Multi-detector CT angiography for lower gastrointestinal bleeding: Can it select patients for endovascular intervention?

This is a retrospective review of the results at our institution of using multi-detector CT angiography (CTA) to localise lower gastrointestinal (GI) bleeding. We hypothesised that in our patient population: (i) CTA was unlikely to demonstrate bleeding in patients who were haemodynamically stable; (ii) in haemodynamically unstable patients in whom CTA was undertaken, the results could be used to select patients who would benefit from catheter angiography; and (iii) in haemodynamically unstable patients in whom CTA was undertaken, a subgroup of patients could be identified who would benefit from primary surgical treatment, avoiding invasive angiography completely. A retrospective review was conducted of the clinical records of all patients undergoing CTA for lower GI haemorrhage at our institution between 1 January 2005 and 30 June 2007. Out of the 20 patients examined, 10 had positive CTAs demonstrating the bleeding site. Nine were haemodynamically unstable at the time of the study. Four patients with positive CT angiograms were able to be treated directly with surgery and avoided invasive angiography. Ten patients had negative CTAs. Four of these were haemodynamically unstable, six haemodynamically stable. Only one required intervention to secure haemostasis, the rest stopped spontaneously. No haemodynamically stable patient who had a negative CTA required intervention. CTA is a useful non-invasive technique for localising the site of lower GI bleeding. In our patient population, in the absence of haemodynamic instability, the diagnostic yield of CTA was low and bleeding was likely to stop spontaneously. In haemodynamically unstable patients, a positive CTA allowed patients to be triaged to surgery or angiography, whereas there was a strong association between a negative CTA and spontaneous cessation of bleeding.     

多层螺旋CT在胰腺癌诊断中的应用

多层螺旋CT（MSCT）使扫描速度，薄层，覆盖范围达到了很好的统一，是胰腺癌最佳的单项检查手段。本文介绍了MSCT运用于胰腺的技术优势以及具体检查方法，重点叙述其在胰腺癌的诊断，术前可切除性的评估等方面的应用。     

多排螺旋CT三维成像诊断颌面部骨折

目的:探讨多层螺旋CT三维成像诊断颌面部骨折的价值.方法:对32例颌面部骨折患者用多层螺旋CT薄层扫描,分别用多平面重建(MPR)法,表面阴影遮盖(SSD)法和容积渲染成像(VR)法进行三维成像,观察3种方法对颌面部骨折的显示情况.结果:32例颌面部骨折患者,MPR法能清晰显示全部骨折及周围软组织损害情况,但图像缺乏立体感;SSD法图像立体感强,但对细小骨折显示欠佳;VR法对所有骨折能清晰显示,特别是对细小骨折及无移位的骨折显示明显优于SSD法,但其对复杂解剖结构的立体显示则不及SSD.结论:多层螺旋CT三维成像对颌面部骨折的诊断具有重要价值,MPR法、SSD法和VR法显示病变各有优劣,在实际应用中,最好三者结合使用.     

输卵管卵巢脓肿与卵巢良性肿瘤的CT鉴别诊断

目的:分析输卵管卵巢脓肿的CT特征,探讨CT对输卵管卵巢脓肿与卵巢附件良性肿瘤的鉴别诊断价值。材料和方法:回顾性分析13例输卵管卵巢脓肿和11例卵巢良性肿瘤的CT表现。结果:绝经前患者输卵管卵巢脓肿12例(12/13例),良性肿瘤组4例(4/11例)。脓肿13例(13/13例)、良性肿瘤9例(9/11例),CT表现为附件区囊实性肿块,脓肿和良性肿瘤边缘轮廓模糊不清分别为11例(11/13例)和4例(4/11例),两组显示囊壁增厚和边缘层状增强分别为10例(10/13例)和2例(2/11例)。脓肿的子宫骶骨韧带增厚和骶前直肠周围脂肪模糊分别为10/13例和9/11例,而良性肿瘤组无1例发生。结论:附件脓肿壁增厚和层状增强,子宫骶骨韧带增厚及骶前直肠周围脂肪模糊有助于鉴别输卵管卵巢脓肿和卵巢良性肿瘤。     

Alveolar hydatid disease of the liver: Brief review and spectrum of adjacent organ invasion

The purpose of this study is to show the spectrum of adjacent organ invasion and to make a brief review of hepatic alveolar hydatid disease (AHD), using CT and MR imaging. We retrospectively reviewed CT and MR images of three patients with various adjacent organ invasions surgically and histologically proven to be AHD. Local invasion to right kidney and adrenal, right hemidiaphragm and lung were detected in one patient, right adrenal in another patient and gall bladder, duodenum, gastric wall and pancreas invasion in the other. AHD may rarely extend to the gall bladder, stomach, duodenum, pancreas, right adrenal and kidney, diaphragm, pleura and lung. The extension of the disease outside the liver is usually encountered in patients with large, peripherally located masses in the advanced stage of the disease.     

16层螺旋CT及其三维重建与多平面重组在胫骨平台骨折诊断中的应用

目的探讨16层螺旋CT(16层SCT)及其三维重建(3-D)与多平面重组(MPR)在胫骨平台骨折诊断中的应用价值。方法39例胫骨平台骨折病例经膝关节常规X线平片检查后，采用16层SCT进行膝关节的多层面螺旋CT扫描，在工作站上作3D及MPR影像后处理，就胫骨平台骨折的平片与16层SCT影像进行比较及综合分析。结果39例胫骨平台骨折中，X线平片漏诊1例髁间隆突骨折、1例内髁骨折及1例双髁骨折，此3例(7．69％)平片漏诊的骨折均为16层SCT予以诊断。16层SCT的3-D影像可清晰显示胫骨平台骨折的立体形态；MPR影像则可明确显示胫骨平台内部的骨质损伤情况如骨折的具体部位、关节面碎裂及塌陷程度、骨折移位距离。结论16层SCT能够显示X线平片难于诊断的胫骨平台隐匿性骨折；3-D及MPR成像技术十分有利于全面观察胫骨平台骨折的形态变化，是16层SCT横轴位扫描的重要补充。     

慢性心力衰竭的CT表现

目的:探讨慢性心力衰竭的CT表现。材料和方法:回顾性分析28例慢性心力衰竭的CT表现。结果:左心室增大16例、右心室增大8例、左心房增大6例、右心房增大4例,左、右心房增大3例,肺水肿24例、胸腔积液25例、肺动脉扩张3例、升主动脉扩张5例和冠状动脉钙化7例。左心衰CT示肺水肿、左心室扩大和胸腔积液。右心衰CT示右心室扩大、主肺动脉扩张和胸腔积液。全心衰竭CT示左右心室扩大,肺水肿和双侧胸腔积液。结论:CT可显示心脏各房室扩大、大动脉扩张、肺水肿、胸腔和心包积液以及冠状动脉钙化,为诊断原发心脏疾病及慢性心力衰竭提供重要依据。     

多层螺旋CT血管成像在肝静脉解剖中的应用研究

目的 探讨16层螺旋CT显示肝静脉的价值,优化扫描延迟时间和各种后处理技术,并分析国人肝静脉的解剖构成比.资料与方法 选取30例患者,分别于注射对比剂后50 s.60 s.70 s、80 s.90 s行肝区扫描,测量肝右或肝中静脉主干与肝实质的CT值,采用重复设计资料的方差分析得到肝静脉的最佳延迟时间;将重组原始图像进行最大密度投影(MIP)、容积再现(VR)和表面遮蔽显示(SSD)后处理,记录各种重组方法对肝静脉的显示级别,采用K related Friedman秩和检验得到最佳的后处理方法.以Nakamura和Marcos的解剖分类为标准,分析75例患者的解剖构成情况.结果 延迟70 s和VR为肝静脉的最佳延迟时间和后处理方法.国人肝静脉解剖以Nakamura Ⅰ型和Marcos Ⅰ型为主.结论 多层螺旋CT可清晰、准确地显示肝静脉,为临床提供了一种无创性的检查方法.     

寰枢关节旋转运动CT扫描的临床意义

目的了解不同旋转状态下CT扫描寰枢关节的影像学变化,探讨CT对寰枢关节旋转固定的诊断价值。方法分别对正常组30例、寰枢关节旋转固定患者组16例、新鲜尸体标本组5例行头部功能位CT扫描,测量并比较各组的寰齿前间隙、寰齿侧间隙及寰枢椎相对旋转角的变化。结合标本解剖观察寰枢关节不同旋转状态在SSD法重建图像上的表现。结果不同旋转状态下CT扫描寰枢关节的影像表现变化较大。旋转前后正常组与寰枢关节旋转固定患者组相比:寰齿前间隙及寰枢关节相对旋转范围变化差异有显著性(P<0·01),寰齿侧间隙的变化差异无显著性(P>0·05),寰枢关节不同旋转状态下在SSD法重建图像上表现与标本解剖观察基本一致。结论静态CT扫描不能准确诊断Ⅰ型寰枢关节旋转固定,功能位CT扫描能够准确诊断寰枢关节旋转固定。     

MSCT支气管动脉三维成像对中心型肺癌的血供研究

目的：探讨多层螺旋CT(MSCT)三维支气管动脉成像在中心型肺癌中的影像学表现．为显示中心型肺癌的血供来源及介入治疗提供理论依据。方法：对18例中心型肺癌的患者行MSCT造影增强检查，采用实时螺旋薄层CT扫描，在独立工作站行支气管动脉三维重建，使用不同的旋转轴观察支气管动脉的空间解剖细节。结果：其中6例(33．33％)中心型肺癌的支气管动脉三维图像能够清晰显示出支气管动脉的起源、走行的路径(肺内段和纵隔段)和血管直径等。有肺动脉明显狭窄截断的病例支气管动脉显示率最高，且明显增粗，表明此类肺癌的血供来源主要以支气管动脉为主。三维成像中以容积再现(VR)技术显示最佳。结论：MscT三维支气管动脉成像能够准确、直观地显示支气管动脉的空间解剖特点，为中心型肺癌的血供研究及介入治疗提供理论基础。