64层螺旋CT仿真内镜对老年大肠癌的诊断价值

目的 评价64层螺旋CT仿真内镜(CTVE)在老年人大肠癌诊断中的临床应用价值.方法 对纤维结肠镜和钡灌肠诊断为大肠癌的患者行CTVE检查,评价CTVE对老年人大肠癌的检出情况及患者的耐受性.结果 CTVE成功检出56例患者的大肠癌,准确性100%,并且有助于对肿瘤的浸润情况和肠外转移进行全面评估.患者对CTVE的耐受性明显高于纤维结肠镜和钡灌肠检查.56例行CTVE、纤维结肠镜和钡灌肠检查的患者耐受性分别为89.3%、62.5%和56.7%.结论 CTVE技术在老年大肠癌的诊断中是安全有效,是纤维结肠镜的重要补充手段.     

CT结肠镜在临床研究中的进展

CT结肠镜（computer tomography colonography,CTC）是一种侵袭性小、安全、方便的结直肠影像学检查方法。多项研究结果表明,CTC对大肠癌和大腺瘤的检出能力与结肠内镜相仿,明显优于钡灌肠检查。准确地了解CTC的作用,无论对临床医生还是患者都是非常重要的,可以最大限度地从该项检查中获益,从而尽可能避免检查潜在的不足。本文通过既往数据的整理,对CTC诊断效能、报告、数据系统及临床诊治中应用的最新进展进行论述。     

未完成结肠镜后续检查的研究进展

结直肠癌(colorectal cancer,CRC)是癌症引起死亡的主要原因。纤维结肠镜检查是人们普遍认可的结直肠癌筛查及诊断的金标准。临床结肠镜操作过程中存在进镜困难、难以到达回盲部完成全结肠检查的情况,从而增加近端结肠疾病的漏诊率,甚至延误病情,因此,成功的盲肠插管、完成全结肠检查对疾病的诊断及治疗至关重要。临床上,内镜操作医师通过重复结肠镜检查、细口径内镜、水辅助结肠镜、透明帽等辅助设备可以促进完成全结肠检查。另外,使用其他成像技术也可以完成全结肠检查,包括双重造影钡剂灌肠、CT或MR结肠成像术、胶囊结肠内镜。     

结肠镜普查及随访对老年人早期结直肠癌的诊断价值

目的 通过对老年人进行结肠镜临床普及及随访,提高老年人结直肠癌的防治水平。方法 结合每年查体对2196例60－89岁老年人进行结肠镜临床普查及随访,结肠镜随访1740例,随访率为79．2％。结果 共检出结直肠癌52例,检出率为2．4％,早期结直肠癌19例,占36．5％,结肠镜随访中检出早期结肠癌9例,占随访检出直肠癌20例的45．0％。结直肠癌手术切除率及术后5年生存率分别为97．7％和80．9％。结肠镜插镜成功率为98．9％,并发症的发生率为0．05％。结论 开展老年人结肠镜临床普查及随访,使结直肠癌及癌前病变－－腺瘤性息肉患者得到了早期诊断,提高了早期结直肠癌的检出率及结直肠癌的Ⅱ级防治水平。     

64层螺旋CT仿真结肠镜对结直肠占位性病变的筛选价值

目的 探讨64层螺旋CT仿真结肠镜（CTC）对结直肠占位性病变的筛选价值.方法 65例疑为结肠占位的患者,经肛门注气后行64层螺旋CT腹盆腔连续薄层扫描,应用64层螺旋CT仿真结肠镜软件对获取的数据进行三维仿真结肠镜图像重建,与结肠镜和临床病理结果进行对照分析.结果 结肠镜诊断结肠息肉患者36例共56枚息肉,CTC发现32例共45枚息肉,CTC结直肠息肉检出率为86.5％;结肠镜诊断结肠癌12例,CTC诊断结肠癌15例,能够显示结肠癌的大体分型、＞5.0mm的癌结节,能直观反映癌肿处肠壁及肠周受侵状况,对癌肿肠周受侵判断准确率较高.结论 CTC对结肠占位性病变是一种无创、有效的检查方法,可成为高危人群结肠肿瘤筛选的方法之一.     

粪便检查在结直肠癌筛查中的作用

结直肠癌（CRC）是消化系统常见的恶性肿瘤之一,近年来其发病率和病死率呈上升趋势.结直肠癌具有较明确的癌前病变,西方国家很早就致力于推广筛查方案,在过去的30年中其发病率和病死率明显下降.目前,结直肠癌筛查手段主要分为两大类：粪便检查和结肠结构性检查.前者包括粪便潜血、钙卫蛋白、粪便基因学及粪便MicroRNA检查等,后者包括全结肠镜、乙状结肠镜检查、钡灌肠、CT仿真结肠镜等.     

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。     

结构分析电子清肠X线断层结肠成像术检测结直肠平坦型病变

目的 评价结构分析电子清肠软件应用于粪便标记三维X线断层结肠成像术(SAEC-3D CTC)检测结直肠平坦型病变的可行性和检出敏感度,并与Viatronix三维CT结肠成像(V3D CTC)和无电子清肠的二维CT结肠成像(2D CTC)比较.方法 40例经CT结肠成像(CTC)检查的患者发现69个结直肠平坦型病变.结肠镜检查证实后,将这些病例分别独立进行SAEC-3D、V3D和2D CTC研究分析其检出敏感度.以结肠镜观察为金标准,结直肠平坦型病变定义为病变高度≤2 mm或小于其宽度的1/2.结果 69个结直肠平坦型病变中,直径2～3 mm 27个、4～6 mm 28个、7～9 mm 11个、≥10 mm 3个.SAEC-3D CTC的结直肠平坦型病变检出敏感度为51%(35/69),明显高于V3D CTC的32%(22/69)和2D CTC的29%(20/69)(P<0.05);SAEC-3D、V3D和2D CTC对不位于结肠黏膜皱襞的平坦型病变检出敏感度分别为61%(23/38)、45%(17/38)和42%(16/38).高于对位于结肠黏膜皱襞内的平坦型病变检出敏感度的39%(12/31)、16%(5/31)和13%(4/31).这三种CTC方法均未检出所有8个位于盲肠的病变(直径2～9 mm).除盲肠病变外,SAEC-3D CTC对直径≥4 mm平坦型病变的检出敏感度达84%(31/3F).结论 结构分析电子清肠软件应用于粪便造影剂标记3D CTC检测直径≥4 mm结直肠平坦型病变可达到较高的敏感度;而且对不位于结肠黏膜皱襞的病变检出敏感度高于位于结肠黏膜皱襞的病变.盲肠平坦型病变町能是CTC的盲区.     

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。     

Colon Neoplasia Co-existing with Coeliac Disease in Older Patients: Coincidental,Probably; Important,Certainly

Background: Coeliac disease and colorectal neoplasia are both common, present most often in patients over 40 and cause similar symptoms. Greater awareness and early use of serological tests have improved the diagnosis of coeliac disease, but raise the concern that co-existing colorectal neoplasia may be missed. This study assessed the prevalence of colorectal neoplasia among patients with coeliac disease diagnosed after the age of 40 who presented with altered bowel habit or iron deficiency. Methods: All patients meeting the above criteria underwent colonoscopy unless this or barium enema had been performed shortly before. Results: Of 69 patients with coeliac disease undergoing colonoscopy, 7 (10%) had colon neoplasia: 5 had tubulovillous polyps, and 2 had carcinoma. The prevalence figures for coeliac patients undergoing colonoscopy with iron deficiency and altered bowel habit alone were 11% (5 of 47) and 10% (2 of 22), respectively None of a further 13 who had undergone previous colon investigation (all by barium enema) had neoplasia, although these were probably a selected population. The seven patients with colorectal neoplasia had not reported rectal bleeding. The prevalence of colorectal neoplasia was not significantly higher than in two series of non-coeliac patients undergoing colonoscopy for investigation of iron deficiency (12%) or altered bowel habit (8%). Conclusions: There is a high prevalence of colorectal neoplasia among older patients with coeliac disease who present with iron deficiency or altered bowel habit, though this is no higher than for non-coeliac patients with these presentations. The possibility of dual pathology should be considered and excluded by colon investigation.     

Temporal trends in colorectal procedure use after colorectal cancer resection

BACKGROUND: After curative cancer resection, routine colon surveillance is recommended. It is not known whether trends over time in cancer survivors parallel that of the general population. OBJECTIVE: Our purpose was to describe temporal changes in the use of posttreatment procedures. DESIGN: Retrospective cohort study. SETTING: Linked tumor registry and Medicare claims data. PATIENTS: Medicare beneficiaries >65 years old who were diagnosed with local or regional stage colorectal cancer from 1992-2002 and who underwent surgical resection. MAIN OUTCOME MEASUREMENTS: Use of colonoscopy, sigmoidoscopy, or barium enema within 1 year, 18 months, or 3 years of diagnosis. RESULTS: A total of 62,882 patients were followed up for 1 year and 35,784 for 3 years. Colonoscopy within 1 year was performed in 25.9%, within 18 months in 53.8%, and within 3 years in 70.3%. Corresponding rates for sigmoidoscopy were 7.4%, 10.2%, and 14.9%, respectively, and were 3.4%, 5.1%, and 7.9%, respectively, for barium enema. There was a decrease over time in the receipt of colonoscopy within 1 year of diagnosis (31.3% in 1992 to 20.6% in 2002), no change in 18-month rates, and a smaller increase in colonoscopy use within 3 years (66.5% to 72.3%). The use of sigmoidoscopy and barium enema declined over time. Overall procedure use within 1 year and 18 months also decreased and 3-year rates were essentially unchanged. These differences were maintained in multivariate analyses. LIMITATIONS: Accuracy of procedure coding and indications for tests could not be measured. CONCLUSIONS: Temporal trends in procedure use in cancer survivors were consistent with the general population. Importantly, despite guideline recommendations and Medicare reimbursement, 25% of patients who undergo curative treatment do not receive surveillance examinations and this was unchanged over time.     

Colon neoplasia co-existing with coeliac disease in older patients: coincidental,probably; important,certainly

BACKGROUND: Coeliac disease and colorectal neoplasia are both common, present most often in patients over 40 and cause similar symptoms. Greater awareness and early use of serological tests have improved the diagnosis of coeliac disease, but raise the concern that co-existing colorectal neoplasia may be missed. This study assessed the prevalence of colorectal neoplasia among patients with coeliac disease diagnosed after the age of 40 who presented with altered bowel habit or iron deficiency. METHODS: All patients meeting the above criteria underwent colonoscopy unless this or barium enema had been performed shortly before. RESULTS: Of 69 patients with coeliac disease undergoing colonoscopy, 7 (10%) had colon neoplasia: 5 had tubulovillous polyps, and 2 had carcinoma. The prevalence figures for coeliac patients undergoing colonoscopy with iron deficiency and altered bowel habit alone were 11% (5 of 47) and 10% (2 of 22), respectively None of a further 13 who had undergone previous colon investigation (all by barium enema) had neoplasia, although these were probably a selected population. The seven patients with colorectal neoplasia had not reported rectal bleeding. The prevalence of colorectal neoplasia was not significantly higher than in two series of non-coeliac patients undergoing colonoscopy for investigation of iron deficiency (12%) or altered bowel habit (8%). CONCLUSIONS: There is a high prevalence of colorectal neoplasia among older patients with coeliac disease who present with iron deficiency or altered bowel habit, though this is no higher than for non-coeliac patients with these presentations. The possibility of dual pathology should be considered and excluded by colon investigation.     

Cancellation rates and gas scores for air contrast barium enema immediately after 65-CM flexible sigmoidoscopy. A randomized clinical trial

A randomized prospective study examined the impact of bowel gas introduced by 65-cm flexible sigmoidoscopy (FS) on the ability to perform air-contrast barium enema (ACBE) on the same day. Seventy-five patients at risk for colorectal cancer were randomly assigned to two groups. Of these, 28 patients in each group completed the protocol. The study group received flexible sigmoidoscopy and air-contrast barium enema on the same day, whereas the control group had their air-contrast barium enema on a different day. Bowel gas observed on an abdominal scout film prior to air-contrast barium enema was quantified on a scale of 1 (excessive gas) to 5 (no gas). The cancellation rate for the air-contrast barium enema was measured in each of the groups. The study group had significantly more bowel gas compared with the control group (p = 0.000003). The air-contrast barium enema cancellation rate was also higher in the study group (36%) than in the control group (14%) (p = 0.06). Greater than 60% of the study group patients were successfully examined. Same-day scheduling would reduce the number of bowel preparations required in the evaluation of patients at risk for colorectal cancer. Although retrospective studies have suggested no impact of same-day FS on ACBE quality, radiologists in this study canceled approximately one-third of scheduled patients due to perceived excessive bowel gas.     

The role of colonoscopy in screening persons with family history of colorectal cancer

Abstract First-degree relatives of colorectal cancer patients are at increased risk for developing colorectal neoplasms. In order to assess the potentiality of colonoscopy screening in this high-risk population, 213 asymptomatic family members (age range 30-69 years, mean 42.8 years) of those patients with colorectal cancer received colonoscopic examination at Chang-Gung Memorial Hospital from April 1992 to May 1994. Twenty-eight persons with 42 lesions (polyps or cancer) were identified, including 28 adenomas, nine hyperplastic polyps and five adenocarcinomas. The positive detection rate was 9.9% for adenoma and 2.3% for cancer. Colorectal neoplasms afflicted males more frequently than females (16.7 vs 5.7%, P < 0.05) and occurred less frequently in those < 40 years of age (5.5 vs 17.2%, P < 0.05). Forty-two per cent of the detected neoplastic lesions were beyond the reach of 60 cm flexible sigmoidoscopy and 36% of adenomas were < 0.5 cm in size and would be missed if patients were screened by air contrast barium enema. Cost analysis revealed that the charges of both screening colonoscopy and screening flexible sigmoidoscopy/air contrast barium enema were approximate. Colonoscopy also has a high acceptability and safety. It appears appropriate to use colonoscopy, rather than flexible sigmoidoscopy or air contrast barium enema, as an initial screening procedure for persons with a family history of colorectal cancer, especially those > 40 years of age.     

Proximal shift of colorectal cancer in the Australian Capital Territory over 20 years

Background : Several studies in other countries have demonstrated a change in subsite distribution of colorectal cancer, with increasing proximal cancers. Confirmation of such a change in Australia would have implications for screening and diagnosis of colorectal cancer.
Aims : To determine whether there has been an increase in the proportion of proximal colorectal cancers in Australia, and whether there have been changes in other clinical and pathological aspects of colorectal cancer.
Methods : A study of the hospital files of patients with colorectal cancer diagnosed and treated at all hospitals in the Australian Capital Territory (ACT) between 1989 and 1995 was compared with data from a published study of patients diagnosed between 1969 and 1976.
Results : There was a proximal shift of cancers with a significant increase in the proportion of tumours in the hepatic flexure, ascending colon and caecum, more marked for females than males. There was a corresponding reduction in distal colorectal cancers. Time from onset of symptoms to diagnosis decreased, risk factors for colorectal cancer were noted more frequently, and endoscopy replaced barium enema X-ray as the main diagnostic modality. The resectability of cancers increased, stay in hospital and 30 day mortality declined. Despite apparent earlier presentation and improved surgical resectability, the proportion of patients with localised disease (Dukes' stage A and B) had not changed significantly.
Conclusions : We have detected a number of changes in clinical and pathological aspects of colorectal cancer over a 20 year period in the ACT, including a proximal shift in the subsite distribution of colorectal cancer. These changes suggest that proximal and distal colorectal cancers may have a different aetio-pathogenesis, and have implications for the investigation of patients with suspected colorectal cancer and in screening high-risk groups.     

Role of virtual computed tomographic colonography in patients with colorectal cancers and obstructing colorectal lesions

PURPOSE: The aim of this study was to assess the ability of computed tomographic colonography to diagnose colorectal masses, stage colorectal cancers, image the proximal colon in obstructing colorectal lesions, and evaluate the anastomoses in patients with previous colorectal surgery. METHODS: We prospectively performed computed tomographic colonography examinations in 34 patients (20 males; mean age, 64.2; range, 19–91 years): 20 patients had colorectal masses (defined at endoscopy as intraluminal masses 2 cm or larger), 7 patients had benign obstructing colorectal strictures, and 7 patients had a prior colorectal resection. Final tumor staging was available in all 16 patients who had colorectal cancers and 15 patients were referred after incomplete colonoscopy. The ability of computed tomographic colonography to stage colorectal cancers, identify synchronous lesions in patients with colorectal masses, and image the proximal colon in patients with obstructing colorectal lesions was assessed. RESULTS: Computed tomographic colonography identified all colorectal masses, but overcalled two masses in patients who were either poorly distended or poorly prepared. Computed tomographic colonography correctly staged 13 of 16 colorectal cancers (81 percent) and detected 16 of 17 (93 percent) synchronous polyps. Computed tomographic colonography overstaged two Dukes Stage A cancers and understaged one Dukes Stage C cancer. A total of 97 percent (87/90) of all colonic segments were adequately visualized at computed tomographic colonography in patients with obstructing colorectal lesions compared with 60 percent (26/42) of segments at barium enema (P<0.01). Colonic anastomoses were visualized in all nine patients, but in one patient, computed tomographic colonography could not distinguish between local tumor recurrence and surgical changes. CONCLUSION: Computed tomographic colonography can accurately identify all colorectal masses but may overcall stool as masses in poorly distended or poorly prepared colons. Computed tomographic colonography has an overall staging accuracy of 81 percent for colorectal cancer and is superior to barium enema in visualizing colonic segments proximal to obstructing colorectal lesions.Read at The American Society of Colon and Rectal Surgeons' 100th Anniversary and Tripartite Meeting, Washington D.C., May 1 to 6, 1999.     

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.     

Symptom-based approach to colorectal cancer: survey of primary care physicians in Italy

Background. Colorectal cancer is a frequent cause of mortality in Western countries, including Italy, where a definite screening policy has not yet been adopted. It is likely that most patients with colorectal cancer refer, first of all, to their primary care physician at onset of symptoms.

Aim. To perform a survey on the approach, of primary care physicians, to patients with symptoms suggesting the presence of colorectal cancer.

Methods. A total of 280 consecutive symptomatic patients without previous diagnosis of organic colon disease or recent colon investigation in whom, after consulting, 159 primary care physicians in Lazio (Italy) prescribed colonoscopy or double-contrast barium enema.

Results. Most frequent presenting symptoms were lower abdominal pain (79.6%), bloating (59.6%), constipation (47.8%), diarrhoea (30.3%), iron deficiency anaemia (24.6%), change in bowel habits (20.3%) and weight loss (15%). Colonoscopy and barium enema were equally advised by physicians to rule out the presence of cancer (56% versus 44%, P=ns). Cancer was found in 14.6% of patients. Age >50 years and iron deficiency anaemia were the only independent variables associated with colorectal cancer (Odds ratios 9.0 and 8.8 at multivariate analysis, respectively).

Conclusion. The symptom-based selection criteria used by primary care physicians have been shown to be scarcely effective. Colonic investigation should be requested, irrespective to the symptoms, in patients aged >50 years with iron deficiency anaemia.