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排序方式: 共有644条查询结果,搜索用时 31 毫秒
41.
Regional myocardial dysfunction: evaluation of patients with prior myocardial infarction with fast CT 总被引:1,自引:0,他引:1
Lipton MJ; Farmer DW; Killebrew EJ; Bouchard A; Dean PB; Ringertz HG; Higgins CB 《Radiology》1985,157(3):735-740
A prototype ultrafast cine computed tomographic (CT) scanner, designed specifically for cardiac imaging, was used to evaluate a preliminary series of patients with prior myocardial infarction (n = 21) and a control group without coronary artery disease (n = 5). Multilevel 50-msec CT scan exposures were obtained during peripheral intravenous bolus injections of contrast medium. A comparison was made between cine-CT scans and standard left ventriculographic images in assessing segmental left ventricular motion. Results indicate that cine CT, performed at sufficiently rapid speeds (20 scans per second) to allow useful analysis of regional ventricular wall motion, can provide adequate image quality. Analysis of 110 segments revealed a good correlation (90.9%) between the two techniques in characterizing normal from abnormal regional wall motion. Cine CT, based on this initial study, demonstrates considerable potential for evaluating not only cardiac chamber dimensions but also segmental wall dynamics. 相似文献
42.
A number of surgical clips and other metallic materials embedded within patients have ferromagnetic properties that present a potential hazard when in the strong fields associated with magnetic resonance imaging. Several types of magnetometers and metal detectors were investigated as possible pre-imaging screening devices. The sensitivities and costs of these devices are given. 相似文献
43.
44.
Background Sequentially evolving intracranial bilateral haematomas, where the second haematoma develops after the surgical removal of
the first one is rarely reported.
Aim To report a patient who developed an epidural haematoma after evacuation of a contralateral subdural haematoma.
Methods A 49-year-old male was admitted to our department after head injury. A brain computerized tomography (CT) scan revealed an
acute subdural haematoma in the right temporal area which was evacuated. During his stay in the intensive care unit, he was
submitted to intracranial pressure monitoring, which soon rose.
Results A new CT scan showed an acute epidural haematoma in the contralateral parietal area that was also evacuated.
Conclusions While rising intracranial pressure after the evacuation of a traumatic haematoma is usually attributed to brain oedema or
recurrent haematoma at the craniotomy site, the development of a contralateral epidural haematoma requiring surgical treatment
should not be overlooked. 相似文献
45.
MEG studies have shown that the timing (latency) of the evoked response that peaks approximately 100 ms post-stimulus onset (M100) decreases as frequency increases for sinusoidal tones. We investigated M100 latency using a continuum of synthesized vowel stimuli in which the dominant formant frequency increases from 250 Hz (perceived /u/) to 750 Hz (perceived /a/) in 50 Hz steps. While M100 latency did vary inversely with formant frequency overall, frequency modulation was flattened within each vowel category. However, for mid-continuum ambiguous tokens (i.e. those with increased reaction time/decreased accuracy in the concurrent behavioral identification task), M100 reverted to formant frequency differences, agreeing with previous findings of frequency-dependence. A theory is proposed in which phonological categorization emerges from specific spatial distribution of frequency-tuned neurons. 相似文献
46.
Seymour JD Calle EE Flagg EW Coates RJ Ford ES Thun MJ;American Cancer Society 《American journal of epidemiology》2003,157(11):980-988
The Diet Quality Index (DQI) was developed to measure overall dietary patterns and to predict chronic disease risk. This study examined associations between DQI and short-term all-cause, all-circulatory-disease, and all-cancer mortality in the American Cancer Society Cancer Prevention Study II Nutrition Cohort, a cohort of US adults aged 50-79 years enrolled in a prospective study. After 4 years of follow-up (1992-1996), there were 869 deaths among 63,109 women and 1,736 deaths among 52,724 men. All study participants reported being disease free at baseline in 1992-1993. In age-adjusted Cox models, a higher DQI, which was indicative of a poorer quality diet, was positively related to all-cause and all-circulatory-disease mortality rates in both women and men and to cancer mortality in men only. However, in fully adjusted Cox models, only circulatory disease mortality was clearly positively related to DQI and only in women (medium-low-quality diet vs. highest-quality diet: rate ratio = 1.86, 95% confidence interval: 1.19, 2.89). Although trend tests indicated significant positive relations between DQI and all-cause mortality, effects were small (rate ratios = 1.31), and confidence intervals were wide, generally including 1.0. DQI was unrelated to cancer mortality. As currently constructed, the DQI may have limited ability to predict mortality. 相似文献
47.
Fifteen infants with life-threatening gastrointestinal anomalies received total parenteral feeding for periods ranging from 10 to 54 days; their ages ranged from one day to 5 months. The solutions were administered through peripheral veins. All patients gained weight during the period of observation and no cases of septicaemia were encountered. 相似文献
48.
目的 通过凝血酶对成骨细胞的增殖及分化作用的研究来探讨受体介导的凝血酶的功能.方法 原代成骨细胞分别取自于蛋白酶激活受体(protease-activated receptor,PAR)-1敲除鼠和野生对照鼠的头颅骨.并利用凝血酶,人工合成的PAR-1或PAR-4特异性激活短肽对细胞进行处理,通过对5.溴-2-脱氧尿嘧啶的嵌入及细胞碱性磷酸酶活性的测定探讨PAR-1或PAR-4激活对细胞增殖和分化的影响.结果 在野生鼠成骨细胞,凝血酶及PAR-1激活肽均能促进的细胞增殖和降低碱性磷酸酶的活性,但PAR-4激活肽却无这些作用.然而在PAR-1 敲除鼠的成骨细胞无论是凝血酶还是PAR-4激活肽均不能改变细胞的增殖及碱性磷酸酶的活性.结论 本研究结果 表明凝血酶促进成骨细胞增殖及抑制其分化是通过PAR-1介导的.其他凝血酶受体并不具有此作用. 相似文献
49.
Data obtained on 426 consecutive patients referred to a breast center by 122 physicians, including family practitioners, general surgeons, and other specialists, showed that the obstetricians-gynecologists referred the greatest average number of patients per physician, with more than 50% of these referrals for screening mammography. Internists referred fewer patients by nearly a factor of ten, with only one-third of these patients referred for screening mammography. Internists may be the weakest link in the utilization of screening mammography. 相似文献
50.