{'fraction_non_alphanumeric': 0.034511784511784514, 'fraction_numerical': 0.02356902356902357, 'mean_word_length': 5.257894736842105, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Embedded MR fluoroscopy: High temporal resolution real‐time imaging during high spatial resolution 3D MRA acquisition

A method termed “embedded fluoroscopy” for simultaneously acquiring a real‐time sequence of 2D images during acquisition of a 3D image is presented. The 2D images are formed by periodically sampling the central phase encodes of the slab‐select direction during the 3D acquisition. The tradeoffs in spatial and temporal resolution are quantified by two parameters: the “redundancy” (R), the fraction of the 3D acquisition sampled more than once; and the “effective temporal resolution” (T), the time between temporal updates of the central views. The method is applied to contrast‐enhanced MR angiography (CE‐MRA). The contrast bolus dynamics are portrayed in real time in the 2D image sequence while a high‐resolution 3D image is being acquired. The capability of the 2D acquisition to measure contrast enhancement with only a 5% degradation of the spatial resolution of the 3D CE‐MR angiogram is shown theoretically. The method is tested clinically in 15 CE‐MRA patient studies of the carotid and renal arteries. Magn Reson Med 4:690–698, 2001. © 2001 Wiley‐Liss, Inc.