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21.
Performance measurement of the microPET focus 120 scanner.   总被引:6,自引:0,他引:6  
The microPET Focus 120 scanner is a third-generation animal PET scanner dedicated to rodent imaging. Here, we report the results of scanner performance testing. METHODS: A (68)Ge point source was used to measure energy resolution, which was determined for each crystal and averaged. Spatial resolution was measured using a (22)Na point source with a nominal size of 0.25 mm at the system center and various off-center positions. Absolute sensitivity without attenuation was determined by extrapolating the data measured using an (18)F line source and multiple layers of absorbers. Scatter fraction and counting rate performance were measured using 2 different cylindric phantoms simulating rat and mouse bodies. Sensitivity, scatter fraction, and noise equivalent counting rate (NECR) experiments were repeated under 4 different conditions (energy window, 250 approximately 750 keV or 350 approximately 650 keV; coincidence window, 6 or 10 ns). A performance phantom with hot-rod inserts of various sizes was scanned, and several animal studies were also performed. RESULTS: Energy resolution at a 511-keV photopeak was 18.3% on average. Radial, tangential, and axial resolution of images reconstructed with the Fourier rebinning (FORE) and filtered backprojection (FBP) algorithms were 1.18 (radial), 1.13 (tangential), and 1.45 mm full width at half maximum (FWHM) (axial) at center and 2.35 (radial), 1.66 (tangential), and 2.00 mm FWHM (axial) at a radial offset of 2 cm. Absolute sensitivities at transaxial and axial centers were 7.0% (250 approximately 750 keV, 10 ns), 6.7% (250 approximately 750 keV, 6 ns), 4.0% (350 approximately 650 keV, 10 ns), and 3.8% (350 approximately 650 keV, 6 ns). Scatter fractions were 15.9% (mouse phantom) and 35.0% (rat phantom) for 250 approximately 750 keV and 6 ns. Peak NECR was 869 kcps at 3,242 kBq/mL (mouse phantom) and 228 kcps at 290 kBq/mL (rat phantom) at 250 approximately 750 keV and 6 ns. Hot-rod inserts of 1.6-mm diameter were clearly identified, and animal studies illustrated the feasibility of this system for studies of whole rodents and mid-sized animal brains. CONCLUSION: The results of this independent field test showed the improved physical characteristics of the F120 scanner over the previous microPET series systems. This system will be useful for imaging studies on small rodents and brains of larger animals.  相似文献   
22.
OBJECTIVE: The recent development of fetal ultrasonography has allowed for an increasing number of prenatal diagnoses for congenital cystic adenomatoid malformation (CCAM). However, the appropriate surgical timing of these patients has not been studied as of yet. The aim of this study is to suggest a safe strategy for the treatment of CCAM by identifying the relationship between the timing of surgery and postoperative outcome. METHODS: Between 1987 and 2003, 40 patients (28 males, 12 females) underwent surgical resection for CCAM. The mean age was 38.6+/-9.1 (2 days-13 years) months. CCAM was diagnosed by prenatal ultrasonography in eight patients. Early operations were performed in four out of the eight. Operation was deferred until 2-12 months of age for the remaining four patients. RESULTS: Type I CCAM was found in 20 patients, type II in 20 and no patient exhibited type III. Five patients had associated pectus excavatum anomaly. There were no cases of operative mortality. Seventeen minor postoperative complications developed in 16 patients (40.0%): prolonged chest tube drain in 10, wound infection in 4, and 1 case of pneumonia, empyema and pleural space, respectively. The average hospital stay was 11.8 (6-29) days. During the mean follow-up period of 67.5 months, one patient died of accidental aspiration 7 months after operation during the postoperative recovery course of Ravich operation for pectus excavatum. The remaining patients reported doing well with normal physical activity. All five patients who underwent surgery at the age of under 1 month did not exhibit increased postoperative morbidity. CONCLUSIONS: We concluded that surgery for CCAM could be safely performed in all age groups with satisfactory long-term outcomes. It is suggested that early elective surgical correction can be recommended for a patient whose diagnosis was made in utero.  相似文献   
23.
北京市东城区和平里社区居民慢性病防治探讨   总被引:3,自引:0,他引:3  
为探索慢性病的防治方法,我们于1989 ̄1994年社区居民中开展了以高血压为主的循环系统慢性病防治课题,经过5年的干预,观察组与对照组居民及接受管理的高血压病人在减少吸烟,饮酒,控制食盐摄入,掌握慢性病防治知识等方面有显著性差异,取得了满意的结果,从而为今后全面开展慢性病防治积累了经验。  相似文献   
24.
复方山绿茶缓释袋泡剂的研究   总被引:6,自引:0,他引:6  
董泽民 《中成药》1993,15(12):7-9
用网状多孔性纤维包念材料制备的复方山绿茶缓袋泡剂,具有速释和缓释作用,在1-8h内按埝级方式释药。T0.5为1.3h,Td为3.2h,1-8h的平均释药速率72.35mg/h。与传统的半生药型袋泡剂比较,具有栽药量高,使用方便,性质稳定,疗效确切的优点。  相似文献   
25.
人细胞色素p450IA1基因cDNA的克隆和鉴定   总被引:5,自引:1,他引:4  
在用3-甲基胆蒽诱导培养人羊膜FL细胞24h后,抽提细胞总RNA并直接合成cDNA第一链。利用人工合成的一对寡核苷酸引物,采用PCR技术特异性地扩增Cyt p50IA1 cDNA。30个循环后琼脂糖凝胶电泳显示1.5Kb大小片段,长度与预计相符。Southern杂交结果证实此片段确为Cyt p450IA1 cDNA。将此片段克隆至质粒pGEM-3Z并进行部份序列分析。结果显示克隆片段包含Cyt p  相似文献   
26.
目的探讨几个问题:(1)Ⅰ期非小细胞肺癌淋巴结微转移比率;(2)淋巴结微转移与肿瘤大小、病理类型、细胞分化程度、部位、分型、分期进行Logstic回归分析,确定影响微转移的主要因素;(3)探讨微转移的方式、顺序。方法对91例非小细胞肺癌清扫的肺门和隆突下淋巴结进行MCK(AEI/AE3)免疫组化标志检测微转移的存在。另外收集45例肺部良性病变手术时切除的肺门淋巴结45枚和Ⅱ期、Ⅲ期肺癌常规病理检查阳性的肺门淋巴结45枚进行MCK(AEI/AE3)免疫组化(SP法)标志,分别作为阴性和阳性对照。结果45例肺部良性病变手术时切除的肺门淋巴结45枚进行MCK(AEI/AE3)免疫组化标志均为阴性;Ⅱ期和Ⅲ期常规病理检查阳性的肺门淋巴结45枚进行MCK(AEI/AE3)免疫组化标志均为阳性。91例Ⅰ期非小细胞肺癌总的微转移率为49%(45/91)。结论Ⅰ期非小细胞肺癌淋巴结中存在微转移;Ⅰb期非小细胞肺癌微转移率明显高于Ⅰa期;有必要对Ⅰb期非小细胞肺癌进行术后化疗;肿瘤分期和分化程度是影响淋巴结微转移的主要因素;淋巴结微转移遵循肺门到纵隔的途径;腺癌存在跳跃式微转移。  相似文献   
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29.
特殊型前列腺增生症的诊治   总被引:1,自引:1,他引:0  
收治特殊型前列腺增生症110例,分别伴有逼尿肌无力、不稳定性膀胱、前列腺结石、膀胱结石、前列腺炎或糖尿病。认为:治疗前认真检查发现特殊前列腺增生症,是提高治愈率、减少并发症的关键步骤之一。  相似文献   
30.
本文将生化自动分析仪应用于健康检诊中,就其中1089名健康者的血清进行12项生化指标的检测,并对测得的结果进行分析整理,确定国人的正常值范围。同时又对自动分析仪的质量管理进行了探讨。  相似文献   
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