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    ABSTRACT: At clinical MRI field strengths (1.5 and 3 T), quantitative maps of the longitudinal relaxation time T(1) of the myocardium reveal diseased tissue without requiring contrast agents. Cardiac T(1) maps can be measured by Look-Locker inversion recovery sequences such as ShMOLLI at 1.5 and 3 T. Cardiovascular MRI at a field strength of 7 T has recently become feasible, but doubts have remained as to whether magnetization inversion is possible in the heart due to subject heating and technical limitations. This work extends the repertoire of 7 T cardiovascular MRI by implementing an adiabatic inversion pulse optimized for use in the heart at 7 T. A "ShMOLLI+IE" adaptation of the ShMOLLI pulse sequence has been introduced together with new postprocessing that accounts for the possibility of incomplete magnetization inversion. These methods were validated in phantoms and then used in a study of six healthy volunteers to determine the degree of magnetization inversion and the T(1) of normal myocardium at 7 T within a 22-heartbeat breathhold. Using a scanner with 16 × 1 kW radiofrequency outputs, inversion efficiencies ranging from -0.79 to -0.83 (intrasegment means; perfect 180° would give -1) were attainable across the myocardium. The myocardial T(1) was 1925 ± 48 ms (mean ± standard deviation). Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
    Full-text · Article · Oct 2013 · Magnetic Resonance in Medicine
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    ABSTRACT: Background Aortic stenosis (AS) leads to diffuse fibrosis in the myocardium, which is linked to adverse outcome. Myocardial T1 values change with tissue composition. Objective To test the hypothesis that our recently developed non-contrast cardiac magnetic resonance (CMR) T1 mapping sequence could identify myocardial fibrosis without contrast agent. Design, setting and patients A prospective CMR non-contrast T1 mapping study of 109 patients with moderate and severe AS and 33 age- and gender-matched controls. Methods CMR at 1.5 T, including non-contrast T1 mapping using a shortened modified Look–Locker inversion recovery sequence, was carried out. Biopsy samples for histological assessment of collagen volume fraction (CVF%) were obtained in 19 patients undergoing aortic valve replacement. Results There was a significant correlation between T1 values and CVF% (r=0.65, p=0.002). Mean T1 values were significantly longer in all groups with severe AS (972±33 ms in severe asymptomatic, 1014±38 ms in severe symptomatic) than in normal controls (944±16 ms) (p<0.05). The strongest associations with T1 values were for aortic valve area (r=−0.40, p=0.001) and left ventricular mass index (LVMI) (r=0.36, p=0.008), and these were the only independent predictors on multivariate analysis. Conclusions Non-contrast T1 values are increased in patients with severe AS and further increase in symptomatic compared with asymptomatic patients. T1 values lengthened with greater LVMI and correlated with the degree of biopsy-quantified fibrosis. This may provide a useful clinical assessment of diffuse myocardial fibrosis in the future.
    Full-text · Article · Jan 2013 · Heart (British Cardiac Society)
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    ABSTRACT: Music goes back a very long way in human experience. Music therapy is now used in many disparate areas-from coronary care units to rehabilitation after a stroke. But its widespread adoption has a poor scientific evidence base, founded more on enthusiasm than on proper evaluation in any controlled way. This has led to a lack of clarity about whether any particular type of music is superior, or whether different types of music should be tailored to differing individuals. We therefore conducted a series of controlled studies in which we examined the effects of different styles of music-from raga to jazz-presented in random order to normal young subjects (both musically trained or not). We found that contrary to many beliefs the effect of a style of music was similar in all subjects, whatever their individual music taste. We also found that this effect appeared to operate at a sub-conscious level through the autonomic nervous system. Furthermore, musical or verbal phrases of a 10 s duration (which coincided with the normal circulatory 'Mayer' waves) induced bigger excursions in blood pressure and heart rate (reciprocal of pulse interval) and so triggered more vagal slowing and feelings of calm. These findings need to now be tested in the clinical setting since, if confirmed, this would greatly simplify the practical use of this promising tool.
    No preview · Article · Dec 2012 · Netherlands heart journal: monthly journal of the Netherlands Society of Cardiology and the Netherlands Heart Foundation
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