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排序方式: 共有1116条查询结果,搜索用时 15 毫秒
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Milena G. J. Jahoda Helen Brandenburg Titia Cohen-Overbeek Frans J. Los Eva S. Sachs Juriy W. Wladimiroff 《American journal of medical genetics. Part A》1993,46(5):483-485
Data from 4,300 consecutive cases following prenatal diagnosis by transcervical (TC) CVS (n = (1,570) and transabdominal (TA) CVS (n = 2,370) were evaluated. In the follow-up study only infants examined by a physician were included. Gestational age varied between 8.5 and 11.6 weeks (mean 10.3 weeks) for TC-CVS and between 9.3 and 20 weeks (mean 12.3 weeks) for TA-CVS 98% of TC-CVS was performed at 9–10 weeks, 80.7% of TA-CVS procedures were carried out at 12–15 weeks. Selective termination took place in 97 cases of TC-CVS (6.1%) and in 72 cases of TA-CVS (2.6%). Another 8 Women had a termination for psychosocial reasons, resulting in 4,123 (1,469 TC, 2,645 TA) continuing pregnancies. The overall fetal loss rare <28 weeks was 5.4% (n = 80) for TC-CVS and 2.6% (n = 70) for TA-CVS. The overall incidence of congenital abnormalities after birth was 0.9%. Two terminal transversal limb defects were detected in the TC-CVS group (0.14%) against one (0.04%) in the TA-CVS group. © 1993 Wiley-Liss, Inc. 相似文献
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Short-Ti inversion-recovery pulse sequence: analysis and initial experience in cancer imaging 总被引:2,自引:0,他引:2
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy. 相似文献
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Sixteen cases of histopathologically proved solitary rectal ulcer syndrome were encountered. Fifteen patients underwent barium enema study; in nine cases the findings--including rectal stricture, granularity of the mucosa, and thickened rectal folds-were nonspecific. In six cases the study was normal. All patients had a long history of defecation disorders, and defecography was performed in all. In seven cases, intussusception of the rectal wall was seen; in another case the intussusception was accompanied by a rectocele. One case showed rectal prolapse. In four cases, failed relaxation of the puborectalis occurred and prevented the passage of the bolus; in another case there was abnormal perineal descent. In two patients studies were normal. In patients with defecation disorders, the possibility of this syndrome should be considered. Defecography is the method of choice for establishing the diagnosis. 相似文献
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A S M Vinkesteijn P C Struijk N T C Ursem W C J Hop J W Wladimiroff 《Ultrasound in obstetrics & gynecology》2004,23(5):461-465
OBJECTIVES: To study heart rate and umbilical artery blood flow velocity variability in growth-restricted fetuses and investigate the influence of the autonomic nervous system on these parameters. METHODS: Doppler velocity waveforms were collected from long-lasting umbilical artery recordings in 15 fetuses with growth restriction and 15 normal age-matched controls at 23-35 weeks of gestation. Absolute heart rate and umbilical artery blood flow velocity as well as the coefficient of variation were determined. Using power spectral analysis the low- and high-frequency bands of heart rate variability and blood flow velocity variability were calculated. The low-to-high (LH) ratio of heart rate variability and blood flow velocity variability were examined as a measure of sympathovagal balance. RESULTS: In growth-restricted fetuses umbilical artery velocities were significantly reduced. Heart rate variability was significantly reduced in the presence of growth restriction, but no significant difference was demonstrated for blood flow velocity variability. The LH ratio for heart rate variability was significantly decreased in growth restriction, but no difference in LH ratio was demonstrated for blood flow velocity variability. CONCLUSION: Flow velocity variability in growth restriction seems not to be predominantly influenced by the autonomic nervous system, whereas the decreased heart rate variability seems to be influenced by altered sympathetic-parasympathetic balance. 相似文献
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