摘要:

One hundred twenty‐seven patients undergoing coronary artery bypass graft surgery were monitored by transcranial Doppler ultrasonography. Five patients had more than 50% increases in middle cerebral artery mean flow velocity during the initial phase (10–120 sec) of cardiopulmonary bypass. Four of these 5 developed neurological complications including stroke and encephalopathy. These results indicate that overperfusion of the basal cerebral arteries during cardiopulmonary bypass procedures may contribute to neurological dysfunction after the surgery

ISSN:1051-2284    

DOI:10.1111/jon199553135

出版商:Wiley    

年代:2016

数据来源: WILEY

ISSN:1051-2284    

DOI:10.1111/jon199553141

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

The role of interictal brain single‐photon emission computed tomography (SPECT) was examined using (99mTc)‐labeled hexamethylpropyleneamine oxime (HMPAO) in refractory partial epilepsy. The accuracy with which SPECT localized an epileptic focus and whether it predicted long‐term postoperative seizure relief were assessed. Twenty patients were evaluated, 14 of whom ultimately had anterior temporal lobectomy with followup rangmg from 41 to 56 months. A single‐headed gamma camera was used. The interictal SPECT showed ipsilateral temporal hypoperfusion in 8 (47%) of 17 patients with temporal lobe epilepsy and showed either multilobar hypoperfusion or no perfusion defects in the rest. The sensitivity and specificity were similar in patients with a more complex clinical picture who required intracranial electrodes and those who did not. Presence or absence of temporal lobe hypoperfusion did not correlate with postoperative seizure relief. It is concluded that interictal SPECT with99mTcHMPAO with a single‐headed gamma camera does not add useful information in preoperative localization or predicting postoperative seizure relief.

ISSN:1051-2284    

DOI:10.1111/jon199553142

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

The sensitivity of single‐photon emission computed tomography (SPECT) in evaluating posterior mculation infarcts compared with that of computed tomography (CT) or magnetic resonance imaging (MRI) remains unknown. In a hospital‐based population, the authors studied SPECT, CT, and MRI in 35 consecutive patients presentmg with acute infarction clinically localized in the thalamus (7), posterior cerebral artery (PCA) territory (15), bramtem (19), and cerebellum (3) Multiple infarcts were noted m 8 patients. Overall, the SPECT sensitivity was lower than that of MRI (21% vs 93%, p ~ 0 004) and CT (42% vs 65%, p = 0 046) The SPECT and CT sensitivities were not Significantly different (67% vs 73%) for PCA Infarcts. Performed within 24 hours, SPECT showed a relevant hypoperfusion in all PCA mfarcts. For brainstem infarcts, CT (33%,p= 0 074) and MRI (91 %,p= 0.004) were more sensitive than SPECT, which showed no hemispheric hypoperfusion. The sensitivity of the three imaging techniques was 100% for large cerebellar infarcts. For the small group of thalamic infarcts, the SPECT, CT, and MRI sensitivities were 14, 71, and 100%, respectively. Thus, SPECT compared to CT and MRI is not helpful in the subacute phase to localize PCA and cerebellar infarcts and is of limited value for thalamic infarcts. In the first hours, the absence of cerebral hypoperfusion in brainstem mfarcts may help to differentiate them from hemispheric infarcts usually associated with profound hypoperfusion.

ISSN:1051-2284    

DOI:10.1111/jon199553145

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

A combination of extracranial and transcranial color‐coded sonography was used to identify the patterns of vascular occlusion in 47 patients with acute ischemic stroke. Total anterior circulation infarction (n = 20) was associated with internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion (n = 8 and 9, respectively), or with significant reduction in ipsilateral MCA velocities (n = 5) Patients with partial anterior circulation (n = 22) infarction had patency of the ipsilateral ICA and MCA. In this group, significant reduction of ipsilateral MCA velocities (n = 7) was associated with more extensive infarcts on conventional neuroimaging (n = 6), suggesting multiple MCA branch occlusions. Ultrasound imagmg was unable to identify underlying vascular pathology in patients with postenor circulation infarction or with lacunar infarction (n = 5). An ultrasound‐based approach enables noninvasive identification of major vascular pathology of the anterior cerebral circulation in patients with acute cerebral infarction. It may be useful for the rapid identification of patients most and those least likely to benefit from acute intervention, and for monitoring their response.

ISSN:1051-2284    

DOI:10.1111/jon199553152

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Results of magnetic resonance spectroscopic (MRS) studies of the chemical patterns in brain tumors have been mconsistent. Actual biochemical correlations are needed. In 2 patients with heterogeneous intracranial tumors, in vivo1H MRS and in vitro biochemical analyses were correlated. Histology confirmed the tumor heterogeneity. Choline was elevated in the cellular portion of both tumors but decreased in the necrotic or cystic portions. Creatine was diffusely decreased while lactate was elevated in all regions of both tumors. Furthermore, the increase in the choline peak on1H MRS appeared to be due to increases in water‐soluble choline compounds. This study illustrates the value of small localized voxels for differentiating regional chemical differences in tumors.

ISSN:1051-2284    

DOI:10.1111/jon199553157

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Six patients for whom computed tomography revealed a curvilinear calcific mass anterior to their brainstem were evaluated and magnetic resonance imaging and magnetic resonance angiography were performed on each. Magnetic resonance studies confirmed the suspicion of basilar artery dolichoectasia, and demonstrated a partial thrombus in the basilar artery in 1 patient. The patients' clinical features were combined with those of basilar artery dolichoectasia patients reported in the literature (n = 122) who had case histories sufficiently detailed enough to determine each person's mode of clmical presentation. Basilar artery dolichoectasia patients were more often men (95/128, 74%) and had a mean age of 59 ± 11 years. Of the 128 patients studied, there were cranial nerve compressive signs in 74 (58%), especially facial spasm (29/74, 39%) and trigeminal neuralgia (20/74, 27%); vertebral basilar insufficiency or vertebral basilar stroke or both in 61 (48%); hydrocephalus in 40 (31 %); compressive brainstem symptoms and signs that progressed clinically in 31 (24%); and arterial hypertension in 31 (24%) Magnetic resonance imaging and magnetic resonance angiography safely diagnose this interesting arterial abnormality. The modes of clinical presentation of this disorder are reviewed.

ISSN:1051-2284    

DOI:10.1111/jon199553164

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Computer‐assisted diagnostic systems enhance the mformation available from magnetic resonance imaging. Segmentations are the basis on which three‐dimensional volume renderings are made. The application of a raw data‐based, operator‐Independent (automatic), magnetic resonance segmentation technique for tissue differentiation is demonstrated. Segmentation images of vasogenic edema with gross and histopathological correlation are presented for demonstration of the technique. A pixel was classified mto a tissue class based on a feature vector using unsupervised fuzzy clustering techniques as the pattern recognition method. Correlation of fuzzy segmentations and gross and histopathology were successfully performed. Based on the results of neuropathological correlation, the application of fuzzy magnetic resonance image segmentation to a patient with a brain tumor and extensive edema represents a viable technique for automatically displaying clinically Important tissue differentiation. With this pattern recognition technique, it is possible to generate automatic segmentation images that display diagnostically relevant neuroanatomical and neuropathological tissue contrast information from raw magnetic resonance data for use in three‐dimensional volume reconstructions.

ISSN:1051-2284    

DOI:10.1111/jon199553171

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

The results of a positron emission tomography study of regional cerebral metabolic rates for glucose are reported for 8 healthy old subjects (mean age, 66 yr; standard deviation [SD], 5) and 9 young subjects (mean age, 27 yr; SD, 4.6) using a high‐resolution positron emission tomograph and the glucose metabolic tracer 18F‐fluorodeoxyglucose. Older subjects showed significantly lower cerebral metabolic rates than did the young subjects, in anterior, middle, and posterior temporal neocortex and in mesial temporal cortex, with the largest differences occurring in anterior temporal cortex (temporal pole). The current findings may reflect either decreases in regional cerebral metabolic rates for glucose that occur with normal aging, or early indications of cognitive dysfunction that is associated with age‐related disorders

ISSN:1051-2284    

DOI:10.1111/jon199553178

出版商:Wiley    

年代:2016

数据来源: WILEY

ISSN:1051-2284    

DOI:10.1111/jon199553182

出版商:Wiley    

年代:2016

数据来源: WILEY