CT仿真结肠镜在结直肠病变诊断中的应用价值

目的探讨评估CT仿真结肠镜(CT Virtual Colonscopy,CTVC)在结肠息肉、结肠癌、溃疡性结肠炎、结肠黑变病中的检出能力，初步评阶其在结直肠病灶中的临床应用前景。方法对44例病人行CTVC检查，并与全结肠镜、病理结果进行对比研究。结果CTVC对结肠癌、结肠息肉具有较高辨别力，成功检出了全部10例结肠癌，并得到病理证实。10mm以上结直肠息肉CTVC与结肠镜都做出了正确诊断，CTVC发现5～10mm息肉14枚，＜5mm息肉CTVC仅发现2枚；CCTV发现2例。溃疡性结肠炎，结肠黑变病未检出。结论CTVC在结直肠癌和＞5mm以上结直肠息肉样病变诊断上具有较高的临床应用价值。     

双源计算机断层扫描双能量结肠镜检测结肠肿瘤准确性的临床研究

目的：比较常规 CT 结肠镜（CTC）与双能量 CTC 检测占位性病变的准确性。方法选择临床怀疑有结肠占位性病变患者28例,均采用双能量增强 CT 扫描,并进行结肠镜重建和双能量碘图重建。比较结肠占位性病变的直径、增强后 CT 值和含碘值。以结肠镜及病理结果作为金标准,比较常规 CTC 和双能量 CTC 诊断结肠占位性病变的敏感度、特异度、准确率、阳性预测值和阴性预测值。多组间的计量资料比较采用方差分析,计数资料比较采用卡方检验。结果28例患者中,CTC 检出结肠占位性病变24例,经结肠镜及病理证实假阳性4例,假阴性1例。双能量 CTC 检出结肠占位性病变20例,经结肠镜及病理证实无假阳性患者,假阴性1例。腺瘤样息肉、腺瘤、腺癌和粪块增强后的 CT 值分别为（38．54±6．82）、（49．16±7．31）、（52．61±5．93）和（34．00±1．41）Hu,腺瘤和腺癌的强化值明显高于腺瘤样息肉和粪块,差异有统计学意义（F ＝10．760,P ＝0．001）;息肉与粪块两组间比较,差异无统计学意义（t ＝1．44,P ＝0．188）。常规 CTC 与双能量 CTC 检测占位性病变的敏感度分别为95．6％（95％CI ：77．9％～99．2％）和95．6％（95％CI ：77．9％～99．2％）,特异度分别为42．8％（95％CI ：15．4％～93．5％）和100．0％（95％CI ：47．9％～100．0％）。结论与传统的 CTC 相比,双能量 CTC 可区分粪便残渣与肿块,有助于肿瘤良恶性的鉴别,进一步提高 CTC 诊断的准确性。     

CT结肠造影的应用现状及前景

CT结肠造影(computed tomography colonography, CTC)为新近发展起来地结直肠病变检查手段, 是用多排螺旋CT技术将充气扩张的全结肠薄层扫描后的原始数据经相应的计算机软件处理后获得的一系列重建图像.因其简单、快速、安全、非侵入性等优点, 易于被患者接受.随着多层螺旋CT(multi-slice spiral computed tomography, MSCT)的应用和计算机软件的不断改进, CTC的图像质量和分析能力有了明显改善, CTC对1 cm以上息肉有很高的敏感性和特异性, 且在结直肠癌的准确诊断和正确的术前分期中显示了明显的优势.     

仿真CT肠镜在结直肠增殖性病变诊断中的应用

目的 评估仿真ＣＴ肠镜在结直肠镜证实的增殖性病灶中的检出能力及其临床应用前景。方法 ２３例结肠镜检查发现异常的患者在１ｈ内行腹腔和盆腔薄层螺旋ＣＴ扫描,扫描数据经特殊软件处理后作二维和三维图像重建,将ＣＴ肠镜诊断结果与全结肠镜、病理和手段结果进行对比研究。结果 ２０例结肠镜诊断为结直肠癌的１例为结肠狭窄原因待查者。ＣＴ肠镜诊断为结肠癌,并得到病理和手术证实;１１ｍｍ以上的结直肠息肉结肠镜和ＣＴ肠镜     

CT仿真肠镜诊断结肠癌及局部浸润范围的价值

目的探讨16层螺旋CT仿真肠镜对结肠癌诊断及局部浸润范围的判断价值。方法73例手术证实的结肠癌患者，手术前1周分别进行电子结肠镜及16层螺旋CT检查，CT扫描后进行图像后处理对局部浸润范围进行判断，与术后病理分期进行对照。结果16层螺旋CT仿真肠镜对结肠癌总确诊率为90．4％，对肿瘤浸润深度总诊断准确率为83．3％。结论16层螺旋CT增强扫描结合肠道重建技术是诊断结肠癌的有效方法，并且能较好地进行局部浸润范围判断。     

CT结肠成像在老年人结直肠癌诊断中的价值

目的 评估CT结肠成像(CT colonography，CTC)在老年人结直肠癌诊断中的价值。方法 对纤维结肠镜和钡灌肠诊断为结直肠癌的患者行CTC检查，评价CTC对老年人结直肠癌的检出情况及患者对它的耐受性。结果 CTC成功检出30例患者的结直肠癌，准确性100％，并且有助于对肿瘤的浸润情况和肠道外转移进行全面评估。患者对CTC的耐受性明显高于纤维结肠镜和钡灌肠检查。30例行CTC和纤维结肠镜检查的患者耐受性分别为83．3％和63．3％。在16例行全部3种检查的患者中，耐受性分别为87．5％，68．8％，56．3％。结论 CTC技术在老年人结直肠癌的诊断中是一种安全有效的方法，并且可以全面的评价全结肠和腹腔内情况。CTC可以与纤维结肠镜互补来诊断结直肠癌，并可作为高龄、高危人群的普查方法。     

结肠癌术前多层面CT一站式检查的临床价值

目的:评估结肠充气多层CT(MSCT)多期增强扫描对结肠癌患者术前检查的价值.方法:63例结肠癌患者术前1 wk内行全腹MSCT平扫与多期增强MSCT扫描.采用Toshiba Aquilion16扫描仪,增强扫描是在对比剂开始注射后22 s(Ⅰ期)、37-40 s(Ⅱ期)、60 s(Ⅲ期)采集数据.在工作站对采集数据行CT仿真内镜(CTC)、X线模拟投影(XRP)、多平面重组(MPR)、表面遮盖显示(SSD)、CT血管造影(CTA)等后处理观察,并与手术病理对照.结果:CT显示64个癌灶,升结肠18个,结肠肝曲2个,横结肠4个,结肠脾曲2个,降结肠6个,乙状结肠20个(包括乙状结肠与直肠交界区5个),直肠12个;16例发现肠外病变;与手术所见同.在不同扫描期相,原发灶为均匀或不均匀强化.增强扫描肿物峰值强化Ⅱ期30个,Ⅱ期-Ⅲ期17个,Ⅲ期13个,Ⅰ-Ⅲ期4个.58个原发灶(90.6%)可见相应供血动脉增粗,分支增多.CT判断是否累及肠周脂肪敏感性100%,特异性64.2%,准确性92.1%.CT对腹部淋巴结转移瘤诊断总的敏感性78.5%,特异性86.7%,准确性86.1%.结论:MSCT多期增强扫描一次检查为结肠癌术前了解肿瘤位置、数量、范围、血供及其他组织器官病变情况提供了其他影像技术难于同时提供的信息.     

上海市嘉定区2652枚结直肠息肉临床病理分析

背景:结直肠息肉特别是腺瘤性息肉为结直肠癌前病变,结肠镜检查检出并切除息肉对结直肠癌的预防具有重要意义。目的:对上海市嘉定区1 613例结直肠息肉患者进行回顾性分析,为结直肠息肉的内镜监测管理提供依据。方法:2013年1月—2014年8月上海瑞金医院北院内镜中心检出的2 652枚结直肠息肉纳入研究,对息肉临床病理特征、活检与内镜切除标本病理诊断符合率以及随访期间息肉再次检出情况进行统计分析。结果:2 652枚结直肠息肉中75.3%(1 996枚)为远端结肠息肉,腺瘤性息肉占77.5%(2 056枚),其中39.1%(804枚)发生上皮内瘤变。447枚息肉同时取活检并在切除后送病理检查,两次病理诊断总体符合率为60.4%,其中腺瘤性息肉符合率为68.1%。术后1.5年复查结肠镜再次检出息肉并送病理检查共218枚,腺瘤性息肉占74.3%,近端结肠和直径≤1.0 cm的息肉再次检出率分别显著高于远端结肠和直径1.0 cm者(12.3%对6.9%,9.0%对4.5%,P均0.01)。结论:腺瘤性息肉在结肠镜检查检出的息肉中占比较高;应重视息肉切除后标本的病理检查和定期随访。     

低剂量16层螺旋CT结肠成像对结直肠癌的诊断价值

目的评价低剂量16层螺旋CT结肠成像（multisliceCTcolonlgraphy，MSCT）对结直肠癌的诊断应用价值。方法对37例经临床拟诊为结直肠癌患者行结肠充气的低剂量50mAs16层螺旋CT扫描（MSCT），利用工作站的后处理软件可获得多平面重建（multiplanarreformation，MPR）。三维表面遮盖显示（shaded．surfacedisplay，SSD）和透明显示像及CT仿真结肠内镜图像（CTVC）及结直肠黏膜剖开图像，将低剂量MSCT诊断结果与结直肠镜或手术病理进行对比。结果37例经手术或结直肠镜病理证实结肠癌29例和非结肠癌8例，低剂量MSCT正确诊断29例结肠癌病例（包括并发病灶及转移灶）中的28例和8例非结直肠癌中的5例，诊断的敏感度、特异度和准确度分别为：96．55％（28／29），62．5％（5／8），89．19％（33／37）。结论低剂量MSCT是安全、无创、快速、全面评价结直肠癌的方法，可以完全替代钡剂灌肠检查，是结直肠癌筛选、术前分期、预后评估及术后随诊的首选方法。     

CT仿真结肠镜与电子结肠镜对结直肠疾病诊断的对照研究

目的探讨CT仿真结肠镜(CTVC)在结直肠疾病,尤其是溃疡性结肠炎诊断中的价值。方法应用螺旋CT对2004年5月至2005年1月就诊于首都医科大学附属北京友谊医院的58例疑诊结直肠病变患者进行容积扫描,获取仿真结肠镜图像,将所得结果与结肠镜结果进行比较分析。结果CTVC检查均获得成功,共检出结直肠癌14例,结直肠息肉15例,溃疡性结肠炎14例,正常者6例。CTVC对结直肠疾病总的敏感性为82.7%(43/52),特异性为100%,准确性为84.5%(49/58),阳性预测值87.8%(43/49),阴性预测值40.0%(6/15),Kappa值为0.497;CTVC对溃疡性结肠炎诊断的敏感性为70.0%(14/20),特异性为100%,准确性为76.9%(20/26),阳性预测值70.0%(14/20),阴性预测值50.0%(6/12),Kappa值为0.519。结论CTVC是一种无创的检查方法,具有一定优势,但仍存在一些弊端,因此对于溃疡性结肠炎诊断仅是一种有效的补充,尚不能完全替代常规结肠镜检查。     

Virtual colonoscopy for the detection of colorectal polyps and cancers in a Chinese population

AIM: The aim of this study is to assess the sensitivity of virtual colonoscopy in detecting colorectal polyps and cancers in a Chinese population. METHODS: Seventy-one consecutive Chinese patients (38 men and 33 women) referred for diagnostic colonoscopy were recruited. Patients received a routine bowel preparation in the morning followed by a helical abdominal computed tomography (CT) scan with air insufflation of the colon. The CT images were then processed by using surface-rendered software and interpreted by a single radiologist who was blinded to the clinical information. Colonoscopy was performed in the same afternoon without knowledge of the radiology results. All polyps and cancers were proven histologically. RESULTS: Five colorectal cancers were diagnosed and all were detected by virtual colonoscopy. The sensitivity and specificity of virtual colonoscopy for the detection of patients with polyps of all sizes, and patients with polyps >/=10 mm were 59, 92, 88 and 100%, respectively. The procedure was well tolerated by all patients. CONCLUSIONS: This study was carried out in a real clinical setting without a preselection of cases. Virtual colonoscopy was satisfactory for the detection of polyps greater than 10 mm, and for the diagnosis of cancer, and it is also a promising imaging modality for colorectal neoplasm detection in a Chinese population.     

Role of computed tomographic colonoscopy of postoperative surveillance in patient with gastric cancer

AIM: To examine the diagnostic yield of colorectal neoplasia at computed tomographic colonoscopy (CTC) as well as the feasibility of contrast enhanced CTC in patients with gastric cancer. METHODS: To examine the incidence of colon polyp we selected postoperative 188 gastric cancer patients, which we refer to as the 'colon polyp survey group'. To examine the feasibility of CTC for early detection of colon cancer or advanced colon adenoma, we selected 47 gastric cancer patients (M:F 29:18, mean age 53.8 years), which we call the 'CT colonoscopy group'. All the 47 patients underwent successive CTC and colonoscopy on the same day. RESULTS: Totally 109 colon polyps were observed from 59 out of 188 gastric cancer patients, the incidence rate of colon polyps in gastric cancer patients being 31.4%. The sensitivity of CTC in detecting individuals with at least 1 lesion of any size was 57.1%, the specificity was 72.7%, the positive predictive value was 47.1%, and the negative predictive value was 71.9%. When the cutoff size was decreased to 6 mm, the sensitivity and specificity were 80.0% and 92.9%, respectively, with positive and negative predictive values of 57.1% and 97.5%, respectively. Only one patient was classified as false negative by virtual colonoscopy. CONCLUSION: The diagnostic yield of colorectal polyp was 31.4% in patients with gastric cancer, and contrast enhanced CTC is an acceptable tool for the detection of synchronous colorectal advanced adenoma andpostoperative surveillance of gastric cancer patients.     

CT仿真结肠镜对结肠病变的临床应用探讨

目的 探讨结肠腺瘤。结肠癌,结肠憩室,溃疡性结肠炎,结肠黑变病等病变的ＣＴ仿真结肠镜表现,初步评价其在结肠病灶诊断中的应用价值。方法 ３７例病人（包括２０例结肠腺瘤,６例结肠癌,４例憩室,５例溃疡性结肠炎,结肠黑变病及结肠淀粉样变各１例）行ＣＴ仿真结肠镜并和结肠镜检查结果作对照,男２６例,女１１例,结果 ＣＴ仿真结肠镜对结肠癌和结肠腺瘤、结肠憩室有较高的辨别率,成功地检出了６例结肠癌、１７例结肠腺     

Computed tomographic virtual colonoscopy computer-aided polyp detection in a screening population

BACKGROUND & AIMS: The sensitivity of computed tomographic (CT) virtual colonoscopy (CT colonography) for detecting polyps varies widely in recently reported large clinical trials. Our objective was to determine whether a computer program is as sensitive as optical colonoscopy for the detection of adenomatous colonic polyps on CT virtual colonoscopy. METHODS: The data set was a cohort of 1186 screening patients at 3 medical centers. All patients underwent same-day virtual and optical colonoscopy. Our enhanced gold standard combined segmental unblinded optical colonoscopy and retrospective identification of precise polyp locations. The data were randomized into separate training (n = 394) and test (n = 792) sets for analysis by a computer-aided polyp detection (CAD) program. RESULTS: For the test set, per-polyp and per-patient sensitivities for CAD were both 89.3% (25/28; 95% confidence interval, 71.8%-97.7%) for detecting retrospectively identifiable adenomatous polyps at least 1 cm in size. The false-positive rate was 2.1 (95% confidence interval, 2.0-2.2) false polyps per patient. Both carcinomas were detected by CAD at a false-positive rate of 0.7 per patient; only 1 of 2 was detected by optical colonoscopy before segmental unblinding. At both 8-mm and 10-mm adenoma size thresholds, the per-patient sensitivities of CAD were not significantly different from those of optical colonoscopy before segmental unblinding. CONCLUSIONS: The per-patient sensitivity of CT virtual colonoscopy CAD in an asymptomatic screening population is comparable to that of optical colonoscopy for adenomas > or = 8 mm and is generalizable to new CT virtual colonoscopy data.     

Colorectal neoplasm detection using virtual colonoscopy: a feasibility study

Background—Virtual colonoscopy is a potentiallypowerful tool for non-invasive colorectal evaluation. In vitro studieshave established its accuracy in simulated polyp detection but little data exist regarding its use in clinical practice.
Aims—To evaluate the ability of virtualcolonoscopy to detect colorectal cancers and polyps in patients withendoscopically proven colorectal neoplasms and to correlate thefindings of virtual colonoscopy with those of conventional colonoscopy,surgery, and histopathology.
Patients—Thirty eight patients with endoscopicfindings suggestive of colorectal carcinoma.
Methods—Virtual colonoscopy was performed usingthin section helical computed tomography (CT) of the abdomen and pelvisafter rectal insufflation of room air. Commercially available software was used to generate endoscopic "fly through" examinations of thecolon from the CT data. Results were correlated with the findings ofconventional colonoscopy and with the surgical and histopathological outcome in each case.
Results—Thirty eight pathologically provencolorectal cancers and 23 adenomatous polyps were present. On virtualcolonoscopy, all cancers and all polyps measuring greater than 6 mm insize were identified; there were two false positive reports of polyps. On conventional colonoscopy, there was one false positive report of amalignant sigmoid stricture; four subcentimetre polyps were overlooked.Virtual colonoscopy enabled visualisation of the entire colon in 35 patients; conventional colonoscopy was incomplete in 14 patients.Virtual colonoscopy correctly localised all 38cancers, compared with32 using conventional colonoscopy.
Conclusion—Virtual colonoscopy is a feasiblemethod for evaluating the colon; it may have role in diagnosis ofcolorectal cancer and polyps.

Keywords:colonic neoplasms; computed tomography; computersimulation

     

Computed tomographic colonography compared with colonoscopy in patients at increased risk for colorectal cancer

BACKGROUND & AIMS: To date, computed tomographic (CT) colonography has been compared with an imperfect test, colonoscopy, and has been mainly assessed in patients with positive screening test results or symptoms. Therefore, the available data may not apply to screening of patients with a personal or family history of colorectal polyps or cancer (increased risk). We prospectively investigated the ability of CT colonography to identify individuals with large (>or=10 mm) colorectal polyps in consecutive patients at increased risk for colorectal cancer. METHODS: A total of 249 consecutive patients at increased risk for colorectal cancer underwent CT colonography before colonoscopy. Two reviewers interpreted CT colonography examinations independently. Sensitivity, specificity, and predictive values were determined after meticulous matching of CT colonography with colonoscopy. Unexplained large false-positive findings were verified with a second-look colonoscopy. RESULTS: In total, 31 patients (12%) had 48 large polyps at colonoscopy. This included 8 patients with 8 large polyps that were overlooked initially and detected at the second-look colonoscopy. In 6 of 8 patients, the missed polyp was the only large lesion. With CT colonography, 84% of patients (26/31) with large polyp(s) were identified, paired for a specificity of 92% (200-201/218). Positive and negative predictive values were 59%-60% (26/43-44) and 98% (200-201/205-206), respectively. CT colonography detected 75%-77% (36-37/48) of large polyps, with 9 of the missed lesions being flat. CONCLUSIONS: CT colonography and colonoscopy have a similar ability to identify individuals with large polyps in patients at increased risk for colorectal cancer. The large proportion of missed flat lesions warrants further study.     

Prospective comparison of contrast enhanced CT colonography and conventional colonoscopy for detection of colorectal neoplasms in a single institutional study using second-look colonoscopy with discrepant results

BACKGROUND: Colorectal cancer is the second leading cause of death from cancer in Western countries. Early detection by colorectal cancer screening can effectively cut its mortality rate. CT colonography represents a promising, minimally invasive alternative to conventional methods of colorectal carcinoma screening. AIMS: The purpose of this prospective single institutional study was to compare the abilities of routine clinical CT colonography and conventional colonoscopy to detect colorectal neoplasms using second-look colonoscopy to clarify discrepant results. PATIENTS AND METHODS: CT colonography was performed in 100 symptomatic patients using contrast enhanced multidetector CT followed by conventional colonoscopy on the same day. If results were discrepant, a second-look colonoscopy was performed after unblinding. CT colonographic findings were compared with those of conventional colonoscopy. RESULTS: Conventional colonoscopy found 122 colorectal neoplasms in 49 patients. The overall sensitivity of CT colonography at detecting patients with at least one polyp 6 mm or larger was 76% and its specificity was 88%. Its by-patient sensitivity for polyps 10 mm or larger was 95% and its specificity was 98%. By-polyp sensitivities were 71% for polyps 10 mm or larger, and 61% for polyps 6 mm or larger. A second-look colonoscopy was performed in 19 patients and two initial false-positive findings of CT colonography were reclassified as true-positive. For conventional colonoscopy, this produced a by-polyp sensitivity of 94% for detection of lesions 6 mm and larger. CONCLUSIONS: CT colonography had both a high by-patient sensitivity and specificity for detection of clinically important colorectal neoplasms 10 mm or larger. This suggests that CT colonography has the potential to become a valuable clinical screening method for colorectal neoplasms.     

CT Colonography: an update on current and future indications

Computed tomographic colonography (CTC) is a minimally invasive, patient-friendly, safe and robust colonic imaging modality. The technique is standardized and consolidated evidence from the literature shows that the diagnostic performances for the detection of colorectal cancer and large polyps are similar to colonoscopy (CS) and largely superior to alternative radiological exams, like barium enema. A clear understanding of the exact role of CTC will be beneficial to maximize the benefits and minimize the potential sources of frustration or disappointment for both referring clinicians and patients. Incomplete, failed, or unfeasible CS; investigation of elderly, and frail patients and assessment of diverticular disease are major indications supported by evidence-based data and agreed by the endoscopists. The use of CTC for symptomatic patients, colorectal cancer screening and colonic surveillance is still under debate and, thus, recommended only if CS is unfeasible or refused by patients.     

Colorectal polyp detection with virtual colonoscopy (computed tomographic colonography); the reliability of the method

BACKGROUND/AIMS: The aim of this study was to compare the reliability of virtual colonoscopy with conventional colonoscopy in detection of colorectal polyps. METHODOLOGY: Between November 1997 and February 2000, 23 patients (14 males, 9 females) aged 43-86 years (mean: 63) with colorectal polyps who underwent colonoscopy in our endoscopy unit, were referred for virtual colonoscopy. The colon was distended with an enema tube for rectal insufflation and subsequently was scanned by helical CT (Toshiba X-vision) using the following parameters: KV 120, mAs 200, table feed 5 mm/sec, slice thickness 5 mm and reconstruction intervals 2.5 mm. Using SPARC Station 20, virtual colonoscopy was generated. RESULTS: A total of 30 polyps (19 with diameter 8-15 mm and 11 larger than 15 mm) were detected with conventional colonoscopy. Virtual colonoscopy visualized 27 polyps (17 with diameter 8-15 mm and 10 with diameter > 15 mm). CONCLUSIONS: Virtual colonoscopy is a non-invasive, well-tolerated, safe technique and can be useful for detection of colorectal polyps. Weaknesses of the method are the inability to detect small lesions and to perform biopsies.     

Editorial: Detection of small polyps: much ado about nothing?

Computed tomographic (CT) colonography (CTC) represents an alternative to optical colonoscopy for colorectal cancer screening. However, diminutive polyps (≤ 5 mm) are not routinely reported for CTC. An observational study comparing the rates of recovery of subcentimeter adenomas in average-risk patients between two screening strategies, CTC and optical colonoscopy, found that the colonoscopy group had a four and a half-fold greater recovery rate of diminutive adenomas. Although the study was not randomized, the results highlight the difference between the two screening strategies. Because of incomplete understanding of the natural history of diminutive adenomas, further study is needed to determine the long-term impact of the use of CTC for colorectal cancer screening.