1/16. Severe ADC decreases do not predict irreversible tissue damage in humans.BACKGROUND AND PURPOSE: A mismatch between diffusion- and perfusion-weighted MRI is thought to define tissue at risk of infarction. This concept is based on the assumption that diffusion slowing of and decreases in the apparent diffusion coefficient (ADC) serve as indicator of tissue proceeding to infarction. We tested this hypothesis. methods: MRI (diffusion weighted, perfusion weighted, MRA, T2 weighted) was performed in 15 patients with acute stroke within 2.9 /-0.8 hours (mean /-SD) of onset and on days 1 and 7. After intraindividual realignment of the ADC maps, the development of ADC range volumes and ADC values was determined. RESULTS: An increase (354%, group A1) in the total ADC-based lesion volume below a threshold of < 80% occurred in 4 patients on day 1, persisting on day 7 with a pronounced increase of ADC range volumes with low ADC values. An increase in total ADC-based lesion volume (201%, group A2) followed by a secondary drop to day 7 was found in 7 patients. A significant reduction in total ADC-based lesion volume (14%, group B) was found in 4 patients. ADC-based lesion volume increase was associated with persistent vessel occlusion in group A, whereas recanalization in group B resulted in ADC volume decrease. ADC normalization was observed independently from the degree of the initial ADC decrease on days 1 and 7 in group B. CONCLUSIONS: In line with results from animal experiments, ADC decreases do not reliably indicate tissue infarction Even severely decreased ADC values may normalize in human stroke, and it seems likely that ADC normalization depends on the duration and severity of ischemia rather than the absolute value.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
2/16. Comparison of 1.5 and 8 tesla high-resolution magnetic resonance imaging of lacunar infarcts.PURPOSE: We present a case report comparing 1.5 fast spin-echo (FSE) and high-resolution 8 Tesla (T) gradient echo (GE) MRI of a patient with multiple lacunar infarcts. methods: A 51-year-old man with a history of previous lacunar infarctions was studied with two-dimensional Fourier transform axial 8 T GE MRI using the following parameters: 3 mm thick slices skip 3 mm, flip-angle approximately 20 degrees, TR 800 milliseconds, TE 12 milliseconds, 1024 x 1024 matrix, field of view (FOV) 20 cm, and bandwidth 50 kHz. These images were then compared with routine clinical 1.5 T T2-weighted FSE images with 5 mm thick sections, 256 x 256, FOV 20, TR 5650, TE 102, and 16 echo train length. RESULTS: The majority of the infarctions were seen as areas of high signal intensity on both the 1.5 and 8 T images. They were seen in the corona radiata or the basal ganglia. More lesions were seen on the 8 T images. Low intensity signal was best demonstrated on the 8 T images at segments of the periphery of a few of the larger infarcts. There were a few small punctate low signal intensity regions localized at the termination of some of the microvessels on the 8 T images only. The foci of decreased signal intensity in regions of chronic hemorrhage appeared larger on the 8 T images compared with the 1.5 T images. The 8 T images demonstrated direct visualization of many small vessels, primarily in the deep white matter, which were not visible on the 1.5 T images. On the 8 T images, some of the infarcts appeared to be located between the medullary veins of the deep white matter. CONCLUSION: This case report indicates that GE 8 T images demonstrate more infarctions compared with the FSE 1.5 T images. It is possible to simultaneously identify the microvessels of the brain, small foci of hemorrhage, and lacunar infarctions using 8 T MRI.- - - - - - - - - - ranking = 3keywords = vessel (Clic here for more details about this article) |
3/16. A rare sign of intracranial internal carotid artery dissection causing cerebral infarction: a case report and review of the literature.We describe a patient with CT-proven ischemic infarction of the left middle cerebral artery (MCA) territory. The emergency CT, on admission, was suggestive of intracranial internal carotid artery dissection by demonstrating gaseous gap defects in the arterial wall and a subsequent thromboembolic process in the MCA. To our knowledge, there is no previous report regarding radiologically detected gas within the vessel wall or lumen secondary to dissection. We discuss this uncommon radiologic sign and its possible pathogenesis with a review of the literature.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
4/16. Trancranial Doppler monitoring of response to therapy for meningovascular syphilis.Meningovascular syphilis is now quite uncommon, but there have been increasing reports in patients immunocompromised with human immunodeficiency virus. The response of syphilis affecting the central nervous system to antibiotic therapy remains a challenge. This is an even greater challenge in patients who have underlying compromise of the immune system. The authors present a 46-year-old male with recurrent stroke who was found to have cerebrospinal fluid compatible with syphilitic involvement of the central nervous system and a cerebral arteriogram, which revealed focal narrowing of the right middle cerebral artery. The baseline transcranial Doppler study demonstrated increased mean and peak flow velocity within the right middle cerebral artery. Despite a 10-day course of intravenous penicillin, with substantial improvement in the cerebrospinal fluid results, this flow velocity elevation persisted, in a remarkably consistent pattern, over a 4-month follow-up period. Thus, the involved vessel remained patent following treatment, but no clear resolution of the stenotic lesion was observed.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
5/16. Reversal of perfusion and diffusion abnormalities after intravenous thrombolysis for a lacunar infarction.perfusion and diffusion magnetic resonance imaging (MRI) have been used to guide therapy in patients with large vessel occlusions. In an analogous fashion, the authors used perfusion and diffusion MRI to demonstrate a perfusion deficit and a matching diffusion lesion in a patient with lacunar infarct. Following thrombolytic therapy, the authors observed a reversal of the perfusion deficit, the diffusion lesion, and clinical recovery. This case suggests that perfusion and diffusion MRI may be informative in patients with lacunar infarction who are candidates for thrombolysis.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
6/16. basilar artery stenosis mimicking the lacunar syndrome of pure motor hemiparesis.BACKGROUND: Stereotyped, repeated transient ischemic attacks manifesting as pure motor hemiparesis are most often attributed to ischemia of the internal capsule or ventral pons resulting from in situ disease of the small penetrating arteries. CASE DESCRIPTION: We report a 61-year-old man presenting with recurrent episodes of left-sided weakness consistent with the lacunar syndrome of pure motor hemiparesis. Subsequent neuroimaging revealed infarction of the right ventral pons and a critical basilar artery stenosis as the inciting lesion. Despite maximal antithrombotic therapy, he continued to have repeated symptoms. angioplasty and stenting were attempted but both failed due to plaque recoil and technical difficulties. After the procedure, the patient had no further ischemic episodes and remained symptom-free at two months. CONCLUSIONS: This case illustrates the imprecise and discordant relationship between the mode of presentation of a stroke syndrome and its presumed pathophysiology. The lacunar syndrome of pure motor hemiparesis should be recognized by clinicians as a mode of stroke presentation due not only to small vessel disease, but also to large artery atherosclerotic disease such as basilar artery stenosis. Prompt institution of treatment can lead to a good clinical outcome.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
7/16. CNS aspergillosis with mycotic aneurysm, cerebral granuloma and infarction.We are reporting a case of an immunocompromised patient with invasive aspergillosis (IA) who developed aspergillotic granulomas and a mycotic aneurysm of the superior cerebellar artery. The route of infection of the central nervous system (CNS) was hematogenous spread from a pulmonary focus. IA was detected with the Galactomannan (GM) technique. However, despite treatment with amphotericin b, progressive involvement of the vessel wall occurred causing fatal subarachnoid hemorrhage and massive brainstem and cerebellar infarction.This case provides pathologic-imaging correlation of one of the most devastating types of fungal involvement affecting the CNS with a fungal aneurysm. Finally the literature regarding the pathogenetic, and diagnostic investigations and the management of CNS aspergillosis is reviewed.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
8/16. Magnetic resonance imaging of suspected cervicocranial arterial dissections.The authors propose that the optimal screening protocol for evaluation of suspected cervicocranial arterial dissections is magnetic resonance imaging (MRI) that includes three components: 1) contrast-enhanced three-dimensional time-of-flight magnetic resonance angiography (MRA) through the superior mediastinum, neck, and skull base; 2) three-dimensional multiple overlapping thin-section acquisition MRA of the skull base and circle of willis region; and 3) axial non-contrast, non-fat-suppressed T1-weighted, fat-suppressed T1-weighted, and T2-weighted spin-echo MRI from the level of the aortic arch through the level of the circle of willis. MRA permits visualization of vascular luminal narrowing or obliteration, which can suggest vascular dissection but can also be caused by congenital variation, dysplasia, intraluminal thrombus, vasospasm, or extramural compression by tumor. By directly visualizing the blood vessel wall, axial T1-weighted and T2-weighted spin-echo MRI can identify the intramural hemorrhage of vascular dissection. This protocol is designed to maximize the sensitivity of a noninvasive technique and may eliminate the need for conventional endovascular angiography.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
9/16. Postpartum cerebellar infarction and haemolysis, elevated liver enzymes, low platelet (HELLP) syndrome.pregnancy is considered to be a hypercoagulable state per se with an increased risk for cerebrovascular events, however cerebellar infarction has been rarely described in pregnant women. A nulliparous pre-eclamptic woman at 25 weeks' gestation was submitted to an echocardiographic exam that showed an impaired cardiac structure and function. After 2 h, the patient underwent caesarean section for diagnosis of haemolysis, elevated liver enzymes, low platelet (HELLP) syndrome. Afterwards her platelet count raised, and eight days later she developed nystagmus, ataxia, dysmetria and motor deficit in the right limbs and sensory impairment in the right side of the face and in the left limbs. Cerebral magnetic resonance imaging (MRI) demonstrated a right cerebellar and median posterior bulbar infarction. Colour-coded sonography of cerebral vessels showed an occlusion of the right vertebral artery. Coagulation pattern analysis evidenced double heterozygosis of the methylenetetrahydrofolate reductase (MTHFR) gene and single mutation of the prothrombin gene. This case report gives evidence of the importance of considering the different risk factors involved in stroke occurrence during pregnancy.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
10/16. The spectrum of presentations of venous infarction caused by deep cerebral vein thrombosis.The classic features of thrombosis of the deep cerebral venous system are severe dysfunction of the diencephalon, reflected by coma and disturbances of eye movements and pupillary reflexes, resulting in poor outcome. However, partial syndromes without a decrease in the level of consciousness or brainstem signs exist, which may lead to initial misdiagnoses. The spectrum of clinical symptoms reflects the degree of venous congestion, which depends not only on the extent of thrombosis in the deep veins but also on the territory of the involved vessels and the establishment of venous collaterals. For example, thrombosis of the internal cerebral veins with (partially) patent basal veins and sufficient collaterals may result in relatively mild symptoms. Deep cerebral venous system thrombosis is an underdiagnosed condition when symptoms are mild, even in the presence of a venous hemorrhagic congestion. Identification of venous obstruction has important therapeutic implications. The diagnosis should be strongly suspected if the patient is a young woman, if the lesion is within the basal ganglia or thalamus, and especially if it is bilateral.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
| | Next -> |