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Background: We aimed to evaluate the role of magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) in determining the correct stage and predicting the pathological response. Methods: Seventy one patients with pathologic proven rectal adenocarcinoma, clinical stage IIA-IVA, and neoadjuvant chemoradiotherapy (CRT) were evaluated retrospectively. Radiotherapy was delivered 45-50 Gy in 25 fractions with concomitant oral capecitabine. Pelvic MRI, colonoscopy, and 18F-FDG PET-CT were performed before the neoadjuvant treatment (NAT). After NAT, MRI and PET-CT were performed for re-evaluation. Results: The median follow-up time was 25 months (range: 3-57 months). Of the 71 patients who underwent NAT, 57 patients underwent surgery. Downstaging was recorded in 48 (84.2%) of 57 patients who underwent surgery. There was no statistically significant difference between both MRI and PET-CT with pathology results in terms of response evaluation. As a result of the comparison of MRI and PET-CT with pathological results; sensitivity and specificity were 91.6% (44/48) and 22.2% (2/9) for MRI, and 100% (47/47) and 12.5% (1/8) for PET-CT, respectively. Conclusion: PET-CT and MRI are effective in predicting response to NAT and predictive for the pathological response. A more accurate response can be judged when both PET-CT and MRI are executed together in restaging after NAT. [ABSTRACT FROM AUTHOR]

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The agreement between reported patient pain and estimated pain by endoscopists and endoscopy assistants in Cohen's Kappa and weighted Kappa. Graph HT ht In special cases, Graph HT ht is the LWK and Graph HT ht is the QWK. [Extracted from the article]

Among the non-invasive Colorectal cancer (CRC) screening approaches, Computed Tomography Colonography (CTC) and Virtual Colonoscopy (VC), are much more accurate. This work proposes an AI-based polyp detection framework for virtual colonoscopy (VC). Two main steps are addressed in this work: automatic segmentation to isolate the colon region from its background, and automatic polyp detection. Moreover, we evaluate the performance of the proposed framework on low-dose Computed Tomography (CT) scans. We build on our visualization approach, Fly-In (FI), which provides "filet"-like projections of the internal surface of the colon. The performance of the Fly-In approach confirms its ability with helping gastroenterologists, and it holds a great promise for combating CRC. In this work, these 2D projections of FI are fused with the 3D colon representation to generate new synthetic images. The synthetic images are used to train a RetinaNet model to detect polyps. The trained model has a 94 % f1-score and 97 % sensitivity. Furthermore, we study the effect of dose variation in CT scans on the performance of the the FI approach in polyp visualization. A simulation platform is developed for CTC visualization using FI, for regular CTC and low-dose CTC. This is accomplished using a novel AI restoration algorithm that enhances the Low-Dose CT images so that a 3D colon can be successfully reconstructed and visualized using the FI approach. Three senior board-certified radiologists evaluated the framework for the peak voltages of 30 KV, and the average relative sensitivities of the platform were 92 % , whereas the 60 KV peak voltage produced average relative sensitivities of 99.5 % . [ABSTRACT FROM AUTHOR]

Background: The association between body composition and survival in rectal cancer patients is still unclear. Therefore, we aimed to evaluate the impact of computed tomography (CT)-measured body composition on survival in rectal cancer patients, stratifying our analyses by sex, tumour location, tumour stage and radiotherapy. Methods: This retrospective cohort study included 173 patients with rectal adenocarcinoma. CT colonography scans at the time of diagnosis were used to assess the skeletal muscle index (SMI) and the visceral adipose tissue area (VAT). The patients were divided into a low or high SMI group and a low or high VAT group according to previously defined cutoff values. Endpoints included cancer-specific survival (CSS) and overall survival (OS). Results: In all patients, low SMI was associated with worse CSS (HR, 2.63; 95% CI, 1.35–5.12; P = 0.004) and OS (HR, 3.57; 95% CI, 2.01–6.34; P < 0.001) compared to high SMI. The differences remained significant after adjusting for potential confounders (CSS: adjusted HR, 2.28; 95% CI, 1.13–4.58; P = 0.021; OS: adjusted HR, 3.17; 95% CI, 1.73–5.82; P < 0.001). Low SMI was still related to a poor prognosis after stratifying by sex, tumour location, stage and radiotherapy (P < 0.05). High VAT was associated with better CSS (HR, 0.31; 95% CI, 0.11–0.84; P = 0.022) and OS (HR, 0.40; 95% CI, 0.17–0.97; P = 0.044) compared to low VAT among men with rectal cancer ≤ 10 cm from the anal verge. High VAT was associated with worse CSS (HR, 4.15; 95% CI, 1.10–15.66; P = 0.036) in women with rectal cancer ≤ 10 cm from the anal verge. Conclusions: Low SMI was associated with worse survival. High VAT predicted better survival in men but worse survival in women. The results suggest that CT-measured body composition is a useful tool for evaluating the prognosis of rectal cancer patients and demonstrate the need to include the sex and the tumour location in the analyses. [ABSTRACT FROM AUTHOR]

Computer-aided polyp detection (CADe) may become a standard for polyp detection during colonoscopy. Several systems are already commercially available. We report on a video-based benchmark technique for the first preclinical assessment of such systems before comparative randomized trials are to be undertaken. Additionally, we compare a commercially available CADe system with our newly developed one. ENDOTEST consisted in the combination of two datasets. The validation dataset contained 48 video-snippets with 22,856 manually annotated images of which 53.2% contained polyps. The performance dataset contained 10 full-length screening colonoscopies with 230,898 manually annotated images of which 15.8% contained a polyp. Assessment parameters were accuracy for polyp detection and time delay to first polyp detection after polyp appearance (FDT). Two CADe systems were assessed: a commercial CADe system (GI-Genius, Medtronic), and a self-developed new system (ENDOMIND). The latter being a convolutional neuronal network trained on 194,983 manually labeled images extracted from colonoscopy videos recorded in mainly six different gastroenterologic practices. On the ENDOTEST, both CADe systems detected all polyps in at least one image. The per-frame sensitivity and specificity in full colonoscopies was 48.1% and 93.7%, respectively for GI-Genius; and 54% and 92.7%, respectively for ENDOMIND. Median FDT of ENDOMIND with 217 ms (Inter-Quartile Range(IQR)8–1533) was significantly faster than GI-Genius with 1050 ms (IQR 358–2767, p = 0.003). Our benchmark ENDOTEST may be helpful for preclinical testing of new CADe devices. There seems to be a correlation between a shorter FDT with a higher sensitivity and a lower specificity for polyp detection. [ABSTRACT FROM AUTHOR]

Background and Aim: Colonoscopy quality, including lesion detectability, is variable, and factors influencing lesion detection are not fully understood. This study investigated lesion detection rates during colonoscopies and the associated factors in the SCREEning of Swedish COlons (SCREESCO) study. Methods: In this cross‐sectional analysis of data from SCREESCO, a large‐scale randomized controlled trial of colorectal cancer screening in the Swedish population aged 60 years, we assessed data of first‐time colonoscopies performed in both colonoscopy and fecal immunochemical test (FIT) arms. Results: This study included 16 552 individuals. The adenoma detection rate was 23.9% and 37.8% in colonoscopy and FIT arms, respectively. Regarding colonoscopy procedures, a withdrawal time ≥ 6 min was associated with higher detection rates of advanced adenomas (adjusted odds ratio [AOR] 2.474, 95% confidence interval [CI] 1.295–4.723), adenomas (2.181, 1.515–3.140), and proximal serrated lesions (pSLs) (1.713, 1.007–2.915). Antispasmodic use was associated with higher detection rates of these lesions and sessile serrated lesions (SSLs) (AOR, 95% CI: 1.523, 1.295–1.791; 1.361, 1.217–1.522; 1.450, 1.247–1.687; and 1.810, 1.512–2.167, respectively). Insertion time > 20 min was related to lower detection rates of adenomas, pSLs, and SSLs (AOR, 95% CI: 0.753, 0.639–0.887; 0.640, 0.495–0.828; and 0.704, 0.518–0.955, respectively). The relationship between a recent period and higher detection rates of pSLs and SSLs was also demonstrated. Conclusion: Lesion detectability in SCREESCO was mostly acceptable with room for improvement. In addition to sufficient withdrawal time, antispasmodic use and acquiring skills enabling short insertion time may improve lesion detection. Trial registration: ClinicalTrials.gov, ID: NCT02078804. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background and aims : Colonoscopy aims to early detect and remove precancerous colorectal polyps, thereby preventing development of colorectal cancer (CRC). Recently, computer-aided detection (CADe) systems have been developed to assist endoscopists in polyp detection during colonoscopy. The aim of this study was to investigate feasibility and safety of a novel CADe system during real-time colonoscopy in three European tertiary referral centers. Methods: Ninety patients undergoing colonoscopy assisted by a real-time CADe system (DISCOVERY; Pentax Medical, Tokyo, Japan) were prospectively included. The CADe system was turned on only at withdrawal, and its output was displayed on secondary monitor. To study feasibility, inspection time, polyp detection rate (PDR), adenoma detection rate (ADR), sessile serrated lesion (SSL) detection rate (SDR), and the number of false positives were recorded. To study safety, (severe) adverse events ((S)AEs) were collected. Additionally, user friendliness was rated from 1 (worst) to 10 (best) by endoscopists. Results: Mean inspection time was 10.8 ± 4.3 min, while PDR was 55.6%, ADR 28.9%, and SDR 11.1%. The CADe system users estimated that < 20 false positives occurred in 81 colonoscopy procedures (90%). No (S)AEs related to the CADe system were observed during the 30-day follow-up period. User friendliness was rated as good, with a median score of 8/10. Conclusion: Colonoscopy with this novel CADe system in a real-time setting was feasible and safe. Although PDR and SDR were high compared to previous studies with other CADe systems, future randomized controlled trials are needed to confirm these detection rates. The high SDR is of particular interest since interval CRC has been suggested to develop frequently through the serrated neoplasia pathway. Clinical Trial Registration: The study was registered in the Dutch Trial Register (reference number: NL8788). [ABSTRACT FROM AUTHOR]

Virtual colonoscopy plays an important role in polyp detection of colorectal cancer. Noise in the colon data acquisition process can result in topological errors during surface reconstruction. Topological denoising can be employed to remove these errors on surfaces for subsequent geometry processing, such as surface simplification and parameterization. Many methods have been proposed for this task. However, many existing methods suffer from failure in computation of all the non-trivial loops, due to high genus or complex topological structures. In this paper, we propose a novel robust topological denoising method for surfaces based on homotopy theory. The proposed method was evaluated on two datasets of colon meshes. We compared our method with the State-of-the-Art persistent-homology-based method. Our method can successfully compute the loops on all colon data for topological denoising, whereas the persistent homology method fails on some colon data. Moreover, our method detects all loops with shorter lengths than those detected by the persistent homology method. Our experimental results show that the proposed method is effective and robust in topological denoising, and that it has the potential for practical application to virtual colonoscopy.

(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.

This article discusses a case of stercoral colitis, a complication of constipation, in a 57-year-old man with a history of stroke and chronic constipation. The man presented to the emergency department with hematochezia (blood in the stool) but no fever or abdominal pain. After initial tests and resuscitation, an emergent colonoscopy was performed, revealing a pseudo-lumen and a bleeding visible vessel in the sigmoid colon. The colonoscopy was terminated after a colon perforation was observed, and subsequent imaging confirmed sigmoid colon stercoral colitis with localized rupture. The man underwent surgery and was discharged two weeks later. The article emphasizes the importance of early diagnosis and emergent surgery for stercoral perforation, and suggests that an abdominal CT should be considered prior to colonoscopy in older patients with constipation and hematochezia. [Extracted from the article]

This article, published in the journal Colorectal Disease, discusses the use of endoluminal surgery as a less invasive alternative for managing complex colonic polyps. The authors present two cases of colonic lesions in different locations that were successfully removed using different endoluminal approaches. The first case involved a 46-year-old woman with a rectosigmoid polyp, which was removed through endoscopic submucosal dissection. The second case involved an 83-year-old woman with an ileocaecal valve polyp, which was removed through hybrid endoscopic submucosal dissection/endoscopic mucosal resection. Both patients had successful outcomes and were discharged without complications. The authors highlight the broad applicability of endoluminal surgery and its potential to improve patient care. [Extracted from the article]

This article discusses the use of colon capsule endoscopy (CCE) as an alternative to CT colonography (CTC) for patients who have had an incomplete colonoscopy. The study found that CCE had comparable diagnostic yields to CTC, but lower completion rates. The researchers reviewed the clinical indications and patient history of 99 patients on the CTC waiting list and found that 41 were eligible for CCE. Of those, 21 patients underwent CCE, with 71% of them being successful and subsequently removed from the CTC waiting list. The study concludes that careful patient selection is important to improve completion rates and reduce unnecessary CTCs and colonoscopies. [Extracted from the article]

Purpose: We explored the predictive effect of intratumor metabolic heterogeneity indices extracted from 18F-FDG PET/CT on recurrence in stage II/III colorectal cancer after radical surgery. Methods: A total of 140 stage II/III colorectal cancer patients who received preoperative 18F-FDG PET/CT and radical resection were enrolled. 18F-FDG traditional parameters including the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) under different thresholds; heterogeneity indices including the coefficient of variation with SUV 2.5 as a threshold (CV2.5), CV40%, heterogeneity index-1 (HI-1) calculated by the fixed-threshold method, and HI-2 calculated by the percentage threshold method; and clinicopathological information were collected. We concluded that relationships exist between these data and patients' disease-free survival (DFS). Results: Regional lymph node status (P < 0.001), nerve invasion (P = 0.036), tumor thrombus (P = 0.005), and HI-1 (P = 0.010) exhibited significant differences between the relapse and non-relapse groups, while SUVmax, MTV2.5, MTV40%, TLG2.5, TLG40%, CV2.5, CV40%, HI-2, and other clinicopathological factors had no differences between the relapse and nonrelapse groups. Multivariate analysis demonstrated that HI-1 (HR = 1.02, 1.00-1.04, P = 0.038), regional lymph node metastasis (HR = 2.95, 1.37-6.38, P = 0.006), and tumor thrombus status (HR = 2.37, 1.13-4.99, P = 0.022) were independent factors significantly related to DFS. Conclusion: HI-1, tumor thrombus status, and regional lymph node status could predict the recurrence of stage II/III colorectal cancer after radical resection and had an advantage over other 18F-FDG PET/CT conventional parameters and heterogeneity indices. [ABSTRACT FROM AUTHOR]

Simple Summary: Electronic cleansing (EC) is used for performing a virtual cleansing of the colon on CT colonography (CTC) images for colorectal cancer screening. However, current EC methods have limited accuracy, and traditional deep learning is of limited use in CTC. We evaluated the feasibility of using self-supervised adversarial learning to perform EC on a limited dataset with subvoxel accuracy. A 3D generative adversarial network was pre-trained to perform EC on the CTC datasets of an anthropomorphic colon phantom, and it was fine-tuned to each input case by use of a self-supervised learning scheme. The visually perceived quality of the virtual cleansing by this method compared favorably to that of commercial EC software on the virtual 3D fly-through examinations of 18 clinical CTC cases. Our results indicate that the proposed self-supervised scheme is a potentially effective approach for addressing the remaining technical problems of EC in CTC for colorectal cancer screening. 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. [ABSTRACT FROM AUTHOR]

Background/Aims: The adenoma detection rate (ADR) does not reflect the complete detection of every adenoma during colonoscopy; thus, many surrogate indicators have been suggested. This study investigated whether the ADR and surrogate quality indicators reflect the adenoma miss rate (AMR) when performing qualified colonoscopy. Methods: We performed a prospective, multicenter, cross-sectional study of asymptomatic examinees aged 50 to 75 years who underwent back-to-back screening colonoscopies by eight endoscopists. The ADR and surrogate quality indicators, including polyp detection rate, total number of adenomas per colonoscopy, additional adenomas found after the first adenoma per colonoscopy (ADR-Plus), and total number of adenomas per positive participant, were calculated for the prediction of AMR. Results: A total of 371 back-to-back colonoscopies were performed. There was a significant difference in ADRs (range, 44% to 75.4%; p=0.024), polyp detection rates (range, 56% to 86.9%; p=0.008) and adenomas per positive participants (range, 1.19 to 2.30; p=0.038), and a tendency of a difference in adenomas per colonoscopy (range, 0.62 to 1.31; p=0.051) and ADR-Plus (range, 0.13 to 0.70; p=0.054) among the endoscopists. The overall AMR was 20.1%, and AMRs were not different (range, 13.9 to 28.6; p>0.05) among the endoscopists. No quality indicators were significantly correlated with AMR. The number of adenomas found during the first colonoscopy was an independent factor for increased AMR (odds ratio, 1.79; p<0.001). Conclusions: The colonoscopy quality indicators were significantly different among high-ADR endoscopists, and none of the quality indicators reflected the AMR of good quality colonoscopy performances. The only factor influencing AMR was the number of adenomas detected during colonoscopy. [ABSTRACT FROM AUTHOR]

Colon screening programs have reduced colon cancer mortality. Population screening should be minimally invasive, safe, acceptably sensitive, cost-effective, and scalable. The range of screening modalities include guaiac or immunochemical fecal occult blood testing and CT colonography and colonoscopy. A number of carefully controlled studies concur that second-generation capsule endoscopy has excellent sensitivity for polyp detection and a high negative predictive value. Colon capsules fulfill the screening expectation of safety, high sensitivity for polyp detection, and patient acceptance, and appear to straddle the divide between occult blood testing and colonoscopy. While meeting these criteria, there remains the challenges of scaling, capsule practitioner training, resource allocation, and implementing change of practice. Like CT colonography, capsule screening presents the clinician with a decision on the threshold for colonoscopy referral. Overall, colon capsules are an invaluable tool in polyp detection and colon screening and offer a filter that determines "who needs a colonoscopy?". [ABSTRACT FROM AUTHOR]

Metastatic ovarian tumors with a gastrointestinal origin have always been a challenge in surgery; in many cases, the primary tumor is diagnosed after the metastasis. This case was presented with bilateral abdominal masses, which were adenocarcinomas originating from gastrointestinal tract. Following colonoscopy and finding a mass, total colectomy was performed. The key clinical message, in this case, is that large, bilateral masses in the absence of ascites are suggestive for an extragonadal origin for which one of the primary sources is GI, so endoscopy and colonoscopy should be carried out for these patients (for gastric and colonic cancers). Resecting the primary tumor with metastasis is controversial, and not currently enough data are available. Our assumption is that we have to rule out the secondary sites of metastasis and peritoneal seeding, for which palliative chemotherapy and ostomy diversion for obstructive cases is the only option. In cases with no secondary site of metastasis surgery is considered an option, but the risk of metachronous metastasis is high, and the prognosis is poor. [ABSTRACT FROM AUTHOR]

In the medical field, Medical diagnosis using Computed tomography (CT) has become increasingly popular due to their non-invasive approach and quick overall turnaround time. 3D visualization for CT Colonography involves the assessment and diagnosis of a patient to find the presence of cancerous polyps in the colon, by taking a Computed Tomography scan of the patient, and evaluating the reports. This technique reduces evaluation time by allowing the doctors themselves to analyze the CT scans without the need for a radiologist to generate an initial report. This technique also avoids an invasive procedure on the patient. This paper gives the insightsof developing computer aided system for the detection of Polyps in CT Colonography images using the principles of Image Processing and the Deep Learning, specifically an ensemble of Convolutional Neural Networks using GoogleNet architecture and 3D reconstruction of the same. The accuracy achieved by the proposed system for region classification, region 1 polyp detection and region 2 polyp detection are 98.75%, 93.75% and 94.03% respectively, and their F1 Scores are 0.88, 0.82 and 0.84 respectively. [ABSTRACT FROM AUTHOR]

To evaluate the impact of root canal preparation in teeth with ultraconservative access cavities (UltraAC) on the development of dentinal microcracks using a nondestructive longitudinal micro–computed tomography (micro-CT) imaging experimental model. Root canal preparation in teeth with traditional access cavities (TradAC) was used as control. Forty mandibular molars were scanned in a micro-CT device, anatomically matched, and distributed into 4 groups according to the type of access cavity and instrumentation system: traditional/Reciproc (TradAC/RC), traditional/XP-endo Shaper (TradAC/XP), ultraconservative/Reciproc (UltraAC/RC), and ultraconservative/XP-endo Shaper (UltraAC/XP). After root canal preparation, the teeth were rescanned. After reconstruction and co-registration procedures, the images were screened from the furcation level to the apex to identify the presence of dentinal microcracks. From a total of 15,340 cross-section images, 19.65% (3014 slices) had some dentinal microcracks. The qualitative analysis demonstrated the presence of some dentinal microcracks in 11%, 33%, 19%, and 15% of the images of cross-sections in TradAC/RC, TradAC/XP, UltraAC/RC, and UltraAC/XP groups, respectively. All dentinal microcracks observed after root canal preparation were already present in the corresponding images before canal instrumentation. Therefore, no new microcracks were detected, regardless of the access cavity and root canal instrumentation system. Root canal preparation with Reciproc or XP-endo Shaper under traditional or ultraconservative access cavities did not create dentinal microcracks in extracted mandibular molars. [ABSTRACT FROM AUTHOR]

Purpose  This article prospectively assesses the feasibility of simple oral preparation contrast-enhanced computed tomography colonography (SOP-CE-CTC) using a large volume of oral 3% mannitol for good colonic distension along with mural and mucosal fold visualization. Methods  A total of 100 patients in whom contrast CT abdomen was requested, recruited as per selection criteria, were advised to take mild oral bowel preparation for two nights, prior to the investigation. Then, after fasting overnight, they were asked to consume 1,500 to 2,000 mL of 3% mannitol solution in about an hour. Thirty minutes after completing the ingestion of oral mannitol, intravenous contrast was injected and SOP-CE-CTC was acquired at 55 seconds. Distension of six segments of the colon was evaluated by assigning scores 1 to 4 for qualitative assessment; and measuring the maximum luminal diameter of the colon, for quantitative assessment. Colonic mucosal and mural visualization were evaluated subjectively. All observations were recorded by two reviewers (with varying levels of experience) independently. Results  On qualitative analysis, the colon showed optimal distension (score 4) in 58 to 89% cases on SOP-CE-CTC. There was agreement between both the reviewers in 89 to 99% cases (weighted kappa 0.820–0.979; p  < 0.001). On quantitative analysis, the mean of the maximum colonic diameter ranged between 3.4 and 5.2 cm; and both the reviewers agreed in 89 to 97% cases (weighted kappa 0.777–0.967; p  < 0.001). Mural and mucosal fold visualization in the proximal four segments of the colon was excellent (in 90–98%) but in the rectum and sigmoid it was 45 and 66%, respectively; both the reviewers agreed in 100% cases (weighted kappa 1.0 and p  < 0.001). Conclusion  Good colonic distension, mural, and mucosal fold visualization can be achieved on SOP-CE-CTC using 1,500 to 2,000 mL of 3% oral mannitol and mild oral bowel preparation agents. [ABSTRACT FROM AUTHOR]

Purpose: This study compared the root canal anatomy between cone-beam computed tomography (CBCT) and micro-computed tomography (micro-CT) images before and after biomechanical preparation and root canal filling. Materials and Methods: Isthmus-containing mesial roots of mandibular molars (n=14) were scanned by micro-CT and 3 CBCT devices: 3D Accuitomo 170 (ACC), NewTom 5G (N5G) and NewTom VGi evo (NEVO). Two calibrated observers evaluated the images for 2-dimensional quantitative parameters, the presence of debris or root perforation, and filling quality in the root canal and isthmus. The kappa coefficient, analysis of variance, and the Tukey test were used for statistical analyses (α=5%). Results: Substantial intra-observer agreement (κ=0.63) was found between micro-CT and ACC, N5G, and NEVO. Debris detection was difficult using ACC (42.9%), N5G (40.0%), and NEVO (40%), with no agreement between micro-CT and ACC, N5G, and NEVO (0.05<κ<0.12). After biomechanical preparation, 2.4%-4.8% of CBCT images showed root perforation that was absent on micro-CT. The 2D parameters showed satisfactory reproducibility between micro-CT and ACC, N5G, and NEVO (intraclass correlation coefficient: 0.60-0.73). Partially filled isthmuses were observed in 2.9% of the ACC images, 8.8% of the N5G and NEVO images, and 26.5% of the micro-CT images, with no agreement between micro-CT and ACC, and poor agreement between micro-CT and N5G and NEVO. Excellent agreement was found for area, perimeter, and the major and minor diameters, while the roundness measures were satisfactory. Conclusion: CBCT images aided in isthmus detection and classification, but did not allow their classification after biomechanical preparation and root canal filling. [ABSTRACT FROM AUTHOR]

Background: Current strategies to prevent colorectal cancer (CRC) vary considerably regarding safety, invasiveness, and patient satisfaction. A known deterrent for patients is the required bowel cleansing for colonoscopy. A new colon-scan capsule system is a unique preparation-free approach that provides structural information on colonic mucosa intended for detection of colorectal polyps and masses. Aims: The aim of this study was to determine safety and patient satisfaction with the colon-scan capsule. Methods: Prospective single-arm pilot study conducted at two tertiary care centers. Patients with a pre-scheduled colonoscopy for CRC screening or surveillance were included. Patients participating in this study underwent the colon-scan capsule and colonoscopy. Safety was defined by the occurrence of procedure or device-related adverse events. Satisfaction was based on survey questionnaires using a scoring system 1 (strongly disagree) to 5 (strongly agree). Patient satisfaction with the colon-scan capsule was compared to colonoscopy. Results: Forty patients were included (52.9 [5.7] years; 64.1% females). There were no serious adverse events and no occurrences of capsule retention. The most common (12.5%) complaint was self-limiting abdominal cramping. Satisfaction questionnaires were completed by more than 87% of patients, with patients likely to recommend the capsule (score 4.1 [1.03]) compared to colonoscopy (score 2.8 [1.2]), p = 0.001. Conclusions: The new prepless colon-scan capsule system is an innovative, minimally invasive technology with demonstrated safety and high patient satisfaction. A multicenter pivotal study is planned to validate the performance, safety, and accuracy of polyp detection using the capsule system in comparison with colonoscopy. [ABSTRACT FROM AUTHOR]

The trade-off between speed and precision is a key step in the detection of small polyps in wireless capsule endoscopy (WCE) images. In this paper, we propose a hybrid network of an inception v4 architecture-based single-shot multibox detector (Hyb-SSDNet) to detect small polyp regions in both WCE and colonoscopy frames. Medical privacy concerns are considered the main barriers to WCE image acquisition. To satisfy the object detection requirements, we enlarged the training datasets and investigated deep transfer learning techniques. The Hyb-SSDNet framework adopts inception blocks to alleviate the inherent limitations of the convolution operation to incorporate contextual features and semantic information into deep networks. It consists of four main components: (a) multi-scale encoding of small polyp regions, (b) using the inception v4 backbone to enhance more contextual features in shallow and middle layers, and (c) concatenating weighted features of mid-level feature maps, giving them more importance to highly extract semantic information. Then, the feature map fusion is delivered to the next layer, followed by some downsampling blocks to generate new pyramidal layers. Finally, the feature maps are fed to multibox detectors, consistent with the SSD process-based VGG16 network. The Hyb-SSDNet achieved a 93.29% mean average precision (mAP) and a testing speed of 44.5 FPS on the WCE dataset. This work proves that deep learning has the potential to develop future research in polyp detection and classification tasks. [ABSTRACT FROM AUTHOR]

Introduction: Adequate bone quality is essential for long term biologic fixation of cementless total knee arthroplasty (TKA). Recently, vertebral bone quality evaluation using dual-energy computed tomography (DECT) has been introduced. However, the DECT bone mineral density (BMD) in peripheral skeleton has not been correlated with Hounsfield units (HU) or central dual-energy X-ray absorptiometry (DXA), and the accuracy remains unclear. Materials and methods: Medical records of 117 patients who underwent TKA were reviewed. DXA was completed within three months before surgery. DECT was performed with third-generation dual source CT in dual-energy mode. Correlations between DXA, DECT BMD and HU for central and periarticular regions were analyzed. Receiver operating characteristic (ROC) curves were plotted and area under the curve (AUC), optimal threshold, and sensitivity and specificity of each region of interest (ROI) were calculated. Results: Central DXA BMD was correlated with DECT BMD and HU in ROIs both centrally and around the knee (all p < 0.01). The diagnostic accuracy of DECT BMD was higher than that of DECT HU and was also higher when the T-score for second lumbar vertebra (L2), rather than for the femur neck, was used as the reference standard (all AUC values: L2 > femur neck; DECT BMD > DECT HU, respectively). Using the DXA T-score at L2 as the reference standard, the optimal DECT BMD cut-off values for osteoporosis were 89.2 mg/cm3 in the distal femur and 78.3 mg/cm3 in the proximal tibia. Conclusion: Opportunistic volumetric BMD assessment using DECT is accurate and relatively simple, and does not require extra equipment. DECT BMD and HU are useful for osteoporosis screening before cementless TKA. [ABSTRACT FROM AUTHOR]

Background: Persistent descending mesocolon (PDM) is a fetal abnormality in which the left‐sided colon is not fused to the retroperitoneum, and it is often accompanied by the adhesion between the mesocolon and small bowel mesentery. Due to its rarity, whether PDM exhibits anatomical characteristics of the inferior mesenteric artery (IMA) and left colic artery (LCA), and how the anomaly affects laparoscopic surgery are largely unknown. We investigated the branches of these arteries and outcomes of patients who underwent laparoscopic surgery. Methods: Based on computed tomography (CT) and three‐dimensional CT angiography, branching patterns of the IMA, LCA and branches originating from the LCA were analysed in 954 patients with left‐sided colon or rectal cancer. PDM was diagnosed by preoperative CT colonography, and confirmed at time of surgery. The anatomical features of the vessels and short‐term outcomes of laparoscopic surgery were compared between patient groups stratified by PDM. Results: Twelve patients (1.3%) were diagnosed with PDM. No branching pattern of the IMA specific to PDM was noted. On the other hand, patients with PDM had fewer branches (mean: 1.0) from the LCA than those without PDM (mean: 1.8, p = 0.009). In patients undergoing laparoscopic surgery, outcomes such as operative time, intraoperative blood loss, and number of harvested nodes were comparable between the two patient groups. Conclusion: Few branches of the LCA characterize PDM. PDM does not complicate laparoscopic surgery of the left‐sided colon and rectum. However, the above anatomical feature increases the risk of poor colonic perfusion when dividing the LCA. [ABSTRACT FROM AUTHOR]

Purpose: 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.Conclusion: 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. [ABSTRACT FROM AUTHOR]

Background: Endoscopic surveillance in patients with Lynch syndrome (LS) is crucial due to a genetically based high risk of colorectal cancer (CRC). We aimed to compare the adenoma detection rate (ADR) between high-resolution white light endoscopy (WLE) alone and WLE plus dye chromoendoscopy (CE) in a cohort of LS patients. Methods: In a context of real-world data, we retrospectively enrolled 50 LS patients who had non-randomly undergone WLE versus CE surveillance examinations from 2007 to 2019. The 2 groups were compared at baseline (BL) in terms of the rate of patients with lesions and the number of lesions, and at follow-up (FU), to evaluate a possible enhanced detection rate. Longitudinal analysis of the effect of the endoscopy type on the main outcomes was performed by generalized linear mixed models. Results: Forty-two patients had undergone at least one diagnostic colonoscopy. At BL and at FU analysis, we found no significant differences in detection rates and clinical-pathological features between WLE and CE groups. At the longitudinal analysis, an increase in the endoscopy rank (i.e., the position of each colonoscopy for all the colonoscopies that a patient had undergone) was associated with an increase in polyp detection rate (p = 0.006) and ADR (p = 0.005), while a trend toward significance (p = 0.069) was found for endoscopy type (CE vs. WLE) in the detection of serrated lesions. Conclusions: CE is not superior to high-resolution WLE in increasing the ADR. Even under standard WLE, an active and careful endoscopic surveillance of LS patients can prevent CRC. [ABSTRACT FROM AUTHOR]

With colonoscopy resources under pressure and inequitable participation rates in our screening programmes, there is an urgent need to consider trialling new testing technology for the detection of colorectal cancer (CRC) in Australasia. Research has shown that volatile organic compounds (VOCs) emitted from the human body can act as biomarkers for CRC, indicating high sensitivity and specificity for early and late‐stage CRC and for adenomatous polyps. Breath‐based VOC testing shows promise due to acceptability and ease of sampling via simple hand‐held devices. Analysis can occur via mass spectrometry, or via 'e‐nose' or sensor techniques. This review summarizes the current state of knowledge in using VOC‐based testing for CRC. Adoption of this technique has the potential to improve CRC survival, reduce incidence and reduce colonoscopy burden in Australasia, and positively impact on ethnic disparities in cancer outcomes. Future multicentre trials should be conducted using standardized processes and protocols. This will ensure accuracy and reproducibility under different environmental and physiological conditions, and for different ethnic groups. Studies should be explicitly targeted to various points along the CRC patient pathway. Research has shown that volatile organic compounds (VOCs) emitted from the human body can act as biomarkers for CRC, indicating high sensitivity and specificity for early and late‐stage CRC and for adenomatous polyps. Breath‐based VOC testing shows promise due to acceptability and ease of sampling. This review summarises the current state of knowledge in using VOC‐based testing for CRC and where it could be utilized in the clinical care pathway to improve on current healthcare delivery. [ABSTRACT FROM AUTHOR]

Abstract 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. Level of Evidence III. Technical Efficacy Stage 2.

Purpose: To assess the feasibility of combining Auto-kVp selection technique, higher preset ASIR-V and noise index (NI) to realize individualized sub-mSv CT colonography (CTC) for accurate colorectal tumor detection and localization.Ninety patients with suspected colorectal cancer (CRC) were prospectively enrolled to undergo standard dose CTC (SDCTC) in the prone and ultra-low dose CTC (ULDCTC) in the supine position. SDCTC used 120 kVp, preset ASIR-V of 30%, SmartmA for a NI of 13; ULDCTC used Auto-kVp selection technique with 80 or 100 kVp, preset ASIR-V of 60%, SmartmA for a NI of 13 for 80 kVp, and NI of 15 for 100 kVp. The effective dose (ED), image quality [signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of colorectal neoplasms] between the two protocols were compared and the accuracies of tumor locations were evaluated for CTC in comparison with the surgery results.The mean ED of the ULDCTC-80 kVp subgroup was 0.70 mSv, 71.43% lower than the 2.45 mSv for the 120 kVp group, while that of the ULDCTC-100 kVp subgroup was 0.98 mSv, 73.00% lower than the 3.63 mSv for the 120 kVp group (P < 0.001). The tumor SNR and CNR of the ULDCTC were higher than those of SDCTC (P < 0.05), while there was no difference in the subjective image quality between them with good inter-observer agreement (Kappa: 0.805–0.923). Both SDCTC and ULDCTC groups had high detection rate of colorectal tumors, along with good consistency in determining tumor location compared with surgery reports (Kappa: 0.718–0.989).The combination of Auto-kVp selection, higher preset ASIR-V and NI achieves individualized sub-mSv CTC with good performance in detecting and locating CRC with surgery and consistent results between SDCTC and ULDCTC.Methods: To assess the feasibility of combining Auto-kVp selection technique, higher preset ASIR-V and noise index (NI) to realize individualized sub-mSv CT colonography (CTC) for accurate colorectal tumor detection and localization.Ninety patients with suspected colorectal cancer (CRC) were prospectively enrolled to undergo standard dose CTC (SDCTC) in the prone and ultra-low dose CTC (ULDCTC) in the supine position. SDCTC used 120 kVp, preset ASIR-V of 30%, SmartmA for a NI of 13; ULDCTC used Auto-kVp selection technique with 80 or 100 kVp, preset ASIR-V of 60%, SmartmA for a NI of 13 for 80 kVp, and NI of 15 for 100 kVp. The effective dose (ED), image quality [signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of colorectal neoplasms] between the two protocols were compared and the accuracies of tumor locations were evaluated for CTC in comparison with the surgery results.The mean ED of the ULDCTC-80 kVp subgroup was 0.70 mSv, 71.43% lower than the 2.45 mSv for the 120 kVp group, while that of the ULDCTC-100 kVp subgroup was 0.98 mSv, 73.00% lower than the 3.63 mSv for the 120 kVp group (P < 0.001). The tumor SNR and CNR of the ULDCTC were higher than those of SDCTC (P < 0.05), while there was no difference in the subjective image quality between them with good inter-observer agreement (Kappa: 0.805–0.923). Both SDCTC and ULDCTC groups had high detection rate of colorectal tumors, along with good consistency in determining tumor location compared with surgery reports (Kappa: 0.718–0.989).The combination of Auto-kVp selection, higher preset ASIR-V and NI achieves individualized sub-mSv CTC with good performance in detecting and locating CRC with surgery and consistent results between SDCTC and ULDCTC.Results: To assess the feasibility of combining Auto-kVp selection technique, higher preset ASIR-V and noise index (NI) to realize individualized sub-mSv CT colonography (CTC) for accurate colorectal tumor detection and localization.Ninety patients with suspected colorectal cancer (CRC) were prospectively enrolled to undergo standard dose CTC (SDCTC) in the prone and ultra-low dose CTC (ULDCTC) in the supine position. SDCTC used 120 kVp, preset ASIR-V of 30%, SmartmA for a NI of 13; ULDCTC used Auto-kVp selection technique with 80 or 100 kVp, preset ASIR-V of 60%, SmartmA for a NI of 13 for 80 kVp, and NI of 15 for 100 kVp. The effective dose (ED), image quality [signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of colorectal neoplasms] between the two protocols were compared and the accuracies of tumor locations were evaluated for CTC in comparison with the surgery results.The mean ED of the ULDCTC-80 kVp subgroup was 0.70 mSv, 71.43% lower than the 2.45 mSv for the 120 kVp group, while that of the ULDCTC-100 kVp subgroup was 0.98 mSv, 73.00% lower than the 3.63 mSv for the 120 kVp group (P < 0.001). The tumor SNR and CNR of the ULDCTC were higher than those of SDCTC (P < 0.05), while there was no difference in the subjective image quality between them with good inter-observer agreement (Kappa: 0.805–0.923). Both SDCTC and ULDCTC groups had high detection rate of colorectal tumors, along with good consistency in determining tumor location compared with surgery reports (Kappa: 0.718–0.989).The combination of Auto-kVp selection, higher preset ASIR-V and NI achieves individualized sub-mSv CTC with good performance in detecting and locating CRC with surgery and consistent results between SDCTC and ULDCTC.Conclusion: To assess the feasibility of combining Auto-kVp selection technique, higher preset ASIR-V and noise index (NI) to realize individualized sub-mSv CT colonography (CTC) for accurate colorectal tumor detection and localization.Ninety patients with suspected colorectal cancer (CRC) were prospectively enrolled to undergo standard dose CTC (SDCTC) in the prone and ultra-low dose CTC (ULDCTC) in the supine position. SDCTC used 120 kVp, preset ASIR-V of 30%, SmartmA for a NI of 13; ULDCTC used Auto-kVp selection technique with 80 or 100 kVp, preset ASIR-V of 60%, SmartmA for a NI of 13 for 80 kVp, and NI of 15 for 100 kVp. The effective dose (ED), image quality [signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of colorectal neoplasms] between the two protocols were compared and the accuracies of tumor locations were evaluated for CTC in comparison with the surgery results.The mean ED of the ULDCTC-80 kVp subgroup was 0.70 mSv, 71.43% lower than the 2.45 mSv for the 120 kVp group, while that of the ULDCTC-100 kVp subgroup was 0.98 mSv, 73.00% lower than the 3.63 mSv for the 120 kVp group (P < 0.001). The tumor SNR and CNR of the ULDCTC were higher than those of SDCTC (P < 0.05), while there was no difference in the subjective image quality between them with good inter-observer agreement (Kappa: 0.805–0.923). Both SDCTC and ULDCTC groups had high detection rate of colorectal tumors, along with good consistency in determining tumor location compared with surgery reports (Kappa: 0.718–0.989).The combination of Auto-kVp selection, higher preset ASIR-V and NI achieves individualized sub-mSv CTC with good performance in detecting and locating CRC with surgery and consistent results between SDCTC and ULDCTC. [ABSTRACT FROM AUTHOR]

Computed tomographic colonography (CTC) is a non-invasive screening test for colorectal cancer (CRC) with high sensitivity and low risk of complications. We used a nationally representative sample of screening-eligible adults to examine trends in and factors associated with CTC use. We examined CTC use among 58,058 adults in the National Health Interview Survey in 2010, 2015, 2018, 2019, and 2021. For each survey year, we estimated CTC use by sociodemographic and health factors. We used multivariable logistic regression to identify factors associated with CTC use. A total of 1.7 % adults reported receiving CTC across all survey years. CTC use was similar in 2010 (1.3 %), 2015 (0.8 %), 2018 (1.4 %), and 2019 (1.4 %) but increased in 2021 (3.5 %, p < 0.05). In multivariable analysis, survey year 2021 [vs. 2010, odds ratio (OR) 2.51, 95 % confidence interval (CI) 1.83–3.43], Hispanic (OR 1.73, 95 % CI 1.34–2.23), non-Hispanic Black (OR 2.07, 95 % CI 1.67–2.57), and household income <200 % federal poverty level (vs. >400 %, OR 1.25, 95 % CI 1.01–1.57) was associated with CTC use. Further, adults with a history of diabetes (OR 1.20, 95 % CI 1.01–1.45), chronic obstructive pulmonary disease (OR 1.58, 95 % CI 1.25–1.99), cancer (OR 1.29, 95 % CI 1.05–1.58), or past-year hospital admissions (OR 1.44, 95 % CI 1.18–1.78) were more likely to receive CTC. CTC use remained low from 2010 to 2019 but increased in 2021. CTC use was more frequent among adults with chronic health conditions, minorities, and adults with lower income, and may help reduce disparities in CRC screening. • The use of CT Colonography more than doubled from 2019 to 2021 after remaining similar for the previous decade. • Hispanic and Non-Hispanic Black individuals are more likely to use CT Colonography than individuals of any other race. • Certain chronic health conditions, such as COPD and cancer, are associated with increased use of CT Colonography. [ABSTRACT FROM AUTHOR]

Early detection and characterization of adenomatous polyps, the precursors to colorectal cancer is crucial for effective diagnosis and treatment of colorectal cancer. A suitably trained machine learning algorithm can perform automatic real-time optical characterization of polyps during colonoscopy procedures with virtual chromoendoscopy systems, such as Narrow Band Imaging (NBI). This study proposes to perform a detailed comparative analysis between the performances of two popular machine learning frameworks, namely training from scratch and transfer learning, using three state-of-the-art architectures ResNet50, EfficientNetB2, and ViTb_32 with one indigenous dataset and one publicly available dataset. The indigenous dataset was created using 1739 NBI frames extracted from colonoscopy videos of 30 polyp masses from 24 patients [870 hyperplastic polyp frames and 869 adenomatous polyp frames]. The publicly available dataset also consisted of NBI frames. Blurry frames or frames with specular reflections were not excluded to closely resemble real-life polyp characterization in a clinical setting. Among the three models used in two different frameworks, EfficientNetB2 in the training from scratch framework yielded the best accuracy, AUC and NPV of 91.91%, 0.99 and 89.06%. The results show that the training from scratch framework outperformed the transfer learning framework in terms of the evaluation metrics. To the best of our knowledge, this is the first indigenous study to focus on polyp classification using solely Narrow Band Imaging (NBI) polyp images. Our results using only NBI polyp frames outperformed those obtained with a combination of white light and NBI frames, as observed in similar existing studies. [ABSTRACT FROM AUTHOR]

Background: Screening with colonoscopy for all average-risk population is probably not cost-effective due to the limited sources and over-generalization of the risk, and risk stratification can be used to optimize colorectal cancer screening. Objectives: We aimed to assess risk factors for advanced neoplasia (AN) and a classification tree algorithm to predict the risk. Design: This is a retrospective cross-sectional study. Methods: This study was composed of consecutive asymptomatic average-risk individuals undergoing first screening colonoscopy between 2008 and 2019. Detailed characteristics including background diseases, habits, and medications were collected. We used multivariable logistic regression to investigate the associations between clinical variables and the presence of AN and built a classification algorithm to predict AN. Results: A total of 3856 patients were included (73.2% male, median age 55). Adenoma and AN detection rate were 15.8% and 3.4%, respectively. On multivariable analysis, predictors of AN [odds ratio (OR), 95% confidence interval (CI)] were age (1.04, 1.01–1.06, p = 0.003), male sex (2.69, 1.56–4.64, p < 0.001), and smoking (1.97, 1.38–2.81, p < 0.001). A classification tree algorithm showed that smoking was the most important risk factor for prediction of AN (4.9% versus 2.4%, p < 0.001), followed by age with a cutoff value of 60 in the smokers (8.4% versus 3.8%, p = 0.001) and 50 in the non-smokers (2.9% versus 0.9%, p = 0.004). Conclusion: Smoking habits, old age, and male gender are highly associated with an increased risk for AN and should be incorporated in the individualized risk-assessment to adapt a screening program. [ABSTRACT FROM AUTHOR]

Textures have become widely adopted as an essential tool for lesion detection and classification through analysis of the lesion heterogeneities. In this study, higher order derivative images are being employed to combat the challenge of the poor contrast across similar tissue types among certain imaging modalities. To make good use of the derivative information, a novel concept of vector texture is firstly introduced to construct and extract several types of polyp descriptors. Two widely used differential operators, i.e., the gradient operator and Hessian operator, are utilized to generate the first and second order derivative images. These derivative volumetric images are used to produce two angle-based and two vector-based (including both angle and magnitude) textures. Next, a vector-based co-occurrence matrix is proposed to extract texture features which are fed to a random forest classifier to perform polyp classifications. To evaluate the performance of our method, experiments are implemented over a private colorectal polyp dataset obtained from computed tomographic colonography. We compare our method with four existing state-of-the-art methods and find that our method can outperform those competing methods over 4%-13% evaluated by the area under the receiver operating characteristics curves. [ABSTRACT FROM AUTHOR]

To evaluate the frequency and clinical outcome of unknown extracolonic findings in patients with cancer who underwent CT colonography (CTC). Consecutive patients who underwent CTC from February 2000–April 2016 for any indication were retrospectively included. One radiologist blinded to clinical data determined C-RADS classification for all extracolonic findings on CTC reports as follows: E1: normal examination or anatomic variant, E2: clinically unimportant, E3: likely unimportant, incompletely characterized, and E4: potentially important. Another radiologist performed an unblinded review of medical records and determined if E4 findings were previously known or new, and classified new E4 findings as clinically important or unimportant on follow-up. Of 855 patients, 686/855 (80.2%) had a normal examination or clinically unimportant extracolonic findings (E1 and E2) and 169/855 (19.8%) had E3–E4 extracolonic findings [99/855 (11.6%) patients had known E4 findings and 102/855 (11.9%) patients had new E4 findings]. On follow-up, among new E4 findings, 71/855 (8.3%) patients had clinically important findings, 66/855 (7.7%) had a malignant outcome previously unknown by the referring physician, and 5/855 (0.6%) had other complications, including bowel obstruction and cirrhosis. Regarding new oncological findings, new extracolonic primary tumors were detected in 13/855 (1.5%) patients, corresponding to 12.7% (13/102) of the new E4 findings. The proportion of new E4 findings on CTC with and without intravenous contrast was not significantly different [41/320 (12.8%) vs 61/535 (11.4%), p = 0.612]. Among oncological patients, detection of new significant E4 extracolonic findings at CTC occurred in 8.3% of all cases, including unknown cancers in 1.5%. • New E4 extracolonic findings on CTC were detected in 8.3% of oncological patients. • Unknown primary cancers were diagnosed in 1.5% of oncological patients on CTC. • Proportion of new E4 findings was higher on CTC with intravenous contrast. [ABSTRACT FROM AUTHOR]

Purpose: We investigated whether or not computed tomographic colonography (CTC) is a viable alternative to double-contrast barium enema (BE) for a preoperative rectal cancer evaluation. Methods: The size and distance from the anal canal to the lower or upper tumor borders were laterally measured in 147 patients who underwent CTC and BE. Measurements were grouped into early cancer, advanced, and after chemoradiation therapy (CRT). Results: In the early and advanced cancer groups, all lesions were visualized by BE. In contrast, 3 (7.8%) early and 8 (7.3%) advanced cases, located at the anterior wall near the anal canal, were not visualized by CTC because of liquid level formation. In the CRT group, 16 (23.5%) and 4 (5.8%) cases were not visualized by CTC and BE, respectively. The BE and CTC size measurements were similar among cohorts. However, the distance from the anal canal's superior margin tended to be longer with BE, especially in early cancer. The differences in distance from the anal canal were significantly larger in the early cancer group than in the other two groups (p = 0.0024). Conclusion: CTC may be a viable alternative imaging modality in some cases. However, BE should be employed in anterior wall cases near the anal canal and CRT cases. [ABSTRACT FROM AUTHOR]

Colonoscopy is used worldwide for screening colon cancer. Routine colonoscopy is considered a safe procedure with relatively fewer adverse events. We present a case of intracolonic and retroperitoneal hematoma following a routine colonoscopy. This case highlights an uncommon life-threatening complication of a common procedure. A 50-year-old female presented with abdominal pain and syncopal episode following an uneventful screening colonoscopy. CT abdomen revealed intracolonic and retroperitoneal hematoma. This eventually led to exploratory laparotomy and right hemicolectomy after failure of conservative management. Clinicians need to be aware of the potentially life-threatening complications associated with colonoscopy for overall safety of colonoscopy. [ABSTRACT FROM AUTHOR]

Simple Summary: The current pathway for the investigation of possible colorectal cancer includes the use of colonoscopy. This is an invasive and unpleasant procedure, and currently, a large number of those performed are normal. Previous research has demonstrated that urinary volatile organic compounds (VOCs) can be used to detect cancer, including colorectal cancer. However, these studies have only taken place in patients already known to have cancer. This study aimed to assess the role of urinary VOC analysis in the NHS two weeks wait for cancer pathway. Three analytical techniques were used to analyze urine samples of 558 patients during the standard NHS assessment pathway. It demonstrated that gas chromatography-mass spectrometry (GCMS) has excellent sensitivity and specificity for the identification of cancer and polyps in this patient group. These results show a potential role for urinary VOC analysis in the NHS cancer screening pathway, to reduce the need for invasive colonoscopy testing. Colorectal symptoms are common but only infrequently represent serious pathology, including colorectal cancer (CRC). A large number of invasive tests are presently performed for reassurance. We investigated the feasibility of urinary volatile organic compound (VOC) testing as a potential triage tool in patients fast-tracked for assessment for possible CRC. A prospective, multi-center, observational feasibility study was performed across three sites. Patients referred to NHS fast-track pathways for potential CRC provided a urine sample that underwent Gas Chromatography-Mass Spectrometry (GC-MS), Field Asymmetric Ion Mobility Spectrometry (FAIMS), and Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) analysis. Patients underwent colonoscopy and/or CT colonography and were grouped as either CRC, adenomatous polyp(s), or controls to explore the diagnostic accuracy of VOC output data supported by an artificial neural network (ANN) model. 558 patients participated with 23 (4%) CRC diagnosed. 59% of colonoscopies and 86% of CT colonographies showed no abnormalities. Urinary VOC testing was feasible, acceptable to patients, and applicable within the clinical fast track pathway. GC-MS showed the highest clinical utility for CRC and polyp detection vs. controls (sensitivity = 0.878, specificity = 0.882, AUROC = 0.896) but it is labour intensive. Urinary VOC testing and analysis are feasible within NHS fast-track CRC pathways. Clinically meaningful differences between patients with cancer, polyps, or no pathology were identified suggesting VOC analysis may have future utility as a triage tool. [ABSTRACT FROM AUTHOR]