Evaluation of three-dimensional high-resolution magnetic resonance imaging in the diagnosis of intracranial atherosclerotic stenosis / Evaluación de resonancia magnética tridimensional de alta resolución en el diagnóstico de la estenosis aterosclerótica intracraneal

SUMMARY: Intracranial artery stenosis (ICAS) was one of the main causes of ischemic stroke onset and recurrence. About 30 % of strokes were caused by intracranial artery stenosis. Intracranial artery stenosis had a high incidence in China and faced a high risk of recurrence for a long time. It affected patient safety and quality of life seriously. At the same time, it caused a heavy financial burden for the patient´s family. Therefore, early detection and accuracy of intracranial artery stenosis evaluation were extremely important. High-resolution magnetic resonance imaging (HR-MRI) had been widely used in clinical examinations, making up for the shortcomings of traditional vascular imaging methods that could only show the degree of luminal stenosis, making it possible to perform lumens, tube wall and plaque features of atherosclerotic intracranial arteries at the same time. There were still some controversies about the credibility of this technique in assessing the intracranial artery lumen stenosis. This article reviewed the application efficacy of HR-MRI technology in evaluating the degree of intracranial atherosclerotic stenosis.

RESUMEN: La estenosis de arterias intracraneales (ICAS) es una de las principales causas del ictus isquémico, como así también de su recurrencia. Alrededor del 30 % de los ataques cerebrovasculares son causados por estenosis de la arteria intracraneal. La estenosis de arterias intracraneales tiene una alta incidencia en China y enfrenta un alto riesgo de recurrencia, afectando gravemente la seguridad y la calidad de vida de los pacientes. Al mismo tiempo, supone una importante carga financiera para la familia de los pacientes. Por lo tanto, la detección temprana y la precisión de la evaluación de la estenosis de arterias intracraneales es extremadamente importante. La resonancia magnética de alta resolución (HR-MRI, por sus siglas en inglés) es utilizada ampliamente en los exámenes clínicos, compensando las deficiencias de los métodos tradicionales de imágenes vasculares que solo pueden mostrar el grado de estenosis luminal, haciendo posible el estudio de las características del lumen, pared vascular y la placa ateroesclerótica, de las arterias intracraneales afectadas, al mismo tiempo. Aún existen algunas controversias sobre la credibilidad de esta técnica en la evaluación de la estenosis del lumen de arterias intracraneales. En este artículo se revisó la eficacia de la aplicación de la tecnología HR-MRI para evaluar el grado de estenosis aterosclerótica intracraneal.

Width of sulcus and thickness of gyrus in patients with cerebral atherosclerosis: a new tool for the prevention of vascular cognitive impairment

SUMMARY BACKGROUND AND PURPOSE Cerebral atherosclerosis is the main cause of lesions that contribute to vascular cognitive impairment and vascular dementia, followed by arteriosclerosis of small vessels and cerebral amyloid angiopathy. The purpose of this study was to compare the post-mortem radiological alterations of autopsied adults with the macroscopic alterations in the posterior region of these brains in order to establish a relationship between the two forms of analysis and to discuss the relevance of the prevention of vascular cognitive impairment in patients with encephalic atherosclerosis. MATERIALS AND METHODS Thirteen brains were analysed macroscopically to assess the degree of atherosclerosis of the basilar and the posterior cerebral arteries. The patients were autopsied in the Subject of General Pathology at General Hospital of Triângulo Mineiro Federal University in Uberaba, state of Minas Gerais, Brazil. The qualitative analysis of atherosclerosis was performed with classification into mild, moderate or severe. In the posterior region of the brains, width of sulcus and thickness of gyrus were measured by macroscopic analysis and by tomographic analysis. RESULTS AND CONCLUSIONS There was a decrease in calcarine sulcus width and an increase in medial temporal occipital gyrus thickness in patients with a higher degree of atherosclerosis, macroscopically and in tomography, respectively. Low oxygenation caused by atherosclerosis probably leads to an encephalic parenchyma inflammation that causes microglial cells hypertrophy provoking increase in the gyrus thickness and decrease in the sulcus width, as observed in the present study.

RESUMO INTRODUÇÃO E OBJETIVO A aterosclerose cerebral é a principal causa de lesões que contribuem para o comprometimento cognitivo vascular (CCV) e demência vascular, seguida da arteriosclerose de pequenos vasos e da angiopatia amiloide cerebral. Sendo assim, este estudo comparou as alterações radiológicas post mortem de adultos autopsiados com as alterações macroscópicas na região posterior desses encéfalos a fim de estabelecer uma relação entre as duas formas de análise e discutir sobre a relevância da prevenção do CCV em pacientes com aterosclerose encefálica. MATERIAL E MÉTODOS Treze encéfalos foram analisados macroscopicamente para avaliar o grau de aterosclerose das artérias basilar e cerebral posterior. Os pacientes foram autopsiados na disciplina de Patologia Geral no HC-UFTM em Uberaba, Minas Gerais, Brasil. A análise qualitativa da aterosclerose foi realizada com as classificações discreta, moderada ou acentuada. A espessura dos giros e a largura dos sulcos na região posterior dos encéfalos foram analisadas macroscopicamente e por tomografia computadorizada. RESULTADOS E CONCLUSÃO Houve diminuição na largura do sulco calcarino e aumento na espessura do giro occipital temporal medial de acordo com o aumento do grau de aterosclerose macroscopicamente e por tomografia, respectivamente. A baixa oxigenação causada pela aterosclerose provoca a inflamação do parênquima encefálico, provavelmente levando à hipertrofia das células da micróglia e ao consequente aumento dos giros e estreitamento dos sulcos, como observado no presente estudo.

Outcome of Endovascular Treatment in Symptomatic Intracranial Vascular Stenosis

OBJECTIVE: The outcome evaluation for the revascularization of intracranial vascular stenoses has not been fully described due to the highly technical nature of the procedure. We report here on the early and late clinical outcomes of angioplasty and/or stenting of symptomatic severe intracranial vascular stenoses at a single institute. MATERIALS AND METHODS: Since 1995, we have treated 35 patients with symptomatic intracranial vascular stenosis (more than 70% stenosis, mean stenosis: 78.6%+/-6.2%). An gioplasty (n = 19) was performed for the horizontal segment of the middle cerebral artery (M1) (n = 16) and the basilar artery (BA) (n = 1), the intradural vertebral artery (VA) (n = 1), and the cavernous internal carotid artery (ICA) (n = 1). Stenting (n = 16) was performed for the cavernous or petrous ICAs (n = 9), the intradural VA (n = 3), BA (n = 2), and M1 (n = 2) artery. We assessed the angiographic success (defined as residual stenosis < 50%) rate, the periprocedural complications during the 30-day periprocedural period, the symptomatic recurrence and restenosis during a mean 22-month follow-up (FU) period. The Kaplan-Meier estimate of the cumulative event-free rate of the major cerebrovascular events, i.e. death, stroke or restenosis, was also done. RESULTS: Angiographic success was achieved in 97% of our patients (34/35). There were four procedure-related complications (11%) including a death and a minor stroke. During the mean 22-month FU, the asymptomatic restenosis rate was 9% and the symptomatic restenosis rate was 6% in the target lesion and 9% in all the vascular territories. The Kaplan-Meier estimate was 70.6% (95% confidence interval = 46.5-94.7) after 33 months of FU. CONCLUSION: In addition to a high angiographic success rate and an acceptable periprocedural complication rate, intracranial angioplasty and/or stenting revealed a relatively low symptomatic recurrence rate. Hemorrhage is a rare, but the physician must aware that potentially fatal periprocedural complications can occur.