{'fraction_non_alphanumeric': 0.03114382785956965, 'fraction_numerical': 0.004530011325028313, 'mean_word_length': 5.4963235294117645, '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}}
Relevance of brain imaging studies for social psychiatry

Computerised tomography (CT) and magnetic resonance imaging (MRI) have dramatically changed diagnostic work-up in neurology. Clinical psychiatry has profited from the potential of both diagnostic tools in ruling out focal intracranial pathology (Becker et al., 1995). Also, a multitude of research studies covering the whole range of psychiatric disorders using CT, MRI, magnetic resonance spectroscopy (MRS), positron emission tomography (PET) and single photon emission computed tomography (SPECT) have been published in recent years. MRI, in comparison with CT, has enhanced diagnostic accuracy, particularly in the middle and posterior cranial fossa. Its advantages include an increase in diagnostic sensitivity, free choice of imaging plane, better differentiation of grey and white matter as well as basal ganglia morphology. However, specificity of findings is limited, e.g. where white matter hyperintense lesions are concerned (Becker et al., 1995). SPECT and PET permit the study of cerebral blood flow, regional brain metabolism and neurotransmitter receptor or transporter densities. Both methods require the administration of radioactive tracers, and functional images are produced on the basis of photon or positron emission. PET imaging requires on-site availability of a cyclotron unit to produce adequate tracer substances (with short half-lives) which makes the method inherently expensive. Brain MRS in psychiatry is still in its infancy, and most studies have been performed using H and P, while some have used Li and F. The first generation of MRS studies, in schizophrenia, have illuminated some pathophysiological aspects. Noteworthy findings include reduction in N-acetyl aspartate (a