Comparative study of conventional colonoscopy and pan-colonic narrow-band imaging system in the detection of neoplastic colonic polyps: a randomized, controlled trial

Background. Detection and removal of adenomas by colonoscopy is an important means for preventing cancer; however, small adenomas may be missed during colonoscopy. The narrow-band imaging (NBI) system clearly enhances the microvasculature in neoplastic lesions, making it appear as a dark complex. Therefore, the NBI system may improve the detection of colonic neoplasias. However, no randomized, controlled trials have evaluated the efficacy of a pan-colonic NBI system in adenoma detection. We conducted a randomized, controlled trial to determine the efficacy of the pancolonic NBI system in adenoma detection. Methods. Two hundred forty-three patients were randomized, 121 to conventional colonoscopy and 122 to pan-colonic NBI system. Demographics, indication for colonoscopy, and quality of preparation were similar between groups. Results. Extubation time was not significantly different between the conventional colonoscopy and pan-colonic NBI system. The proportions of patients with at least one adenoma and those with multiple adenomas were not significantly different between groups. However, the pan-colonic NBI system significantly increased the total number of adenomas detected (P < 0.05) and the number of diminutive (<5 mm) adenomas detected (P < 0.05). The pan-colonic NBI system allowed detection of more diminutive adenomas in the distal colon than did conventional colonoscopy (P < 0.01), and more patients in the NBI group had at least one diminutive adenoma than in the control group (P < 0.05). Conclusions. The pan-colonic NBI system improves the total number of adenomas detected, including significantly more diminutive adenomas, without prolongation of extubation time. These results indicate that routine use of the NBI system for surveillance of diminutive adenomas may be recommended.     

A prospective single centre study comparing computed tomography pneumocolon against colonoscopy in the detection of colorectal neoplasms

BACKGROUND AND AIMS: To determine the sensitivity and specificity of computed tomography (CT) pneumocolon in the detection of colorectal neoplasms. METHODS: A total of 201 consecutive patients with colorectal symptoms or requiring surveillance for colorectal neoplasms underwent both conventional colonoscopy and CT pneumocolon. RESULTS: On conventional colonoscopy 13 invasive colorectal carcinomas were detected in 13 patients, and 118 polyps in 63 patients (14 polyps were > or =1 cm in diameter, 25 were 6-9 mm, and 79 were < or =5 mm). CT pneumocolon detected all 13 cancers, two false positive cancers, but only 20 polyps (seven were > or =1 cm). This resulted in a sensitivity of 100% (95% confidence interval (CI) 87-100%) and specificity of 99% (95% CI 97-100%) for detection of invasive carcinoma, and a sensitivity of 73% (95% CI 56-90%) and specificity of 94% (95% CI 91-98%) for detection of invasive carcinoma and/or > or =1 cm polyps. CT pneumocolon also identified invasive carcinoma not seen at colonoscopy because of incomplete examination in three patients, and detected metastases in six colorectal carcinoma patients and extracolonic carcinoma in a further seven patients. CONCLUSIONS: CT pneumocolon had a high sensitivity and specificity for detection of invasive colorectal carcinoma but not colorectal polyps. CT pneumocolon may be suitable for initial investigation of patients with symptoms of colorectal malignancy.     

重复进镜观察用于结肠镜检查中影响结直肠息肉检出率的相关因素分析

目的 运用重复进镜观察的方法研究结直肠息肉检出率的影响因素。方法 选取2016年8月至2017年3月期间在新疆维吾尔自治区人民医院消化内镜中心行无痛结肠镜检查的900例患者,随机抽取其中300例患者行二次镜检,300例患者行三次镜检,检查过程中严格控制内镜医师经验、进镜方式、肠道清洁度、退镜时间等影响检查结果的客观因素,记录检出息肉的特征（数量、位置、形态、大小、病理类型）。比较同一患者前后两次进镜和三次进镜观察发现的息肉特征;比较第1次进镜组、第2次进镜组和第3次组检出的息肉特征;进一步运用Logistic回归方法,分析结直肠息肉镜检漏诊的独立影响因素。结果 多发性息肉、升结肠息肉、横结肠息肉、乙状结肠息肉、无蒂息肉、小息肉（≤5mm）漏诊率较高（P均＜0.05）,而病理类型与息肉的漏诊无关（P＞0.05）;Logistic回归结果显示,息肉的数量、位置、形态,以及大小均为其漏诊的独立影响因素（P均＜0.05）;第2次进镜组较第1次进镜组的息肉检出率高,但第3次进镜组与第2次进镜组息肉检出率无统计学差异（P＞0.05）。结论 结直肠息肉的数量、位置、形态,以及大小均是其漏诊的独立影响因素;在结肠镜检查中运用二次进镜观察的方法有可能使息肉的检出率得到提高。     

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.     

Virtual colonoscopy using oral contrast compared with colonoscopy for the detection of patients with colorectal polyps

BACKGROUND & AIMS: Virtual colonoscopy using abdominal spiral computed tomography scanning allows total colonic evaluation with minimal invasiveness. Two-dimensional images and selective 3-dimensional images of the colon are used to detect colorectal lesions. This trial used conventional colonoscopy with segmental unblinding to determine the ability of virtual colonoscopy to identify patients with colorectal lesions who need conventional colonoscopy. METHODS: We studied 205 patients with virtual colonoscopy using oral iodinated contrast preceding conventional colonoscopy. Colonic lavage was achieved with an oral sodium phosphosoda preparation and colonic distention with a carbon dioxide electronic insufflator. RESULTS: The overall sensitivity and specificity of virtual colonoscopy in identifying patients with colorectal lesions was 61.8% and 70.7%, respectively. Virtual colonoscopy was more accurate in identifying patients with lesions >/=6 mm (sensitivity 84.4% and specificity 83.1%) and those with lesions >/=10 mm (sensitivity 90% and specificity 94.6%). The negative predictive value of virtual colonoscopy was 95% for a 6-mm cutoff size and 98.9% for a 10-mm cutoff. Using a 10-mm cutoff, virtual colonoscopy precludes the need for conventional colonoscopy in 86% of patients with a 1% false-negative rate (68% with a 3.4% false-negative rate when using a 6-mm cutoff). CONCLUSIONS: Virtual colonoscopy has a high sensitivity and specificity for detecting patients with significant colorectal lesions. Its high negative predictive value may help reduce the number of negative screening colonoscopies. Further studies are needed to determine what lesion cutoff size is clinically acceptable and the appropriate interval time for repeat virtual colonoscopy when it detects lesions below this cutoff size.     

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 gastrointestinal colonoscopy in combination with large bowel endoscopy: Clinical application

Although colorectal cancer (CRC) has no longer been the leading cancer killer worldwide for years with the exponential development in computed tomography (CT) or magnetic resonance imaging, and positron emission tomography/CT as well as virtual colonoscopy for early detection, the CRC related mortality is still high. The objective of CRC screening is to reduce the burden of CRC and thereby the morbidity and mortality rates of the disease. It is believed that this goal can be achieved by regularly screening the average-risk population, enabling the detection of cancer at early, curable stages, and polyps before they become cancerous. Large-scale screening with multimodality imaging approaches plays an important role in reaching that goal to detect polyps, Crohn’s disease, ulcerative colitis and CRC in early stage. This article reviews kinds of presentative imaging procedures for various screening options and updates detecting, staging and re-staging of CRC patients for determining the optimal therapeutic method and forecasting the risk of CRC recurrence and the overall prognosis. The combination use of virtual colonoscopy and conventional endoscopy, advantages and limitations of these modalities are also discussed.     

Detection and treatment of synchronous lesions in colorectal cancer： The clinical implication of perioperative colonoscopy

AIM： To evaluate the clinical significance of preand intra-operative colonoscopy for the detection of synchronous lesions in colon cancer.
METHODS： Two hundred and sixty-five pre-operative and 51 intra-operative colonoscopic evaluations were performed in 316 colorectal cancer patients who underwent curative resection from January 2001 to June 2006. The incidence and characteristics of synchronous lesions and their influence on surgery were evaluated.
RESULTS： Two hundred and eighty-two synchronous lesions were detected in 124 （39.2%） of 316 patients including all lesions regardless of their histologic type. True adenomatous polyps were found in 91 （28.8%） of 326 patients, and 27 （5.4% of all patients） patients had synchronous colon cancers. The preoperative identification of synchronous lesions altered the planned surgery in 37 （14.0%） of 265 patients. In 18 patients among the surgically removed cases, the lesions were removed by extending the resection range. Further segmental resection or polypectomy through enterotomy was necessary in 29 patients. Nineteen （37.2%） of 52 intraoperative colonoscopy cases had synchronous lesions. Additional surgical procedures including segmental bowel resection and polypectomy with enterotomy were necessary in 7 （23.7%） of 52 intraoperative colonoscopy cases to remove the lesions.
CONCLUSION： Synchronous colorectal polyps or cancer are frequent and their preoperative detection is important for optimal surgical planning and treatment. Intraoperative colonoscopy is a useful option in cases where a preoperative colonoscopy is not feasible.     

Evaluation of magnifying colonoscopy in the diagnosis of serrated polyps

AIM: To elucidate the colonoscopic features of serrated lesions of the colorectum using magnifying colonoscopy.METHODS: Broad division of serrated lesions of the colorectum into hyperplastic polyps (HPs), traditional serrated adenomas (TSAs), and sessile serrated adenomas/polyps (SSA/Ps) has been proposed on the basis of recent molecular biological studies. However, few reports have examined the colonoscopic features of these divisions, including magnified colonoscopic findings. This study examined 118 lesions excised in our hospital as suspected serrated lesions after magnified observation between January 2008 and September 2011. Patient characteristics (sex, age), conventional colonoscopic findings (location, size, morphology, color, mucin) and magnified colonoscopic findings (pit pattern diagnosis) were interpreted by five colonoscopists with experience in over 1000 colonoscopies, and were compared with histopathological diagnoses. The pit patterns were categorized according to Kudo’s classification, but a more detailed investigation was also performed using the subclassification [type II-Open (type II-O), type II-Long (type II-L), or type IV-Serrated (type IV-S)] proposed by Kimura T and Yamano H.RESULTS: Lesions comprised 23 HPs (23/118: 19.5%), 39 TSAs (39/118: 33.1%: with cancer in one case), 50 SSA/Ps (50/118: 42.4%: complicated with cancer in three cases), and six others (6/118: 5.1%). We excluded six others, including three regular adenomas, one hamartoma, one inflammatory polyp, and one juvenile polyp for further analysis. Conventional colonoscopy showed that SSA/Ps were characterized as larger in diameter than TSAs and HPs (SSA/P vs HP, 13.62 ± 8.62 mm vs 7.74 ± 3.24 mm, P < 0.001; SSA/Ps vs TSA, 13.62 ± 8.62 mm vs 9.89 ± 5.73 mm, P < 0.01); common in the right side of the colon [HPs, 30.4% (7/23): TSAs, 20.5% (8/39): SSA/P, 84.0% (42/50), P < 0.001]; flat-elevated lesion [HPs, 30.4% (7/23): TSAs, 5.1% (2/39): SSA/Ps, 90.0% (45/50), P < 0.001]; normal-colored or pale imucosa [HPs, 34.8% (8/23): TSAs, 10.3% (4/39): SSA/Ps, 80% (40/50), P < 0.001]; and with large amounts of mucin [HPs, 21.7% (5/23): TSAs, 17.9% (7/39): SSA/Ps, 72.0% (36/50), P < 0.001]. In magnified colonoscopic findings, 17 lesions showed either type II pit pattern alone or partial type II pit pattern as the basic architecture, with 14 HPs (14/17, 70.0%) and 3 SSA/Ps. Magnified colonoscopy showed the type II-O pit pattern as characteristic of SSA/Ps [sensitivity 83.7% (41/49), specificity 85.7% (54/63)]. Cancer was also present in three lesions, in all of which a type VI pit pattern was also present within the same lesion. There were four HPs and four TSAs each. The type IV-S pit pattern was characteristic of TSAs [sensitivity 96.7% (30/31), specificity 89.9% (72/81)]. Cancer was present in one lesion, in which a type VI pit pattern was also present within the same lesion. In our study, serrated lesions of the colorectum also possessed the features described in previous reports of conventional colonoscopic findings. The pit pattern diagnosis using magnifying colonoscopy, particularly magnified colonoscopic findings using subclassifications of surface architecture, reflected the pathological characteristics of SSA/Ps and TSAs, and will be useful for colonoscopic diagnosis.CONCLUSION: We suggest that this system could be a good diagnostic tool for SSA/Ps using magnifying colonoscopy.     

Accuracy of colonoscopy for the detection of colorectal polyps

The findings at colonoscopy were compared with the pathologic findings of the surgical specimen in 235 patients who underwent a colon resection for a primary colorectal neoplasm from January 1980 to December 1987 at Roswell Park Cancer Institute. Seven patients (3 percent) were found to have synchronous primary colon carcinomas, and 100 patients (43 percent) were found to have synchronous adenomatous polyps identified by colonoscopy and/or pathology. In patients with polyps 10 mm or greater in diameter, the findings on colonoscopy agreed with the pathology report 96 percent of the time. When polyps of all sizes were included, with many less than 5 mm in diameter, colonoscopy agreed with the pathology in 89 percent of patients. When only the area of the colon resected was used to determine the ability of colonoscopy to locate polyps, 58 percent of polyps of all sizes were located. The majority of the missed polyps were adjacent to a carcinoma. One cecal carcinoma was not seen by colonoscopy because of technical inabilities to reach the cecum. A second carcinoma (20 mm × 17 mm) was not seen at the splenic flexure.     

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     

Computed tomographic colonography without cathartic preparation for the detection of colorectal polyps

BACKGROUND AND AIMS: We prospectively compared the performance of low-dose multidetector computed tomographic colonography (CTC) without cathartic preparation with that of colonoscopy for the detection of colorectal polyps. METHODS: A total of 203 patients underwent low-dose CTC without cathartic preparation followed by colonoscopy. Before CTC, fecal tagging was achieved by adding diatrizoate meglumine and diatrizoate sodium to regular meals. No subtraction of tagged feces was performed. Colonoscopy was performed 3-7 days after CTC. Three readers interpreted the CTC examinations separately and independently using a primary 2-dimensional approach using multiplanar reconstructions and 3-dimensional images for further characterization. Colonoscopy with segmental unblinding was used as reference standard. The sensitivity of CTC was calculated both on a per-polyp and a per-patient basis. For the latter, specificity, positive predictive values, and negative predictive values were also calculated. RESULTS: CTC had an average sensitivity of 95.5% (95% confidence interval [CI], 92.1%-99%) for the identification of colorectal polyps > or =8 mm. With regard to per-patient analysis, CTC yielded an average sensitivity of 89.9% (95% CI, 86%-93.7%), an average specificity of 92.2% (95% CI, 89.5%-94.9%), an average positive predictive value of 88% (95% CI, 83.3%-91.5%), and an average negative predictive value of 93.5% (95% CI, 90.9%-96%). Interobserver agreement was high on a per-polyp basis (kappa statistic range, .61-.74) and high to excellent on a per-patient basis (kappa statistic range, .79-.91). CONCLUSIONS: Low-dose multidetector CTC without cathartic preparation compares favorably with colonoscopy for the detection of colorectal polyps.     

Simple colonoscopy reporting system checking the detection rate of colon polyps

AIM: To present a simple colonoscopy reporting system that can be checked easily the detection rate of colon polyps.METHODS: A simple colonoscopy reporting system Kosin Gastroenterology (KG quality reporting system) was developed. The polyp detection rate (PDR), adenoma detection rate (ADR), serrated polyp detection rate (SDR), and advanced adenoma detection rate (AADR) are easily calculated to use this system.RESULTS: In our gastroenterology center, the PDR, ADR, SDR, and AADR test results from each gastroenterologist were updated, every month. Between June 2014, when the program was started, and December 2014, the overall PDR and ADR in our center were 62.5% and 41.4%, respectively. And the overall SDR and AADR were 7.5% and 12.1%, respectively.CONCLUSION: We envision that KG quality reporting system can be applied to develop a comprehensive system to check colon polyp detection rates in other gastroenterology centers.     

Improved adenoma detection with linked color imaging technology compared to white-light colonoscopy

Abstract

Objectives

Linked color imaging (LCI) is a new endoscopic technology that may increase colorectal adenoma detection rate (ADR) and polyp detection rate (PDR) by virtual chromoendoscopy. Aim of the present study was to evaluate the effectiveness of LCI in ADR and PDR compared to the HD white-light colonoscopy (WLC) technique.     

Virtual colonoscopy in the detection of colonic polyps and neoplasms

First introduced in 1994, CT colonography (Virtual colonoscopy) has emerged as an accurate, non-invasive test that will likely play a future role in colorectal cancer screening. Over the past 3 years, there have been dramatic improvements in both hardware and software technology relating to CT colonography resulting in shorter scan times, enhanced user-friendliness and improved performance statistics. Published results show the accuracy of CT colonography to be comparable to conventional colonoscopy for detection of polyps >6mm in size with few false-positives. While many of the technical aspects of CT colonography have now been standardised current interest focuses on the development of faecal tagging agents to avoid full bowel catharsis and the use of low dose multislice CT acquisition to reduce patient radiation exposure. This chapter will summarise the development of CT colonography to date, document its published performance in detection of colorectal polyps and cancers, and review its current and potential future uses.