轴扫技术在64层螺旋CT腹部检查中降低辐射量的作用

目的:研究64层螺旋CT和轴扫技术降低腹部CT检查辐射量的作用。方法:18例腹部CT扫描和复诊两次的患者自身对照,按照就诊顺序分成3组。均采用120kV管电压,自动毫安,噪声指数(NI)设定为8,A组为第一次扫描,采用螺旋扫描;B组为患者复诊时扫描,采用轴扫(Cine,Full)扫描;C组为再次复诊时扫描,采用轴扫(Cine)节段扫描。分别进行平扫和增强动脉期、静脉期扫描,比较各组图像质量、噪声水平和有效辐射量。结果:各组图像平扫、动脉期和静脉期图像得分之间的差异无统计学意义(P>0.05)。平扫3组图像噪声差异无统计学意义,增强后A组和B组图像噪声之间差异无统计学意义(P>0.05),C组和其他两组之间差异有显著统计学意义(P<0.01)。X线辐射量C组比A组降低约46.3%,比B组降低约33.2%的,差异有显著统计学意义(P<0.01),B组比A组降低约19.6%,差异有统计学意义(P<0.05)。结论:轴扫和轴扫节段扫描技术在保证图像质量的同时能有效降低腹部CT扫描的辐射量。     

应用定量CT测定胸椎骨矿密度

目的对行心脏CT检查的病人应用定量CT进行胸椎骨矿密度(BMD)测定,获得标准值,并将该值(来自各亚组)与行腰椎定量CT检查所获得的骨矿密度值进行比较。材     

定量CT在骨密度测量中的应用

骨质疏松症已逐渐成为全社会日益关注的医疗问题之一,早期的诊断对其疾病本身的治疗和骨折等并发症的预防至关重要.目前,许多骨密度(BMD)测量方法已广泛地用于骨质疏松的诊断、骨折危险性的预测和骨量变化监测的研究和临床工作中.定量CT(quantitative computered tomograpy,QCT)测量即为众多BMD测量方法之一,这是一种依赖临床CT机和特有的体膜(phantom)进行BMD测量的方法.     

High resolution CT spinal scanning with ACTA 0200 FS

Summary The diagnostic features of CT images of the spine are constantly influenced by some limitations of the method because of the peculiar configuration of the human spine. Recent generations of CT scanners greatly improve the results but with the second generation (Acta 0200 FS Pfizer Scanner) we have been able to develop a modified scan reconstruction method to maintain the quality of our spinal images, thanks to the very flexible software of our CT scanner.     

Assessment of vertebral bone mineral density using volumetric quantitative CT

PURPOSE: The purpose of this work was to determine the precision and diagnostic efficacy of bone mineral density (BMD) measures based on volumetric quantitative CT (QCT) of the spine. METHOD: Volumetric CT scans of L1 and L2 (GE-9800Q; 80 kVp, 140 mAs, 3 mm slices) were acquired in a cohort of 62 osteoporotic women (mean age 70.4 years, T(DXA hip or spine) < -2.5), of whom 20 had vertebral fractures and 42 were nonfractured control subjects. An image analysis technique delineated trabecular, cortical, and integral regions in reference to a vertebra-fixed coordinate system. We computed precision values and fracture control differences for these new regions and for single-slice QCT and dual X-ray absorptiometry (DXA) measures synthesized from the volumetric data. RESULTS: Volumetric trabecular BMD showed higher precision (1.3%) than the synthesized single-slice measures (2.1-2.8%). Volumetric and single-slice trabecular BMD showed equivalent decrements between fractured and nonfractured subjects (17-19%), with integral BMD showing smaller and less significant differences (7-8%). CONCLUSION: Volumetric and single-slice QCT techniques are equivalent for vertebral fracture risk estimation, but volumetric techniques should be superior for monitoring therapy efficacy.     

Spinal bone mineral density by quantitative CT in a normal Italian population

The purpose of this study was to describe the normal cross-sectional pattern of spinal bone loss associated with aging in an Italian population and to compare these values to the American normative database. A group of 472 healthy subjects (382 females and 90 males) were recruited for bone mineral density (BMD) assessment by quantitative computed tomography (QCT). To eliminate technique-related differences in a comparison of Italian and American normal values obtained with two different scanners we performed a cross-calibration analysis scanning the same computerized imaging reference system (CIRS) phantom at both centers. The results of the cross-calibration study using the CIRS phantom were used to compare regression slopes of BMD with age and age-adjusted mean BMD of American men and women vs cross-calibrated Italian men and women. American men and women decrease more rapidly vs Italian men and women, and Italian men have significantly lower age-adjusted mean BMD than American men. For these reasons we recommend normal values to be locally obtained for an Italian population. Correspondence to: G. Guglielmi     

我国定量CT骨量测量的临床评估

骨质疏松症是老年人常见的骨关节疾患,其骨折并发症严重地影响老年人的生活质量.为了早期预防骨质疏松症及其并发症,各国相关学者均对此给予了极大的关注,特别是对骨质疏松症诊断的骨矿含量测量进行了大量的研究工作.     

CT scanning in two cases of lipoma of the spinal cord.

Two cases of lipoma of the spinal cord are presented. CT gives a specific diagnosis in this condition without any contrast being given. It is important to make a preoperative diagnosis, as in lipoma of the spinal cord biopsy is dangerous and frequently makes the patient worse. CT is also valuable as the length of the required decompression laminectomy can be assessed.     

CT scanning for the diagnosis of the cerebellar and spinal lesions of von Hippel-Lindau's disease

Summary The CT features of cerebellar lesions with von Hippel-Lindau's disease are analyzed. The use of CT scanning for associated spinal hemangioblastomas is discussed in the light of a case with a low cervical lesion. The role of computed tomography in the neuroradiological investigations is discussed.     

脊柱结核的CT诊断分析

结核病在我国是一种常见的慢性传染病,在骨关节结核中脊柱为最好发之部位,以腰椎最多,其次为胸椎、胸腰段,而颈椎及骶尾椎较少。如不能早发现、早治疗,则会给患者带来严重的后果,甚至截瘫。所以,只要有症状即使X线片上未见明显异常也需做CT检查。1资料与方法1.1一般资料本组48例患者中,男性26例,女性22例,年龄20岁～78岁。病变发生在腰椎24例,胸椎18例,胸腰椎6例;病变累及一个椎体的9例,病变累及两个相邻椎体的29例;累及3个及3个以上椎体的10例;有4例伴有椎弓根及椎小关节破坏。椎旁冷脓肿42例。主要症状为腰痛无力,部分患者伴有下肢疼痛…     

腰椎峡部裂并滑脱CT扫描技术与CT征象分析

1资料与方法本组共35例,男25例,女10例,年龄25~56岁。其中腰痛伴单或双侧下肢疼痛及麻木19例,单纯腰痛15例,骶尾部疼痛1例,均无急性外伤史。使用美国GE公司Pro-speedAI螺旋CT机,层厚3 mm,层距3 mm。20例采用常规扫描,即L3~S1三个椎间盘,对峡部裂椎体从椎体下缘向上按椎间盘扫描     

低剂量CT筛查肺癌的研究进展

肺癌是目前世界上恶性肿瘤死亡的首要原因,且其发病率和死亡率呈上升趋势,由于其病因和发病机制复杂,目前尚缺乏有效的预防措施.肺癌诊断方法很多,但各自具有自己的优缺点,探索早期肺癌的诊断方法尤为重要.     

Dedicated CT technique for scanning neonates

Two 10-cm-diameter phantoms were made to simulate newborn babies undergoing computed tomographic scanning. The image-evaluation phantom was used for comparison of spatial and contrast resolution between an adult and a neonate. It was found that the establishment of a dedicated machine setting for imaging of the newborn is of utmost importance for obtaining acceptable image quality. With the dose-determination phantom, the dose measured at the same machine settings was found to be 30% higher to the infant than to the adult. Contrary to popular belief, the measurements showed that, for the same setting of the milliampereseconds (mAs), the small phantom received a higher radiation dose than the large phantom. Therefore, clinically, the same mAs setting delivers a higher dose to an infant than to an adult because of the infant's smaller size.     

重视冠状动脉多层CT成像的低剂量检查

近年来,随着MSCT技术的飞速发展,尤其是64层MSCT和双源CT(DSCT)的问世,MSCT在心脏冠状动脉成像方面应用越来越广泛,在诊断冠状动脉粥样硬化以及评价支架术后再狭窄和搭桥血管等方面发挥着越来越重要的作用,冠状动脉CTA已成为冠心病检查的一项重要的无创性成像手段.     

重视冠状动脉多层CT成像的低剂量检查

近年来,随着MSCT技术的飞速发展,尤其是64层MSCT和双源CT(DSCT)的问世,MSCT在心脏冠状动脉成像方面应用越来越广泛,在诊断冠状动脉粥样硬化以及评价支架术后再狭窄和搭桥血管等方面发挥着越来越重要的作用,冠状动脉CTA已成为冠心病检查的一项重要的无创性成像手段.     

重视冠状动脉多层CT成像的低剂量检查

近年来,随着MSCT技术的飞速发展,尤其是64层MSCT和双源CT(DSCT)的问世,MSCT在心脏冠状动脉成像方面应用越来越广泛,在诊断冠状动脉粥样硬化以及评价支架术后再狭窄和搭桥血管等方面发挥着越来越重要的作用,冠状动脉CTA已成为冠心病检查的一项重要的无创性成像手段.