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Background Type 2 Diabetes Mellitus (T2DM) and prediabetes are associated with an increased cardiovascular risk and heart failure independent of the presence of obstructive coronary artery disease, caused in part by myocardial microvascular dysfunction. Recent studies have reported contractile dysfunction and increased rotation with the onset of diabetic cardiomyopathy in uncomplicated T2DM patients. Independently, higher resting myocardial blood flow (MBF) has been reported in T2DM. The objective of this study was to determine whether there is a correlation between LV Epicardial Rotation (LV ER) and resting MBF in T2DM patients with angiographically normal coronaries, measured by tissue tagging and perfusion cardiovascular Magnetic Resonance (CMR). Methods Sixty five patients with no coronary stenosis >30% on invasive angiography were recruited and categorized into T2DM, prediabetes and normal controls groups according to American Diabetes Association guidelines. All patients underwent rest and adenosine stress myocardial perfusion CMR at a single mid-LV location, cine imaging covering the entire heart and myocardial tissue tagging in three LV short axis locations (apical, mid LV and basal). LV volumes and mass were calculated from cine images. LV rotation in three myocardial layers (endocardial, midmyocardial and epicardial) was calculated from CSPAMM tissue images using Tag Track (Gyrotools, Zurich). For this study, only rest MBF was calculated using Fermi-constrained deconvolution for the entire myocardium. Results Patient characteristics and results are shown in Table 1. Patients with T2DM had significantly higher resting MBF than the two other groups. Corresponding mid LV ER was higher in T2DM patients compared to patients with prediabetes and normal controls (Figure 1) (not statistically significant). Univariate analysis showed a significant positive correlation between MBF and LV ER in the entire study population (Pearson coefficient (r) of 0.25, p = 0.05). In the individual groups, the linear determination coefficient (R2) showed that LV ER in T2DM patients had stronger positive correlation (R2 = 0.31) with resting MBF than in patients with prediabetes (R2 = 0.16) and controls (R2 = 0.29), Figure 1. Conclusions T2DM patients when compared to age-matched patients with prediabetes and normal controls have higher peak LV ER. Resting MBF correlates with LV ER. These results suggest that LV ER analysis in uncomplicated T2DM patients may be useful for non-invasive screening of early subtle contractile dysfunction associated with microvascular dysfunction in diabetes patients.

This study has shown that in patients with suspected and confirmed CAD, estimates of MBF by perfusion-CMR are significantly higher in diastole than systole during maximal hyperemic stress.

We have calculated the inter-study reproducibility of myocardial strain and twist measured by CSPAMM and calculated the number of subjects required to detect a significant change in these parameters.

Introduction Dynamic contrast enhanced myocardial perfusion MRI (DCE-MRI) has the potential to be superior to other currently available imaging techniques for the assessment of myocardial ischaemia. Quantitative analysis of cardiac perfusion is currently not routinely carried out because of the time consuming process of manually segmenting the myocardium from large DCE-MRI datasets. A range of automated segmentation algorithms have been proposed which quote results in terms of distance error or estimated myocardial blood flow (MBF). However, the relationship between these two evaluation measures is not clear, making objective comparisons of algorithm performance difficult.

Introduction First pass cardiac magnetic resonance (CMR) myocardial perfusion imaging (MPI) requires the acquisition of large amounts of image data in a short time. Acceleration techniques like k-t SENSE exploit spatiotemporal correlations to speed up data acquisition. In myocardial perfusion CMR k-t SENSE has been used to improve spatial resolution, temporal resolution or slice coverage with improvements of endocardial dark rim artefacts reported. To date, there has been no direct comparison between these strategies.

Type 2 Diabetes Mellitus (T2DM) is associated with an increased risk of heart failure independently of underlying coronary artery disease (CAD) [1]. Myocardial blood flow (MBF) and MBF reserve can be abnormal in patients with T2DM due to myocardial microvascular dysfunction, contributing to the development of heart failure [2]. The myocardial layers may be affected differently by this disease process.

Methods 12 healthy volunteers (6 males, mean age 33±7 years) underwent CMR studies on a 1.5T system (Intera CV, Philips Healthcare, The Netherlands). Tagged CMR images were acquired at the apex, mid-ventricle and base with a CSPAMM pulse sequence (field of view: 300mm, matrix 128 x 128, slice thickness 10mm, tag separation 8mm, 18 phases, typical TR/TE 30ms/6ms, flip angle 25 degrees). In 6 volunteers repeat data sets were acquired after a mean interval of 8±3 days. Data were analysed by two independent observers using Tagtrack software (Gyrotools, CH). Circumferential Langranian strain, radial Langranian strain and rotation were calculated for the three short axis slices. Endocardial and epicardial borders were drawn, and a midline calculated automatically. Left ventricular twist was calculated by subtracting the basal rotation from the apical rotation. The mean difference between paired measurements, the standard deviation (SD) of the differences and the coefficient of variability (Co-V) were calculated.

Methods Thirty-nine patients with 3VD at X-ray coronary angiography and 39 matched patients with no significant coronary disease were identified from the CE-MARC study population [1]. Patients were matched by age, gender, hypertension and diabetes. CMR adenosine stress perfusion imaging was undertaken using a saturation-recovery gradient echo pulse sequence producing three image slices per R-R interval. Visual and Fermi deconvolutionderived CMR myocardial perfusion reserve (MPR) analyses were performed. Gated SPECT imaging was performed and interpreted by an experienced observer blinded to other test results.

Methods 10 volunteers (7 male, mean age 38 years) were studied on a 1.5 T Philips Intera system during adenosine induced hyperaemia (140 mcg/kg/min for 3 minutes, 0.05 mmol/ kg Gd-DTPA) and at rest. A pulse sequence optimised for acquisition of a single midventricular slice at systole was used (saturation recovery segmented gradient echo, 2 × SENSE TR/TE/flip 2.7 ms/1.0/15°, typical FOV 380 × 380 mm, matrix 160 × 160, slice thickness 10 mm, preparation pulse delay 150 ms, shot duration 130 ms). Endo and epicardial contours were drawn and the slice segmented into 6 equidistant sectors. These were further subdivided into epicardial, mid-myocardial and endocardial thirds. Based on LV and blood pool time intensity curves, an inhouse mathematical Fermi Function deconvolution algorithm was implemented to estimate absolute myocardial blood flow [2].

Summary Dynamic contrast-enhanced (DCE) MRI was performed in 16 healthy subjects to measure myocardial microvascular characteristics. In addition, repeatability was assessed in 11 of those subjects who underwent a second examination. The results showed that Gd-DTPA transport in the myocardium is not perfusion limited at rest or under adenosine stress. Background DCE MRI has been used to estimate myocardial perfusion (blood flow, Fb) but there has been little work published on using this technique to measure related microvascular characteristics, such as microvessel permeability-surface area product (PS) and interstitial volume (extra-vascular extra-cellular volume, ve). The reason may be that transport of Gd-DTPA in resting myocardium is thought to be perfusion limited (with near complete first pass extraction). This study aimed to assess the potential of measuring microvascular characteristics in healthy individuals at rest and under adenosine stress and to assess the repeatability of the measurements.

Methods 11 volunteers (6 males, mean age 33 ± 7 years) underwent CMR perfusion on 2 separate days (mean interstudy delay = 84 ± 111 days, median delay = 7 days) on a 1.5 T Philips Intera system during adenosine-induced hyperaemia (140 mcg/kg/min, 0.05 mmol/kg Gd-DTPA) and rest. A pulse sequence optimised for acquisition of a single midventricular slice at systole was used (saturation recovery segmented gradient echo, 2 × SENSE TR/TE/flip 2.7 ms/1.0/ 15°, typical FOV 380 × 380 mm, matrix 160 × 160, slice thickness 10 mm, preparation pulse delay 150 ms, shot duration 130 ms). Endoand epicardial contours were drawn. "Semi"-quantitative analysis calculated maximal upslopes of myocardial signal intensity of the entire slice, normalised to the LV blood-pool (Myocardial perfusion index, MPI) using MASS 6.0 (Medis, Leiden, The Netherlands). The myocardial perfusion reserve index (MPRI) was calculated as the ratio of hyperaemic over rest MPI.