Mechanisms of blood-brain barrier breakdownGreenwood, J.
doi: 10.1007/BF00588242pmid: 2046916
234 33 33 2 2 J. Greenwood Department of Clinical Science Institute of Ophthalmology London UK Summary The functional status of the blood-brain barrier (BBB) must be taken into account when designing and interpreting brain imaging techniques. The integrity of the BBB is affected in many diseases of the brain, with the potential involvement of a number of different but poorly understood cellular mechanisms. Factors known to disrupt the BBB experimentally include arachidonic acid and the eicosanoids, bradykinin, histamine and free radicals. These active compounds, released in pathological tissue, may alter cytosolic calcium levels and induce second messenger systems leading to an alteration in BBB permeability. Extravasation of plasma proteins may occurvia disrupted tight junctions, stimulation of fluid-phase vesicular transport or the formation of transcellular pores or channels.
Treatment of cerebral arteriovenous malformations with PVASchumacher, M.; Horton, J.
doi: 10.1007/BF00588243pmid: 2046890
234 33 33 2 2 M. Schumacher J. A. Horton Section of Neuroradiology University of Freiburg Federal Republic of Germany Division of Neuroradiology University of Pittsburgh PA USA Summary 35 Patients with cerebral arteriovenous malformations treated by endovascular embolization were analyzed. The treatment was performed in most cases with polyvinylalcohol with additional applications of silk, coils, gelfoam or detachable balloon in some patients. 8 patients developing mild to moderate neurological deficits persisting in three patients (8.6%). No correlation of complications with history of bleeding, neurological deficit, AVM localization, AVM size, angioarchitecture, amount of occlusion and duration of the procedure could be found. Technical factors of the procedure itself are assumed to be responsible for the rate of complications.
Hyperperfusion syndrome after carotid endarterectomyHarrison, P.; Wong, M.; Belzberg, A.; Holden, J.
doi: 10.1007/BF00588244pmid: 2046891
234 33 33 2 2 P. B. Harrison M. J. Wong A. Belzberg J. Holden Department of Radiology St Paul's Hospital Vancouver BC Canada Department of Medicine St Paul's Hospital Vancouver BC Canada Department of Nuclear Medicine St Paul's Hospital Vancouver BC Canada Department of Pathology St Paul's Hospital Vancouver BC Canada Summary This article describes the CT scans of two patients who, following carotid endarterectomy, developed headache and seizures suggestive of hyperperfusion syndrome. Their CT scans demonstrated ipsilateral mass effect and white matter hypodensity. One patient progressed to hemorrhage and died. Although infarction is described as the commonest neurologic event to occur after carotid endarterectomy, autopsy or cerebral blood flow studies in these patients suggests that the changes were due to hyperperfusion rather that infarction.
MRI in spontaneous dissection of vertebral and carotid arteriesGelbert, F.; Assouline, E.; Hodes, J.; Reizine, D.; Woimant, F.; George, B.; Hagueneau, M.; Merland, J.
doi: 10.1007/BF00588245pmid: 2046892
234 33 33 2 2 F. Gelbert E. Assouline J. E. Hodes D. Reizine F. Woimant B. George M. Hagueneau J. J. Merland Department of Neuroradiology and Therapeutic Angiography Lariboisière Hospital Paris France Department of Neurology Lariboisière Hospital Paris France Department of Neurosurgery Lariboisière Hospital Paris France Summary Fifteen patients were observed between 1987 and 1990: there were six with angiographically confirmed vertebral artery dissection, and 9 with carotid artery dissection. Results showed concordance of MRI and angiographic findings, in all cases but one. The dissected portion consistently showed a semilunar hyperintensity narrowing the residual eccentric signal void of the lumen when the artery was not completely occluded. In one angiographically occluded vessel, MR detected a small signal void within the hyperintensity, indicating that the artery was not completely occluded. The length of the dissected portion was clearly demonstrated by MR. Follow up MR and angiographic studies confirmed the regression of the dissection, and also allowed examination of the cerebral parenchyma.
Colour doppler flow imaging of the carotid arteriesKessler, C.; Maravic, C.; Maravic, M.; Kömpf, D.
doi: 10.1007/BF00588246pmid: 2046893
234 33 33 2 2 C. Kessler C. v. Maravic M. v. Maravic D. Kömpf Department of Neurology Medizinische Universität zu Lübeck Lübeck Federal Republic of Germany Summary 53 patients with carotid artery atherosclerosis were examined by colour Doppler flow imaging. These results were compared with real time duplex sonography and continuous wave Doppler sonography. In 48 low degree stenoses (<50%) the B-mode showed 36 smooth and 12 ulcerated plaque surfaces. In 24 high degree stenoses (>50%) 10 plaques were smooth and 14 ulcerated. In the low degree stenoses, which exhibited smooth surfaces in B-mode examination, colour flow Doppler showed nine additional cases with turbulences in the area of the stenotic site. This indicates that plaque ulcerations in low degree stenoses are underestimated. In contrast, in nearly all cases with high degree stenoses marked turbulences could be demonstrated by colour Doppler flow imaging independent of the B-mode showing regular or ulcerated plaque surfaces. Additionally, the duplex ultrasound diagnosed a carotid artery occlusion in 11 cases, but the colour coded Doppler was able to assess a remaining blood flow in two out of these 11 cases. Our results suggest that the colour Doppler flow imaging as a noninvasive technique is an advantage in diagnosing plaque ulcerations and it is more precise in diagnosing carotid occlusions than duplex-sonography is.
Stereoscopic display of MR angiogramsWentz, K.; Mattle, H.; Edelman, R.; Kleefield, J.; O'Reilly, G.; Liu, C.; Zhao, B.
doi: 10.1007/BF00588249pmid: 2046895
234 33 33 2 2 K. U. Wentz H. P. Mattle R. R. Edelman J. Kleefield G. V. O'Reilly C. Liu B. Zhao Department of Radiology Beth Israel Hospital Boston Massachusetts USA Klinikum Mannheim University of Heidelberg FRG Department of Radiology New England Deaconess Hospital Boston Massachusetts USA Shandong Medical Imaging Research Institute Jinan Peoples Republic of China Summary Recent developments in magnetic resonance (MR) allow high resolution imaging of flowing blood. To overcome the tomographic nature of conventional MR acquisitions, projection angiograms can be produced. These angiograms are similar in their display of blood vessels to plain film or digital subtraction angiograms. However, the three-dimensional information inherent in them is partly lost when single projections are viewed. We describe a method of three-dimensional display consisting of stereo pairs of the MR angiograms. With these an examiner experienced in stereo viewing can recover depth perception.
Computed tomography of intracranial tuberculosisJinkins, J.
doi: 10.1007/BF00588250pmid: 2046896
234 33 33 2 2 J. R. Jinkins Division of Neuroradiology King Faisal Specialist Hospital and Research Centre Riyadh Kingdom of Saudi Arbia Neuroradiology Section The University of Texas Health Science Center 7703 F. Curl Drive 78284-7800 San Antonio TX USA Summary The many clinico-radiological manifestations of intracranial tuberculosis have been well documented; however, few long-term retrospective serial studies of large series of patients on therapy have been reported utilizing computed imaging. The computed tomographic appearance, sequential periodic evolution, and final outcome of all patients with cranial tuberculosis seen at this institution in a period of ten years have been evaluated. A total of 80 subjects with intracranial tuberculosis revealed 17.5% with Type I isolated meningeal involvement, 71.25% with Type II isolated parenchymal forms, and 11.25% with Type III compound parenchymal/meningeal lesions. Only 28.8% had concommitant manifestations of TB outside the CNS. Seventy four of these patients were followed on medical or combined medical/surgical therapy which demonstrated 24.3% ( n =18) resolution without radiographic sequellae, 66.2% ( n =49) resolution with residual stroke, atrophy and/or calcification, and 4.1% ( n =3) with persistent enhancement of the lesion(s), after two years of treatment. Four deaths occurred all of which were in patients with Type III TB. This large group of patients followed from presentation to radiologic resolution of the disease process by computed tomography yields important information on the presentation, prognosis and sequelae of intracranial tuberculosis.
Sequential gadolinium-DTPA enhanced MRI studies in neuro-Behçet's diseaseKazui, S.; Naritomi, H.; Imakita, S.; Yamada, N.; Ogawa, M.; Sawada, T.
doi: 10.1007/BF00588251pmid: 2046897
234 33 33 2 2 S. Kazui H. Naritomi S. Imakita N. Yamada M. Ogawa T. Sawada Cerebrovascular Division, Department of Medicine National Cardiovascular Center Osaka Japan Department of Radiology National Cardiovascular Center Osaka Japan Summary Sequential gadolinium-DTPA (Gd-DTPA) enhanced MR images were obtained before and after steroid therapy in a case of neuro-Behçet's disease. Multiple scattered lesions, which could not be detected on pre-and post-contrast CT, were demonstrated mainly in the white matter of the pons and/or the cerebrum with both T1-and T2-weighted images. Some of these lesions, however, were not enhanced at all by infusion of Gd-DTPA. The Gd-DTPA infusion study demonstrated marked enhancement in the white matter of the pons and cerebrum. Some lesions not seen with T2-weighted images were also strongly enhanced by Gd-DTPA infusion at the acute stage. After steroid therapy, the symptoms and abnormal laboratory findings were resolved. The pontine and cerebral lesions on plain MR images remained unchanged even after resolution of the symptoms, suggesting that they were inactive old foci. On the other hand, the lesions detected in the enhancement study before steroid therapy disappeared with the repeat Gd-DTPA enhanced MR images which were performed after resolution of the symptoms. Some active inflammatory lesions in, neuro-Behçet's disease may be demonstrated only on Gd-DTPA enhanced MR images. Gd-DTPA enhanced MR imaging appears to be potentially useful for detecting active inflammatory lesions in neuro-Behçet's disease and for evaluating the efficacy of treatment.