Optical Colonoscopy Research Articles

Intestinal malrotation in adults: prevalence and findings based on CT colonography.

Intestinal malrotation is largely a pediatric diagnosis, but initial detection can be made in adulthood. CT colonography (CTC) provides an ideal means for estimating prevalence. Our purpose was to evaluate the prevalence and imaging findings of intestinal malrotation in asymptomatic adults at CTC screening, as well as incomplete optical colonoscopy (OC) referral. The CTC database of a single academic institution was searched for cases of intestinal malrotation (developmental nonrotation). Prevalence was estimated from 11,176 adults undergoing CTC. Demographic, clinical, imaging (CTC and other abdominal exams), and surgical data were reviewed. 27 cases of malrotation were confirmed (mean age 62 ± 9years; 15M/12F), including 17 from the CTC screening cohort (0.17% prevalence) and 10 from incomplete OC (0.75% prevalence; p < 0.001). Most cases (59%; 16/27) were initially diagnosed at CTC. In 67% (12/18); the presence of malrotation was missed on at least one relevant abdominal imaging examination. At least 22% (6/27) had a history of unexplained, chronic intermittent abdominal pain. At CTC, the SMA-SMV relationship was normal in only 11% (3/27). The ileocecal valve was located in the RLQ in only 22% (6/27). Two patients (7%) had associated findings of heterotaxy (polysplenia). The prevalence of intestinal malrotation was four times greater for patients referred from incomplete OC compared with primary screening CTC, likely related to anatomic challenges at endoscopy. Malrotation was frequently missed at other abdominal imaging examinations. CTC can uncover unexpected cases of malrotation in adults, which may be relevant in terms of potential for future complications.

Colonosight: Multitarget RNA-FIT assay for noninvasive detection of advanced colorectal neoplasia.

25 Background: Effective colorectal cancer (CRC) prevention and screening requires sensitive detection of all advanced neoplasias (colorectal cancer and advanced adenomas). Existing noninvasive screening approaches cannot accurately detect precancerous adenomas with high sensitivity. Here we describe a multi-factor assay (RNA-FIT test) that combines 8 stool-derived eukaryotic RNA (seRNA) biomarkers, patient demographic information (smoking status), and a fecal immunochemical test (FIT) to sensitively detect advanced colorectal neoplasias and other precancerous adenomas in a 1,305 average risk (45-75 age) prospective cohort. Methods: Average-risk patients undergoing colorectal cancer screening were prospectively evaluated with the RNA-FIT assay prior to an optical colonoscopy. RNA-FIT test results were generated using an ordinal regression model and results were compared to the colonoscopy findings. The model was initially assessed via 5-fold internal cross-validation of the training set and the ultimate model performance was assessed on a hold out testing set. Results: Of the 1,305 eligible patients recruited, 939 were included in the training set and 366 samples were reserved for the hold out testing set. When evaluating all 5 folds of the training set, internal cross validation attained a 61% sensitivity for advanced neoplasias (n = 69), 22% sensitivity for other adenomas (n = 279), 80% specificity for hyperplastic polyps (n = 155) and 86% specificity for no findings on a colonoscopy (n = 436). When employed on the testing set, the RNA-FIT test attained a 62% sensitivity for advanced neoplasias (n = 52), 27% sensitivity for other adenomas (n = 139), 78% specificity for hyperplastic polyps (n = 74) and 84% specificity for no findings on a colonoscopy (n = 101). Sensitivity for colorectal cancer and advanced adenomas with high-grade dysplasia / carcinoma in-situ was 100% in both the training set (n = 6) and hold out testing set (n = 5). Sensitivity for villous / tubulovillous adenomas was 65% in the training set (n = 23) and 60% in the hold out testing set (n = 15). Additional retrospective sample collection from patients with CRC is ongoing to further validate assay sensitivity for CRC. Conclusions: The RNA-FIT assay demonstrated clinically relevant detection of all advanced neoplasia, including early carcinomas, advanced adenomas, and other precancerous lesions. This assay could represent a noninvasive option to prevent colorectal cancer development through precancerous adenoma detection.

Is there need for routine CT colonography after CT-verified uncomplicated diverticulitis of the sigmoid colon?

BackgroundFollowing an episode of acute diverticulitis, surgical guidelines commonly advise routine colonic follow-up to rule out underlying malignancy. However, as a CT of the abdomen is frequently performed during clinical work-up, the routine need for colonic follow-up has become debated. PurposeTo evaluate the need for routine CT colonography after an episode of CT-verified uncomplicated sigmoid diverticulitis to rule out underlying colorectal malignancy. Material and methodsThis study retrospectively evaluated 312 patients routinely referred to colonic evaluation by CT colonography following an episode of acute diverticulitis. Patients were excluded if lacking diagnostic CT of the abdomen at time of diagnosis, if presenting with atypical colonic involvement, or if CT findings were suggestive of complicated disease (e.g., abscess or perforation). CT colonography exams were routinely reviewed by experienced abdominal radiology consultants on the day of the procedure. If significant polyps were detected, or if colorectal malignancy could not be excluded, patients were referred to same-day optical colonoscopy. For these patients, medical records were reviewed for optical colonoscopy results and histology reports if applicable. ResultsAmong 223 patients with CT-verified uncomplicated sigmoid diverticulitis, no patients were found to have underlying colorectal malignancy. 27 patients were referred to optical colonoscopy based on CT colonography findings. 18 patients consequently underwent polypectomy, all with either hyperplastic or adenomatous histology. ConclusionsThis study indicates that routine colonic evaluation by CT colonography following an episode of CT-verified uncomplicated sigmoid diverticulitis may be unwarranted, and should arguably be reserved for patients with protracted or atypical clinical course.

Automatic Polyp Detection Using Microwave Endoscopy for Colorectal Cancer Prevention and Early Detection: Phantom Validation

A system to integrate microwave imaging with optical colonoscopy is presented. The overarching goal is to improve the prevention and early diagnosis of one of the main health and economic burdens of an increasingly aging population, i.e., colorectal cancer. For a colonoscopy, the gold standard for colorectal cancer diagnosis, 22% of polyps are not detected, and the risk of cancer after a negative colonoscopy can be up to 7.9%. To remedy this, a microwave imaging system able to generate an alarm when a polyp is detected is designed, manufactured and validated with a colon phantom composed of tissue-mimicking oil-gelatin materials reproducing the anatomy and dielectric properties of a human colon with a polyp. The acquisition was performed by a miniaturized ring-shaped switched array of 16 antennas attachable at the tip of a conventional colonoscope. This has been conceived to satisfy endoscopy size restrictions, patient safety and intercompatibility with current clinical practice. A Modified Monofocusing imaging method preceded by a previous frame average subtraction as a calibration technique shows a perfect detection of a 10-mm polyp (100% sensitivity and specificity) in the eight analyzed trajectories. The phantom results demonstrate the feasibility of the system in future preclinical trials.

Multicentre, prospective, randomised study comparing the diagnostic yield of colon capsule endoscopy versus CT colonography in a screening population (the TOPAZ study)

ObjectiveColon capsule endoscopy (CCE) has shown promise for colorectal neoplasia detection compared with optical colonoscopy (OC), but has not been compared with other screening tests in average risk screening patients.DesignPatients...

Aspects of colorectal cancer screening, methods, age and gender

Colorectal cancer (CRC) is, besides breast, prostate, lung and skin cancers, the most common cancer worldwide and is suitable for screening. The incidence of CRC varies considerably in different parts of the world: in well‐developed countries, the incidence is between 30 and 70 per 100 000 inhabitants, whereas in less‐developed countries such as sub‐Saharan Africa, it is 10–20/100 000 inhabitants. Women have a lower incidence of CRC, which is usually one‐third of total incidence. Several studies have shown that it is possible to decrease mortality from CRC with about 20%, which is evidenced through the data from countries with screening programmes. Though the method of choice to identify blood samples in faecal matter is under debate, the most feasible way is to perform colonoscopy. Other methods include more advanced faecal analyses, testing for mutations from CRC, sigmoidoscopy, CT colonoscopy or optical colonoscopy. Colonoscopy is in most countries not available in sufficient amount and has to be carried out with great accuracy; otherwise, lesions will be missed to identify, thus leading to complications. Gender is an issue in CRC screening, as women have about 20% fewer colorectal adenomas and CRCs, but they also have more right‐sided lesions, which are more difficult to detect with tests for faecal blood since they create less blood in faeces. Thus, other strategies may have to be developed for women in order for screening to have the same effect. It is essential to introduce colorectal cancer screening in all countries together with other clinical pieces of advice such as information on smoking, obesity and exercise in order to reduce one of the most dangerous cancers.

PET/CT Integrated With CT Colonography in Preoperative Obstructive Colorectal Cancer by Incomplete Optical Colonoscopy: A Prospective Study.

The aim of this study was to evaluate if integrating whole-body PET/CT with CT colonography (PET/CTC) improves the preoperative diagnosis of obstructive colorectal cancer (CRC). We prospectively included 47 consecutive patients (18 women and 29 men; mean age, 71 ± 14 years) suspected of having CRC by optical colonoscopy, which was not completed due to obstructive masses. To perform PET/CTC, a small caliber Foley catheter was inserted to distend the colon with CO2 insufflations. Polyps measuring 10 mm or larger were considered as high risk of malignancy. All findings were histologically confirmed. Colorectal cancer was localized in the sigmoid (n = 21), rectum (n = 7), rectosigmoid junction (n = 5), ascending (n = 7), descending (n = 5), and transverse (n = 2) colon. All tumors showed FDG uptake (mean ± SD SUVmax, 20.02 ± 9.9) including one synchronic tumor (SUVmax, 10.46). Forty-seven polyps were histologically confirmed as smaller than 10 mm (n = 35) and 10 mm or larger (n = 12). All 12 polyps 10 mm or larger showed FDG uptake (SUVmax range, 3.08-19.5), but only one smaller than 10 mm could be identified by PET. Pathological lymph nodes were diagnosed in 17/47 cases after surgical removal with a sensitivity and specificity for CTC and PET/CTC of 71% and 97% and 59% and 100%, respectively. Liver metastases were confirmed in 9 patients and in 4/9 along with lung metastases (n = 2) or implants (n = 2), showing a sensitivity and specificity for CTC of 89% and 100% and both 100% for PET/CTC. PET/CTC is a reliable technique for staging CRC and diagnosing synchronous tumors. In this series, PET/CTC was not able to identify small polyps but showed potential use for ruling out 10 mm or larger polyps at high risk of malignancy.

Cost-effectiveness of surveillance with CT colonography after resection of colorectal cancer

ObjectiveSurveillance following colorectal cancer (CRC) resection uses optical colonoscopy (OC) to detect intraluminal disease and CT to detect extracolonic recurrence. CT colonography (CTC) might be an efficient use of resources...

Diagnostic Performance of Multitarget Stool DNA and CT Colonography for Noninvasive Colorectal Cancer Screening.

BackgroundMultitarget stool DNA (mt-sDNA) screening has increased rapidly since simultaneous approval by the U.S. Food and Drug Administration and Centers for Medicare and Medicaid Services in 2014, whereas CT colonography screening remains underused and is not covered by Centers for Medicare and Medicaid Services.PurposeTo report postapproval clinical experience with mt-sDNA screening for colorectal cancer (CRC) and compare results with CT colonography screening at the same center.Materials and MethodsIn this retrospective cohort study, asymptomatic adults underwent clinical mt-sDNA screening during a 5-year interval (2014-2019). Electronic medical records were searched to verify test results and document subsequent optical colonoscopy and histopathologic findings. A similar analysis was performed for CT colonography screening during a 15-year interval (2004-2019), with consideration of thresholds for positivity of both 6-mm and 10-mm polyp sizes. χ2 or two-sample t tests were used for group comparisons.ResultsA total of 3987 asymptomatic adult patients (mean age, 64 years ± 9 [standard deviation]; 2567 women) underwent mt-sDNA screening and 9656 patients (mean age, 57 years ± 8; 5200 women) underwent CT colonography. Test-positive rates for mt-sDNA and for 6-mm- and 10-mm-threshold CT colonography were 15.2%, 16.4%, and 6.7%, respectively. Optical colonoscopy follow-up rates for positive results of mt-sDNA and 6-mm- and 10-mm-threshold CT colonography were 13.1%, 12.3%, and 5.9%, respectively. Positive predictive values (PPVs) for any neoplasm 6 mm or greater, advanced neoplasia, and CRC for mt-sDNA were 54.2%, 22.7%, and 1.9% respectively; for 6-mm-threshold CT colonography, PPVs were 76.8%, 44.3%, and 2.7%; for 10-mm-threshold CT colonography, PPVs were 84.5%, 75.2%, and 5.2%, respectively (P < .001 for mt-sDNA vs CT colonography for all except 6-mm CRC at CT colonography). For mt-sDNA versus 6-mm-threshold CT colonography, overall detection rates for advanced neoplasia were 2.7% and 5.0%, respectively (P < .001); corresponding detection rates for CRC were 0.23% and 0.31%, respectively (P = .43).ConclusionThe detection rates of advanced neoplasia at CT colonography screening were greater than those of multitarget stool DNA. Detection rates were similar for colorectal cancer.© RSNA, 2020See also the editorial by Yee in this issue.

CT Colonography in Review With Tips and Tricks to Improve Performance

Abstract CT colonography (CTC) is growing in its utilization and availability as a screening or diagnostic test for colorectal cancer detection. Its performance stands up to optical colonoscopy and it has become a growing alternative in many situations. This leaves a rising need for training and proficiency in how to perform and interpret CTC. Optimization of exam technique and colonic preparation raises the detection rate of colorectal lesions and renders interpretation easier. Since colorectal cancer remains the second most common cause of cancer death in the United States in men and women combined, the role for CTC is further fortified.

Quality of same-day CT colonography following incomplete optical colonoscopy.

Same-day CT colonography (CTC) following incomplete optical colonoscopy allows patients to avoid both a delayed diagnosis and the need for repeat bowel preparation. The aim of our study is to establish the diagnostic quality of same-day CT colonography following an incomplete optical colonoscopy. We performed a retrospective review of patients undergoing same-day CT colonography following an incomplete colonoscopy at our center between July 2015 and December 2017 (N= 245). We divided the large bowel into thirteen subsegments in each patient. Using a semiquantitative scoring system, the quality of bowel preparation, adequacy of fecal tagging, and luminal distension were assessed in each subsegment on all views performed. A combined score for each subsection was obtained. Ninety-nine percent of studies did not require a repeat CTC or optical colonoscopy. Median values for bowel preparation and fecal tagging were satisfactory across the bowel segments for the cohort and luminal distension was acceptable in all but three patients. Same-day CTC should be considered in centers with capacity, following an incomplete optical colonoscopy. Same-day completion CTCs are of high diagnostic quality and this approach allows patients to avoid repeat bowel cleansing or a delayed diagnosis. • Same-day CT colonography is a high-quality examination that can be performed following incomplete optical colonoscopy. • Same-day CT colonography should be considered for patients with incomplete optical colonoscopy in centers with the capacity to offer this service. • Same-day CTC can avoid a delay in diagnosis and avoids repeat bowel preparation.

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.

An observational study to compare the utilisation of computed tomography colonography with optical colonoscopy as the first diagnostic imaging tool in patients with suspected colorectal cancer

To evaluate the clinical and cost implications of using computed tomography colonography (CTC) compared to optical colonoscopy (OC) as the initial colonic investigation in patients with low-to-intermediate risk of colorectal cancer (CRC). A non-randomised, prospective single-centre study recruited 180 participants to compare the cost implications of two clinical pathways used in the diagnosis of low-to-intermediate risk of CRC that differ in the initial diagnostic test, either CTC or OC. Costs were compared using generalised linear models (GLM) and combined with quality-adjusted life years (QALYs, based on the EQ-5D-5L) to estimate cost-effectiveness at 6 months post-recruitment. Secondary outcomes assessed access to care and patient satisfaction. Mean (SD, n) cost at 6 months post-recruitment per participant was £991 (£316, n=105) for the OC group and £645 (£607, n=68) for the CTC group, leading to an estimated cost difference of -£370 (95% CI: -£554, -£185, p<0.001). Assuming a £20,000 willingness-to-pay per QALY threshold, there was a 91.4% probability of CTC being cost-effective at month 6. The utilisation of CTC led to improved access to care, with a shorter mean time from referral from primary care to results (6.3 days difference, p=0.005). No differences in patient satisfaction were detected between both groups. The utilisation of CTC as the first-line investigation for patients with low-to-intermediate risk of CRC has the potential to release OC capacity, of pivotal importance for patients more likely to benefit from an invasive diagnostic approach.

Augmenting Colonoscopy using Extended and Directional CycleGAN for Lossy Image Translation.

Colorectal cancer screening modalities, such as optical colonoscopy (OC) and virtual colonoscopy (VC), are critical for diagnosing and ultimately removing polyps (precursors of colon cancer). The non-invasive VC is normally used to inspect a 3D reconstructed colon (from CT scans) for polyps and if found, the OC procedure is performed to physically traverse the colon via endoscope and remove these polyps. In this paper, we present a deep learning framework, Extended and Directional CycleGAN, for lossy unpaired image-to-image translation between OC and VC to augment OC video sequences with scale-consistent depth information from VC, and augment VC with patient-specific textures, color and specular highlights from OC (e.g, for realistic polyp synthesis). Both OC and VC contain structural information, but it is obscured in OC by additional patient-specific texture and specular highlights, hence making the translation from OC to VC lossy. The existing CycleGAN approaches do not handle lossy transformations. To address this shortcoming, we introduce an extended cycle consistency loss, which compares the geometric structures from OC in the VC domain. This loss removes the need for the CycleGAN to embed OC information in the VC domain. To handle a stronger removal of the textures and lighting, a Directional Discriminator is introduced to differentiate the direction of translation (by creating paired information for the discriminator), as opposed to the standard CycleGAN which is direction-agnostic. Combining the extended cycle consistency loss and the Directional Discriminator, we show state-of-the-art results on scale-consistent depth inference for phantom, textured VC and for real polyp and normal colon video sequences. We also present results for realistic pendunculated and flat polyp synthesis from bumps introduced in 3D VC models.

Cancer-related diagnostic and treatment capabilities of hospitals in the context of racial residential segregation

ObjectiveTo evaluate distribution of hospital-level cancer diagnosis and treatment technologies along dimensions of racial residential segregation. Study designCross-sectional analysis of residential segregation and availability of technologies associated with cancer diagnosis and treatment. MethodsAmerican Hospital Association data were merged with American Community Survey data, and hospital was the unit of analysis. Isolation index and Atkinson's index were calculated for racial residential segregation for the census tract in which the hospital is located based on the composite census block groups. Logistic regression was used to model presence of cancer technologies as a function of percent below poverty (scaled 1–10), number of neighboring hospitals, and rural status. ResultsSegregation measured by isolation index was associated with the availability of some technologies, independent of percentage below 125% poverty line, number of neighboring hospitals, and rural status. Diagnostic cancer technologies, such as CT scan (odds ratio [OR] = 0.928, 95% confidence interval [CI]: 0.894, 0.964), ultrasound (OR = 0.961, 95% CI: 0.927, 0.997), mammography (OR = 0.943, 95% CI: 0.914, 0.974), optical colonoscopy (OR = 0.932, 95% CI: 0.904, 0.961), and full-field digital mammography (OR = 0.948, 95% CI: 0.920, 0.977) and therapeutic cancer technology such as chemo therapy (OR = 0.963, 95% CI: 0.934, 0.992) appear to be less available in neighborhoods with higher isolation index. However, when segregation is measured by Atkinson's index, CT scan (OR = 1.064, 95% CI: 1.010, 1.121), ultrasound (OR = 1.087, 95% CI: 1.035, 1.141), mammography (OR = 1.094, 95% CI: 1.049, 1.141), and optical colonoscopy (OR = 1.053, 95% CI: 1.012, 1.095) are more available in neighborhoods with higher Atkinson's index. ConclusionThese results suggest that cancer diagnostic capabilities in segregated areas are in the pathway between residential segregation and cancer treatment process, and future studies should evaluate individual-level associations.

CT colonography has low sensitivity but high specificity in the detection of internal hemorrhoids.

We aimed to evaluate the diagnostic performance of computed tomography colonography (CTC) in the detection of internal hemorrhoids. Three gastroenterologists systematically reported on the presence of internal hemorrhoids in patients with incomplete colonoscopy, for whom they considered a subsequent CTC. For 44 patients with internal hemorrhoids revealed by optical colonoscopy, an age- and gender-matched cohort of 66 patients with normal findings in the rectum was selected. Endoluminal and transaxial CTC views of the rectum were evaluated for the presence of internal hemorrhoids, the anal verge prominence, asymmetry, and cushion-like appearance on a Likert scale by two experienced radiologists and two gastroenterologists. The sensitivity, specificity, and AUC for identification of internal hemorrhoids were 0.61 (95% CI, 0.53-0.68), 0.69 (95% CI, 0.63-0.75) and 0.66 (95% CI, 0.62-0.70), respectively. The radiologists showed a better specificity, the gastroenterologists a slightly better sensitivity. When only the rating "very likely" was considered as positive, the specificity rose to 0.89 (95% CI, 0.81-0.94) with a sensitivity of 0.50 (95% CI, 0.38-0.62). The interobserver agreement was fair. The best predictor of the presence of hemorrhoids was a prominent anal verge in the supine position (OR=1.789, 95% CI, 1.267-2.525). The difference between supine and prone positions in the evaluated features in patients with internal hemorrhoids was not significant. CTC has low sensitivity but high specificity in the detection of internal hemorrhoids, if the rater is confident in detecting them. Internal hemorrhoids do not substantially change their shape between prone and supine positions.

Learning colon centreline from optical colonoscopy, a new way to generate a map of the internal colon surface.

Optical colonoscopy is known as a gold standard screening method in detecting and removing cancerous polyps. During this procedure, some polyps may be undetected due to their positions, not being covered by the camera or missed by the surgeon. In this Letter, the authors introduce a novel convolutional neural network (ConvNet) algorithm to map the internal colon surface to a 2D map (visibility map), which can be used to increase the awareness of clinicians about areas they might miss. This was achieved by leveraging a colonoscopy simulator to generate a dataset consisting of colonoscopy video frames and their corresponding colon centreline (CCL) points in 3D camera coordinates. A pair of video frames were used as input to a ConvNet, whereas the output was a point on the CCL and its direction vector. By knowing CCL for each frame and roughly modelling the colon as a cylinder, frames could be unrolled to build a visibility map. They validated their results using both simulated and real colonoscopy frames. Their results showed that using consecutive simulated frames to learn the CCL can be generalised to real colonoscopy video frames to generate a visibility map.

Traditional Serrated Adenomas on CT Colonography: International Multicenter Experience With This Rare Colorectal Neoplasm.

OBJECTIVE. Serrated polyps include hyperplastic polyps, sessile serrated polyps, and traditional serrated adenomas (TSAs). Hyperplastic polyps and sessile serrated polyps account for approximately 99% of all serrated lesions; TSAs are rare. However, both sessile serrated polyps and TSAs are now recognized as precursor lesions to carcinogenesis, representing approximately one-fourth of all sporadic colorectal cancers. We report what is, to our knowledge, the first series describing the characteristics of CTAs on CT colonography (CTC). MATERIALS AND METHODS. An international, multicenter, retrospective review of CT colonography-detected TSAs diagnosed between 2008 and 2018 was conducted. Data collected included patient demographics and data from CTC, optical colonoscopy, and pathologic analysis. RESULTS. A total of 67 proven TSAs in 58 patients (mean age, 67 years) were identified. The majority (66%) were located in the distal colon (descending colon, sigmoid colon, and rectum), and their mean size was 19 mm (range, 3-80 mm). Small (< 10 mm) TSAs typically had a simple sessile or pedunculated morphologic appearance, whereas large (≥ 10 mm) TSAs tended to be more lobulated and irregular, pedunculated, or carpetlike. The majority (88%) showed at least some contrast medium surface coating. CONCLUSION. We report what we believe to be the first multicenter experience describing the characteristics of TSAs on CTC. Unlike sessile serrated lesions, TSAs are more often left-sided and tend to be more lobulated and irregular. However, like sessile serrated polyps, most TSAs show contrast medium surface coating. Detection of these rare lesions on CTC is important, given their malignant potential.

Comparison of efficiencies of colon capsule endoscopy and optical colonoscopy in patients with a positive immunochemical fecal occult blood test – a multicentre, prospective study

Comparison of efficiencies of colon capsule endoscopy and optical colonoscopy in patients with a positive immunochemical fecal occult blood test – a multicentre, prospective study

Development of a real-time endoscopic image diagnosis support system using deep learning technology in colonoscopy

Gaps in colonoscopy skills among endoscopists, primarily due to experience, have been identified, and solutions are critically needed. Hence, the development of a real-time robust detection system for colorectal neoplasms is considered to significantly reduce the risk of missed lesions during colonoscopy. Here, we develop an artificial intelligence (AI) system that automatically detects early signs of colorectal cancer during colonoscopy; the AI system shows the sensitivity and specificity are 97.3% (95% confidence interval [CI] = 95.9%–98.4%) and 99.0% (95% CI = 98.6%–99.2%), respectively, and the area under the curve is 0.975 (95% CI = 0.964–0.986) in the validation set. Moreover, the sensitivities are 98.0% (95% CI = 96.6%–98.8%) in the polypoid subgroup and 93.7% (95% CI = 87.6%–96.9%) in the non-polypoid subgroup; To accelerate the detection, tensor metrics in the trained model was decomposed, and the system can predict cancerous regions 21.9 ms/image on average. These findings suggest that the system is sufficient to support endoscopists in the high detection against non-polypoid lesions, which are frequently missed by optical colonoscopy. This AI system can alert endoscopists in real-time to avoid missing abnormalities such as non-polypoid polyps during colonoscopy, improving the early detection of this disease.