDIR with 110% slice-thickness significantly reduced signal heterogeneity in both the left ventricle (LV) and right ventricle (RV) (LV: p=0.006, RV: p<0.0001) and the extent of RV dropout (p<0.0001), while RDIR with 200% slice-thickness significantly reduced RV signal heterogeneity (p=0.001) and the extent of RV dropout (p=0.0002). In patients, RDIR significantly reduced RV myocardial signal heterogeneity (0.31 vs. 0.43; p=0.003) and the extent of RV dropout (24% vs. 46%; p=0.0005). LV signal heterogeneity exhibited a trend towards improvement with RDIR (0.12 vs. 0.16; p=0.06). Qualitative evaluation showed a significant improvement of LV and RV visualization in RDIR compared to DIR (LV: p= 0.04, RV: p=0.0007) and a significantly improved overall image quality (p=0.03). Data Conclusion RDIR TSE is less sensitive to through-plane motion, potentiating increased clinical utility for black-blood TSE.

Cardiac T2 mapping: robustness and homogeneity of standardized in-line analysis

“…T2w dark-blood sequences are currently used and widely accepted [6]. However, this sequence type can suffer from signal loss in higher heart rates and poor contrast between myocardium and blood in areas of insufficient blood signal suppression [7,8]. A promising alternative technique is T2 mapping.…”

Black‐Blood Contrast in Cardiovascular MRI

“…This may be compensated for by slice‐tracking to account for through‐plane cardiac motion, 59 although it is nontrivial to accurately track and compensate for this complex motion. An alternative approach is to perform the selective inversion pulse in the preceding cardiac cycle, but the same cardiac phase as the imaging that minimizes through‐plane cardiac motion 60 . Nevertheless, the susceptibility to artifacts of T 2 ‐weighted STIR‐FSE has led to a questionable clinical usefulness, 61 with bright‐blood T 2 ‐weighted imaging using a flow‐ and motion‐insensitive sequence—T 2 prep with balanced steady‐state free precession readout 62 —showing better diagnostic accuracy 63,64 .…”

“…An alternative approach is to perform the selective inversion pulse in the preceding cardiac cycle, but the same cardiac phase as the imaging that minimizes through‐plane cardiac motion. 60 Nevertheless, the susceptibility to artifacts of T 2 ‐weighted STIR‐FSE has led to a questionable clinical usefulness, 61 with bright‐blood T 2 ‐weighted imaging using a flow‐ and motion‐insensitive sequence—T 2 prep with balanced steady‐state free precession readout 62 —showing better diagnostic accuracy. 63 , 64 Quantitative T 2 mapping has been proposed as an approach to provide more objective detection of edema compared to T 2 ‐weighted imaging.…”

Dark blood T2-weighted imaging of the human heart with AI-assisted compressed sensing: a patient cohort study

“…Dark blood T2-weighted (DB-T2W) imaging with fat saturation is routinely used for cardiac morphological evaluation, which is valuable for the diagnosis of myocardial edema (1)(2)(3). The 2-dimensional (2D) dual inversion recovery fast spin echo sequence is conventionally used for cardiac DB-T2W morphological imaging (4), which acquires k-space data in multi-shot acquisition across multiple cardiac cycles.…”