{'fraction_non_alphanumeric': 0.019300361881785282, 'fraction_numerical': 0.0024125452352231603, 'mean_word_length': 5.484375, '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}}
[Aortic arch angiography in the preoperative diagnosis of cerebrovascular diseases. Comparison of the conventional technic and intra-arterial DSA].

Demonstration of the aortic arch is necessary in the investigation of cerebrovascular insufficiency for showing the origins and course of the cerebral arteries and for detecting steal syndromes and anatomical variations. Intra-arterial DSA is comparable in this respect with the traditional film technique; it has the advantage of reducing contrast doses by 75% and of reducing film costs and the examination time. Reliable evaluation of the carotid bifurcations is possible in less than half the cases. Selective carotid angiography cannot be replaced, therefore, by this technique. Selective angiography is also necessary for the pre-operative study of the intracranial vessels.