CT三维成像与传统钡餐诊断胃癌的比较研究

目的研究螺旋CT三维成像(3D CT)包括仿真胃镜(CTVG)、表面遮盖法(SSD)和透明法(Raysum)在胃癌诊断中的价值,并与上消化道钡餐(UGI)比较.方法 43例胃癌患者(37例进展期胃癌、6例早期胃癌)均经手术病理证实,2位阅片者盲法阅片,对这43例患者4种成像方法(CTVG、SSD 、Raysum、UGI)的172套图像分别进行如下4方面的评价图像质量、伪影情况、病变的诊断可信度、Borrmann分型.根据手术和病理结果计算各种方法检出病变的敏感度和对进展期胃癌Borrmann分型的敏感度,将3D CT的结果分别与UGI结果进行比较.结果 2位阅片者在CTVG、SSD、Raysum、UGI上的检出病灶敏感度分别为98%、67%、60%、84%与98%、70%、70%、88%,进展期胃癌Borrmann分型的敏感度分别为76%、49%与38%、49%与78%、51%、35%、43%.2位阅片者均认为CTVG、SSD、Raysum的图像质量与UGI类似(P>0.05),CTVG和UGI在检出进展期胃癌(诊断可信度≥3)的敏感度方面差异无显著意义(χ2值为0.50与0.25,P>0.05),而SSD、Raysum检出病灶的敏感度均低于UGI(P<0.05,χ2值为4.17、7.11与5.14、4.17).2位阅片者均认为CTVG对胃癌Borrmann分型的敏感度高于UGI(χ2值为4.90与4.92,P<0.05), 而SSD、Raysum的分型敏感度与UGI间则差异无显著意义(P值均>0.05).CTVG检出早期胃癌的敏感度高于UGI,但差异无显著意义(χ2=2.25,P>0.05).影响诊断的严重伪影(占6.1%)来源于多量潴留液及患者的呼吸运动.结论 CTVG在进展期胃癌的检出上与UGI相仿,对进展期胃癌的分型优于UGI,并有发现早期癌的潜能.SSD、Raysum单独应用,对胃癌的临床诊断价值有限.     

Small bowel: preliminary comparison of capsule endoscopy with barium study and CT

PURPOSE: To retrospectively compare capsule endoscopic (CE) findings with findings at barium studies or computed tomography (CT) in patients without evidence of small-bowel stricture at barium examination. MATERIALS AND METHODS: Fifty-two patients underwent CE, and the majority (43 of 52) did so for obscure gastrointestinal bleeding. Forty-two (81%) of 52 patients underwent 36 small-bowel follow-through examinations; four, enteroclysis; and 19, contrast material-enhanced CT of the abdomen and pelvis within 6 months of CE (either before or after CE). Imaging results were retrospectively reviewed and compared with CE, standard endoscopic, and surgical results. Findings of any examinations between CE and imaging that were discrepant were retrospectively reviewed by a radiologist not blinded to CE results. Proportion of positive findings at CE was compared with proportion of positive findings at barium studies and CT in the same patients. Statistical significance was calculated with McNemar chi2 statistic. RESULTS: Barium examination findings were positive in one (3%) of 40 patients; CE findings were positive in 22 (55%) (P <.001). CT demonstrated small-bowel findings in four (21%) of 19 patients, but CE demonstrated findings in 12 (63%) of 19 patients (P =.02). The most common CE finding, angioectasia (n = 11), was not detected at any imaging study. More ulcers (n = 8) were detected with CE than with barium study (one of eight) and CT (three of six). At CE, three of five surgically confirmed masses (carcinoid, intussusception, lymphangioma) were identified, but two jejunal tumors were not detected in a patient with poor bowel preparation. At barium study, no masses (zero of five) were detected; at CT, one of four masses was detected. CONCLUSION: In patients without a small-bowel stricture at barium study, more small-bowel disease was found at CE when findings were retrospectively compared with barium examination and CT findings.     

Non-neoplastic tracheal lesions: comparison between virtual CT endoscopy and fiberoptic bronchoscopy

PURPOSE: To compare virtual endoscopy of the upper airways with fiberoptic bronchoscopic examination in patients affected by non-neoplastic inflammatory disease of the trachea. MATERIALS AND METHODS: Twelve patients with non-neoplastic tracheal stenosis or with tracheo-oesophageal fistula underwent a fiberoptic endoscopy and a spiral CT examination with the following protocol: collimation/table feed/reconstruction increment 3 mm/6 mm/1 mm from the larynx to the carenabronchial septum. Images were sent to a dedicated workstation equipped with a software allowing generation of 3D reconstructions and virtual endoscopic images. Lesion features were compared in the two examinations. RESULTS: In all cases the lesions features visualized with virtual display modality were confirmed by conventional endoscopy. Measurements were easily made on the 3D MPR images while conventional endoscopy allowed only a qualitative assessment of the lesion. In no cases did virtual endoscopy provide information on the mucosa appearance. Swallowing and breathing never caused significant artifacts during the 3D post processing. CONCLUSION: Virtual bronchoscopy is a useful technique for preoperative evaluation and for the follow-up of patients with non-neoplastic inflammatory disease of the upper airways.     

Evaluation of tracheobronchial lesions with spiral CT: comparison between virtual endoscopy and bronchoscopy]

INTRODUCTION: The aim of this study is to describe the scanning parameters for virtual bronchoscopy in the evaluation of the tracheobronchial tree and to compare the results of this examination with the endoscopic findings. MATERIAL AND METHODS: 27 patients with tracheobronchial neoplasms suspected at preliminary clinical and chest film findings or postoperative follow-up for malignant disease were evaluated with spiral CT of the chest and bronchoscopy. Virtual endoscopy was performed on the pulmonary volume involved by the lesion, using narrow axial images (thickness 2 mm, table index 3 mm, reconstruction index 1 mm.) so as to obtain MPR, MIP and 3D reconstructions with 3D Endo Vew program (Philips Medical System, Eindhoven, Holland). We compared these reconstructions and the findings the normal spiral CT scanning with the corresponding endoscopic examinations. RESULTS: In all patients we were able to study the lobar and segmental bronchi in all patients and in 2 we also evaluated the subsegmental bronchi. 25 lesions in 23 patients were shown by virtual endoscopy (8 occlusions, 8 stenosis, 5 compressions, 3 flogosis with endobronchial mucus, 1 bronchocele) and in 4 patients the examinations were negative. The bronchoscopy was negative in 4 patients and positive in 23 patients with 25 lesions, but we had agreement in 23/27 patients (85,1%). In 2 patients virtual endoscopy showed the lesions in a different bronchus compared to bronchoscopy. In one patient we interpreted the obstruction as neoplastic instead of mucus inside the bronchi and in the last patient bronchoscopy was not performed due to his old age and the virtual endoscopy showed total obstruction of a segmental bronchus. DISCUSSION AND CONCLUSIONS: The results show that virtual endoscopy can study the tracheobronchial tree as far as the segmental bronchi, and sometimes also the subsegmental bronchi and the bronchi below a closed obstruction. In addition, it can evaluate the extraluminal location of the lesions. For these reasons virtual endoscopy provides a road map for bronchoscopy as a guide for transbronchial biopsy and for endobronchial treatment planning. The limitation of this technique is its inability to evaluate the mucosal surface and distinguish flogosis from neoplastic lesions by biopsy. It can be used however in the postoperative follow-up both for cancer and transplant, when immediate biopsy is not necessary.     

仿真胃镜与钡餐比较评价胃部溃疡性病灶:ROC曲线分析

目的：与上消化道钡餐(UGl)比较研究CT仿真胃镜(CTVG)对胃部溃疡性病变诊断的价值。方法：经胃镜证实为溃疡性病变的患者39例，手术病理证实29例为胃癌，10例为良性溃疡。所有患者均在3天内行螺旋CT及UGI检查，两位阅片者对所有的CTVG及UGI图像进行主观性盲法阅片。图像质量的评价分3级，检出的可信度、良恶性溃疡的鉴别及恶性溃疡分型的鉴别评价分5级，后两项采用ROC曲线进行分析。结果：两位阅片者均认为对于图像质量、病灶检出率、溃疡病灶的良恶性鉴别，CTVG与UGI类似(P＞0.05)；对于溃疡型胃癌分型的准确性，CTVG明显优于钡餐(P＜0．05)。结论：CTVG对溃疡型胃癌分型的判断优于UGI，但对溃疡病灶的良恶性鉴别，CTVG与UGI无明显差异；胃部螺旋CT扫描是一种简便、有效的检查方法，值得进一步研究。     

CT仿真内窥镜对鼻腔结构与病变显示能力的研究

目的通过与纤维内窥镜比较，评价ＣＴ仿真内窥镜的显示能力和临床应用价值。方法 将１１例病人（２２个鼻腔）的轴位螺旋ＣＴ资料进行计算机工作站Ｅｘｐｌｏｒｅｒ软件处理，制作成仿真内窥镜影像并观察分析，其中９例（１８个鼻腔）进行了纤维内窥镜检查。结果 ＣＴ仿真内窥镜能清楚地显示鼻腔内解剖结构，鼻中隔弯曲，鼻道狭窄和阻塞，鼻甲肥大和直径〉３ｍｍ的肿块，但可出现“假性粘连”，不能评价粘膜状况及帮助组织学诊断。     

早期胃癌气-钡双对比造影检查与胃镜对照分析

目的:对于早期胃癌的检查,通过气钡双对比造影图像与胃镜检查图像对照观察,分析气钡双对比造影在检出早期胃癌中的价值。方法:42例经病理证实早期胃癌病例,采用低张气钡双对比造影方法,辅以充盈法、黏膜法及加压法观察胃壁改变,并实时点片。常规胃镜检查。结果:Ⅰ型6例,Ⅱa型4例,Ⅱb型2例,Ⅱc型11例,Ⅲ型4例,混合型15例。结论:气钡双对比钡餐检查能够较好显示早期胃癌病变。     

Subtraction CT angiography for evaluation of intracranial aneurysms: comparison with conventional CT angiography

The purpose of our study was to compare the diagnostic performance of subtraction computed tomography angiography (CTA) with conventional nonsubtracted CTA and digital subtraction angiography (DSA) for the detection of intracranial aneurysms. A total of 76 patients underwent both subtraction CTA and conventional CTA for the detection and therapy planning of suspected intracranial aneurysms. Subtraction and conventional CTA images were independently assessed by two readers in a blinded manner. The possibility of endovascular treatment or surgical clipping was also assessed based on information provided by CT angiograms alone. In 64 patients, 75 aneurysms were present on DSA. On a per-aneurysm basis, the sensitivity of subtraction CTA was 98.6% for reader 1, and 100% for reader 2. However, sensitivity of conventional CTA was 94.6% for reader 1, and 93.3% for reader 2. Therapeutic decisions could be made regarding 63 patients based on information provided by subtraction CTA images. However, conventional CTA provided sufficient information to make this decision for 55 patients. Conventional CTA has limited sensitivity in detecting very small aneurysms as well as aneurysms adjacent to bone. Subtraction CTA performed on a 64-row multidetector CT is an accurate and promising diagnostic tool that seems to be equivalent to 2D DSA for the detection and pretreatment planning of intracranial aneurysms.     

静脉膀胱造影CT仿真内窥镜的实验和临床应用研究

目的　探讨静脉膀胱造影CT仿真内窥镜 (CTVE)成像技术的可行性 ,并与空气CTVE成像技术比较 ,评价其临床应用价值。方法　 (1 )应用相同的扫描条件对充盈不同浓度的高密度对比剂 (将 76 %的泛影葡胺稀释成 1 / 8,1 / 1 2 ,1 / 1 6 ,1 / 32 ,1 / 4 8,1 / 64 ,1 / 1 2 8)、水、空气的直肠内模拟隆起性病变行螺旋CT容积扫描 ,经工作站软件处理获得CTVE图像 ,相互间进行比较 ;(2 )对 30例患者 ,经肘静脉注射对比剂 30min后行膀胱CT容积扫描 ,亦经软件处理获得膀胱CTVE图像 ,并与纤维膀胱镜和手术结果对照。结果　 (1 )以不同浓度高密度对比剂和空气为对比剂进行三维重建均可获得清晰的CTVE图像 ,以水作对比剂未能重建出满意的CTVE图像。 (2 )不同浓度的高密度对比剂之间及其与空气之间重建出的CTVE图像整体差异有显著性意义 (F =1 59 95 ,P <0 0 5) ,较低浓度高密度对比剂 (1 / 32～ 1 / 1 2 8)重建出的CTVE图像对直径 2～ 3mm的病灶显示较好 ;对直径 5mm及其以上的病灶各组间则差异无显著性意义。 (3)静脉膀胱造影 2 6例获得满意的CTVE图像 ,能显示输尿管内口 ,检出病灶直径最小者为 3mm。 2例CTVE图像欠佳 ,2例未重建出CTVE图像。结论高密度对比剂CTVE成像能达到空气CTVE成像同等效果 ,且一定范围内的低浓     

Real-time interactive virtual endoscopy of the tracheo-bronchial system: influence of CT imaging protocols and observer ability

OBJECTIVE: To evaluate the influence of different spiral CT examination protocols suitable for clinical use on image quality and to assess the observer dependence in interactive real-time virtual bronchoscopy. METHODS AND PATIENTS: Real-time perspective volume rendering of the airways in twenty normal patients based on four different spiral CT examination protocols was evaluated by four observers in regard to the order of depictable bronchi. RESULTS: Best results were obtained using an examination protocol with a small beam collimation and a maximum pitch. Depending on the observer's ability to control the fly path and the orientation of the bronchi with respect to the slice plane up to sixth order bronchi could be depicted. Inter-observer variability was up to two branching orders. CONCLUSION: The performance of virtual bronchoscopy strongly depends on the applied CT examination protocol and the observers experience with perspective volume rendering. Both of which have to be taken into account when virtual bronchoscopy is compared with fiberoptic bronchoscopy.     

喉部螺旋CT仿真内窥镜的临床应用

目的：评价CT仿真内窥镜成像在显示喉部疾病的应用价值。方法：22例喉部疾病患者包括15例喉癌，3例声带息肉，1例披裂炎症，1例咽喉后壁脓肿，以及2例声带固定，均经螺旋CT扫描，获自所有病例的仿真内窥镜成像均与纤维喉镜及手术所见对照分析。所有病例或细胞学证实。结果：CT仿真喉镜对正常解剖结构显示与纤维喉镜一致，显示病变范围优于纤维喉镜，CT仿真喉镜能从足端入路观察，但对较小病灶的显示不如纤维喉镜。结论：CT仿真喉镜能对喉部病变提供较全面的信息，因而它是纤维喉镜的一种很好的补充手段。     

CT仿真内镜及多平面重建在胃部疾病中的临床应用

多排螺旋CT仿真内窥镜是近几年来运用于临床的一项新技术,它一般应用于副鼻窦、喉、胃、气管、膀胱、血管。笔者对52例胃部病变患者采用螺旋CT仿真内窥镜等检查技术,取得了良好效果,现分析如下。1材料与方法本组52例患者中,男性34例,女18例,年龄39~72岁,平均年龄56岁。52例中胃炎性息肉1例,胃平滑肌瘤2例,胃良性溃肠5例,胃癌44例。其中15例行胃气钡双重造影检查,其余病例均为电子胃镜检查,46例手术切除,所有病列均由术后病理证实。使用Marconi Mx8000 4排螺旋CT。仿真内窥镜(CTVE)、多平面重建(MPR)、表面遮盖法成像(SSD)软件。患者…     

Adult ankle fractures: comparison of plain films and interactive two- and three-dimensional CT scans

Thirteen patients with 15 ankle fractures potentially requiring surgical reduction according to plain film criteria were studied with transaxial CT, from which static and animated interactive two-dimensional (2-D) images and animated volumetric three-dimensional (3-D) images were generated. CT criteria believed to parallel well-accepted plain film criteria for triage of ankle fractures were developed and applied. The tibiofibular, talofibular, and tibiotalar articulations were characterized and, where possible (nine cases), compared with the (presumably normal) contralateral ankle. Talocrural angle measurements were made on interactive coronal measurements and compared with standard plain film measurements. Fracture fragment displacement, rotation, and impaction were noted. Posterior tibial lip disruption was quantified. Information derived from the 2-D/3-D CT study led to cancellation of proposed surgery in three of the distal fibular fractures and in two distal tibial fractures. There was far less variation than anticipated between the talocrural angles of the injured and normal ankles, and both injured and normal ankles deviated significantly from the accepted standard of 84 degrees. Displacement at the level of the fibular fracture was a poor predictor of more distal disruption. Two-dimensional CT was found to provide anatomic detail and information superior to either plain film or 3-D CT; 3-D CT was preferred by the surgeons for final surgical planning and for integration of the 2-D data. CT altered management in five of the 13 patients studied, supporting our belief that 2-D/3-D CT can be of significant value in assessing ankle fractures.     

螺旋CT仿真内窥镜与纤维内窥镜诊断膀胱癌的临床对比研究

膀胱癌发病率较高,早期无明显临床症状,如何正确诊断越来越被人们重视.螺旋CT仿真内窥镜(CTVE)技术自1993年ving等[1]首次报道以来,国内外有不少学者对此技术进行实验和临床应用研究[2-4],但使用膀胱充气螺旋CT仿真内窥镜对膀胱癌的临床应用相关研究报道较少.     

CT仿真内窥镜技术的模型研究

目的　系统分析主要扫描参数对CT仿真内窥镜 (CTVE)图像质量的影响 ,寻找可获得较好图像质量的扫描参数组合。评价CTVE对不同大小、形态的模拟病变的分辨能力 ,进一步确定图像的真实性。方法　应用不同扫描参数分别对不同组别模拟病变的模型进行扫描 ,观察图像质量及模拟病变的分辨情况。结果　准直器宽度、螺距、重叠重建率及重建方式的变化均会不同程度地影响CTVE图像质量。在准直器宽度≤ 3mm、螺距 1.0～ 2 .0、重叠重建率 6 0 %、标准 (STD)重建方式的参数范围内可获得较满意的图像质量 ,并具有可分辨微小结构及较真实显示结构形态的能力。结论　适当选择扫描参数、有效分辨伪影及变形 ,CTVE技术将成为显示空腔脏器病变及结构的有效方法之一。     

CT evaluation of blunt abdominal trauma in children: comparison of ultrafast and conventional CT

Previous reports describing the use of ultrafast CT have emphasized its value in evaluating the heart, chest, and airway. We describe our experience using this technology on children with blunt abdominal trauma. We retrospectively reviewed 54 consecutive ultrafast CT studies and 30 consecutive conventional dynamic CT studies performed on children after blunt abdominal trauma. Thirty percent of the scans showed abnormalities. CT or pathologic follow-up was available for all abnormal cases. We compared scans made with these two techniques for diagnostic accuracy, amount of visible motion on each slice, and contrast enhancement seen on each study. A protocol of 0.4-sec images and 2 ml/kg IV contrast material administered before scanning was used for the ultrafast CT scans. A standard protocol of 2-sec scanning and 3 ml/kg IV contrast material was used for conventional CT studies. There was no difference in diagnostic accuracy between the two techniques. There was significantly less visible motion (p less than .0001) and significantly better contrast enhancement (p less than .0001) seen on the ultrafast CT studies. Two of 54 ultrafast scans had images with sufficient motion to require repeated scanning, compared with 13 of 30 conventional CT studies. In addition, ultrafast scans required less sedation, decreased radiation dose, and improved accessibility of the patient to support personnel. Ultrafast CT is a valuable technique for abdominal imaging, offering equal diagnostic accuracy with improved image quality and important benefits to the patient.     

Multidimensional interactive display of CT and MRI data

This paper presents a technique for the multiplanar display and manipulation of standard CT and MRI data. Using this interactive tool one can display axial, coronal, and sagittal plane from standard CT or MRI data sets, as well as selecting arbitrary oblique planes. This system uses a bi-cubic interpolation technique to produce high quality reformatted images. The tool allows interactive roaming of the CT or MRI data volume and facilitates communication between the radiologist and the referring physician.     

Three-dimensional display modes for CT colonography: conventional 3D virtual colonoscopy versus unfolded cube projection

The authors compared a conventional two-directional three-dimensional (3D) display for computed tomography (CT) colonography with an alternative method they developed on the basis of time efficiency and surface visibility. With the conventional technique, 3D ante- and retrograde cine loops were obtained (hereafter, conventional 3D). With the alternative method, six projections were obtained at 90 degrees viewing angles (unfolded cube display). Mean evaluation time per patient with the conventional 3D display was significantly longer than that with the unfolded cube display. With the conventional 3D method, 93.8% of the colon surface came into view; with the unfolded cube method, 99.5% of the colon surface came into view. Sensitivity and specificity were not significantly different between the two methods. Agreements between observers were kappa = 0.605 for conventional 3D display and kappa = 0.692 for unfolded cube display. Consequently, the latter method enhances the 3D endoluminal display with improved time efficiency and higher surface visibility.     

Pictorial review: CT urography and virtual endoscopy: promising imaging modalities for urinary tract evaluation

CT urography and virtual endoscopy images are generated from dedicated multislice helical CT data sets and various three-dimensional reconstruction techniques. These imaging techniques can provide external and endoscopic images of the urinary tract and also provide high spatial resolution images helping overcome some of the limitations of intravenous urography and ultrasound. This pictorial review presents clinical applications of CT urography and virtual endoscopy in various urinary tract abnormalities.     

CT virtual intravascular endoscopy assessment of coronary artery plaques: A preliminary study

Purpose

The purpose of this study was to investigate the potential value of CT virtual intravascular endoscopy (VIE) in the visualization and assessment of coronary plaques in patients suspected of coronary artery disease.

Materials and methods

20 (13 men, 7 women, mean age 54 years) consecutive patients with suspected coronary artery disease undergoing 64-slice CT angiography were included in the study. Four main coronary artery branches were assessed with regard to the presence of coronary plaques based on 2D axial, multiplanar reformation, 3D volume rendering and VIE visualizations. The coronary plaques were characterized into calcified, noncalcified and mixed plaques. The intraluminal appearances of these coronary plaques were demonstrated with VIE images and correlated with 2D and 3D images to determine the diagnostic value of VIE for the assessment of the plaques.

Results

VIE was able to identify and demonstrate the intraluminal appearances of coronary plaques in 18 patients involving 32 coronary artery branches which were shown as an irregularly intraluminal protruding sign in extensively calcified plaques and smooth protruding appearance in noncalcified or focally calcified plaques. An irregular intraluminal appearance was also noticed in the presence of mixed plaques due to variable components with different CT attenuations contained within the plaques. VIE accurately confirmed the degree of coronary stenosis or occlusion despite the presence of heavy calcification.

Conclusion

VIE could be used as a complementary tool to conventional CT visualizations for the analysis of luminal changes and assessment of disease extent caused by the coronary plaques.