Three-dimensional reconstruction of computed tomography colonography discloses anatomic features associated with colonoscopy failure.

Objectives: Three-dimensional virtual reality (3D VR) permits precise reconstruction of computed tomography (CT) images, and these allow precise measurements of colonic anatomical parameters. Colonoscopy proves challenging in a subset of patients, and thus CT colonoscopy (CTC) is often required to visualize the entire colon. The aim of the study was to determine whether 3D reconstructions of the colon could help identify and quantify the key anatomical features leading to colonoscopy failure. Design: Retrospective observational study. Methods: Using 3D VR technology, we reconstructed and compared the length of various colonic segments and number of bends and colonic width in 10 cases of CTC in technically failed prior colonoscopies to 10 cases of CTC performed for non-technically failure indications. Results: We found significant elongation of the sigmoid colon (71 ± 23 cm versus 35 ± 9; p = 0.01) and of pancolonic length (216 ± 38 cm versus 158 ± 20 cm; p = 0.001) in cases of technically failed colonoscopy. There was also a significant increase in the number of colonic angles (17.7 ± 3.2 versus 12.7 ± 2.4; p = 0.008) in failed colonoscopy cases. Conclusion: Increased sigmoid and pancolonic length and more colonic bends are novel factors associated with technical failure of colonoscopy.

Acceptability of alternative technologies compared with faecal immunochemical test and/or colonoscopy in colorectal cancer screening: A systematic review.

OBJECTIVE: Colorectal cancer (CRC) is the third most common cancer and the second largest cause of cancer-related death worldwide. Current CRC screening in various countries involves stool-based faecal immunochemical testing (FIT) and/or colonoscopy, yet public uptake remains sub-optimal. This review assessed the literature regarding acceptability of alternative CRC screening modalities compared to standard care in average-risk adults. METHOD: Systematic searches of MEDLINE, EMBASE, CINAHL, Cochrane and Web of Science were conducted up to February 3rd, 2022. The alternative interventions examined were computed tomography colonography, flexible sigmoidoscopy, colon capsule endoscopy and blood-based biomarkers. Outcomes for acceptability were uptake, discomfort associated with bowel preparation, discomfort associated with screening procedure, screening preferences and willingness to repeat screening method. A narrative data synthesis was conducted. RESULTS: Twenty-one studies met the inclusion criteria. Differences between intervention and comparison modalities in uptake did not reach statistical significance in most of the included studies. The findings do suggest FIT as being more acceptable as a screening modality than flexible sigmoidoscopy. There were no consistent significant differences in bowel preparation discomfort, screening procedure discomfort, screening preference and willingness to repeat screening between the standard care and alternative modalities. CONCLUSION: Current evidence comparing standard colonoscopy and stool-based CRC screening with novel modalities does not demonstrate any clear difference in acceptability. Due to the small number of studies available and included in each screening comparison and lack of observed differences, further research is needed to explore factors influencing acceptability of alternative CRC modalities that might result in improvement in population uptake within different contexts.

Colonic lipomas revisited on CT colonography.

PURPOSE: CT colonography (CTC) is growing in its utilization as a nationally approved colorectal cancer screening test. After colonic polyps, lipomas are the second most common colonic lesions and their accurate and rapid recognition are important. METHODS: This retrospective Institutional Review Board approved study was performed at two large academic university-based institutions. 1044 patients underwent CTC at Institution A from 2010 to 2018 and 1094 patients underwent CTC at Institution B from 2003 to 2015. All CTC examinations with at least one colonic lipoma in their report were evaluated by a fellowship-trained abdominal imaging radiologist. 47 CTC examinations containing 59 colonic lipomas were detected and included. Segmental location, sessile versus pedunculated morphology, multiplicity, average attenuation, and largest lesion diameter were evaluated. A review of the current literature on colonic lipomas is entailed. RESULTS: The overall incidence of colonic lipoma was 2.2% in women and 2.3% in men. Mean age for detection of colonic lipomas on CTC was 66.9 years. Segmental locations of colonic lipomas include ascending colon (39%), transverse colon (19%), ileocecal valve (12%), cecum (12%), descending colon (10%), and rectosigmoid (8%). 9% of colonic lipomas were multiple, 42% were pedunculated, and 58% were sessile. The mean (range) size of detected lipomas was 19 (6-59) mm. The mean (range) attenuation was - 132 (- 41 to - 258) HU. CONCLUSION: Most colonic lipomas are located in the ascending colon. Although they are typically solitary, just under 10% are multiple, and although they are most often sessile, slightly under half are pedunculated mimicking polyps. CTC detects smaller lipomas than optical colonoscopy.

The Present and Future of Colorectal Cancer Screening.

There have been multiple recent updates for recommendations pertaining to colorectal cancer (CRC) screening. Among the most notable is the recommendation from several guideline-issuing bodies to initiate CRC screening examinations at 45 years of age for individuals at average risk for CRC. Current CRC screening methods include stool-based tests and colon visualization examinations. Currently recommended stool-based tests include fecal immunochemical testing, high-sensitivity guaiac-based fecal occult blood testing, and multitarget stool DNA testing. Visualization examinations include colonoscopy, computed tomography colonography, colon capsule endoscopy, and flexible sigmoidoscopy. Although these screening tests have shown encouraging results for CRC detection, there are important differences between these testing modalities for precursor lesion detection and management. In addition, emerging CRC screening methods are being developed and evaluated. However, additional large, multicenter clinical trials in diverse populations are needed to validate the diagnostic accuracy and generalizability of these new tests. This article reviews the recently updated CRC screening recommendations and current and emerging testing options.

Radiologic Imaging Modalities for Colorectal Cancer.

BACKGROUND: Studies reported various diagnostic value of radiologic imaging modalities for diagnosis and management of colorectal cancer (CRC). AIMS: To summary the diagnosis and management of CRC using computed tomography colonography (CTC), magnetic resonance colonography (MRC), and positron emission tomography (PET)/computed tomography (CT). METHODS: Comprehensive literature searches were conducted in PubMed, EmBase, and the Cochrane library for studies published before April 2021. The diagnostic performance of CTC, MRC, and PET/CT for CRC was summarized. RESULTS: A total of 54 studies (17 studies for CTC, 8 studies for MRC, and 29 studies for PET/CT) were selected for final analysis. The sensitivity and specificity for CTC ranged from 27 to 100%, 88 to 100%, respectively, and the pooled sensitivity and specificity for CTC were 0.97 (95% CI 0.88-0.99) and 0.99 (95% CI 0.99-1.00). The sensitivity and specificity for MRC ranged from 48 to 100%, 60 to 100%, respectively, and the pooled sensitivity and specificity for MRC were 0.98 (95% C: 0.77-1.00) and 0.94 (95% CI 0.84-0.98). The sensitivity and specificity for PET/CT ranged from 84 to 100%, 33 to 100%, respectively, and the pooled sensitivity and specificity for PET/CT were 0.94 (95% CI 0.92-0.96) and 0.94 (95% CI 0.90-0.97). The area under the receiver operating characteristic curve for CTC, MRC, and PET/CT was 1.00 (95% CI 0.99-1.00), 0.99 (95% CI 0.98-1.00), and 0.97 (0.95% CI 0.95-0.98), respectively. CONCLUSIONS: This study suggested both CTC and MRC with relative higher diagnostic value for diagnosing CRC, while PET/CT with higher diagnostic value in detecting local recurrence for patients with CRC.

Colorectal Cancer Screening with Computed Tomography Colonography: Single Region Experience in Kazakhstan.

BACKGROUND/AIMS: The aim of our study was to determine the efficacy of computed tomography colonography (CTC) in screening for colorectal cancer (CRC). METHODS: A total of 612 females and 588 males aged 45 to 75 years were enrolled in CTC screening. CTC was performed following standard bowel preparation and colonic insufflation with carbon dioxide. The main outcomes were the detection rate of CRC and advanced adenoma (AA), prevalence of colorectal lesions in relation to socio-demographic and health factors, and overall diagnostic performance of CTC. RESULTS: Overall, 56.5% of the 1,200 invited subjects underwent CTC screening. The sensitivity for CRC and AA was 0.89 and 0.97, respectively, while the specificity was 0.71 and 0.99, respectively. The prevalence of CRC and AA was 3.0% (18/593) and 7.1% (42/593), respectively, with the highest CRC prevalence in the 66-75 age group (≥12 times; odds ratio [OR], 12.11; 95% confidence interval [CI], 4.45-32.92). CRC and AA prevalence were inversely correlated with Asian descent, physical activity, and negative fecal immunochemical test results (OR=0.43; 95% CI, 0.22-0.83; OR=0.16; 95% CI, 0.04-0.68; OR=0.5; 95% CI, 0.07-3.85, respectively). CONCLUSION: Our study revealed high accuracy of CTC in diagnosing colonic neoplasms, good compliance with CTC screening, and high detection rate of CRC.

Role of CT colonography in differentiating sigmoid cancer from chronic diverticular disease.

PURPOSE: To evaluate the accuracy of computed tomography colonography (CTC) in differentiating chronic diverticular disease from colorectal cancer (CRC), using morphological and textural parameters. MATERIALS AND METHODS: We included 95 consecutive patients with histologically proven chronic diverticular disease (n = 53) or CRC (n = 42) who underwent CTC. One radiologist, unaware of histological findings, evaluated CTC studies for the presence of potential discriminators including: maximum thickness, involved segment length, shouldering phenomenon, growth pattern, diverticula, fascia thickening, fat tissue edema, loco-regional lymph nodes, mucosal pattern. Another radiologist performed volumetric texture analysis on the involved segment. RESULTS: Several qualitative imaging parameters resulted to significantly correlated with colorectal cancer, including absence of diverticula in the affected segment, straightened growth pattern and shouldering phenomenon. A maximum wall thickness/involved segment length ratio < 0.1 had 98% specificity and 47% sensitivity in identifying diverticular disease. Regarding first-order texture analysis parameters, kurtosis resulted to be significantly different between the two groups. CONCLUSIONS: Absence of diverticula, straightened growth pattern and shouldering phenomenon are significantly associated with CRC (71-91% sensitivity; 82-91%).

Recent trends in the prevalence and distribution of colonic diverticula in Japan evaluated using computed tomography colonography.

BACKGROUND: Computed tomography colonography (CTC) may be superior to colonoscopy and barium enema for detecting diverticula. However, few studies have used CTC to diagnose diverticula. AIM: To evaluate the current prevalence and distribution of colonic diverticula in Japan using CTC. METHODS: This study was conducted as part of the Japanese National Computed Tomographic Colonography Trial, which included 1181 participants from 14 hospitals in Japan. We analyzed the prevalence and distribution of colonic diverticula and their relationships with age and sex. The relationship between the diverticula and the length of the large intestine was also analyzed. RESULTS: Diverticulosis was present in 48.1% of the participants. The prevalence of diverticulosis was higher in the older participants (P < 0.001 for trend). The diverticula seen in younger participants were predominantly located in the right-sided colon. Older participants had a higher frequency of bilateral type (located in the right- and left-sided colon) diverticulosis (P < 0.001 for trend). The length of the large intestine with multiple diverticula in the sigmoid colon was significantly shorter in those without diverticula (P < 0.001). CONCLUSION: The prevalence of colonic diverticulosis in Japan is higher than that previously reported. The prevalence was higher, and the distribution tended to be bilateral in older participants.

Computed tomography colonography and radiation risk: How low can we go?

Computed tomography colonography (CTC) has become a key examination in detecting colonic polyps and colorectal carcinoma (CRC). It is particularly useful after incomplete optical colonoscopy (OC) for patients with sedation risks and patients anxious about the risks or potential discomfort associated with OC. CTC's main advantages compared with OC are its non-invasive nature, better patient compliance, and the ability to assess the extracolonic disease. Despite these advantages, ionizing radiation remains the most significant burden of CTC. This opinion review comprehensively addresses the radiation risk of CTC, incorporating imaging technology refinements such as automatic tube current modulation, filtered back projections, lowering the tube voltage, and iterative reconstructions as tools for optimizing low and ultra-low dose protocols of CTC. Future perspectives arise from integrating artificial intelligence in computed tomography machines for the screening of CRC.

Colon Capsule Endoscopy vs. CT Colonography Following Incomplete Colonoscopy: A Systematic Review with Meta-Analysis.

Following incomplete colonoscopy (IC) patients often undergo computed tomography colonography (CTC), but colon capsule endoscopy (CCE) may be an alternative. We compared the completion rate, sensitivity and diagnostic yield for polyp detection from CCE and CTC following IC. A systematic literature search resulted in twenty-six studies. Extracted data included inter alia, complete/incomplete investigations and polyp findings. Pooled estimates of completion rates of CCE and CTC and complete colonic view rates (CCE reaching the most proximal point of IC) of CCE were calculated. Per patient diagnostic yields of CCE and CTC were calculated stratified by polyp sizes. CCE completion rate and complete colonic view rate were 76% (CI 95% 68-84%) and 90% (CI 95% 83-95%). CTC completion rate was 98% (CI 95% 96-100%). Diagnostic yields of CTC and CCE were 10% (CI 95% 7-15%) and 37% (CI 95% 30-43%) for any size, 13% (CI 95% 9-18%) and 21% (CI 95% 12-32%) for >5-mm and 4% (CI 95% 2-7%) and 9% (CI 95% 3-17%) for >9-mm polyps. No study performed a reference standard follow-up after CCE/CTC in individuals without findings, rendering sensitivity calculations unfeasible. The increased diagnostic yield of CCE could outweigh its slightly lower complete colonic view rate compared to the superior CTC completion rate. Hence, CCE following IC appears feasible for an introduction to clinical practice. Therefore, randomized studies investigating CCE and/or CTC following incomplete colonoscopy with a golden standard reference for the entire population enabling estimates for sensitivity and specificity are needed.

Colon capsule endoscopy versus CT colonography after incomplete colonoscopy. Application of artificial intelligence algorithms to identify complete colonic investigations.

BACKGROUND: Guidelines suggest computed tomography colonography (CTC) following incomplete optical colonoscopy (OC). Colon capsule endoscopies (CCE) have been suggested as an alternative, although completion rates have been unsatisfactory. Introduction of artificial intelligence (AI)-based localization algorithms of the camera capsules may enable identification of incomplete CCE investigations overlapping with incomplete OCs. OBJECTIVE: The study aims to investigate relative sensitivity of CCE compared with CTC following incomplete OC, investigate the completion rate when combining results from the incomplete OC and CCE, and develop a forward-tracking algorithm ensuring a safe completeness of combined investigations. METHODS: In this prospective paired study, patients with indication for CTC following incomplete OC were included for CCE and CTC. Location of CCE abortion and OC abortion were registered to identify complete combined investigations. AI-based algorithm for localization of capsules were developed reconstructing the passage of the colon. RESULTS: In 237 individuals with CTC indication; 105 were included, of which 97 underwent both a CCE and CTC. CCE was complete in 66 (68%). Including CCEs which reached most oral point of incomplete OC, 73 (75%) had complete colonic investigations; 78 (80%) had conclusive investigations. Relative sensitivity of CCE compared with CTC was 2.67 (95% confidence interval (CI) 1.76;4.04) for polyps >5 mm and 1.91 (95% CI 1.18;3.09) for polyps >9 mm. An AI-based algorithm was developed. CONCLUSION: Sensitivity of CCE following incomplete OC was superior to CTC. Introducing and improving algorithm-based localization of capsule abortion may increase identification of overall complete investigation rates following incomplete OC.ClinicalTrials.gov identifier: NCT02826993.

Computed Tomography Colonography Versus Standard Optical Colonoscopy for the Detection of Colorectal Polyp in Patients Who Faced Curative Surgery for Colorectal Cancer: A Diagnostic Performance Study.

Data regarding computed tomography colonography, standard optical colonoscopy, and enhanced colonoscopy/histopathology at 1-year after surgery and at 6-month intervals for the next 2 years of 345 patients who faced curative surgery for colorectal cancer were included in this analysis. Computed tomography colonography and standard optical colonoscopy both detected 298 polyps as suspicious. With reference to enhanced colonoscopy/histopathology, sensitivities for the detection of any polyps for computed tomography colonography and standard optical colonoscopy were 0.952 and 0.906, while, accuracies were 0.783 and 0.641, respectively. Computed tomography colonography may be a sensitive and accurate surveillance tool for colorectal cancer patients.

Comparison of two Meglumine-Diatrizoate based bowel preparations for computed tomography colonography: Comparison of patient symptoms and bowel preparation quality.

INTRODUCTION: To investigate the impact of two Meglumine-Diatrizoate based bowel preparation regimes for computed tomography colonography (CTC) on the patient experience and image quality. METHODS: 100 patients consumed Meglumine-Diatrizoate at 24 h and 12 h prior to the CTC examination. 50 patients followed regime 1 (50:50), 50 ml of Meglumine-Diatrizoate at both 24 and 12 h prior to the examination. 50 patients followed regime 2 (75:25), 75 ml of Meglumine-Diatrizoate at 24 h prior to the examination and 25 ml of Meglumine-Diatrizoate at 12 h prior to the examination. All patients completed a questionnaire to indicate the time of onset of adverse effects and when they were most severe. Five advanced practitioners assessed the image quality in a visual grading study. Visual grading characteristic (VGC) analysis was applied with regime 1 as the reference condition and regime 2 and test condition; test alpha was set at 0.05. RESULTS: Image quality was assessed with successful bowel cleansing as the scoring criteria for the visual grading study. The bowel cleansing as provided by the two Meglumine-Diatrizoate regimes was revealed not to be statistically different, with the area under the VGC curve and 95% confidence intervals 0.487 (0.287, 0.701), p = 0.887. Patients taking the 75:25 bowel preparation experienced a shorter median time to the onset of adverse effects. CONCLUSION: There was no observed difference in Image quality criteria score for the two Meglumine-Diatrizoate based bowel preparation with more predictable adverse effects of Meglumine-Diatrizoate with the 75:25 preparation. IMPLICATIONS FOR PRACTICE: Providing patients with a higher contrast burden 24 h prior to CTC may have a positive impact on the patient experience without compromising image quality.

Diagnostic accuracy of computed tomography colonography in patients at high risk for colorectal cancer: a meta-analysis.

AIM: The aim was to explore the diagnostic value of computed tomographic colonography (CTC) compared with conventional colonoscopy in individuals at high risk for colorectal cancer. METHOD: PubMed, Embase, the Cochrane Library and the Web of Science were searched by two independent reviewers for potentially eligible studies published up to 31 October 2018 that were based on a per-patient analysis. stata, meta-disc and revman were used to perform this meta-analysis. A random-effect model was used, and a subgroup analysis was conducted to explore the sources of heterogeneity. RESULTS: A total of 14 full-text articles, involving 3578 patients, were included in this meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and the area under the summary receiver operating characteristic curve of CTC for detecting polyps ≥ 6 mm were 0.87 (95% CI 0.83-0.90), 0.90 (95% CI 0.86-0.93), 9.08 (95% CI 6.28-13.13), 0.14 (95% CI 0.11-0.18) and 0.94 (95% CI 0.92-0.96), respectively. For polyps ≥ 10 mm, the pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of CTC were 0.91 (95% CI 0.86-0.94), 0.98 (95% CI 0.95-0.99), 40.36 (95% CI 19.16-85.03), 0.90 (95% CI 0.06-0.14) and 0.98 (95% CI 0.96-0.99), respectively. CONCLUSION: In this meta-analysis, CTC had high diagnostic accuracy for detecting polyps ≥ 6 mm and ≥ 10 mm in patients at high risk of developing colorectal cancer and it had a higher sensitivity and specificity for detecting polyps ≥ 10 mm than polyps ≥ 6 mm. However, the results should be used cautiously due to the significant heterogeneity.

Pneumatosis cystoides intestinalis accompanied by intestinal spirochetosis.

Pneumatosis cystoides intestinalis (PCI) is a rare but well-recognized entity characterized by multiple gas-filled cysts in the intestinal wall. Although the pathogenesis of PCI remains unclear, several theories, including a bacterial theory, have been postulated. Intestinal spirochetosis (IS) is an uncommon condition defined by the presence of spirochetes attached to the surface of the colonic epithelium. The nature of IS as a commensal or pathogenic process remains debatable. However, recent evidence supports the idea that IS can be invasive and highly pathogenic in both immunocompromised and immunocompetent individuals. We present the case of a 35-year-old asymptomatic and immunocompetent man who underwent colonoscopy because of a positive fecal blood test. Multiple submucosal cystic lesions were detected accompanied by erythematous areas along the ascending colon. Computed tomography-colonography and biopsy specimens from the erythematous areas confirmed coexisting PCI and IS. Both PCI and IS recovered completely 3 months after administration of metronidazole. To the best of our knowledge, this case represents only the second report of the extremely rare concurrence of PCI with IS. Taking into account the published literature, we also discuss the possibility that the development of PCI may be related to IS.

Computed tomography colonography: Radiographer independent preliminary clinical evaluation for intraluminal pathology.

INTRODUCTION: We evaluated the reporting competency of radiographers providing preliminary clinical evaluations (PCE) for intraluminal pathology of computed tomography colonography (CTC). METHOD: Following validation of a suitable tool, audit was undertaken to compare radiographer PCE against radiology reports. A database was designed to capture radiographer and radiologist report data. The radiographer's PCE of intraluminal pathology was given a score, the "pathology discrepancy and significance" (PDS) score based on the pathology present, any discrepancy between the PCE and the final report, and the significance of that discrepancy on the management of the patient. Agreement was assessed using percentage agreement and Kappa coefficient. Significant discrepancies between findings were compared against endoscopy and pathology reports. RESULTS: There was agreement or insignificant discrepancy between the radiographer PCE and the radiology report for 1736 patients, representing 97.0% of cases. There was a significant discrepancy between findings in 2.8% of cases and a major discrepancy recorded for 0.2% of cases. There was a 98.4% agreement in the 229 cases where significant pathologies were present. CONCLUSION: From a database of 1815 studies acquired over three years and representing work done in a clinical environment, this study indicates a potential for trained radiographers to provide a PCE of intraluminal pathology.

Colorectal Cancer Outcomes in a Large Negative Computed Tomography Colonography Screening Cohort.

INTRODUCTION: At our institution, the most common cohort of individuals having computed tomography colonography (CTC) are those that require primary screening for colorectal cancer and were unable to tolerate or failed optical colonoscopy (OC). CTC is an efficient method for detecting polyps, masses, flat-lesions, and overt colorectal cancer, serving as a viable alternative to colonoscopy. This study follows patients with negative CTC results to evaluate the number of clinically significant lesions that may have been potentially missed by CTC. We suspect this number will be exceedingly low given the high sensitivity of this technique. METHODS: All patients with negative CTC screening (n = 509) in the Eastern Health Medical Health Region, located in Newfoundland and Labrador, Canada were included. An electronic medical record review was undertaken, encompassing provider, colonoscopy, imaging, and histopathology reports. Subjects were also checked through the Newfoundland Cancer Clinic Registry Database. All incidents of colorectal cancer were recorded. RESULTS: The study cohort comprised 509 subjects. These subjects were followed for an average of 7.88 years. Two colorectal adenocarcinomas in this cohort were identified representing a crude cancer incidence rate of 0.49 cancers per 1000 patient years, and a rate of 0.39% following a normal CTC. CONCLUSIONS: Colorectal cancer presenting clinically is rare in the 7.88 years following a negative CTC, suggesting CTC is equally effective for colorectal screening compared to OC. Furthermore, current guidelines that recommend interval CTC screening every 5 years is conservative, and interval screening can likely be recommended over a longer time frame.

Diagnostic accuracy of computed tomography colonography for tumor depth in colorectal cancer: A systematic review and meta-analysis.

BACKGROUND: Accurate preoperative determination of tumor depth is a major concern in colorectal cancer. Assessment of tumor depth can influence the treatment strategy for colorectal cancer, but there is currently no universal diagnostic standard. This review sought to evaluate the diagnostic performance of computed tomography (CT) colonography for tumor infiltration depth in colorectal cancer. METHODS: The PubMed, Scopus, and Cochrane Central Register of Controlled Trials databases were searched to identify studies that compared the tumor depth using CT colonography with that determined using pathological assessment. Relevant data were extracted from the eligible studies by two review authors working independently. Any disagreement was resolved by discussion. The quality of the studies was assessed using the QUADAS-2 tool. The diagnostic performance of CT colonography for tumor depth in colorectal cancer was evaluated by meta-analysis using sensitivity and specificity values and diagnostic odds ratios. RESULTS: The systematic literature search identified 16 eligible studies. The pooled sensitivity and specificity values and diagnostic odds ratios were 97.8% (95% confidence interval [CI] 88.1-99.6), 76.4% (95% CI 59.9-87.5), and 142.6 (95% CI 20.0-1071.0) for T2 invasion, 97.7% (95% CI 92.1-99.3), 83.5% (95% CI 75.9-89.0), and 212.1 (95% CI 50.6-888.1) for T3 invasion, and 84.9% (95% CI 61.7-95.1), 97.5% (95% CI 93.2-99.1), and 219.5 (95% CI 37.8-1273.6) for T4 invasion, respectively. CONCLUSIONS: CT colonography was found to have high diagnostic performance and was useful for determining tumor depth in colorectal cancer.

The yield and patient factors associated with CT colonography C-RADS results in a non-screening patient population.

OBJECTIVES: To determine the proportion of diagnostic computed tomography colonography (CTC) Reporting and Data System (C-RADS) categories in a non-screening population, and which patient factors are associated with a positive CTC (C2-4), a non-diagnostic CTC (C0), and potentially relevant extracolonic findings (ECF, E3-4). METHODS: Diagnostic CTCs performed at a single academic center from 2017 to 2018 were retrospectively reviewed. For each examination, the indications, age, sex, admission status, and C-RADS categories were recorded. Multivariate logistic regression was performed of patient demographic factors and clinical indications, with adjusted odds ratios (OR) and 95% confidence intervals. RESULTS: 1373 CTCs were included. The mean age was 66.4 ± 13 years (range 24-97). There were 782 women and 75 inpatients. The number of CTCs reported as C0-C4 were 194/1373 (14.1%), 970/1373 (70.6%), 77/1373 (5.6%), 86/1373 (6.3%), and 46/1373 (3.4%), respectively, and 134/1373 (9.8%), 960/1373 (69.9%), 173/1373 (12.6%), and 106/1373 (7.7%) CTCs were reported as E1-4, respectively. Factors that demonstrated the strongest associations were as follows: with C2-4, age groups 50-79 (OR 2.8, 95% confidence interval 1.4-6.1), 80-89 (6.2, 2.9-14.5) and ≥ 90 (7.6, 2.0-29.1), and inpatients (3.4, 1.8-6.4); with C0, age groups 50-79 (5.9, 2.2-24.4), 80-89 (9.8, 3.4-41.8), and ≥ 90 (22.5, 5.8-113.0), incomplete colonoscopy (3.2, 2.0-5.1) and melena or gastrointestinal bleeding (4.1, 1.8-9.4); and with E3-4, age groups 50-79 (1.6, 1.0-2.9), 80-89 (2.0, 1.1-3.9), and ≥ 90 (3.2, 1.2-8.8), and inpatients (2.3, 1.3-3.9). CONCLUSION: Older age is increasingly associated with a positive test, a non-diagnostic test and potentially relevant ECF. Inpatients are also associated with positive tests and E3-4 findings. Symptoms are not strongly associated with a positive CTC.

Computed tomography colonography: a retrospective analysis of outcomes of 2 years experience in a district general hospital.

BACKGROUND: Colonoscopy is the gold-standard investigation for direct luminal visualization of the large bowel. Studies have shown the efficacy of computed tomography colonography (CTC) is equivalent to colonoscopy in both cancer and polyp detection. METHODS: A retrospective review of patients undergoing CTC from January 2013 to October 2014 was performed. Patient demographics, indication for investigation, computed tomography findings, optical colonoscopy findings and histology results were recorded. RESULTS: Seven hundred and fifty-eight CTC were performed. Three hundred and seventeen patients were male (42%) and 441 (58%) were female. Endoscopy was advised in 209 cases. One hundred and twenty (16%) were deemed suspicious for cancer of whom 96 (80%) had optical colonoscopy. A total of 12 colorectal cancers were detected. Potential polyps were noted in 58 cases (8%). Forty-four patients underwent endoscopy (75%) and 17 polyps confirmed (38%). Two patients had foci of invasive cancer histologically. Significant extracolonic findings were identified in 60%, including five cases of gastric carcinomas. The most common other findings were gallstones and hernias. CONCLUSION: The rate of colorectal cancer detection in this study was 2%. The rate of biopsy proven cancer was 10% following a suspicious colonogram. Endoscopic correlation was not obtained in 20% of cases of radiological suspicion. CTC is as efficacious as optical colonoscopy for colorectal cancer and polyp detection.