Multiple Sclerosis Associated with Cerebral Mass Lesions on Computed Tomography

Two patients with multiple sclerosis presenting as a rapidly progressive intracerebral mass lesion are described. Both showed irregular ring enhancement on computed tomography. Brain biopsy specimens showed features of acute demyelination and intense glial reaction. Treatment with oral corticosteroids was followed by clinical improvement.     

Computed Tomography Detection of a Cerebral Calcific Embolus Following Coronary Catheterization

A 77-year-old man underwent coronary artery angiography quite well. However, several attempts were required to pass the pigtail catheter across a calcified stenotic aortic valve. On return to the floor, motor aphasia and right hemiparesis developed and improved steadily within a few days. Computed tomography (CT) of the head revealed a calcific density in the left middle cerebral artery. The authors believe the calcific plaque originated from the calcified aorta and aortic valve. The patient was discharged within 48 hours with minimal neurological signs. Spontaneous calcified emboli to cranial vessels from calcific aortic stenosis or other sources are rare. CT detection of a calcific plaque in a cranial vessel following coronary vessel catheterization is well documented in this patient.     

脑CT在急性进展性脑梗死中的应用价值

目的:探讨脑CT在急性进展性脑梗死(APCI)变化特点,为临床早期诊断和治疗提供客观依据。方法:对103例发病2．5～24小时、急性脑梗死患者进行前瞻性研究,其中APCI患者32例,分析脑CT早期变化特点,并与71例非进展性脑梗死进行对比。结果:103例患者,70例脑CT出现异常(68．0％),其中进展组27例(84．4％)出现脑梗死早期表现,明显高于非进展组(43例,60．6％)。进展组患者病情进展至高峰时,脑CT显示,16例(50％)出现梗死体积增大,5例(15．6％)有出血性梗死,3例(9．4％)有新部位的梗死,8例(25％)梗死体积无明显变化。结论:脑CT可作为早期诊断APCI的预测指标,导致神经功能恶化的直接原因可能与梗死体积增大、出血性脑梗死和再梗死有关。     

原发性脑淋巴瘤CT与MRI诊断

目的分析原发性脑淋巴瘤的CT和MRI表现,以提高对其的认识,减少误诊。方法回顾性分析17例经手术病理证实的原发性脑淋巴瘤的CT和MRI资料。结果CT和MRI主要表现为：（1）CT平扫示脑内单发或多发的等密度或较高密度瘤灶,肿瘤可沿脑脊液播散;MRI T1WI呈等或稍低信号,T2WI呈等或稍高信号;1例出现坏死及出血;②少部分病例瘤周水肿及占位效应轻至中度;（3）MRI增强扫描大多呈团块状均匀强化;1例环形强化。④除病变主体位于胼胝体膝部和压部外,瘤灶长轴多与颅脑前后径走行平行或大致相同。结论原发性脑淋巴瘤多在大脑深部,明显强化,CT和MRI表现具有一定的特异性,结合CT与MRI影像特点和临床资料综合分析,有可能在术前作出正确诊断。     

Computed Tomography Angiogram Derived From Computed Tomography Perfusion Done with Low Iodine Volume Protocol Preserves Diagnostic Yield for Middle Cerebral Artery-M2 Occlusions

Background: Computed tomography angiogram (CTA) derived from computed tomography perfusion (CTP) has been proposed to avoid addition of separate CT perfusion protocol for selection of large vessel occlusion in acute stroke patients. Previous studies have validated this technique for proximal large vessel occlusions. In this study, we test reliability for identifying M2 occlusions on CTA derived from CTP. Methods: Through a retrospective search of the institutional thrombectomy database, we identified 28 cases with M2-MCA occlusion, of which 24 met the inclusion criteria for analysis. An additional 20 cases without M2-MCA occlusion (either normal or M1-MCA occlusion) were randomly mixed in the database to reduce observer bias. The baseline images of the CTP study in these 48 cases were then independently analyzed by 3 readers with varying level of expertise. The digital subtraction angiography (DSA) images were also independently reviewed where available. The percentage of agreement among reviewers as well as the probability of agreement of the reviewers, when compared to the DSA findings was also calculated. Results: The observed agreement for the image quality amongst the 3 readers (n = 48) varied between 0.78 and 0.95 and tended to be higher for the M1 segment MCA and lower for distal M2-MCA. The observed agreements comparing 3 image reviewers versus DSA in M2 patients (n = 24) was 98% for identifying occlusion (95% CI 95%-100%), 94% for identifying proximal M2 occlusion (95% CI 88%-98%), and 91% (95% CI 84%-97%) and 90% (95% CI 83%-95%), respectively for correctly identifying inferior and superior branch of M2 occlusion. Conclusion: CTA data derived from CT Perfusion study preserves diagnostic yield for correctly identifying M2 occlusion.     

Clinically Unsuspected Cerebral Infarction Revealed by Computed Tomography Scanning in Late Onset Epilepsy

The computed tomography (CT) scans of 132 patients with late onset epilepsy were compared with the CT scans of an age- and sex-matched control group. Patients with neurologic symptoms in addition to epilepsy, patients with a definite antecedent cause for epilepsy, and patients with tumours on CT scanning were excluded. Fifteen of the patients with epilepsy, as opposed to two of the controls, had infarcts on their CT scans (p = 0.003 Fisher exact test, two-tailed). In nine of these patients only lacunar infarcts were present. No patient had a history of stroke. We concluded that cerebrovascular disease was the major underlying contributory factor to the development of epilepsy in these patients. Twelve of the 15 patients were aged greater than 60 years, representing 21% of the patients in this age group. There was no difference between the epileptic patients and controls in the presence of clinical features of systemic vascular and cardiac disease. CT scan evidence of cerebral atrophy was as common in the control subjects as in the patients with epilepsy.     

大脑中动脉狭窄或闭塞患者侧支循环320排计算机断层扫描血管成像联合脑灌注成像研究

目的   利用320排计算机断层扫描血管成像（computed tomography angiography,CTA）及脑灌注成像（computed tomography perfusion imaging,CTP）探讨单侧大脑中动脉（middle cerebral artery,MCA）重度狭窄或闭塞的急性缺血性卒中患者侧支循环与脑灌注的关系。 方法  对72例单侧MCA重度狭窄或闭塞的急性缺血性卒中患者行头部320排CTA及CTP检查,根据有无侧支循环分为2组,对2组CTA和CTP情况进行分析比较。 结果  共入组72例患者,有侧支循环组58例,无侧支循环组14例。有侧支循环组38例（65.52%）MCA闭塞,无侧支循环组中5例（35.71%）MCA闭塞,两组差异有显著性（P=0.041）。有侧支循环组脑灌注代偿率高于无侧支循环组（68.97% vs 21.43%,χ2＝10.595,P＝0.001）;在CTP异常的68例患者中,有侧支循环者54例,无侧支循环者14例,有侧支循环组患侧的脑血容量［35.00（29.92,41.13）ml/100?g vs 26.25（18.23,37.18）ml/100?g］及脑血流量［（2.39±0.73）ml/100?g·min vs （1.75±0.72）ml/100?g·min］高于无侧支循环组,P分别为0.007和0.040。但2组患侧平均通过时间（mean transit time,MTT）及平均达峰时间（time to peak,TTP）差异无显著性。 结论  320排CTA联合CTP检查显示急性缺血性卒中患者中有侧支循环者脑灌注代偿率高,而且其脑血容量和脑血流量均高于无侧支循环者。     

Computed Tomography Angiographic Correlates of Early Computed Tomography Signs in Acute Ischemic Stroke

BACKGROUND AND PURPOSE: Early computed tomography (CT) signs of stroke signify major arterial occlusion. CT angiogram (CTA) is useful in detecting major arterial occlusion and may help triaging patients for intra-arterial thrombolysis. The correlation between the early signs of stroke and arterial occlusion on CTA was studied. METHODS: Consecutive patients with suspected acute anterior circulation ischemic stroke presenting within 6 hours of symptom onset underwent noncontrast CT of the head followed by CTA. The scans were later reviewed for evidence of early signs of stroke on CT scan and intracranial arterial occlusion on CTA. RESULTS: Sixteen of 65 patients had arterial occlusion on CTA; 12 (75%) of these showed the early CT signs of stroke. All the early signs except M2 "dot" sign significantly correlated with middle cerebral artery (MCA) occlusion on CTA. Hyperdense MCA sign was the only independent predictor of a MCA occlusion. CONCLUSION: In a small sample, early CT signs of stroke strongly correlated with arterial occlusion, with hyperdense MCA sign being the most predictive of a MCA occlusion.     

Single-Photon Emission Computed Tomography Studies of Regional Cerebral Blood Flow in Multiple Infarct Dementia

Multiinfarct dementia (MID) and Alzheimer's disease (AD), both characterized by a decline in cognitive function, are often difficult to differentiate and may coexist. This study reports the findings of single-photon emission computed tomography (SPECT) using [²³¹]N-isopropyl-p-iodoamphetamine to determine cerebral blood flow patterns in patients with MID (n = 11 ), as compared with patients with AD (n = 22) and nondemented control subjects (n = 12). Data were acquired at two tomographic levels for dorsolateral frontal, parietal, orbitofrontal, and temporal areas of the cortex. Analyses of variance revealed that the blood flow pattern for the MID group was very similar to that in the AD patients, with both groups showing hypoperfusion in the temporal area, although blood flow in the left parietal region was lower for the patients with AD. When normal regional cerebral blood flow (rCBF) was defined as within 2 standard deviations of control values, most of the patients with MID had normal rCBF, while a few patients showed abnormal rCBF in all regions. In contrast, the majority of AD patients showed abnormal rCBF in the temporal part of the cortex. This suggests that while AD is characterized by hypoperfusion in the temporal and parietal areas, there is no characteristic rCBF pattern in MID. These findings emphasize the need to use multiple modalities when clinically evaluating patients with MID.     

Cerebral Perfusion in Patients With Syndrome X: A Single Photon Emission Computed Tomography Study

OBJECTIVE: To test the hypothesis that syndrome X is a systemic vascular disorder, the authors studied 40 patients with this diagnosis using technetium-99m hexamethylpropylene amine oxime and single photon emission computed tomography (SPECT) brain images. Twenty-three of 25 cases with definite myocardial perfusion defects diagnosed by thallium-201 myocardial perfusion SPECT also had multiple hypoperfusion areas in the brain versus 2 of 15 patients without thallium myocardial defects. The parietal lobes were the most common hypoperfusion areas, and cerebellum was the least common. Syndrome X is a systemic vascular disorder with a high incidence of hypoperfusion lesions of the brain and is usually coincident with myocardial defects.