A novel pulse sequence scheme is presented that allows the measurement and mapping of myocardial T 1 in vivo on a 1.5 Tesla MR system within a single breath-hold. Two major modifications of conventional Look-Locker (LL) imaging are introduced: 1) selective data acquisition, and 2) merging of data from multiple LL experiments into one data set. Each modified LL inversion recovery (MOLLI) study consisted of three successive LL inversion recovery (IR) experiments with different inversion times. We acquired images in late diastole using a single-shot steady-state free-precession (SSFP) technique, combined with sensitivity encoding to achieve a data acquisition window of <200 ms duration. We calculated T 1 using signal intensities from regions of interest and pixel by pixel. T 1 accuracy at different heart rates derived from simulated ECG signals was tested in phantoms. Key words: spin-lattice relaxation time; Look-Locker; heart; myocardium Despite recent technological advances, in vivo T 1 quantification of the myocardium with modern magnetic resonance (MR) systems remains a challenge because of severe time constraints due to cardiac and respiratory motion. While myocardial T 1 is shorter and therefore relatively easier to measure at low field strengths, it has a value of ϳ1000 ms at a field strength of 1.5 T, exceeding the duration of the cardiac cycle (ϳ600 -1200 ms) in most subjects (1,2). Since standard inversion recovery (IR) measurements require a relaxation period of four to five times T 1 to allow for full magnetization recovery after each 180°pulse (3), only four to five such single-point IR experiments can be performed within one breath-hold (ca. 20 s). To achieve accurate T 1 estimates from a three-parameter curve-fitting procedure, as is commonly employed, data from at least six to 10 time points should be available (4). The multipoint approach, as first described by Look and Locker (5), samples the relaxation curve multiple times after an initial preparation pulse (6). This technique has been shown theoretically to be highly efficient (7), and has been widely used for T 1 measurements of the brain (8 -11). It is not suitable for pixel-by-pixel T 1 mapping of the heart because data acquisition is performed continuously throughout the cardiac cycle without regard for cardiac motion, which means that T 1 values can only be derived for regions of interest (ROIs) that must be defined manually for every frame (1). The resultant T 1 values may consequently be subject to inaccuracy caused by misregistration effects.In this work we present a pulse sequence scheme that allows for accurate in vivo T 1 measurements and T 1 mapping of myocardium with high spatial resolution and within a single breath-hold. To overcome the limitations of the conventional LL approach for cardiac applications, we propose a modified LL IR scheme (MOLLI), which introduces two principles to the standard LL sequence: 1) selective data acquisition at a given time of the cardiac cycle over successive heartbeats, and (2) merging of image sets...

SummaryBackgroundIn patients with suspected coronary heart disease, single-photon emission computed tomography (SPECT) is the most widely used test for the assessment of myocardial ischaemia, but its diagnostic accuracy is reported to be variable and it exposes patients to ionising radiation. The aim of this study was to establish the diagnostic accuracy of a multiparametric cardiovascular magnetic resonance (CMR) protocol with x-ray coronary angiography as the reference standard, and to compare CMR with SPECT, in patients with suspected coronary heart disease.MethodsIn this prospective trial patients with suspected angina pectoris and at least one cardiovascular risk factor were scheduled for CMR, SPECT, and invasive x-ray coronary angiography. CMR consisted of rest and adenosine stress perfusion, cine imaging, late gadolinium enhancement, and MR coronary angiography. Gated adenosine stress and rest SPECT used 99mTc tetrofosmin. The primary outcome was diagnostic accuracy of CMR. This trial is registered at controlled-trials.com, number ISRCTN77246133.FindingsIn the 752 recruited patients, 39% had significant CHD as identified by x-ray angiography. For multiparametric CMR the sensitivity was 86·5% (95% CI 81·8–90·1), specificity 83·4% (79·5–86·7), positive predictive value 77·2%, (72·1–81·6) and negative predictive value 90·5% (87·1–93·0). The sensitivity of SPECT was 66·5% (95% CI 60·4–72·1), specificity 82·6% (78·5–86·1), positive predictive value 71·4% (65·3–76·9), and negative predictive value 79·1% (74·8–82·8). The sensitivity and negative predictive value of CMR and SPECT differed significantly (p<0·0001 for both) but specificity and positive predictive value did not (p=0·916 and p=0·061, respectively).InterpretationCE-MARC is the largest, prospective, real world evaluation of CMR and has established CMR's high diagnostic accuracy in coronary heart disease and CMR's superiority over SPECT. It should be adopted more widely than at present for the investigation of coronary heart disease.FundingBritish Heart Foundation.

Background: Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of heart failure hospitalization and cardiovascular death in patients with heart failure and reduced ejection fraction (HFrEF). However, their effects on cardiac structure and function in HFrEF are uncertain. Methods: We designed a multicenter randomized, double-blind, placebo-controlled trial to investigate the cardiac effects of empagliflozin in patients in NYHA functional class II to IV with a left ventricular (LV) ejection fraction ≤40% and type 2 diabetes or prediabetes. Patients were randomized 1:1 to empagliflozin 10 milligrams once daily or placebo, stratified by age (<65 and ≥65 years) and glycemic status (diabetes or prediabetes). The co-primary outcomes were change from baseline to 36 weeks in LV end-systolic volume indexed to body surface area (LVESVi) and LV global longitudinal strain (LV GLS) measured using cardiovascular magnetic resonance (CMR). Secondary efficacy outcomes included other CMR measures (LVEDVi, LVEF), diuretic intensification, symptoms (Kansas City Cardiomyopathy Questionnaire Total Symptom Score (KCCQ-TSS)), 6-minute walk distance (6MWD), B-lines on lung ultrasound and biomarkers (including NT-proBNP). Results: From April 2018 to August 2019, 105 patients were randomized: 77 (73.3%) male, mean age 68.7 [SD 11.1] years, 82 (78.1%) diabetes and 23 (21.9%) prediabetes, mean LVEF 32.5% [9.8%], and 81 (77.1%) NYHA II and 24 (22.9%) NYHA III. Patients received standard treatment for HFrEF. Compared with placebo, empagliflozin reduced LVESVi by 6.0 (-10.8 to -1.2) ml/m 2 (p=0.015). There was no difference in LV GLS. Empagliflozin reduced LVEDVi by 8.2 (-13.7 to -2.6) ml/m 2 (p=0.0042) and reduced NT-proBNP by 28 (2 to 47) %, p=0.038. There were no between-group differences in other CMR measures, KCCQ-TSS, 6MWD or B-lines. Conclusions: The SGLT2 inhibitor empagliflozin reduced LV volumes in patients with HFrEF and type 2 diabetes or prediabetes. Favorable reverse LV remodeling may be a mechanism by which SGLT2 inhibitors reduce HF hospitalization and mortality in HFrEF. Clinical Trial Registration: URL: https://www.clinicaltrials.gov Unique Identifier: NCT03485092.

Stepping-table digital subtraction contrast material-enhanced MR angiography has high accuracy compared with catheter angiography in patients with arterio-occlusive disease of the aorta and outflow vessels. These preliminary study results suggest that this technique may ultimately provide a safe, noninvasive, and cost-effective alternative to catheter angiography.