Cartesian dictionary‐based native T₁and T₂mapping of the myocardium

Abstract

In the past decade, there has been tremendous interest in developing and clinically applying MRI techniques for quantitatively mapping relaxation times in the myocardium. 1-3 Myocardial T 1 and T 2 mapping can be used to discriminate between a range of different cardiomyopathies. 4 T 1 mapping can be used to detect diffuse and focal fibrosis,

Open‐source myocardial T1 mapping with simultaneous multi‐slice acceleration: Combining an auto‐calibrated blipped‐bSSFP readout with VERSE‐MB pulses

“…This would have the advantage of not prolonging the apnea period by an additional heartbeat but could potentially perturb the measurements following the second inversion pulse. In any case, their impact on the measured signal could be taken into account using a dictionary‐based estimation approach, as in the method proposed by Henningsson, 29 instead of relying on the standard 3‐parameter fit.…”

Improved cardiac T1 mapping accuracy and precision with a new hybrid MOLLI and SASHA technique: MOSHA

“…To address this, MOSHA could also be acquired with free-breathing techniques [10,30,[32][33][34]. Dictionary matching algorithms [35], instead of exponential fitting, or image denoising [36] could also be used to reduce the number of heartbeats, and acquisition time. In addition, we did not compare the performance of MOSHA that needs a long breath-hold of 21 s with the combination of MOLLI and SASHA sequences that are acquired in two different scans with a shorter breath-hold time.…”

The future of cardiovascular magnetic resonance: All-in-one vs. real-time (Part 1)

“…Estimated T 1 and T 2 values were in agreement with literature values, with coefficients of variance (CoVs) of ∼4.6% and ∼2.6%, respectively. The combination of IR and T2prep for parametric encoding has been used in several studies [8] , [9] , [10] , [11] , using both exponential fitting and dictionary matching, and have provided high-accuracy cardiac T 1 and T 2 quantification [12] , [13] , [14] , [15] . Joint T 1 /T 2 estimation has also been developed using saturation recovery (SR) instead of IR, acquired in a single breath-hold [16] , achieving a resolution of 2 × 2 × 8 mm 3 with a scan time of ∼13 s. Negligible biases were observed relative to saturation recovery single-shot acquisition (SASHA; ∼−9.6 ms) and T2prep-balanced steady state free precession (bSSFP; ∼0.7 ms) for T 1 and T 2 , respectively, along with similar precision (estimated via the standard deviation in each heart segment).…”