{'fraction_non_alphanumeric': 0.016755521706016754, 'fraction_numerical': 0.00456968773800457, 'mean_word_length': 5.636363636363637, '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}}
Hidebound sign: Small bowel in systemic sclerosis

The appearance of the small bowel in scleroderma on a small bowel series was first described by Horowitz in 1973. Scleroderma, or systemic sclerosis, is characterised by dilated small bowel loops, without an increased distance between the valvulae conniventes and with closely packed mucosal folds. This is due to the replacement of the inner circular and outer longitudinal layers of muscle with fibrous tissue, thus restricting contractility and longitudinal lengthening. Horowitz et al. chose the name “hidebound” for the radiological appearance to match the clinical description of hidebound skin in scleroderma, which is tightly adherent to the underlying subcutaneous tissues. Systemic sclerosis is a multisystem autoimmune disease. 90% of patients have involvement of the gastrointestinal tract with dysmotility being the most common manifestation. The oesophagus and anorectal regions are the most common segments involved. The pathogenesis of dysmotility is related to a progression of myopathy, neuropathy and fibrosis leading to abnormalities in compliance and contractility of the GI tract wall. Small bowel involvement can lead to pseudo-obstruction. Secondary manifestations of small bowel involvement include bacterial overgrowth and malnutrition.