Free‐breathing, motion‐corrected, highly efficient whole heart T₂ mapping at 3T with hybrid radial‐cartesian trajectory

Abstract

Purpose-To develop and test a time-efficient, free-breathing, whole-heart T 2 mapping technique at 3.0T.Methods-ECG-triggered three-dimensional images were acquired with different T 2 preparations at 3.0T during free breathing. Respiratory motion was corrected with a navigatorguided motion correction framework at near perfect efficiency. Image intensities were fit to a mono-exponential function to derive myocardial T 2 maps. The proposed approach (3D-FB-MoCo) was studied in ex-vivo hearts and kidneys, healthy volunteers and canines with acute myocardial infarction (AMI).Results-Ex-vivo T 2 values from proposed 3D T 2 -prep GRE was not different from 2D SE (p=0.7) and T 2 -prep bSSFP (p=0.7). In volunteers, compared to the proposed approach (3D-FBMoCo) and breath-held 2D T 2 -prep bSSFP (2D-BH), non-motion-corrected (3D-FB-Non-MoCo) myocardial T 2 was longer, had larger coefficient-of-variation (COV) and lower image quality (IQ) score (T 2 =40.3 ms, COV=38% and IQ=2.3, all p<0.05). Conversely, the mean and COV and IQ of 3D-FB-MoCo (T 2 =37.7 ms, COV=17% and IQ=3.5.) and 2D-BH (T 2 =38.0 ms, COV=15% and IQ=3.8) were not different (p=0.99, p=0.74, and p=0.14, respectively). In AMI, T 2 values and edema volumes from 3D-FB-MoCo and 2D-BH approaches were closely correlated (R 2 =0.88 and 0.96, respectively). Conclusion-The proposed whole-heart T 2 mapping approach can be performed within 5 minutes with similar accuracy to 2D-BH T 2 mapping approach.

Cardiovascular Magnetic Resonance in Acute ST-Segment–Elevation Myocardial Infarction

“…There have already been some advances in free-breathing and motion corrected T2 92 and T2*-mapping 93 and late gadolinium enhancement imaging 94 negating the need for breath-holding and helping to accelerate the acquisition of these sequences. Other developments in real-time cine imaging for LV ejection fraction and future refinements in CMR fingerprinting techniques (for robust and fast acquisition of simultaneous T1 and T2-mapping data per slice within one breath-hold) will further reduce scan time, and will be highly desirable in the acute STEMI setting.…”

Respiratory‐ and cardiac motion‐corrected simultaneous whole‐heart PET and dual phase coronary MR angiography

“…In both cases, similar motion‐corrected approaches could be used, for example, by extending the approach proposed in Ginami et al to a 3T PET/MR system, allowing for simultaneous visualization of the coronary anatomy and scar by MR and myocardial viability by 18 F‐FDG PET. Similarly, simultaneous whole‐heart T2 mapping and myocardial viability by 18 F‐FDG PET could be achieved by extending the approach proposed in Yang et al…”

Dictionary-Driven Ischemia Detection From Cardiac Phase-Resolved Myocardial BOLD MRI at Rest

“…Overall performance is also expected to increase moving from 2D to 3D, when full cardiac coverage cine BOLD sequences using free-breathing approaches [43] become available. We rely on radially-defined myocardial wall thickness to assess myocardial function, which is not translatable to the pixel-level.…”