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排序方式: 共有627条查询结果,搜索用时 15 毫秒
91.
Deepu Nair MD ; Thomas P. Carrigan MD ; Ronan J. Curtin MD ; Zoran B. Popovic MD PhD ; Stacie Kuzmiak RT ; Paul Schoenhagen MD ; Scott D. Flamm MD ; Milind Y. Desai MD 《Preventive cardiology》2009,12(1):19-26
The authors assessed the association between an elevated total cholesterol to high-density lipoprotein cholesterol (TC/HDL-C) ratio (≥4) and proximal coronary artery disease (CAD), as observed on multislice computed tomography. Coronary multislice computed tomographic angiography (96% on 40- or 64-slice) was performed in 295 individuals (39% women; mean age, 54±13 years) without documented CAD who were referred for coronary evaluation. Significant CAD was defined as ≥50% stenosis in the left main, proximal left anterior descending, or ≥2 epicardial vessels. Proximal plaque was defined as presence of any plaque in left main or proximal left anterior descending vessels. Individuals with an elevated TC/HDL-C ratio vs those without had a higher prevalence of proximal plaque (62% vs 48%, P =.04) and significant CAD (19% vs 9%, P =.009). On multivariate logistic regression analysis, only age, sex, and TC/HDL-C ratio ≥4 were associated with significant CAD and proximal plaque. 相似文献
92.
93.
Alessandro Beneduce MD Cristina Capogrosso MD Francesco Moroni MD Francesco Ancona MD Giulio Falasconi MD Luigi Pannone MD Stefano Stella MD Giacomo Ingallina MD Francesco Melillo MD Marco Bruno Ancona MD Vittorio Romano RT Anna Palmisano MD Azeem Latib MD Antonio Colombo MD Matteo Montorfano MD Antonio Esposito MD Eustachio Agricola MD 《Echocardiography (Mount Kisco, N.Y.)》2020,37(12):2071-2081
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95.
Simple modification of arm position improves B1+ and signal homogeneity in the thoracolumbar spine at 3T
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![点击此处可从《Journal of magnetic resonance imaging : JMRI》网站下载免费的PDF全文](/ch/ext_images/free.gif)
96.
Improvement of the repeatability of parallel transmission at 7T using interleaved acquisition in the calibration scan
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97.
T1ρ mapping of articular cartilage grafts after autologous osteochondral transplantation for osteochondral lesions of the talus: A longitudinal evaluation
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98.
99.
Brooke V. Williams RT R.T. John Horton Ph.D. Ann Lawyer M.S. Jane Chapman C.M.D. 《Medical Dosimetry》1999,24(4):335-277
Treatment of prostate cancer utilizing iodine 125 (125I) interstitial seed implants has become an accepted and widely used modality. Numerous variations in 125I seed implant loading distribution techniques have developed as a result of the preferences of individual institutions implementing the modality. No particular universal standard is currently used for 125I seed implants. A major concern with 125I seed implants is coverage of the prostate with the desired dose and the minimization of dose to the urethra. A variation of seed distribution per individual anatomy is desirable. Historically, brachytherapy relied on dosimetry systems, such as the Paris, Quimby, and Manchester systems to achieve the desired dose distribution. Use of various peripherally loaded 125I seed implant distributions to accommodate anatomic variations within the same institution prompted the interest of how the results compare to the Manchester system. 相似文献
100.
Emanuel Gaziano MD Cecilie Gaziano PhD Debra Brandt RT RDMA 《American journal of obstetrics and gynecology》1998,178(6):1359-1367
OBJECTIVE: Our purpose was to study fetal growth and blood flow distribution in diamniotic monochorionic compared with dizygotic (diamniotic dichorionic) twins by use of Doppler velocimetry of the umbilical artery and middle cerebral artery. STUDY DESIGN: Study candidates were divided into group A, consisting of 33 pairs (66 fetuses) of diamniotic monochorionic twins, and group B, 50 pairs (100 fetuses) of diamniotic dichorionic twins. Diamniotic monochorionic placentation was confirmed by microscopic placental examination for group A. Diamniotic dichorionic placentation was ensured for group B by selecting only twins with different-sex pairs (dizygotic twins). Targeted ultrasonography with biometry was performed in each twin, and Doppler recordings of the umbilical artery and middle cerebral artery were obtained. Waveforms were analyzed and the systolic/diastolic ratio, the resistance index, and a measure of blood flow redistribution (brain-sparing effect), the cerebral/placental ratio, was calculated for each fetus. Growth status at birth was assessed by the number of small-for-gestational-age infants (≤10th percentile), low-birth-weight infants (≤25th percentile), and percent of growth discordance between twins. Intertwin differences were assessed by Δ values (value of larger twin minus value of smaller twin). RESULTS: Diamniotic monochorionic compared with dizygotic twins demonstrated a significantly greater probability of blood flow redistribution. For the study population as a whole, the brain-sparing effect was noted in 67% of small-for-gestational-age babies and only 7% of non-small-for-gestational-age infants (p ≤ 0.001). For the diamniotic monochorionic pregnancies blood flow redistribution occurred in 6 of 10 small-for-gestational-age infants (60%) and 6 of 46 non-small-for-gestational-age infants (13%). In the diamniotic monochorionic group small-for-gestational-age compared with non-small-for-gestational-age infants were more likely to show blood flow redistribution, which was the result of significantly decreased resistance in the middle cerebral artery and significantly increased resistance in the umbilical artery. Small-for-gestational-age infants (≤10th percentile) occurred much less frequently in the dizygotic group. Two of two small-for-gestational-age infants in the dizygotic group showed blood flow redistribution. Although the extremes of birth weight were more common in the diamniotic monochorionic group, both groups had relatively large numbers of small babies with birth weights in the lower 25th percentile (50.0% for diamniotic monochorionic and 44.0% for dizygotic twins, not significant). However, 42.3% (11/26) of diamniotic monochorionic twins who were in the low-birth-weight group showed blood flow redistribution compared with only 3.3% (1/30) whose birth weights were ≥25th percentile (p ≤ 0.001). In the dizygotic twins 10% of lower-birth-weight infants redistributed blood flow compared with 1% in the higher-birth-weight group, a nonsignificant difference. Diamniotic monochorionic compared with dizygotic twins were delivered earlier (32.9 weeks vs 34.8 weeks, p ≤ 0.001), were smaller (1832 gm vs 2304 gm, p ≤ 0.001), showed higher birth weight discordance (29.8% vs 14%, p ≤ 0.05), and had greater numbers (19.7% vs 2.3%, p ≤ 0.01) of infants at ≤10th percentile birth weight. CONCLUSIONS: Diamniotic monochorionic twins from the lower-birth-weight groups more often show blood flow redistribution compared with dizygotic twins of similar low birth weights. Placental vascular connections and the attendant hemodynamic changes in the fetuses of diamniotic monochorionic twins probably account for this difference. Brain-sparing events occur commonly without clinical twin transfusion syndrome in this group. These findings have implications for management. (Am J Obstet Gynecol 1998;178:1359-67.) 相似文献