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要旨

Introduction: The hemo-sensitive flash sequence 1 is a working horse in clinical MRI of intracerebral hemorrhage. Due to the higher sus- ceptibility of blood, the dephasing of spins happens much faster within hemorrhagic lesions than in the surrounding tissue, which results in faster T 2* relaxation and leads to a strong dark appearance of blood products when using sufficiently long echo times. Due to B 0 field blurring effects, those lesions appear even more prominent. This effect, called blooming, is actually an imaging artifact; however, it leads to a desirable clear distinction of even very small hemorrhages. An overall acceleration of MR imaging is favoured to reduce the patient’s burden and to increase the capacity utilization of MR scanners. The shortening of acquisition times of hemo-sensitive flash sequences is not limited by technical restrictions like the minimal echo time but by the time necessary for the spins to de-phase and develop reasonable image contrast. Here, we present a method to accelerate the hemo-sensitive flash measurement by acquiring a double echo flash (‘‘double flash’’) with two shorter echo times and creating the hemo-sensitive contrast at longer echo times by calculating the T 2* relaxation parameters from those two images.