Parametric mapping techniques provide a non-invasive tool for quantifying tissue alterations in myocardial disease in those eligible for cardiovascular magnetic resonance (CMR). Parametric mapping with CMR now permits the routine spatial visualization and quantification of changes in myocardial composition based on changes in T1, T2, and T2*(star) relaxation times and extracellular volume (ECV). These changes include specific disease pathways related to mainly intracellular disturbances of the cardiomyocyte (e.g., iron overload, or glycosphingolipid accumulation in Anderson-Fabry disease); extracellular disturbances in the myocardial interstitium (e.g., myocardial fibrosis or cardiac amyloidosis from accumulation of collagen or amyloid proteins, respectively); or both (myocardial edema with increased intracellular and/or extracellular water). Parametric mapping promises improvements in patient care through advances in quantitative diagnostics, inter- and intra-patient comparability, and relatedly improvements in treatment. There is a multitude of technical approaches and potential applications. This document provides a summary of the existing evidence for the clinical value of parametric mapping in the heart as of mid 2017, and gives recommendations for practical use in different clinical scenarios for scientists, clinicians, and CMR manufacturers.

Background— Delivery and tracking of endomyocardial stem cells are limited by the inability to image transplanted cells noninvasively in the beating heart. We hypothesized that mesenchymal stem cells (MSCs) could be labeled with a iron fluorophore particle (IFP) to provide MRI contrast in vivo to assess immediate and long-term localization. Methods and Results— MSCs were isolated from swine. Short-term incubation of MSCs with IFP resulted in dose-dependent and efficient labeling. Labeled cells remained viable for multiple passages and retained in vitro proliferation and differentiation capacity. Labeled MSCs (10 ⁴ to 10 ⁶ cells/150 μL) were injected percutaneously into normal and freshly infarcted myocardium in swine. One, 3, and 1 animals underwent serial cardiac MRI (1.5T) for 4, 8, and 21 days, respectively. MRI contrast properties were measured both in vivo and in vitro for cells embedded in agar. Injection sites containing as few as 10 ⁵ MSCs could be detected and contained intact IFP-bearing MSCs on histology. Conclusions— IFP labeling of MSCs imparts useful MRI contrast, enabling ready detection in the beating heart on a conventional cardiac MR scanner after transplantation into normal and infarcted myocardium. The dual-labeled MSCs can be identified at locations corresponding to injection sites, both ex vivo using fluorescence microscopy and in vivo using susceptibility contrast on MRI. This technology may permit effective in vivo study of stem cell retention, engraftment, and migration.

Purpose: The primary toxicity of trastuzumab therapy for human epidermal growth factor receptor 2–overexpressing (HER2-positive) breast cancer is dose-independent cardiac dysfunction. Angiotensin-converting enzyme inhibitors and β-blockers are recommended first-line agents for heart failure. We hypothesized that angiotensin-converting enzyme inhibitors and β-blockers could prevent trastuzumab-related cardiotoxicity. Patients and Methods: In this double-blinded, placebo-controlled trial, patients with HER2-positive early breast cancer were randomly assigned to receive treatment with perindopril, bisoprolol, or placebo (1:1:1) for the duration of trastuzumab adjuvant therapy. Patients underwent cardiac magnetic resonance imaging at baseline and post–cycle 17 for the determination of left ventricular volumes and left ventricular ejection fraction (LVEF). Cardiotoxicity was evaluated as the change in indexed left ventricular end diastolic volume and LVEF. Results: Thirty-three patients received perindopril, 31 received bisoprolol, and 30 received placebo. Baseline demographic, cancer, and cardiovascular profiles were similar between groups. Study drugs were well tolerated with no serious adverse events. After 17 cycles of trastuzumab, indexed left ventricular end diastolic volume increased in patients treated with perindopril (+7 ± 14 mL/m²), bisoprolol (+8 mL ± 9 mL/m²), and placebo (+4 ± 11 mL/m²; P = .36). In secondary analyses, trastuzumab-mediated decline in LVEF was attenuated in bisoprolol-treated patients (−1 ± 5%) relative to the perindopril (−3 ± 4%) and placebo (−5 ± 5%) groups ( P = .001). Perindopril and bisoprolol use were independent predictors of maintained LVEF on multivariable analysis. Conclusion: Perindopril and bisoprolol were well tolerated in patients with HER2-positive early breast cancer who received trastuzumab and protected against cancer therapy–related declines in LVEF; however, trastuzumab-mediated left ventricular remodeling—the primary outcome—was not prevented by these pharmacotherapies.

Purpose: To validate a new saturation recovery single‐shot acquisition (SASHA) pulse sequence for T₁ mapping and to compare SASHA T₁ values in heart failure patients and healthy controls.Theory: The SASHA sequence consists of 10 electrocardiogram‐triggered single‐shot balanced steady‐state free precession images in a breath‐hold. The first image is acquired without magnetization preparation and the remaining nine images follow saturation pulses with variable saturation recovery times.Methods: SASHA was validated through Bloch equation simulations, Monte Carlo simulations, and phantom experiments. Pre‐ and postcontrast myocardial and blood T₁ values were measured in 29 healthy volunteers and 7 patients with heart failure.Results: SASHA T₁ values had excellent agreement (bias, 5 ± 5 ms) with spin echo experiments in phantoms with a wide range of physiologic T₁ and T₂ values and its accuracy was independent of flip angle, absolute T₁, T₂, and heart rate. The average baseline myocardial T₁ in heart failure patients was higher than in healthy controls (1200 ± 32 vs. 1170 ± 9 ms, P < 0.05) at 1.5T, as was the calculated blood–tissue partition coefficient, λ, (0.42 ± 0.04 vs. 0.38 ± 0.02, P < 0.05), consistent with diffuse myocardial fibrosis.Conclusions: The SASHA sequence is a simple and fast approach to in vivo T₁ mapping with good accuracy in simulations and phantom experiments. Magn Reson Med 71:2082–2095, 2014. © 2013 Wiley Periodicals, Inc.

Saturation recovery single-shot acquisition and saturation pulse prepared heart rate independent inversion recovery have superior accuracy, inferior precision, and similar reproducibility compared ... PurposeTo compare accuracy, precision, and reproducibility of four commonly used myocardial T1 mapping sequences: modified Look-Locker inversion recovery (MOLLI), shortened MOLLI (ShMOLLI), saturat...