CT and MRI diagnosis]

This section surveys the clinical usefulness of spiral-computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of thrombotic arteriovenous diseases. Spiral CT is useful to detect arterial occlusive disease by using 3D rendering, so call, "CT angiography (CTA)". 3D rendering techniques have been predominantly applied to CTA are the shaded surface display (SSD) and the maximum intensity projection (MIP). These renderings have the lacks that in an MIP no depth cues are inherent and SSD lose the majority of the scan data. The volume rendering (VR) makes up for this loss by rendering what is effectively a binary image of pixel values above the threshold. As the application of MRI in the evaluation of vascular diseases, MR angiography using time-of-flight or phase contrast techniques was performed in the past. However, according to the progress in high speed imaging method, contrast-enhanced 3D MR angiography is now used routinely and will be still more important in the diagnosis of various vascular diseases.     

Potential role of three-dimensional rotational angiography and C-arm CT for valvular repair and implantation

Imaging modalities utilized in the interventional cardiology suite have seen an impressive evolution and expansion recently, particularly with regard to the recent interest in three-dimensional (3D) imaging. Despite this, the backbone of visualization in the catheterization laboratory remains two-dimensional (2D) X-ray fluoroscopy and cine-angiography. New imaging techniques under development, referred to as three-dimensional rotational angiography (RA) and C-arm CT, hold great promise for improving current device implantation and understanding of cardiovascular anatomy. This paper reviews the evolution of rotational angiography and advanced 3D X-ray imaging applications to interventional cardiology.     

64层螺旋CT在脑动脉造影中的应用

目的探讨64层CT在脑动脉三维成像(3DCTA)中的应用价值。方法对24例临床疑有颅内动脉瘤患者进行3DCTA检查,后处理技术包括最大信号强度投影(MIP)以及容积重建(VRT)。结果发现19例22个动脉瘤,3例动静脉畸形,2例阴性,均经手术或DSA证实。结论64层CT 3DCTA可显示脑动脉全貌,提高了对脑动脉病变的检出率。     

计算机辅助三维CT重建椎动脉横突段的走行及解剖变异

背景:目前不同影像学方法对椎动脉的检查仍然存在差异和争论,计算机断层扫描血管造影技术的发展,为血管及骨关节结构的解剖观察及疾病诊断提供了新的手段。目的:评价三维CT血管造影显示椎动脉横突段的效果,明确其走行及变异。方法:从2009-12-01/2010-05-31头颈部联合CT血管造影检查的三维影像资料中,去除椎动脉不显影或显影不清楚的资料,选出无明显异常病变者250例,在三维图像上观察椎动脉在横突段的走行及血管管径的变异。获得原始断层图像后,通过容积重建、多层面重建、表面遮盖成像来显示椎动脉。结果与结论:椎动脉经C6横突孔进入占所有样本的92.6%,经异常横突孔进入占所有样本的7.4%(37条),经C4,C5,C7横突孔进入的发生率分别为2.2%(n=11,占不正常的29.7%),4.6%(n=23,占不正常的62.2%),0.6%(n=3,占不正常的8.1%)。20例为右侧异常(54.1%),17例为左侧异常(45.9%)。所有患者中27例为单侧异常(10.8%),5例为双侧异常(2%)。比较椎动脉管腔直径,左侧直径明显大于右侧53例,右侧直径明显大于左侧30例,左右侧差异具有显著性意义(P<0.01)。提示椎动脉在横突段的解剖变异发生率较高,三维CT血管造影能客观地反映椎动脉的病理改变,并清晰显示椎动脉与骨性结构的关系。     

64层CT造影断层图像虚拟技术和CT仿真结肠镜的临床应用

背景:虚拟内窥镜能够充分显示结肠的解剖形态以及病变部位,并从狭窄、梗阻处两端观察肠腔的解剖和病变。结合三维图像还可了解肠壁以及腔外的情况,更有利于肿瘤的定性以及分期诊断。目的:探讨64层CT造影断层图像虚拟技术和64层螺旋CT三维成像与仿真内镜在结肠肿瘤诊断中的应用价值。方法:应用Philips/Brilliance 64 CT对10例术后病理标本证实的结肠癌(8例)和结肠息肉(2例)进行容积扫描。Mimics软件用Marching Cubes算法对肠管进行面绘制及用虚拟内镜法重建三维图像及基于CT造影二维图像对大肠及周围结构等各种组织进行三维重建,并与Brilliance workspace工作站三维成像和仿真内镜结果相比较。结果与结论:10例三维成像效果良好,虚拟内镜与CT仿真内镜显示基本一致。虚拟结肠镜结合多结构数字模型重建可以提供更多信息,有助于病变的准确定位,能准确反映其复杂的解剖结构及空间毗邻关系。说明64层CT造影断层图像虚拟技术能达到与CT仿真内镜结合三维成像同样的敏感性和特异性,加上各种组织三维重建技术可以提供较仿真内镜更丰富的信息。     

Contrast-enhanced CT and MR imaging of renal vessels

In the evaluation of renal vessels, the accepted diagnostic gold standard digital subtraction angiography is now being challenged by state of the art CT and MR imaging. Currently in many centers, cross-sectional imaging modalities are being used as a first line diagnostic tool to evaluate arterial and venous system of the kidneys and conventional angiography has been reserved only for therapeutic intervention. CT and MR imaging display not only the lumen of the vessel as in conventional angiography, but also allow the visualization of the vessel wall, renal parenchyma, collecting system, and other adjacent soft tissue structures. Therefore, CT and MRI have each become a one-stop shop for a thorough evaluation of kidneys. In this pictorial essay, we reviewed normal anatomical variants and wide range of pathologies involving renal arteries and veins with illustrated contrast-enhanced CT and MR imaging samples.     

利用CT三维软件实现MRA图像后处理

目的：探讨如何利用螺旋CT三维成像软件进行磁共敌国管成像（MRA）后处理,材料与方法：以颅底动脉环3D-TDFMRA图像后处理为例,将图像数据经PACS工作站传输至CT机,利用其3D图像处理软件包实施图像后处理。结果：18例中,利用最大密度投影（MIP）结合仿真内窥镜（MRVE）与表面遮盖法（SSD）等后处理,共发现病变12个,其中动脉瘤5例,大脑中动脉狭窄或闭塞3例,脑血管畸形3例。烟雾病1例。结论：我们用螺旋CT的三维成像软件成功的进行了MRA的图像后处理（SSD和MRVE）,丰富了图像处理手段,提高了病变检出率,且无需增加投入,方法简捷,经济,值得推广。     

Crohn disease of small bowel: multidetector row CT with CT enteroclysis, dynamic contrast enhancement, CT angiography, and 3D imaging

Background CT could be used to evaluate abnormalities in the bowel wall, mesentery, adjacent structures, vasculature, and even the activity of Crohn disease (CD). To our knowledge, few direct comparisons of CD characterization using multidetector row CT with dynamic contrast enhancement, 3D imaging, CT angiography (CTA), and CT-enteroclysis (CT-E) on the same cohort of patients. The purpose of this study was to evaluate the diagnostic value of CD using multidetector helical CT with CT-E, dynamic contrast enhancement, 3D imaging, and CTA. Methods Twenty-eight patients known or suspected CD underwent CT-E, dynamic contract enhancement, CTA, and 3D imaging. The multidetector CT series images were performed on eight-slice CT scanner. All the examinations were performed when water was used as an oral contrast starting 25 s after 140 mL of intravenous contrast agent was administered, followed by portal venous phase (60 s), and a 60–70 s delay, then sending 1.25-mm slices to the 3D workstation, CT angiograms and 3D images were reconstructed. All the images were reviewed to detect abnormalities of CD. The abnormalities of the bowel wall, mucosal and submucosal ulceration, prominent perienteric vasculature, sinus tracts or fistulae, abscess were evaluated. Results Crohn disease was diagnosed in 28 patients by CT images, and 54 inflammatory segments were revealed. In active inflammatory cases, the diseased bowel wall thickened and the enhancement of diseased bowel wall increased significantly in 34 inflammatory segments of 22 cases, the enhancement of diseased bowel wall increased significantly but without the wall thickened in three patients. Prominent vasculature was found in CTA and 3D images in 21 patients with active diseases. In 16 patients, the sharp interface between bowel and mesentery was lost and the attenuation of fat increased. Sinus tracts or fistulae were observed in eight patients, four of 28 patients demonstrated abscesses, all were active inflammatory patients. In three chronic inflammatory patients, normal bowel, bowel lumen stricture, and the normal enhancement of the wall were displayed. Conclusion The abnormalities of CD and its complications can be identified by multidetector CT with CT-E, dynamic enhancement, CTA, and 3D imaging, and they are important methods in diagnosing CD. Complications of CD can be shown better when CT-E is performed.     

State of the Art Hybrid Technology: PET/CT

In the recent years, hybrid positron emission tomography (PET)/computed tomography (CT) scanners have been increasingly utilized in cardiac applications. PET imaging quality has been improved by the use of new scintillators, small detector element size, and fully 3D iterative reconstruction techniques with time-of-flight information and resolution recovery. Further quality enhancements for cardiac imaging can be obtained by tracking and correcting for cardiac and breathing motion with respiratory gating devices and advanced software techniques. The primary tracers used for PET/CT cardiac imaging are Rubidium-82 (⁸²Rb) and Nitrogen-13-ammonia (¹³N-ammonia) and 18-F fluorodeoxyglucose used for myocardial viability imaging. A new F-18 perfusion tracer (F-18 Flurpiridaz) is being evaluated. High-resolution multi-slice CT component of the hybrid scanner allows accurate attenuation correction for PET, measurement of CT calcium, and contrast CT angiography. Hybrid PET/CT protocols have demonstrated increased diagnostic accuracy for the detection of obstructive disease compared with standalone techniques. Radiation dose to the patient is a concern in hybrid imaging because multiple scans are performed in one scanning session. 3D PET acquisition combined with the new low-dose CT protocols can reduce the doses significantly. Hybrid PET/CT scanners have also been utilized for anatomically-guided molecular imaging of plaque biology in the carotid vessels, aorta, and coronary vessels. This review summarizes the state-of-the-art hybrid imaging PET/CT instrumentation and advances in the image quality related to cardiac imaging.     

64层CT造影断层图像虚拟技术和CT仿真结肠镜的临床应用

背景：虚拟内窥镜能够充分显示结肠的解剖形态以及病变部位,并从狭窄、梗阻处两端观察肠腔的解剖和病变。结合三维图像还可了解肠壁以及腔外的情况,更有利于肿瘤的定性以及分期诊断。目的：探讨64层CT造影断层图像虚拟技术和64层螺旋CT三维成像与仿真内镜在结肠肿瘤诊断中的应用价值。方法：应用Philips/Brilliance 64 CT对10例术后病理标本证实的结肠癌（8例）和结肠息肉（2例）进行容积扫描。Mimics软件用Marching Cubes算法对肠管进行面绘制及用虚拟内镜法重建三维图像及基于CT造影二维图像对大肠及周围结构等各种组织进行三维重建,并与Brilliance workspace工作站三维成像和仿真内镜结果相比较。结果与结论：10例三维成像效果良好,虚拟内镜与CT仿真内镜显示基本一致。虚拟结肠镜结合多结构数字模型重建可以提供更多信息,有助于病变的准确定位,能准确反映其复杂的解剖结构及空间毗邻关系。说明64层CT造影断层图像虚拟技术能达到与CT仿真内镜结合三维成像同样的敏感性和特异性,加上各种组织三维重建技术可以提供较仿真内镜更丰富的信息。     

CT和MRI诊断颈动脉及其周围间隙孤立性病变

目的 探讨CT和MRI对颈动脉及其周围间隙孤立性病变的定位、定性诊断价值。 方法 收集65例经病理证实的颈动脉及其周围间隙孤立性病变患者,对38例行CT检查,其中29例行3D VR血管重建;对27例行MR检查,其中16例行三维对比增强MRA(3D CE-MRA)检查。分析病变的大小、形态、边界、密度、信号、内部结构、强化特征及其与颈动静脉的关系。 结果 神经鞘瘤、神经纤维瘤、颈动脉体瘤、颈内动脉瘤、淋巴结转移瘤、巨淋巴结增生症、腮裂囊肿及腮裂囊肿合并感染的CT或MRI表现具有一定特征性;血管瘤、淋巴瘤、淋巴结结核、结节病及支气管囊肿罕见,影像学表现缺乏特征性。神经鞘瘤和神经纤维瘤使颈动静脉向外或前外侧移位。淋巴结病变使颈动静脉向内或前内侧移位。颈动脉体瘤和颈内动脉瘤使颈动脉分叉角度增大,但颈内动脉瘤使受累血管呈瘤样增粗,CTA或MRA可直接定性诊断。 结论 CT和MRI分别结合3D VR血管成像和3D CE-MRA是定位诊断颈动脉及其周围间隙孤立性病变的有效手段,根据平扫和增强特征及其与颈动静脉的关系,可对大部分孤立性病变做出定性及鉴别诊断。     

3D CT of renal pathology: initial experience with cinematic rendering

3D computed tomography (CT) visualizations of volumetric data have become an important aspect of diagnostic imaging. The utility of 3D CT has been well described for the imaging of a number of renal pathologies. Recently, a new 3D visualization technique known as cinematic rendering (CR) has become available and provides photorealistic images derived from standard CT acquisitions by use of a complex global lighting model. Herein, we describe a number of normal variant and pathologic conditions of the kidney visualized with CR. We provide comparisons of findings with CR to traditional methods of 3D imaging and comment on the potential applications of this new method of 3D CT rendering.

     

螺旋CT血管造影在主动脉病变诊断中的临床价值

目的：探讨螺旋CT血管造影（SCTA）在主动脉病变诊断中的临床应用及其价值。方法：对25例主动脉病变患者进行兴趣区域的螺旋CT增强扫描，用表面覆盖法（SSD）、最大密度投影法（MIP）、多平面重组法（MPR）对获得的容积数据进行重建。分析所有3D和轴向影像表现。结果：SSD能较好地显示主动脉病变的全貌，显示病变的范围，大小及分支血管受累情况：MIP可清楚显示血管管壁钙化和动脉瘤内腔的形态；MPR可以对病变进行任意角度重建和观察，清楚地显示附壁血栓、真假腔、破口、钙化和内膜瓣。结论：应用SCTA的各种成像技术，能够较全面直观地显示主动脉病变，为主动脉病变提供一种安全可靠的诊断手段。在较大血管疾病的诊断上，有望取代X线血管造影检查。     

CT 和MR三维血管成像技术对于TIPSS的价值

目的 探讨CT血管造影及MR血管造影对门脉高压患者TIPSS治疗的价值。方法 TIPSS术前10例患者进行了三维MR血管造影，2例用MR团注技术测量门脉血流速度。60例进行了三维CT血管造影。所有病例经临床和DSA证实为肝硬化门脉高压，其中，68例行TIPSS治疗。MR血管造影使用西门子1．5T MR机，CT血管造影使用GE High Speed CT／i扫描机。结果 MR血管造影：10例患者均可见门静脉主干及其肝内分支扩张，但其中2例有布加综合征的表现。3例患者可见侧支循环及静脉曲张，表现为胃左静脉丛和左肾静脉曲张、脾肾分流。应用MR“团块追踪”技术测量了2例门脉主干的血流速度，分别为11．8cm／s和10．6cm/s。CT血管造影：准确地显示了60例患者的肝动静脉解剖、门脉主干扩张及其小血管分支，以及19例侧支循环及曲张血管。结论 CT血管造影和MR血管造影是一种无创性的检查方法，可充分显示肝静脉和门静脉解剖及变异，为TIPSS术前提供了重要信息。CT血管造影的空间分辨率优于MR血管造影。     

16排螺旋CT脑血管造影(CTA)的临床应用

目的 探讨16排螺旋CT在颅内血管造影(CTA)的临床价值。方法 利用16排螺旋CT作脑血管增强扫描，获得原始横断面图像，采用VR、SSD和MIP技术重建三维脑血管图像。本组29例，包括正常15例，异常14例，其中Willis环发育异常8例，动脉狭窄6例，血管闭塞2例．动脉瘤3例，AVMl例。结果 16排螺旋CT颅内血管成像清楚显示颅内血管，能显示异常血管的类型、位置、形成、大小。结论 16排螺旋CT的CTA是一种显示内血管病变有价值的检查方法，它较普通螺旋CT更快捷、更安全，对临床治疗方案有指导作用。     

多层螺旋CT血管成像对冠状动脉畸形的诊断价值

目的探讨多层螺旋CT冠状动脉成像在分析诊断先天性冠状动脉畸形中的价值。方法回顾性分析2051例行多层螺旋CT冠状动脉成像影像资料,统计冠状动脉畸形的发生率,并分析冠状动脉畸形的CT影像表现。结果2051例行多层螺旋CT冠状动脉成像的人群中,发现冠状动脉畸形57例,检出率为2.8%,其中51例为冠状动脉起源和走行异常,3例为冠状动脉瘤,3例为冠状动脉瘘。结论多层螺旋CT成像在冠状动脉畸形的诊断和预后判断中有应用价值。     

16层与64层螺旋CT冠状动脉成像质量的同比研究

目的比较16层螺旋CT与64层螺旋CT冠状动脉成像质量。方法回顾性收集2003年5月至2006年6月于我院先后行16层及64层螺旋CT冠状动脉成像的28例患者的影像资料,评价每位患者16层及64层螺旋CT冠脉成像的影像质量,使用配对样本t检验了解该组患者的16层CT与64层CT冠状动脉成像质量间的差异。结果64层螺旋CT冠状动脉成像各主要分支的影像质量明显优于16层螺旋CT(P<0.001)。结论64层螺旋CT冠状动脉成像质量优于16层螺旋CT。     

烟雾病的螺旋ct诊断

目的:探讨CT平扫、增强扫描及脑血管造影对烟雾病的诊断价值.材料与方法:5例病人均行CT平扫,2例增强扫描.3例行CT脑血管造影检查.回顾性分析烟雾病的CT影像学特征.结果:CT检查平扫:右额顶叶脑实质出血1例,蛛网膜下腔出血2例,脑梗塞2例.2例CT增强扫描:脑底动脉环显影不良,基底节大脑半球增粗迂曲血管影.3例CT脑血管造影:双侧颈内动脉前床突上段动脉闭塞1例,双侧大脑前中动脉多发闭塞2例,脑底烟雾状异常血管网及大量的侧枝循环形成3例.结论:烟雾病患者行头颅CT检查主要显示脑实质的病变,头颅增强CT仅能显示部分血管病变,对典型病例可作出诊断,对轻度病变的诊断尚有一定度难度.多排CT脑血管造影不仅能够清晰显示颈内动脉内段基底动脉环各血管闭塞、狭窄的部位、形态、管壁状况及狭窄程度,还能清晰显示增多迂曲的脑底部的异常血管网,可作为烟雾病的首选检查方法.     

螺旋CT血管造影及最大信号强度投影重建技术在颅内动脉瘤诊断中的应用价值

目的在于探讨ＣＴ血管造影及最大信号强度投影重建技术检查颅内动脉瘤的准确性以及ＳＣＴＡ取代常规血管造影的可能性。方法２５例临床疑诊颅内动脉瘤的病人中２３例接受了ＳＣＴＡ和常规血管造影。２例单独经ＳＣＴＡ诊断后直接手术治疗。结果２５例动脉瘤中,ＳＣＴＡ准确检出了２３例另２例小于３ｍｍ的动脉瘤未被ＳＣＴＡ检查发现。与传统血管造影相对照,ＳＣＴＡ的诊断准确率为９２％。对于检测血栓性动脉瘤ＳＣＴＡ优于传统血管造影。结论本组研究表明ＳＣＴＡ结合ＭＩＰ图像重建技术能较准确地诊断３ｍｍ以上的颅内动脉瘤,并判断其大小,形态,瘤颈以及瘤内血栓的存在。     

肝动脉供血原发性肝癌320排CT血管成像的低剂量研究

目的探讨320排CT低剂量血管成像在肝癌供血动脉评价中的辐射剂量及对图像质量的影响。方法将87例拟行介入治疗的肝癌患者随机分为两组,术前均以动态容积模式进行320排CT动态增强间隔时间扫描,其中研究组43例的扫描参数采用管电压100 kV,管电流75 mA,对比剂流率5 ml/s,总量50 ml,而对照组40例采用管电压120 kV,管电流100 mA,对比剂速率6 ml/s,总量70 ml;选取最佳纯肝动脉期图像进行三维重建,利用4 D-DSA成像软件测量并比较两组间的肝动脉的强化峰时间和CT值;以DSA为参照,评估两组间肝癌3、4级肝动脉供血支图像质量的优良率和可诊断率,同时比较两组间的辐射剂量。结果研究组的肝动脉达峰值和达峰绝对值均低于对照组（P〈0.05）,而肝动脉达峰时间和肝动脉平扫CT值与对照组比较均无明显差异（P〉0.05）;研究组对3、4级肝动脉图像质量评价的可诊断率为97.1%、优良率89.3%,与对照组比较均无明显差异（P〉0.05）;研究组的有效辐射剂量为（15.07±2.58）m Sv,明显低于对照组（P〈0.05）。结论 320排CT低剂量的三维肝动脉成像,不仅图像质量能达到诊断和评价肝癌供血动脉的要求,而且能明显降低患者的辐射剂量。