These images involved the case of a 51-year-old woman who had a history of chronic abdominal pain, iron deficiency, and diarrhoea but no blood or mucus in her stool. She had never undergone major abdominal surgery, and her past medical evaluation diagnosed her with celiac disease, leading to the adoption of a gluten-free diet alleviating most of her gastrointestinal symptoms. However, years later, her abdominal pain returned, so she underwent an abdominal ultrasound, revealing non-specific bowel loop dilation, and a weakly positive faecal occult blood test led to a colonoscopy. Despite many efforts to advance the scope beyond the transverse colon, colonoscopy was arduous and not complete, even after several changes in decubitus and abdominal compressions. Therefore, a virtual colonoscopy was conducted, revealing no intraluminal masses, but the entire colon was located on the left side of the abdomen. Indeed, the results showed sigma and that most of the colon was curled up in the small pelvis. This rare anatomical variant, known as \"Mesenterium commune\" (MC), is a type of gut malrotation that develops in childhood due to a lack of omphalomesenteric loop rotation during the embryonic period. This condition can lead to episodes of intestinal obstruction, potentially resulting in an acute abdomen and leading to surgical correction. Symptoms include chronic recurring abdominal pain, nausea, vomiting, and occasionally bloody stools. Few cases of this extremely rare condition have been reported in the literature so far.

OBJECTIVE: This review aims to summarize the different colorectal cancer guidelines for average-risk and high-risk individuals from various countries.
METHODS: A comprehensive literature search regarding guidelines, consensus recommendations, or position statements about colorectal cancer screening published within the last 10 years (1st January 2012 to 27th August 2022), was performed at EBSCOhost, JSTOR, PubMed, ProQuest, SAGE, and ScienceDirect.
RESULTS: A total of 18 guidelines were included in this review. Most guidelines recommended screening between 45 and 75 years for average-risk individuals. Recommendations regarding colorectal cancer screening in high-risk individuals were more varied and depended on the risk factor. For high-risk individuals with a positive family history of colorectal cancer or advanced colorectal polyp, screening should begin at age 40. Some frequently suggested screening modalities in order of frequency are colonoscopy, FIT, and CTC. Furthermore, several screening intervals were suggested, including colonoscopy every 10 years for average-risk and every 5-10 years for high-risk individuals, FIT annually in average-risk and every 1-2 years in high-risk individuals, and CTC every five years for all individuals.
CONCLUSIONS: All individuals with average-risk should undergo colorectal cancer screening between 45 and 75. Meanwhile, individuals with higher risks, such as those with a positive family history, should begin screening at age 40. Several recommended screening modalities were suggested, including colonoscopy every 10 years in average-risk and every 5-10 years in high-risk, FIT annually in average-risk and every 1-2 years in high-risk, and CTC every five years.

(1) Although new imaging methods for examining the GIT with high diagnostic capabilities were introduced, the improvement and implementation of safe, efficient, and cost-effective approaches continue, and GIT diseases are still challenging to diagnose; (2) Methods: We aim to show the possibilities of computed tomography (CT) colonography for early diagnosis of colon diseases using a multidetector 32-channel CT scanner after appropriate preparation; (3) Results: After a colonoscopy was performed earlier, 140 patients were examined with CT colonography. Complete colonoscopy was performed in 80 patients (57.1%) out of 140 who underwent CT colonography. Incomplete colonoscopy was observed in 52 patients (37.2%); in 5 patients (3.6%), it was contraindicated, and in 3 patients (2.1%), it was not performed because of patients\' refusal. We determined that in cases of complete FCS in 95% of patients, CT colonography established the same clinical diagnosis as FCS. In cases of incomplete, refused, or contraindicated FCS in 32.7% (17 patients), FCS failed to diagnose correctly. The main reasons for incomplete colonoscopy were: intraluminal obturation of tumor nature-17 patients (33%), extraluminal obturation (compression) from a tumor formation-4 patients (8%), stenotic changes of non-tumor nature-11 patients (21%), congenital diseases with changes in the length of the lumen of the intestinal loops-7 patients (13%), and subjective factors (pain, poor preparation, contraindications) in 13 patients (25%); (4) Conclusions: Our results confirmed that CT colonography is a method of choice in cases of negative FCS results accompanied by clinical data for the neoplastic process and in cases of incomplete and contraindicated FCS. Also, the insufflation system we developed optimizes the method by improving the quality of the obtained images and ensuring good patient tolerance.

OBJECTIVE: To compare MiraLAX, a hypo-osmotic lavage, and magnesium citrate (MgC), a hyper-osmotic agent for bowel preparation at CTC.
METHODS: 398 total screening CTC studies were included in this retrospective, single institution study. 297 underwent preparation with a double-dose MgC regimen (mean age, 61 ± 5.5 years; 142 male/155 female) and 101 with 8.3 oz (equivalent to 238 g PEG) of MiraLAX (mean age, 60 ± 9.6 years; 45 male/56 female). Oral contrast for tagging purposes was utilized in both regimens. Studies were retrospectively analyzed for residual fluid volume and attenuation by automated analysis, as well for subjective oral contrast coating of the normal colonic wall and polyps. 50 patients underwent successive CTC studies utilizing each agent (mean, 6.1 ± 1.7 years apart), allowing for intra-patient comparison. Chi-squared, Fisher\'s exact, McNemar, and t-tests were used for data comparison.
RESULTS: Residual fluid volume (as percentage of total colonic volume) and fluid density was 7.2 ± 4.2% and 713 ± 183 HU for the MgC cohort and 8.7 ± 3.8% and 1044 HU ± 274 for the MiraLAX cohort, respectively (p = 0.001 and p < 0.001, respectively). Similar results were observed for the intra-patient cohort. Colonic wall coating negatively influencing interpretation was noted in 1.7% of MgC vs. 6.9% of MiraLAX examinations (p = 0.008). Polyps were detected in 12% of all MgC vs. 16% of all MiraLAX CTCs (p = 0.29).
CONCLUSIONS: CTC bowel preparation with the hypo-osmotic MiraLAX agent appears to provide acceptable diagnostic quality that is comparable to the hyper-osmotic MgC agent, especially when factoring in patient safety and tolerance.

Existing electronic cleansing (EC) methods for computed tomographic colonography (CTC) are generally based on image segmentation, which limits their accuracy to that of the underlying voxels. Because of the limitations of the available CTC datasets for training, traditional deep learning is of limited use in EC. The purpose of this study was to evaluate the technical feasibility of using a novel self-supervised adversarial learning scheme to perform EC with a limited training dataset with subvoxel accuracy. A three-dimensional (3D) generative adversarial network (3D GAN) was pre-trained to perform EC on CTC datasets of an anthropomorphic phantom. The 3D GAN was then fine-tuned to each input case by use of the self-supervised scheme. The architecture of the 3D GAN was optimized by use of a phantom study. The visually perceived quality of the virtual cleansing by the resulting 3D GAN compared favorably to that of commercial EC software on the virtual 3D fly-through examinations of 18 clinical CTC cases. Thus, the proposed self-supervised 3D GAN, which can be trained to perform EC on a small dataset without image annotations with subvoxel accuracy, is a potentially effective approach for addressing the remaining technical problems of EC in CTC.

OBJECTIVE: CT colonography (CTC) is a minimally invasive screening test with high sensitivity for colonic polyps (>1 cm). Prior studies suggest that CTC utilization remains low. However, there are few studies evaluating recent CTC utilization and predictors of CTC utilization. Our purpose was to estimate recent nationwide CTC utilization and evaluate predictors of CTC utilization using 2019 nationally representative cross-sectional survey data.
METHODS: Participants between ages 50 and 75 without colorectal cancer history in the 2019 National Health Interview Survey cross-sectional data were included. The proportion of participants reporting utilization of CTC was estimated, accounting for complex survey design elements. Multiple variable logistic regression analyses evaluated predictors of CTC utilization. Analyses were conducted accounting for complex survey design elements to obtain valid estimates for the civilian, noninstitutionalized US population.
RESULTS: In all, 13,709 respondents were included, and 1.4% reported undergoing CTC, of whom 39.9% underwent CTC within the last year, 18.5% within the last 2 years, 13.0% within the last 3 years, 7.8% within the last 5 years, 11.2% within the last 10 years, and 9.6% underwent CTC 10 years ago or more. Multiple variable logistic regression analyses revealed that Hispanic (odds ratio 2.67, 95% confidence interval 1.66-4.29, P < .001) and Black (odds ratio 2.47, 95% confidence interval 1.60-3.82, P < .001) participants were more likely than White participants to undergo CTC.
CONCLUSIONS: Survey results suggest that nationwide utilization of CTC remains low. Black and Hispanic participants were more likely than White participants to report undergoing CTC. Promotion of CTC may reduce racial and ethnic disparities in colorectal cancer screening.

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths globally. Nonetheless, with early detection of CRC or its precancerous lesions, mortality, and CRC incidence can be reduced. Although colonoscopy is currently the gold standard for CRC screening and diagnosis, its invasive nature, and troublesome bowel preparation deter patient participation. Therefore, there is a need to expand the use of noninvasive or minimally invasive methods to increase patient compliance.
This review summarizes advances in different methods for CRC screening, including stool bacterial and metagenomic markers, fecal proteins, genetic and epigenetic markers in blood and stools, and imaging modalities. The cost-effectiveness of these methods is also discussed. FIT is more cost-effective compared to virtual colonoscopy, mSEPT9 test, and Multitarget Stool DNA test, while the cost-effectiveness of other noninvasive methods requires further evaluation.
Recent evidence has well demonstrated the usefulness of gut microbiome and certain fecal bacterial markers in the noninvasive diagnosis of CRC and its precancerous lesions. Many of the fecal biomarkers, from host cells or the gut environment, show better diagnostic sensitivity than FIT. New screening tests based on these fecal biomarkers can be expected to replace FIT with higher cost-effectiveness in the near future.

The pre-operative work-up for non-metastatic colon cancer includes colonoscopy and thoraco-abdomino-pelvic computed tomography (CT) with intravenous (IV) contrast. Colonoscopic determination of the anatomical location of the tumor may be erroneous, particularly with a long redundant colon (dolichocolon), and the search for synchronous colon neoplasms is limited when the endoscope cannot traverse the tumor-bearing segment. While computed tomography colonography angiography (CTC-A) makes it possible to assess distant tumor metastasis, it remains limited for the assessment of loco-regional extension. CTC-A requires specific colonic preparation, controlled colonic insufflation with CO2, and an injection of IV contrast. CTC-A provides a 3-D view of the overall morphology of the colon and precisely localizes the site of the colonic tumor. Merging the images of the colon with those of mesenteric and colonic vessels provides a representation of anatomical vascular variations. This information could help the surgeon to better plan the colectomy. The use of two-dimensional images of CTC-A with sections perpendicular to the major axis of the tumor-bearing colonic segment can provide precise information on the degree of parietal extension and be useful in evaluating the value of neo-adjuvant chemotherapy.

Optical colonoscopy (OC), the most prevalent colon cancer screening tool, has a high miss rate due to a number of factors, including the geometry of the colon (haustral fold and sharp bends occlusions), endoscopist inexperience or fatigue, endoscope field of view. We present a framework to visualize the missed regions per-frame during OC, and provides a workable clinical solution. Specifically, we make use of 3D reconstructed virtual colonoscopy (VC) data and the insight that VC and OC share the same underlying geometry but differ in color, texture and specular reflections, embedded in the OC. A lossy unpaired image-to-image translation model is introduced with enforced shared latent space for OC and VC. This shared space captures the geometric information while deferring the color, texture, and specular information creation to additional Gaussian noise input. The latter can be utilized to generate one-to-many mappings from VC to OC and OC to OC. The code, data and trained models will be released via our Computational Endoscopy Platform at https://github.com/nadeemlab/CEP.

BACKGROUND: The Chinese Society of Clinical Oncology guidelines 2018 and the recent update of that (version 2020) recommends accurate examination before major treatment for decision(s) in cases of colon cancer. Also, the difficulty in the identification of the lesion during colectomy may lead to resection of a wrong segment of the colon or a more extensive resection than planned. Accurate pre-colectomy local staging of colon cancer is required to make decisions for treatment of colon cancer. The objective of the study was to evaluate the diagnostic performance of the computed tomography colonography (CTC) for pre-colectomy tumor location and tumor, node, and metastasis (TNM) staging of colon cancer.
METHODS: Data of preoperative colonoscopies, CTC, surgeries, and surgical pathology of a total of 269 patients diagnosed with colon cancer by colonoscopy and biopsy and underwent pre-colectomy location and TNM staging by CTC were collected and analyzed. The consistency between the radiological and the surgery/surgical-pathological for location and TN stages of colon tumor were estimated with the weighted kappa or kappa coefficient (κ) at 95% confidence interval (CI).
RESULTS: CTC detected 261 (93%) and colonoscopy detected 201 (72%) correct locations of tumors. Sensitivity and accuracy of CTC for detection of location of colon tumors were 100% and 92.58% (κ = 0.89; 95% Cl: 0.83-0.95). 72.48% sensitivity, 90.64% specificity, and 83.57% accuracy were reported for CTC in differentiation of tumors confined to the colon wall (T1/T2) from advanced tumors (T3/T4) (κ = 0.69, 95% Cl: 0.51-0.75). 81.01% sensitivity, 89.11% specificity, and 83.93% accuracy of CTC was reported for differentiation of tumors between low-intermediate risk and high risk (κ = 0.68, 95% Cl: 0.53-0.75). 69.31% sensitivity, 66.15% specificity, and 67.14% accuracy of CTC were reported for N staging of tumors (κ = 0.41, 95% Cl: 0.59-0.69).
CONCLUSIONS: CTC has high diagnostic parameters for pre-colectomy location and T staging of colon tumors except patients of colon cancer who received neoadjuvant chemotherapy.
METHODS: III.
UNASSIGNED: 2.