Regional Aneurysm Wall Enhancement is Affected by Local Hemodynamics: A 7T MRI Study.

BACKGROUND AND PURPOSE: Aneurysm wall enhancement has been proposed as a biomarker for inflammation and instability. However, the mechanisms of aneurysm wall enhancement remain unclear. We used 7T MR imaging to determine the effect of flow in different regions of the wall. MATERIALS AND METHODS: Twenty-three intracranial aneurysms imaged with 7T MR imaging and 3D angiography were studied with computational fluid dynamics. Local flow conditions were compared between aneurysm wall enhancement and nonenhanced regions. Aneurysm wall enhancement regions were subdivided according to their location on the aneurysm and relative to the inflow and were further compared. RESULTS: On average, wall shear stress was lower in enhanced than in nonenhanced regions (P = .05). Aneurysm wall enhancement regions at the neck had higher wall shear stress gradients (P = .05) with lower oscillations (P = .05) than nonenhanced regions. In contrast, aneurysm wall enhancement regions at the aneurysm body had lower wall shear stress (P = .01) and wall shear stress gradients (P = .008) than nonenhanced regions. Aneurysm wall enhancement regions far from the inflow had lower wall shear stress (P = .006) than nonenhanced regions, while aneurysm wall enhancement regions close to the inflow tended to have higher wall shear stress than the nonenhanced regions, but this association was not significant. CONCLUSIONS: Aneurysm wall enhancement regions tend to have lower wall shear stress than nonenhanced regions of the same aneurysm. Moreover, the association between flow conditions and aneurysm wall enhancement seems to depend on the location of the region on the aneurysm sac. Regions at the neck and close to the inflow tend to be exposed to higher wall shear stress and wall shear stress gradients. Regions at the body, dome, or far from the inflow tend to be exposed to uniformly low wall shear stress and have more aneurysm wall enhancement.

Quantifying Intra-Arterial Verapamil Response as a Diagnostic Tool for Reversible Cerebral Vasoconstriction Syndrome.

BACKGROUND AND PURPOSE: There is mounting evidence supporting the benefit of intra-arterial administration of vasodilators in diagnosing reversible cerebral vasoconstriction syndrome. We prospectively quantified the degree of luminal diameter dilation after intra-arterial administration of verapamil and its accuracy in diagnosing reversible cerebral vasoconstriction syndrome. MATERIALS AND METHODS: Patients suspected of having intracranial arteriopathy on noninvasive imaging and referred for digital subtraction angiography were enrolled in a prospective registry. Intra-arterial verapamil was administered in vascular territories with segmental irregularities. The caliber difference (Caliberpost - Caliberpre) and the proportion of caliber change ([(Caliberpost - Caliberpre)/Caliberpre] × 100%) were used to determine the response to verapamil. The diagnosis of reversible cerebral vasoconstriction syndrome was made on the basis of clinical and imaging features at a follow-up appointment, independent of the reversibility of verapamil. Receiver operating characteristic curve analysis was performed to determine the best threshold. RESULTS: Twenty-six patients were included, and 9 (34.6%) were diagnosed with reversible cerebral vasoconstriction syndrome. A total of 213 vascular segments were assessed on diagnostic angiography. Every patient with a final diagnosis of reversible cerebral vasoconstriction syndrome responded to intra-arterial verapamil. The maximal proportion of change (P < .001), mean proportion of change (P = .002), maximal caliber difference (P = .004), and mean caliber difference (P = .001) were statistically different between patients with reversible cerebral vasoconstriction syndrome and other vasculopathies. A maximal proportion of change ≥32% showed a sensitivity of 100% and a specificity of 88.2% to detect reversible cerebral vasoconstriction syndrome (area under the curve = 0.951). The Reversible Cerebral Vasoconstriction Syndrome-2 score of ≥5 points achieved a lower area under the curve (0.908), with a sensitivity of 77.8% and a specificity of 94.1%. CONCLUSIONS: Objective measurement of the change in the arterial calibers after intra-arterial verapamil is accurate in distinguishing reversible cerebral vasoconstriction syndrome from other vasculopathies. A proportion of change ≥32% has the best diagnostic performance.

Trauma cervicofacial en niños / Facial injuries in children

Se revisaron las historias clínicas de 263 pacientes pediátricos que ingresaron al Hospital Universitario del Valle (HUV) con diagnósticos de lesión cervicofacial por causa externa durante un período de 50 meses (1 de marzo de 1990 a 30 de abril de 1994). La relación masculino: femenino fue de 2 :1 y el promedio de edad 6,5 años. Durante el período estudiado la mayoría de lesiones ocurrieron en día de semana (lunes a viernes). Según el origen de la lesión, los accidentes de tránsito ocuparon el primer lugar con un 49 por ciento, seguido de los accidentes domésticos con un 27 por ciento. El 31 por ciento de los accidentes de tránsito ocurrieron en automotor, 13 por ciento en moto y el 3 por ciento en bicicleta. Los agentes de lesión más frecuentes fueron los traumas contusos 51 por ciento, seguidos por trauma mixto. El maltrato infantil ocurrió en el 9,1 por ciento de casos. 153 niños (58,2 por ciento) sufrieron trauma de tejidos blandos, siendo las heridas en cara las más frecuentes con 102 casos (38,8 por ciento) y las heridas en oreja (13,5 por ciento). El 15 por ciento de los pacientes presentó complicaciones con una mortalidad del 0,8 por ciento. El promedio de estancia en urgencias fue de 2 días y el promedio de hospitalización de 4,4 días