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Stroke and Transient Ischemic Attacks of the Brain and Eye
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Angiography of a carotid or vertebral dissection shows a smoothly stenosed artery with a double lumen or intimal flap, or a smooth tapering occlusion (Figure 12.192). The “string sign” is due to hematoma in the wall of the artery compressing the normal lumen to a “fine thread.” Sometimes, the artery is completely occluded, but the occlusive stump often has a tapered shape, suggestive of dissection. Other angiographic findings include intraluminal clot, intimal flaps, pseudoaneurysm formation (usually at the base of the skull), and evidence of distal emboli obstructing smaller intracranial arteries.
String Sign
Published in Michael E. Mulligan, Classic Radiologic Signs, 2020
Only 2 years after Burrill Crohn and colleagues1 described regional ileitis as a pathologic and clinical entity (see Cobblestone pattern), John Kantor2 reported its diagnostic roentgenographic features. Kantor worked with the same surgeons and pathologists as Crohn and his colleagues’. His report was based on six cases and included a description of the ‘string sign’ (Figure 1). ‘Perhaps the most striking finding is the ‘string sign’… This is a thin, slighdy irregular linear shadow suggesting a cotton string in appearance and extending more or less continuously from the region of the last visualized loop of ileum through the entire extent of the filling defect and ending at the ileocecal valve. It represents the attenuated barium filling of the gready contracted intestinal lumen. A characteristic ‘string sign’ is apparent in the illustration of the original article by Crohn and his collaborators.’2 Kantor said the name ‘string sign’ was ‘borrowed from A.W. Crane.’ In the discussion that followed Kantor’s article, Crohn endorses the sign saying, ‘It is a fitting term. The string sign is absolutely characteristic’ Kantor, however, did not consider it to be a pathognomonic sign. Tuberculomas, syphilitic colitis and stenosing sarcomas of the terminal ileum had also been reported with a similar radiographic appearance.
The Small Intestine
Published in Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie, Bailey & Love's Short Practice of Surgery, 2018
Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie
High-resolution ultrasound in expert hands can demonstrate inflamed and thickened bowel loops, as well as fluid collections and abscesses. The small intestine is traditionally imaged by a small bowel enema (Figure69.3). This is performed by instilling contrast into the small bowel via a nasoduodenal tube, and will show up areas of stricturing and prestenotic dilatation. The involved areas tend to be narrowed, irregular and, sometimes, when a length of terminal ileum is involved, there may be the ‘string sign’ of Kantor (Figure69.3).
Interval growth in an ICA bifurcation aneurysm treated with balloon occlusion, and possible contribution of vasa vasorum hypertrophy
Published in British Journal of Neurosurgery, 2023
Muhammad Usman, Giles Critchley, Panayiotis Koumellis, Marius Poitelea
Enlargement of vasa vasorum in large artery occlusion has been recognised in human and animal studies in literature but reports of vasa vasorum in relation to the carotid vessels are very rare; most of these cases relate to occlusion of the carotid artery by atheroembolic phenomenon in the context of stroke or asymptomatic atheromatous disease,10,11 although rare cases following therapeutic occlusion of Internal carotid artery have previously been reported.12,13 Martin et al.14 described a rare cause of ‘string sign’ on angiogram that was seen as serpiginous channels along the length of ICA rather than a straight string like appearance. They described surgical visualization of the ICA in one of the cases that confirmed complete occlusion of the lumen itself and attributed the serpiginous appearance to a ‘fairly large’ collateral running within the arterial wall. We believe, in our case a similar mechanism might be at play.
Complete recovery of string sign of the internal mammary artery graft 11 years after coronary artery bypass surgery associated with disparition of competitive flow
Published in Acta Cardiologica, 2018
François Simon, Antoine Guedes, Claude Hanet
It is still not known whether and how often reopening of the graft lumen in the case of a string sign happens in case of progression of native stenosis [4]. Although such functional recovery is alluded to in several reports, reopening of a non-functional graft has never been convincingly illustrated. Consequently, string sign is generally considered as graft deterioration at the same level as graft occlusion [3].