The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study. 相似文献
Summary Over a period of 14 years, 7,960 patients were treated in 228 phase I trials. In these patients, there were 75 complete and 432 partial responses for an overall objective response rate of 6%. Complete responses lasted a median of six months (range 1–18), while partial responses lasted a median of three months (range 1–17). Of note is that no drug has made it to the market which has not had a response in phase I trials. Responses were noted in very diverse histologic types of tumors. Although there were responses at doses which were as low as 3–5% of the recommended dose for phase II trials, the majority of responses did occur at 80–120% of the dose recommended for phase II trials. Although the response rate in phase I trials is indeed low, responses do occur. This response rate information should help the clinician provide facts for the patient considering a phase I trial with new anticancer agents. These findings also emphasize that although phase I trials are characteristically dose-finding studies, if no responses are noted in phase I studies, it is unlikely the drug will be used routinely in the clinic. 相似文献
Brain morphology was examined using magnetic resonance imaging in 30 first-episode patients with a schizophreniclike psychosis, 15 chronic schizophrenics, and 20 neurological controls. Statistical analyses of computer-generated measurements of regions of interest were controlled for gender, age, social class, and total brain volume. Lateral ventricular size was increased in both first-episode and chronic schizophrenic patients, with greater significance on the left than on the right side. Only the chronic patients, however, had reduced temporal lobe size, which also was greater on the left side. No major correlations of regional brain morphological measurements with cognitive functioning were found, although some measurements of verbal memory were correlated with parahippocampal size. This is a report of a preliminary study that suggests that some morphological brain changes may be present at the time of first treatment for a psychotic illness, whereas others may occur later in the course of illness. Future prospective studies may determine the clinical significance of these changes and whether they progress with the development of illness chronicity. 相似文献
A case of acute cervical epidural abscess is presented. The use of intraoperative spinal sonography is discussed as a valuable adjunct in the evaluation and treatment of these uncommon lesions. 相似文献
The acute psychological reactions of 101 train drivers to on-the-track accidents were studied by means of clinical interviews and questionnaires (Impact of Event Scale, GHQ-20 and a questionnaire addressing stress symptoms, pre-accident expectancies and worries). More than half of the train drivers reported moderate to high intrusive distress (mean 11.3) within hours to days after the accident but only 1/3 reported symptoms of acute psychophysiological arousal. Intrusive symptoms related to visual impressions were most frequently reported. Avoidance was less prevalent (mean 8.8).
Clinical interviews, relationship between pre-accident worries and severity of the acute responses and positive correlation between GHQ-scores relating to the fortnight preceding the accident and IES-intrusion scores, suggest that premorbid variables may influence the stress response. Involvement in more than two previous accidents invoked a feeling of vulnerability and produced stronger acute responses. Post-accident experiences involving various personal contacts did not correlate with the stress responses in this study and only a few drivers experienced such events in a negative way. Denial of the possibility of being involved in accidents was not associated with increased risk of strong acute responses, indicating that denial does not predict poor outcome in healthy persons exposed to situations where possibility of avoiding the event is outside the control of the person. 相似文献