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BACKGROUND T1 mapping is a robust and highly reproducible application to quantify myocardial relaxation of longitudinal magnetisation. Available T1 mapping methods are presently site and vendor specific, with variable accuracy and precision of T1 values between the systems and sequences. We assessed the transferability of a T1 mapping method and determined(More)
BACKGROUND Limitations to the coronary calcium score include its requirement for noncontrast imaging and radiation exposure that approaches current methods for contrast-enhanced CT angiography. OBJECTIVES We sought to derive and validate a method of measuring the coronary artery calcium score (CACS) from standard contrast-enhanced CT, obviating the need(More)
OBJECTIVES The aim of this study was to determine the contribution of pre-load and heart rate to pump flow in patients implanted with continuous-flow left ventricular assist devices (cfLVADs). BACKGROUND Although it is known that cfLVAD pump flow increases with exercise, it is unclear if this increment is driven by increased heart rate, augmented(More)
The aim of this article is to describe a novel hardware perfusion phantom that simulates myocardial first-pass perfusion allowing comparisons between different MR techniques and validation of the results against a true gold standard. MR perfusion images were acquired at different myocardial perfusion rates and variable doses of gadolinium and cardiac(More)
Although pulmonary toxicity from sirolimus is well recognized, the biochemically homologous everolimus has until recently been thought to be free from this side effect. Emerging evidence suggests an association between high-dose everolimus and symptomatic pneumonitis. Toxicity at typical immunosuppressive doses has also been described. In support of these(More)
BACKGROUND Acute coronary syndrome (ACS) along with myocardial ischemic injury are the leading causes for chest pain. Platelet surface expression of stromal-cell-derived factor-1 (SDF-1) is enhanced during ischemic events and may play an important role in trafficking hematopoietic progenitor cells for tissue regeneration and neovascularization. This study(More)
BACKGROUND Aggressive dose reduction strategies for cardiac CT require the prospective selection of limited cardiac phases. At lower heart rates, the period of mid-diastole is typically selected for image acquisition. We aimed to identify the effect of heart rate on the optimal CT acquisition phase within the period of mid-diastole. METHODS We utilized(More)
BACKGROUND Image noise and multiple sources of artifact may affect the accurate interpretation of myocardial CT perfusion (CTP) studies. Although artifact within the image is often time dependent, tissue characteristics remain unchanged irrespective of cardiac phase. OBJECTIVE We assessed a new technique of 4-dimensional, spatiotemporal analysis, using(More)
The excellent paper by Arbab-Zadeh et al. (1) highlights the issues surrounding imaging coronary artery disease in the presence of a high calcium score; however, we are concerned that the outcome, at least in part, may result from statistical artifact. First, the negative predictive value of cardiac computed tomog-raphy in the setting of a calcium score(More)