Computed Tomography Colonography as a Sensible Option for Colorectal Cancer Screening: Evidence Based on Metanalysis / Colonografia por tomografia computadorizada como uma opção sensível para o rastreamento do câncer colorretal: Evidências baseadas em metanálise

Abstract Objective This metanalysis aimed to evaluate the sensitivity and specificity of computed tomography colonography in colorectal polyp detection. Methods A literature search was performed in the PubMed and Web of Science databases. Results A total of 1,872 patients (males 57.2%, females 42.8%) aged 49 to 82 years old (mean age 59.7 ± 5.3 years) were included in this metanalysis. The estimated sensitivity of computed tomography colonography was 88.4% (46.3-95.7%, coefficient of variation [CV]=28.5%) and the estimated specificity was 73.6% (47.4-100.0%, CV=37.5%). For lesions up to 9mm, the sensitivity was 82.5% (62.0-99.9%, CV =25.1%) and the specificity was 79.2% (32.0-98.0%, CV=22.9%). For lesions>9mm, the sensitivity was 90.2% (64.0-100.0%, CV=7.4%) and the specificity was 94.7% (80.0-100.0%, CV=6.2%). No statistically significant differences in sensitivity according to the size of the lesion were found (p=0.0958); however, the specificity was higher for lesions>9mm (p<0.0001). Conclusions Most of the studies analyzed in the present work were conducted before 2010, which is about a decade after computed tomography colonography started being indicated as a screening method by European and American guidelines. Therefore, more studies aimed at analyzing the technique after further technological advancements are necessary, which could lead to the development of more modern devices.

Resumo Objetivo Esta meta-análise teve como objetivo avaliar a sensibilidade e especificidade da colonografia por tomografia computadorizada na detecção de pólipos colorretais. Métodos Foi realizada uma pesquisa bibliográfica nas bases de dados da PubMed e da Web of Science. Resultados Um total de 1.872 pacientes, 57,2% homens e 42,8% mulheres, com idades entre 49 a 82 anos de idade (média de 59,7 ± 5,3 anos) foram incluídos nesta meta análise. A sensibilidade da colonografia por tomografia computadorizada foi estimada em 88,4% (46,3-95,7%; coeficiente de variância [CV]=28,5%) e a especificidade em 73,6% (47,4%-100,0%; CV=37,5%). Para lesões de até 9mm, a sensibilidade foi de 82,5% (62,0-99,9%; CV=25,1%) e a especificidade de 79,2% (32,0-98,0%; CV=22,9%). Para lesõesmaiores que 9mm, a sensibilidade foi de 90,2% (64,0-100,0%; CV=7,4%) e a especificidade de 94,7% (80,0-100,0%; CV=6,2%). Não houve diferença estatisticamente significante entre as sensibilidades por tamanho da lesão (p=0,0958), porém a especificidade foi maior em lesões acima de 9mm (p<0,0001). Conclusão A maioria dos estudos analisados no presente trabalho foi realizada antes de 2010, cerca de uma década depois que a colonografia por tomografia computadorizada passou a ser indicada como método de triagem pelas diretrizes europeias e americanas. Portanto, são necessários mais estudos com o objetivo de analisar a técnica apósmaiores avanços tecnológicos, o que poderia levar ao desenvolvimento de dispositivos mais modernos.

Electronic cleaning of intestinal contents tagging by diatrizoate meglumine for single-source dual-energy CT colonography with sequential acquisitions and volume scanning / 重庆医学

Objective To study the feasibility of applying electronic cleaning to intestinal contents tagging by diatrizoate meglumine for single-source dual-energy CT colonography with sequential acquisitions and volume scanning.Methods Twenty-four volunteers had fine effect of intestinal contents tagging by diatrizoate meglumine,good colorectal distension effect,fine image quality of dual-energy fusion colorectal images,and with informed consents were enrolled in this study.The single-source dual-energy CT colonography with sequential acquisitions and volume scanning was performed with an Acquilion ONE 320 row CT scanner,tube voltage 135 kVp/80 kVp.The intestinal contents conducted the dual-energy electronic cleaned based on decomposition of intestinal contents tagging by diatrizoate meglumine,soft tissue and air.The intestinal contents in one segment of intestinal lumen being 100％ electronically cleaned served as the basic standard,the electronic cleaning effects were divided into the 5 grades:excellent,good,moderate,fair and poor;and grade 1-3 were effective fecal electronic cleaning.Results The grade 1,2,3,4,5 of electronic cleaning effect for solid as the main intestinal contents were 22.2％,53.3％,17.8％,6.7％ and 0％ respectively;and which of electronic cleaning effect for liquid as the main intestinal contents were 47.5％,47.5％,5.0％,0％ and 0％ respectively.The together total effective electronic cleaning of intestinal contents was 97.9％ and the electronic cleaning effect was good.Conclusion Electronic cleaning could be used in the intestinal contents tagging by diatrizoate meglumine for single-source dual-energy CT colonography with sequential acquisitions and volume scanning.

Influence on image quality in low-dose colonography with adaptive statistical iterative reconstruction algorithm / 中华放射医学与防护杂志

Objective To evaluate the feasibility of adaptive statistical iterative reconstruction-V (ASIR-V) to improve image quality in low-dose CT colonography.Methods A series of thirty artificial polyps were established by ligation in an isolated segment of porcine colon.Volume data was acquired on Revolution CT scanner (GE,USA) with High Definition scan mode and different scan parameter combinations:120 kVp with different mAs (10,30,50,70,90,100,120,140,160,180,200,220,240,260,respectively).Images were reconstructed with six different ASIR-V levels of 0 (filtered back projection,FBP),10％,30％,50％,70％ and 90％.Two radiologists were blinded to measure and analyze the objective data independently,including image noise (SD),signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR).The kappa test was used to assess interobserver agreement in subjective image quality score.ICC test was used to examine the consistency of the measurements between two observers.SD,SNR,CNR were performed for statistical analysis in different tube current and different levels of ASIR-V using variance analysis (ANOVA).Results Interobserver agreement for subjective image quality score was good with a kappa value of 0.683.The variation of the tube current(r =0.734,P =0.000) and ASIR-V level(r =0.220,P =0.044) is related to the subjective score of image quality.Under the condition of the same tube current,image quality score of 50％ ASIR-V reconstruction was the highest.Two objective data consistency is good.The differences of image noise (F =423.58,P ＜ 0.05),SNRs(F =124.26,P ＜ 0.05) and CNRs (F =1 030.17,P ＜ 0.05) of different tube current and different levels of ASIR-V reconstruction were statistically significant.In the same tube current,with increased levels of ASIR-V,image noise reduced,CNRs increased.Only in 10,120,140,160,220,240,260 mA,the differences of SNRs were statistically significant(F =8.75-31.36,P ＜ 0.05).For the same level of ASIR-V reconstruction,with the increase of tube current,the image noise decreased,SNR and CNR increased gradually.Conclusions In the CT colonography,the application of ASIR-V algorithm can significantly reduce the noise and enhance the image contrast noise ratio and improve image quality.ASIR-V algorithm with 50％ has better performance in reducing CT image noise.

Value of the multi-slice spiral CT angiography, CT colonography and image fusion technology in preoperative evaluation of laparoscopic right colon cancer / 中华消化外科杂志

Objective To observe the distribution and variation of right colonic vessels,and investigate the clinical value of computed tomography angiography (CTA),computed tomography colonography (CTC) and image fusion technology in preoperative evaluation of laparoscopic right colonic cancer (RCC).Methods The retrospective and descriptive study was conducted.The clinicopathological data of 38 patients who underwent laparoscopic extended radical resection of RCC + D3 lymphadenectomy in the Affiliated Wuxi Second People's Hospital of Nanjing Medical University between January 2015 and July 2017 were collected.Patients received preoperative plain and enhanced scans of abdominal and pelvic CT.The original images were reconstructed and fused by CTA and CTC,and then coming out with three-dimensional images of blood vessels and gut.Observation indicators:(1) branches of superior mesenteric artery (SMA);(2) positional relationship between SMA and superior mesenteric vein (SMV);(3) composition of gastrocolic venous trunk.Results Scan images of 38 patients had fused with scan images of vessels and primary tumors and reached the diagnostic standard,with a good imaging performance.Distribution of blood vessels of virtual reality (VR) images and were compared with that of naked blood vessels under intraoperative laparoscopy,showing a coincidence rate of 100.0％ (38/38).(1) Branches of SMA:results of CTA and intraoperative anatomy showed that the occurrence rate of the right colonic artery,middle colonic artery and ileocolic artery were respectively 94.7％ (36/38),92.1％ (35/38) and 100.0％ (38/38).A right colonic artery was found in 28 patients.Ten patients had structure variation of right colonic artery,including 3 with 2 right colonic arteries and 2 without right colonic artery.The right colonic artery and middle colonic artery merged into the same trunk and then flowed into SMA were detected in 2 patients;the right colonic artery and ileocolic artery merged into the same trunk and then flowed into SMA were detected in 3 patients.(2) Positional relationship between SMA and SMV:results of CTA and intraoperative anatomy showed that the occurrence rate of both SMA and SMV was 100.0％ (38/38).The SMA in 20 patients was located in the ventral side of SMV;SMA in 18 patients was located in the dorsal side of SMV.(3) Composition of gastrocolic venous trunk:results of CTA and intraoperative anatomy showed that 29 of 38 patients had gastrocolic venous trunks,which belonged to four sources,including right colonic vein,middle colonic vein,fight gastric epiploic vein and anterior superior pancreaticoduodenal vein.Among 29 patients,18 had 2-or 3-branch type of gastrocolic trunk that consisted of the right gastric epiploic vein,middle colonic vein and right colonic vein;3 had 2-branch type of gastric pancreatic trunk that consisted of the right gastric epiploic vein and anterior superior pancreaticoduodenal vein;8 had 3-or 4-branch type of stomach-pancreas-colon trunk that consisted of right gastric epiploic vein,anterior superior pancreaticoduodenal vein,right colonic vein and middle colonic vein.Conclusion CTA,CTC and image fusion technology can intuitively show the anatomy and variation of right colonic vessels,with a high clinical value.

Double-Balloon Endoscopy after Incomplete Colonoscopy and Its Comparison with Computed Tomography Colonography

BACKGROUND/AIMS: Because of the national screening program for colorectal carcinoma in The Netherlands, the number of colonoscopies has increased. In case of incomplete colonoscopy, computed tomography colonography (CTC) and double-balloon colonoscopy (DBc) are alternative options. This study evaluated cecal intubation rate and pathology detection rate in the previously unexplored part of the colon, complication rate of DBc, and CTC results after incomplete colonoscopy. METHODS: Retrospective observational study in a tertiary referral hospital regarding DBc and CTC reports from cases with incomplete colonoscopy. RESULTS: Sixty-three DBcs were performed after incomplete colonoscopy. Cecal intubation rate was 95%. Detection rate was 58% (5% carcinoma and 3% high-grade dysplastic adenoma). CTC preceded 54% of DBcs and 62% of CTC findings were confirmed. In 16%, a biopsy was taken, and in 60%, an intervention (mostly polypectomy) was performed. One major complication (1.5%) occurred, i.e., arterial bleeding due to polypectomy necessitating right hemicolectomy. CTC (n=213) showed a possible lesion in 35%, and could be confirmed by follow-up endoscopy or surgery in 65%. CONCLUSIONS: DBc is effective and safe for completion of colon inspection in incomplete colonoscopy. In patients with a high likelihood of pathology, DBc is preferred over CTC.

Pre- and postoperative imaging methods in colorectal cancer / Métodos de imagem no estadiamento pré e pós operatórios do câncer colorretal

ABSTRACT Introduction: Among the screening tests for colorectal cancer, colonoscopy is currently considered the most sensitive and specific technique. However, computed tomography colonography (CTC), magnetic resonance imaging (MRI), and transrectal ultrasonography have gained significant ground in the clinical practice of pre-treatment, screening and, more recently, post-treatment and surgical evaluation. Objective: To demonstrate the high accuracy of CT and MRI for pre and postoperative colorectal cancer staging. Methods: Search and analysis of articles in Pubmed, Scielo, Capes Periodicals and American College of Radiology with headings "colorectal cancer" and "colonography". Weew selected 30 articles that contained radiological descriptions, management or statistical data related to this type of neoplasia. The criteria for radiological diagnosis were the American College of Radiology. Results : The great majority of patients with this subgroup of neoplasia is submitted to surgical procedures with the objective of cure or relief, except those with clinical contraindication. CTC colonography is not the most commonly used technique for screening; however, it is widely used for treatment planning, assessment of the abdomen for local complications or presence of metastasis, and post-surgical evaluation. MRI colonography is an alternative diagnostic method to CT, recommended by the American Society of Gastrointestinal Endoscopy. Although there are still no major studies on the use of MRI for screening, the high resolution examination has now shown good results for the American Joint Committee on Cancer TNM classification. Conclusion: MRI and CT represent the best means for colorectal neoplasm staging. The use of these methods as screening tools becomes beneficial to decrease complications and discomfort related to colonoscopy.

RESUMO Introdução : Dentre os testes de rastreamento de câncer colorretal, a colonoscopia é atualmente considerada a técnica de maior sensibilidade e especificidade. Entretanto, a colonografia por tomografia computadorizada (CTC), a ressonância nuclear magnética (RNM) e a ultrassonografia transrretal têm ganhado espaço significativo na prática clínica de análise pré-tratamento, rastreio e, mais recentemente, no pós-tratamento e na avaliação cirúrgica. Objetivo: Demonstrar a alta acurácia da CT e RNM para estadiamento pré e pós-operatório do câncer colorretal. Métodos : Busca e análise de artigos no Pubmed, Scielo, Periódicos Capes e Colégio Americano de Radiologia com descritores "câncer colorretal" e "colonografia". Foram selecionados 30 artigos que continham descrições radiológicas, manejo ou dados estatísticos relacionados a este tipo de neoplasia. O critério de diagnóstico radiológico adotado foi o do Colégio Americano de Radiologia. Resultados : A maioria dos pacientes portadores desse subgrupo de neoplasias é submetida a procedimentos cirúrgicos com o objetivo de cura ou alívio, exceto aqueles que possuem contraindicação clínica. A colonografia por tomografia computadorizada não é a técnica de maior utilização para rastreamento; no entanto, ela é amplamente utilizada para o planejamento de tratamento, avaliação do abdome quanto à complicações locais ou presença de metástase e avaliação pós-cirúrgica. A colonografia por RNM é método diagnóstico alternativo à CT recomendado pela American Society Gastrointestinal Endoscopy. Embora ainda não haja grandes estudos sobre o uso da RNM para rastreamento, atualmente o exame de alta resolução tem apresentado bons resultados para a classificação TNM da American Joint Committee on Cancer. Conclusão : RNM e a TC representam os melhores meios para rastreamento de neoplasias colorretais. O uso destes métodos torna-se benéfico para diminuir as complicações e desconforto relacionadas à colonoscopia.

Study on colorectal distension with partially automated and individualized insufflation of air for dual-energy CT colonography / 重庆医学

Objective To study the compliance of examinees,and effectiveness of colorectal distension with partially automated and individualized insufflation of air for dual-energy CT colonography.Methods Forty-six healthy adult volunteers without history of conditions affecting gastrointestinal motor function were enrolled in this study.One day before CT examination,volunteers were asked to orally administered 60 mL 4% diatrizoate meglumine five times for fecal tagging.Air was insufflated by using an inflator in a partially automated and individualized manner.The volunteers were initially asked to assume the right lateral decubitus position,then slowly turn to the supine position.Insufflation rate began at 1.5 L/min,and decreased to 0.5 L/min at later stage.The necessity and volume of air insufflation were decided according to effectiveness of colorectal distension on CT scout images,self-reported sensation of volunteers,and intestinal pressure.Dual-energy CT scanning was performed,and dual-energy blended images were acquired.Compliance of volunteers was statistically analyzed.The effectiveness of colorectal segments distension was statistically analyzed by using Kruskal-Wallis H test.Results No abdominal pain,bloating,nausea or vomiting were noted in the 46 volunteers.All volunteers easily accepted colorectal insufflation of air,with grade 1 compliance.The effectiveness of colorectal distension of grades 1,2,3 and 4 were 0%,2.1%,5.1% and 92.8%,respectively.The difference of effectiveness of colorectal segments distension had no statistical significance(χ2=6.19,P=0.288).The effectiveness of insufflation was poor in 6 colorectal segments,including 2 in sigmoid colon and 2 in rectum.Effectiveness of insufflation was suboptimal in 14 colorectal segments,including 4 in descending colon,4 in sigmoid colon,and 3 in rectum.Conclusion Compliance of examinees with partially automated and individualized insufflation of air for dual-energy CT colonography is excellent,with good effectiveness of colorectal distension.

Clinical Significance of Preoperative Virtual Colonoscopy for Evaluation of the Proximal Colon in Patient With Obstructive Colorectal Cancer

PURPOSE: Virtual colonoscopy is the most recently developed tool for detecting colorectal cancers and polyps, but its effectiveness is limited. In our study, we compared the result of preoperative virtual colonoscopy to result of preoperative and postoperative colonoscopy. We evaluated also the accuracy of preoperative virtual colonoscopy in patients who had obstructive colorectal cancer that did not allow passage of a colonoscope. METHODS: A total of 164 patients who had undergone preoperative virtual colonoscopy and curative surgery after the diagnosis of a colorectal adenocarcinoma between November 2008 and August 2013 were pooled. We compared the result of conventional colonoscopy with that of virtual colonoscopy in the nonobstructive group and the results of preoperative virtual colonoscopy with that of postoperative colonoscopy performed at 6 months after surgery in the obstructive group. RESULTS: Of the 164 patients, 108 were male and 56 were female patients. The mean age was 62.7 years. The average sensitivity, specificity, and accuracy of virtual colonoscopy for all patients were 31.0%, 67.2%, and 43.8%, respectively. In the nonobstructive group, the average sensitivity, specificity, and accuracy were 36.6%, 66.2%, and 48.0%, respectively, whereas in the obstructive group, they were 2%, 72.4%, and 25.4%. Synchronous cancer was detected via virtual colonoscopy in 4 of the 164 patients. CONCLUSION: Virtual colonoscopy may not be an effective method for the detection of proximal colon polyps, but it can be helpful in determining the therapeutic plan when its results are correlated with the results of other studies.

Effect of Reducing Abdominal Compression during Prone CT Colonography on Ascending Colonic Rotation during Supine-to-Prone Positional Change

OBJECTIVE: To determine the effect of reduced abdominal compression in prone position on ascending colonic movement during supine-to-prone positional change during CT colonography (CTC). MATERIALS AND METHODS: Eighteen consecutive patients who had undergone prone CTC scanning with cushion blocks placed under the chest and hip/thigh to reduce abdominal compression and had confirmed sessile polyps > or = 6 mm in the well-distended, straight, mid-ascending colon, were included. Radial location along the ascending colonic luminal circumference (degrees) was measured for 24 polyps and 54 colonic teniae on supine and prone CTC images. The supine-to-prone change ranging between -180degrees and +180degrees (- and + for internal and external colonic rotations, respectively), was determined. In addition, possible causes of any ascending colonic rotations were explored. RESULTS: Abdominal compression during prone CTC scanning completely disappeared with the use of cushion blocks in 17 of 18 patients. However, some degrees of ascending colonic rotation were still observed, with the radial location changes of -22degrees to 61degrees (median, 13.9degrees) for the polyps and similar degrees for teniae. Fifty-four percent and 56% of polyps and teniae, respectively, showed changes > 10degrees. The radial location change of the polyps was significantly associated with the degree of anterior shift of the small bowel and mesentery (r = 0.722, p < 0.001) and the degree of posterior displacement of the ascending colon (r = 0.566, p = 0.004) during supine-to-prone positional change. CONCLUSION: Ascending colonic rotation upon supine-to-prone positional change during CTC, mostly in the form of external rotation, is not eliminated by removing abdominal compression in prone position.

Colon Capsule Endoscopy: Where Are We and Where Are We Going

Colon capsule endoscopy (CCE) is a noninvasive technique for diagnostic imaging of the colon. It does not require air inflation or sedation and allows minimally invasive and painless colonic evaluation. The role of CCE is rapidly evolving; for example, for colorectal screening (colorectal cancer [CRC]) in average-risk patients, in patients with an incomplete colonoscopy, in patients refusing a conventional colonoscopy, and in patients with contraindications for conventional colonoscopy. In this paper, we comprehensively review the technical characteristics and procedure of CCE and compare CCE with conventional methods such as conventional colonoscopy or computed tomographic colonography. Future expansion of CCE in the area of CRC screening for the surveillance of polyps and adenomatous lesions and for assessment of inflammatory bowel disease is also discussed.

Effect on colorectal cleansing of CT colonography with gulping down bisacodyl before or after oral taking polyethylene glycol / 重庆医学

Objective To comparative study the effect on colorectal cleansing of CT colonography with gulping down 10 mg bisacodyl before or 1 h after oral taking 2 liter polyethylene glycol .Methods Forty participants with informed consent were appor‐tioned to group A ,group B randomly ,20 cases in each group .On the day before CT colonography ,participants in group A oral took 20 mL of 40% W/V barium sulfate prior to 3 mealtime ,and 20 mL of 60% diatrizoate meglumine diluted in 250 mL of water after supper ,then gulped down 10 mg bisacodyl enteric‐coated tablets 1 hour before oral taking 2 liter polyethylene glycol electrolyte so‐lution .Participants in group B were the same as that in group A ,with the exception of gulping down 10 mg bisacodyl enteric‐coated tablets 1 hour after oral taking 2 liter polyethylene glycol electrolyte solution .Cleansing efficacy of stool and fluid ,and attenuation value of remainder fluid between the two groups were analyzed statistically .Results In group A ,score of cleansing efficacy of stool (1 .96 ± 0 .11) was lower than that in group B (2 .01 ± 0 .12) ,segments with good cleansing efficacy of stool (87/120 segments , 72 .50% ) was higher than that in group B (83/120 segments ,69 .17% ) ,the difference was not statistically significant (P>0 .05) .In group A ,score of cleansing efficacy of fluid (1 .50 ± 0 .06) was lower than that in group B (1 .53 ± 0 .06) ,segments with good cleansing efficacy of fluid(113/120 segments ,94 .17% ) was higher than that in group B (111/120 segments ,92 .50% ) ,the differ‐ence was not statistically significant (P>0 .05) .Attenuation value of remainder fluid [(729 ± 29)HU ] in group A was higher than that in group B[(653 ± 25)HU] ,the difference was statistically significant(P<0 .05) .Conclusion Gulping down 10 mg Bisacodyl before or after oral taking 2 liter polyethylene glycol has no effect on cleansing of stool and fluid ,with good cleansing efficacy .The former has better cleansing efficacy of fluid ,is beneficial to detecting polyps for CT colonography .

Research progress and clinical applications of computed tomographic colonography in coloretal cancer / 中国癌症杂志

Computed tomography colonography (CTC) is a well-established technique for evaluation of colorectal cancer (CRC). Signiifcant advances have been made in the technique of CTC since its inception. Besides being an excellent tool for detection of CRC, it is minimally invasive, less time-consuming and well tolerated by patients. Furthermore, it has fewer complications than conventional colonoscopy (CC) or barium enema (BE). The application of new technologies, such as electronic cleansing (EC) and dual-energy CT (DECT), enriches the examination of CTC. In 2005, a standardized reporting scheme, CT colonography reporting and data system (C-RADS), was put forward by the working group on virtual colonoscopy. They proposed that the report should include lesion size, number, morphology, location, attenuation and recommendations for lesion surveillance. New research progress and clinical applications of CTC in CRC are reviewed in this article. In addition, the paper also brielfy touches upon technique, indications, contraindications, safety and risk of CTC.

Clinical study on the accuracy of dual-energy computed tomography colonography in colorectal neoplasia detection / 中华消化杂志

[Abstract ] Objective To compare the accuracy between regular computed tomography colonography (CTC)and dual-energy CTC in lesion detection.Methods Twenty-eight patients with clinical suspicious space occupying lesions of the colon were selected.All patients were underwent dual-energy mode contrast-enhanced CT scan and the data were reconstructed with colonography and dual-energy iodine maps methods.The diameter,enhanced computed tomography (CT)value and iodine value were measured.The results of colonoscopy and pathology were taken as gold standard.The sensitivity, specificity,accuracy,positive predictive value and negative predictive value of regular CTC and dual-energy CTC were compared.Variance analysis was performed for measurement data comparison among groups and chi-square test was used for count data analysis.Results Among 28 patients,colorectal lesions were detected in 24 cases by regular CTC,of which four cases were false-positive and one case was false-negative confirmed by colonoscopy and pathology.Colorectal lesions were detected in 20 cases by dual-energy CTC,of which no false-positive and one case was false negative confirmed by colonoscopy and pathology.The contrast enhanced CT value of polyps,adenoma,adenocarcinoma and stool was (38.54± 6.82),(49.16±7.31 ),(52.61 ±5 .93 )and (34.00±1 .41 )Hu,respectively.The enhanced value of adenoma and adenocarcinoma was significantly higher than that of polyps and stool,the differences were statistically significant among groups (F = 10.760,P = 0.001 ).There was no significant difference between polyps and stool (t=1 .44,P =0.188).The sensitivity of regular CTC and dual-energy CTC in lesion detection was 95 .6% (95 %cofidence interval(CI ):77.9%-99.2%)and 95 .6% (95 %CI :77.9%-99.2%),respectively.The specificity was 42.8% (95 %CI :15 .4%-93.5 %)and 100.0% (95 %CI :47.9%-100.0%).Conclusion Compared with traditional CTC,dual-energy CTC would distinguish lesions from stool,help differentiate between benign and malignant tumors and further increase the accuracy of CTC diagnosis.

Diagnóstico de neoplasia colorrectal: descripción de hallazgos en colonoscopia virtual y convencional / Diagnosis of Colorectal Neoplasia: Description of Findings On Virtual Colonoscopy And Conventional Colonoscopy

Introducción: La colonoscopia virtual surge como método diagnóstico en las diferentes patologías del colon. Objetivos: Describir y comparar los hallazgos de la colonoscopia convencional y la virtual relacionados con la presencia de neoplasias y sus características morfológicas de tamaño y localización, en pacientes con sospecha de patología de colon. Métodos: Estudio descriptivo de registro de casos clínicos. Se incluyeron 23 pacientes remitidos al servicio de gastroenterología para realización de colonoscopia, durante septiembre de 2007 y mayo de 2008. Los pacientes fueron llevados a colonoscopia virtual y, posteriormente, a colonoscopia óptica; los hallazgos fueron clasificados por un radiólogo y un gastroenterólogo, respectivamente, según su localización en los diferentes segmentos del colon, así como el tamaño, el tipo de lesión en mucosa, submucosa, carcinomas y lesiones extrínsecas. Resultados: El grado de concordancia de los dos procedimientos para el diagnóstico de pólipos fue de 76 %. Se encontró que la colonoscopia virtual tiene una sensibilidad para el diagnóstico de pólipos de 85,7 % IC (52,6-100) y un valor predictivo negativo de 92,9 % IC (75,8-100), valores considerados importantes, pero con amplios intervalos de confianza atribuidos a la poca cantidad de pacientes. Conclusiones: En el presente estudio se encontró un alto valor predictivo negativo, lo que hace que la colonoscopia virtual pueda ser el método diagnóstico inicial de elección en el tamizaje de las patologías colorrectales. En caso de ser negativa, se descarta patología; si es positiva, el método diagnóstico a seguir para confirmar los hallazgos sería la colonoscopia directa.

Introduction: Virtual colonoscopy emerges as a new diagnostic method to study the pathology that affects the colon. Objectives: To describe and compare the findings of conventional colonoscopy and virtual colonoscopy related to the presence of a neoplasia according to its morphology, size and location in patients suspected of having colonic pathology. Material and Methods: Descriptive study of the review of clinical cases. 23 patients submitted to the gastroenterology service between September 2007 and May 2008 for a conventional colonoscopy were included. The patients were taken to virtual colonoscopy and, subsequently, to optical colonoscopy; the findings were classified by a radiologist and a gastroenterologist, respectively, according to its location in the different segments of the colon, as well as size, the type of lesion in the mucous and submucous membrane, carcinomas and extrinsic lesions. Results: The degree of concordance between the two procedures on the diagnosis of polyps was 76%. Virtual colonoscopy had 85.7% sensibility (IC 52.6-100) and a negative predictive value of 92.9% (IC 75.8-100) for the diagnosis of polyps. These are considered important findings, but with wide intervals of confidence due to the small quantity of patients. Conclusion: In this study we found a high negative predictive value, which means that virtual colonoscopy could be the initial diagnostic method of choice in the screening of colorectal pathologies. In case it is negative, pathology is ruled out. If it is positive, the diagnosis method to follow in order to confirm the findings would be direct colonoscopy.

The Korean guideline for colorectal cancer screening

Colorectal cancer is the third most common cancer in Korea; it is the second most common cancer in men and the third most common in women. The incidence rate in Korea has continuously increased since 1999 when the National Cancer Registry statistics began. Currently; there are several screening modalities; that have been recommended by expert societies, including fecal occult blood test, colonoscopy, computed tomographic colonography The annual fecal immunochemical test (FIT) has been used in adults aged 50 and older as part of the National Cancer Screening Program in Korea since 2004. Although several study results from regional or national colorectal cancer screening programs in other countries have been reported, the National Cancer Screening Program in Korea has not yet been evaluated with evidence-based methods. Herein report the consensus statements on the National Screening Guideline for colorectal cancer developed by a multi-society expert committee in Korea, as follows: 1) We recommend annual or biennial FIT for screening for colorectal cancer in asymptomatic adults, beginning at 45 years of age and continuing until 80 years (recommendation B). 2) There is no evidence for the risks or benefits of FIT in adults older than 80 years (recommendation I). 3) Selective use of colonoscopy for colorectal cancer screening is recommended, taking into consideration individual preference and the risk of colorectal cancer (recommendation C). 4) There is no evidence for the risks or benefits of double-contrast barium enema for colorectal cancer screening in asymptomatic adults (recommendation I). 5) There is no evidence for the risks or benefits of computed tomographic colonography for colorectal cancer screening in asymptomatic adults (recommendation I).

Vascular Map Combined with CT Colonography for Evaluating Candidates for Laparoscopic Colorectal Surgery

Contrast-enhanced computed tomography colonography (CE-CTC) is a useful guide for the laparoscopic surgeon to avoid incorrectly removing the colonic segment and the failure to diagnose of synchronous colonic and extra-colonic lesions. Lymph node dissection and vessel ligation under a laparoscopic approach can be time-consuming and can damage vessels and organs. Moreover, mesenteric vessels have extreme variations in terms of their courses and numbers. We describe the benefit of using an abdominal vascular map created by CE-CTC in laparoscopic colorectal surgery candidates. We describe patients with different diseases (colorectal cancer, diverticular disease, and inflammatory bowel disease) who underwent CE-CTC just prior to laparoscopic surgery.

Using computed tomography colonography in patients at high risk of colorectal cancer - a prospective study in a university hospital in South America

OBJECTIVES: The purpose of our study was to report the results of the implementation of computed tomography colonography in a university hospital setting serving a Brazilian population at high risk of colorectal cancer. METHODS: After creating a computed tomography colonography service in our institution, 85 patients at high risk of colorectal cancer underwent computed tomography colonography followed by a same-day optical colonoscopy from September 2010 to May 2012. The overall accuracy of computed tomography colonography in the detection of lesions ≥6 mm was compared to that of optical colonoscopy (direct comparison). All colonic segments were evaluated using quality imaging (amount of liquid and solid residual feces and luminal distension). To assess patient acceptance and preference, a questionnaire was completed before and after the computed tomography colonography and optical colonoscopy. Fisher's exact test was used to measure the correlations between colonic distension, discomfort during the exam, exam preference and interpretation confidence. RESULTS: Thirteen carcinomas and twenty-two lesions ≥6 mm were characterized. The sensitivity, specificity and accuracy of computed tomography colonography were 100%, 98.2% and 98.6%, respectively. Computed tomography colonography was the preferred method of investigation for 85% of patients. The preparation was reported to cause only mild discomfort for 97.6% of patients. According to the questionnaires, there was no significant relationship between colonic distension and discomfort (p>0.05). Most patients (89%) achieved excellent bowel preparation. There was a statistically significant correlation between the confidence perceived in reading the computed tomography colonography and the quality of the preparation in each colonic segment (p≤0.001). The average effective radiation dose per exam was 7.8 mSv. CONCLUSION: It was possible to institute an efficient computed ...

Colonografia por tomografia computadorizada versus colonoscopia óptica no rastreamento do câncer colorretal: uma revisão sistemática / Computed tomographic colonography versus optical colonoscopy in colorectal cancer screening: a systematic review

Objetivo: comparar, por meio de uma revisão sistematizada, a colonografia por tomografia (CTC) versus colonoscopia óptica (CO) em relação ao rastreamento e vigilância do câncer colorretal (CCR). Método: foram analisados estudos em inglês e português sobre CTC e CO realizados em humanos adultos de ambos os sexos, publicados no MedLine/PubMed (National Library of Medicine) e no Scielo (Scientific Eletronic Library Online) no período entre 1990 a 2013. A busca incluiu combinações de palavras-chave (Colonoscopy, Cólonoscopic surgery, virtual Colonoscopy, CT Colonography) com boolianos AND e OR. Os critérios de inclusão foram ensaios clínicos controlados e randomizados, estudo de revisão, revisões sistemáticas com ou sem metanálise, consenso, pacientes adultos, pacientes assintomáticos ou sintomáticos. Os critérios de exclusão foram pacientes inapropriados e somente em resumo. Resultados: foram selecionados 26 estudos com melhor abordagem dos desfechos selecionados para rastreamento e vigilância do câncer (CCR). O número global de pacientes submetidos às variáveis foi de 397.342 indivíduos. Os valores das variáveis de sensibilidade e especificidade para detecção de pólipos maior ou igual a 10mm e câncer colorretal apresentam percentagens semelhantes, sendo a taxa de sensibilidade da CTC diretamente proporcional ao tamanho do pólipo. A taxa de pacientes submetidos à CO após a CTC variou de 12% a 36,4%; destes, 3,8% apresentaram lesões significativas. A análise da taxa de CO incompleta obteve um padrão de variações entre 11% e 64,8%. A aceitação dos pacientes, tanto para o preparo intestinal como para o procedimento, foi maior para a CTC. Os achados extracólicos nos pacientes submetidos à CTC foram analisados e variaram de 58 a 69%. As complicações dos dois métodos foram baixas, maior na CO. Conclusão: as diferenças na sensibilidade e especificidade entre a CO e a CTC no rastreamento e vigilância do CCR não são relevantes. A indicação de CO após CTC deve seguir critérios consensuais para evitar aumento de custos e de riscos ao paciente. Pacientes com CO incompleta têm indicação de realizar CTC por se enquadrar no grupo de alto risco para desenvolver CCR. A aceitação dos pacientes na realização dos dois métodos é boa e não representa impedimento ao rastreamento e vigilância do CCR. Os achados extracólicos na CTC é um benefício adicional para o paciente. As complicações inerentes aos dois métodos não superam o impacto positivo dos mesmos na prevenção do CCR.

Objective: to compare in a systematic review the computed tomographic Colonography (CTC) and the optical Colonoscopy (OC) methods for the screening and monitoring of colorectal cancer (CRC). Method: english and portuguese studies on CTC and OC that were carried out on adult humans of both genders that had been published in MedLine/PubMed (National Library of Medicine) and SciELO (Scientific Electronic Library Online) between 1990 and 2013 were analyzed. The search included combinations of keywords (Colonoscopy, Cólonoscopic surgery, virtual Colonoscopy, CT Colonography, etc.) with the AND and OR Boolean operators. The inclusion criteria were as follows: controlled and randomized clinical trials, review studies, systematic reviews with or without meta-analysis, consensus, adult patients, and asymptomatic or symptomatic patients. The exclusion criteria were as follows: unsuitable patients and manuscripts only containing abstracts. Results: twenty-six studies that included the selected outcomes for screening for and monitoring CRC were selected. The overall number of patients analyzed was 397, 342 individuals. The sensitivity and specificity percentages for the detection of polyps greater than or equal to 10 mm and for colorectal cancer were similar between the two methods, and the CTC sensitivity rate was directly proportional to the size of the polyp. The rate of patients undergoing OC after CTC ranged from 12% to 36.4%, and of these patients, 3.8% had significant lesions. The analysis of the incomplete OC rate found variation ranging from 11 to 64.8%. The acceptance rates of the patients for both intestinal preparation and for the procedure were greater for CTC. The extracolic findings in patients undergoing CTC were analyzed and ranged from 58 to 69%. Complications were minimal for the patients undergoing both methods and higher for those in the OC group. Conclusion: the differences in the sensitivity and specificity of OC and CTC in screening and monitoring CRC are not significant. The indication of OC after CTC must follow agreed-upon criteria to avoid increased costs and risks to the patient. Patients with an incomplete OC should undergo CTC, as they fall within the high risk group for developing CRC. The acceptance of patients undergoing the two methods is good and does not represent an impediment to screening for and monitoring CRC. The extracolic findings, in the CTC group, is an additional benefit to the patient. The complications inherent in the two methods do not outweigh their positive impacts in the prevention of CRC.

Virtual Colonoscopy is Feasible in Geriatric Patients-A Case Series.

Virtual colonoscopy (VC) or computed tomographic colonography is now an established imaging test in the detection of colorectal cancer. Like other modern imaging tests VC requires highly compliant patients (rectal air insufflation, breath hold, imaging in supine and prone position). As patients are getting older VC is also requested in the elderly. In a case series of geriatric patients (mean age 83 years) undergoing VC after incomplete optical colonoscopy 92.7% of all colonic segments were adequately visualized. VC seems to be feasible in geriatric patients and has therefore replaced barium enema in this patient group after incomplete optical colonoscopy at our department.

Colonografia por tomografia computadorizada na visão do médico encaminhador: qual o seu valor segundo a visão de especialistas? / CT colonography: the value of this method in the view of specialists

Objetivo: Mapear a visão dos cirurgiões sobre o papel da colonografia por tomografia computadorizada (CTC). Materiais e Métodos: Envio de questionário eletrônico aos membros do Colégio Brasileiro de Cirurgiões. O questionário constou de 16 questões de múltipla escolha que abordaram dados demográficos e conhecimentos gerais sobre a CTC. Resultados: Foram obtidas 144 respostas; 90,3% dos especialistas eram homens, 60% com menos de 30 anos de formado, 77,1% eram gastrocirurgiões, 22,9% eram cirurgiões gerais, 53,5% encontravam-se na vida acadêmica e 59,7% exerciam sua atividade profissional em cidades com mais de 500.000 habitantes. Em relação ao conhecimento da CTC, 84,7% conheciam o método, 70,8% sabiam como é realizado, 56,9% relataram conhecer o preparo intestinal utilizado, 31,3% utilizavam o método e 53,5% conheciam algum serviço de CTC na cidade em que atuam. Cerca de metade dos profissionais não conhecia a precisa indicação do método. Profissionais que atuam em cidades com mais de 500.000 habitantes conhecem e utilizam mais o método (p < 0,005). Houve uma tendência de os profissionais com carreira acadêmica utilizarem mais o método. Conclusão: A CTC, embora ainda pouco utilizada em nosso meio, é bastante conhecida, principalmente em grandes centros urbanos e no ambiente acadêmico. .

Objective: To map the view of surgeons on the role played by computed tomography colonography (CTC). Materials and Methods: An electronic questionnaire was sent to members of the Brazilian College of Surgeons. The questionnaire consisted of 16 multiple-choice questions about demographics and general knowledge about CTC. Results: The authors obtained 144 responses; 90.3% of the specialists were men, 60% with less than 30 years from graduation, 77.1% were gastrointestinal surgeons, 22.9% were general surgeons, 53.5% were involved in academic activity, and 59.7% had their professional activity in cities with more than 500,000 inhabitants. As regards the knowledge about CTC, 84.7% of the respondents knew the method, 70.8% knew how it is performed, 56.9% reported knowing the bowel preparation used for the procedure, 31.3% used the method, and 53.5% knew some CTC service in their city. About half of the respondents did not know the precise indication of the method. The method is most frequently known and used by professionals working in cities with more than 500,000 inhabitants (p < 0.005). There was a tendency of a more frequent use of the method by the professionals pursuing an academic career. Conclusion: Despite its infrequent use in Brazil, CTC is a well known method, particularly in large urban centers and in the academic environment. .