Magnetic Resonance Colonography Research Articles

Проблемы и перспективы скрининга колоректального рака

Colorectal cancer (CRC) is a widespread malignancy that is asymptomatic in the early stages, and late diagnosis is associated with poor outcome. Several levels of CRC risk exist. Thus, 80% of CRCs are sporadic (medium risk), and the rate of their detection increases with age, in particular, after 50 years. 15% of CRCs are caused by familial predisposition or pre-existing colon disease (high risk). 5% of CRCs are associated with genetic diseases (very high risk). Methods for preventing CRC are tailored to these levels of risk. If a patient is classified as having high or very high risk, colonoscopy is the first-line choice depending on the level of risk and age. In very high risk, patients are also referred for genetic counseling. Medium-risk patients are the target group for an organized CRC screening program. Regular screening identifies the disease even at the precancer stage. Noninvasive screening tests for CRC detect blood in the stool. These include stool guaiac test and fecal immunochemical tests. Colonoscopy is the "gold standard" for CRC screening. In addition to colonoscopy, flexible sigmoidoscopy is used for CRC screening. In recent years, molecular genetic tests to identify CRC biomarkers, computed tomography colonography, magnetic resonance colonography, and colon capsule endoscopy have emerged. This paper reviews current issues of CRC screening, i.e., age and gender structure of risk groups, the rate and algorithms used in different countries for CRC early detection, and ways to improve screening efficacy, including artificial intelligence technologies. KEYWORDS: colorectal cancer, age, screening, methods, algorithms, artificial intelligence. FOR CITATION: Radygina L.V., Mochalova L.V. Challenges and prospects of colorectal cancer screening. Russian Medical Inquiry. 2023;7(6):359–365 (in Russ.). DOI: 10.32364/2587-6821-2023-7-6-4.

Current and future colorectal cancer screening strategies.

Despite strong evidence of effectiveness, colorectal cancer (CRC) screening remains underused. Currently, there are several options for CRC screening, each with its own performance characteristics and considerations for practice. This Review aims to cover current CRC screening guidelines and highlight future blood-based and imaging-based options for screening. In current practice, the leading non-invasive option is the faecal immunochemical test (FIT) based on its high specificity, good sensitivity, low cost and ease of use in mailed outreach programmes. There are currently five blood-based CRC screening tests in varying stages of evaluation, including one that is currently sold in the USA as a laboratory-developed test. There are ongoing studies on the diagnostic accuracy and longitudinal performance of blood tests and they have the potential to disrupt the CRC screening landscape. Imaging-based options, including the colon capsule, MR colonography and the CT capsule, are also being tested in active studies. As the world attempts to recover from the COVID-19 pandemic and adapts to the start of CRC screening among people at average risk starting at age 45 years, non-invasive options will become increasingly important.

Systematic review: non‐endoscopic surveillance for colorectal neoplasia in individuals with Lynch syndrome

SummaryBackgroundIndividuals with Lynch syndrome are at high risk for colorectal cancer (CRC). Regular colonoscopies have proven to decrease CRC incidence and mortality. However, colonoscopy is burdensome and interval CRCs still occur. Hence, an accurate, less‐invasive screening method that guides the timing of colonoscopy would be of important value.AimTo outline the performance of non‐endoscopic screening modalities for Lynch‐associated CRC and adenomas.MethodsSystematic literature search in MEDLINE and EMBASE to identify studies investigating imaging techniques and biomarkers for detection of CRC and adenomas in Lynch syndrome. The QUADAS‐2 tool was used for the quality assessment of included studies.ResultsSeven of 1332 screened articles fulfilled the inclusion criteria. Two studies evaluated either CT colonography or MR colonography; both techniques were unable to detect CRC and (advanced) adenomas <10 mm. The other five studies evaluated plasma methylated‐SEPTIN9, faecal immunochemical test (FIT), faecal tumour DNA markers (BAT‐26, hMLH1, p53, D9S171, APC, D9S162, IFNA and DCC) and faecal microbiome as screening modalities. Sensitivity for CRC varied from 33% (BAT‐26) to 70% (methylated‐SEPTIN9) to 91% (hMLH1). High specificity (94–100%) for CRC and/or adenomas was observed for methylated‐SEPTIN9, FIT and BAT‐26. Desulfovibrio was enriched in the stool of patients having adenomas. However, all these studies were characterised by small populations, high/unclear risk of bias and/or low prevalence of adenomas.ConclusionsImaging techniques are unsuitable for colon surveillance in Lynch syndrome, whereas biomarkers are understudied. Having outlined biomarker research in Lynch‐associated and sporadic CRC/adenomas, we believe that these non‐invasive markers may hold potential (whether or not combined) for this population. As they could be of great value, (pre‐)clinical studies in this field should be prioritised.

Development of a Novel MR Colonography via Iron-Based Solid Lipid Nanoparticles.

PurposeTo develop an iron-based solid lipid nanoparticle (SLN) absorbable by the intestinal wall and assess the differential diagnostic value of intestinal lesions in magnetic resonance imaging (MRI).MethodsSLNs were prepared with the simultaneous loading of trivalent Fe ions (Fe3+), levodopa methyl ester (DM), and fluorescein isothiocyanate (FITC). We evaluated the particle size, loading rate, encapsulation efficiency, and cytotoxicity of SLNs. The T1 contrast effects of the FeDM-FITC-SLNs and gadolinium-based contrast agent (GBCA) were compared in different mouse models: acute ulcerative colitis (AUC), chronic ulcerative colitis (CUC), colon adenocarcinoma (COAD), and normal control. MRI was performed in the same mouse with intravenous injection of GBCA on day 1 and enema of FeDM-FITC-SLNs on day 2. The signal-to-noise ratios (SNRs) were compared using one-way analysis of variance. Tissues were then collected for histology.ResultsThe average particle size of FeDM-FITC-SLN was 220 nm. The mean FeDM loading rate was 94.3%, and the encapsulation efficiency was 60.3%. The relaxivity was 4.02 mM−1·s−1. After enema with FeDM-FITC-SLNs, MRI showed the following contrast enhancement duration: AUC = COAD > normal > CUC. Confocal fluorescence microscopy confirmed that FeDM-FITC-SLNs were mainly distributed in the intestinal mucosa and tumor capsule.ConclusionIron-based SLNs are promising alternatives for contrast enhancement at T1-weighted MRI and will help in the differential diagnosis of intestinal bowel diseases (IBDs).

Magnetic resonance colonography assessment of acute trinitrobenzene sulfonic acid colitis in pre-pubertal rats.

Pre-pubertal murine models of acute colitis are lacking. Magnetic resonance colonography (MRC) is a promising minimally invasive tool to assess colitis. We aimed to: 1/ Adapt a model of acute experimental colitis to pre-pubertal rats and determine whether MRC characteristics correlate with histological inflammation. 2/ Test this model by administering a diet supplemented in transforming growth factor β2 to reverse inflammation. Twenty-four rats were randomized at weaning to one of 3 groups: Trinitrobenzene Sulfonic Acid (TNBS) group (n = 8) fed a standard diet, that received an intra-rectal 60 mg/kg dose of TNBS-ethanol; Control group (n = 8) fed standard diet, that received a dose of intra-rectal PBS; TNBS+MODULEN group (n = 8) that received a dose of TNBS and were exclusively fed MODULEN-IBD® after induction of colitis. One week after induction of colitis, rats were assessed by MRC, colon histopathology and inflammation markers (Interleukin 1β, Tumor necrosis factor α, Nitric Oxide Synthase 2 and Cyclooxygenase 2). TNBS induced typical features of acute colitis on histopathology and MRC (increased colon wall thickness, increased colon intensity on T2-weighted images, target sign, ulcers). Treatment with MODULEN-IBD® did not reduce signs of colitis on MRC. Inflammatory marker expression did not differ among study groups.

Radiologic Imaging Modalities for Colorectal Cancer.

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

Magnetic resonance colonography with intestine-absorbable nanoparticle contrast agents in evaluation of colorectal inflammation

ObjectivesTo develop a nanoparticle-based MRI protocol based on transrectal administration of intestine-absorbable nanoparticle contrast agents to evaluate ulcerative colitis (UC).MethodsSolid lipid nanoparticles (SLNs) were synthesized by loading gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and octadecylamine-fluorescein isothiocyanate to produce Gd-FITC-SLNs as T1 contrast agents. Twenty mice with acute UC were divided into four groups: enema with Gd-FITC-SLNs, intravenous injection of Gd-FITC-SLNs, enema with Gd-DTPA, and intravenous injection of Gd-DTPA. Five mice with chronic UC and five mice without UC underwent enema with Gd-FITC-SLNs. Axial T1- and T2-weighted MR images were obtained before and 20, 40, 60, 80,100, and 120 min after enema or intravenous injection of the contrast agent. The signal-to-noise ratios (SNRs) of the colorectal wall were measured in both groups. The MRI findings were correlated with subsequent histological confirmation.ResultsAt 20 min after enema with Gd-FITC-SLNs, MRI showed the following contrast enhancement pattern: acute UC > normal intestinal wall > chronic UC. A continuous enhancement effect was observed in mice with acute UC, whereas a slight continuous enhancement of the colorectal wall was observed in mice with chronic UC. The normal intestinal wall rapidly metabolized the contrast agent, and the enhancement decreased on sequential scans. There was no significant difference between the SNRs of the intestinal wall at 20 min after intravenous Gd-DTPA and transrectal Gd-FITC-SLN administration.ConclusionsEnema with Gd-FITC-SLNs may be helpful for the diagnosis and differential diagnosis of acute and chronic UC and can confer the same or better results than with intravenous Gd-DTPA.Key Points• Enema with Gd-FITC-SLNs may be helpful for the diagnosis and differential diagnosis of acute and chronic UC.• Enema with Gd-FITC-SLNs can achieve the same or better result than that with intravenous Gd-DTPA.• SLN-based MR colonography enhances the colorectal wall inflammation, based on the colonic absorption of the nanoparticle contrast agents.

A polymeric diet rich in transforming growth factor beta 2 does not reduce inflammation in chronic 2,4,6-trinitrobenzene sulfonic acid colitis in pre-pubertal rats

BackgroundPediatric Crohn’s disease is characterized by a higher incidence of complicated phenotypes. Murine models help to better understand the dynamic process of intestinal fibrosis and test therapeutic interventions. Pre-pubertal models are lacking. We aimed to adapt a model of chronic colitis to pre-pubertal rats and test if a polymeric diet rich in TGF-β2 could reduce TNBS-induced intestinal inflammation and fibrosis.MethodsColitis was induced in 20 five-week-old Sprague–Dawley male rats by weekly rectal injections of increasing doses of TNBS (90 mg/kg, 140 mg/kg and 180 mg/kg) for 3 weeks, while 10 controls received phosphate-buffered saline. Rats were anesthetized using ketamine and chlorpromazine. After first administration of TNBS, 10 rats were fed exclusively MODULEN IBD® powder, while remaining rats were fed breeding chow. Colitis was assessed one week after last dose of TNBS by histopathology and magnetic resonance colonography (MRC).ResultsHistological inflammation and fibrosis scores were higher in TNBS group than controls (p < 0.05 for both). MRC showed increased colon wall thickness in TNBS group compared to controls (p < 0.01), and increased prevalence of strictures and target sign (p < 0.05). Colon expression of COL1A1, CTGF, α-SMA and COX-2 did not differ between TNBS rats and controls. TNBS colitis was not associated with growth failure. Treatment with MODULEN IBD® was associated with growth failure, increased colon weight/length ratio (p < 0.01), but did not affect histological scores or MRI characteristics. Colon expression of α-SMA was significantly lower in the MODULEN group versus controls (p = 0.005).ConclusionFeatures of chronic colitis were confirmed in this model, based on MRC and histopathology. Treatment with MODULEN did not reverse inflammation or fibrosis.

MR enterocolonography in patients with Crohn's disease and healthy volunteers – Do we achieve diagnostic bowel distension?

PurposeThe aim of our prospective randomized study was to assess diagnostic quality and stability of bowel distension in patients with Crohn’s disease (CD) and healthy volunteers subjected to synchronous magnetic resonance enterography and colonography (MREC), as well as to test the role of water enema and intravenous spasmolytics. The influence of gastric content, age, gender, and body mass on bowel distension was also evaluated. MethodStudy groups included 164 CD patients and 53 healthy volunteers. After bowel preparation, randomized subgroups started ingestion ≥1000 mL of hyperosmolar solution within 30, 45, 60, 75, and 90 min before admission to MRI, respectively. Patients were examined in prone position and water enema was applied. Spasmolytics were administered prior to I.V. gadolinium. Distension of five bowel segments was independently assessed by two experienced radiologists. ResultsMREC yields diagnostic distension of the jejunum in 81.1 % and 79.2 % patients in the CD group and controls, respectively. For the terminal ileum it was >94 % in both groups. Good and excellent distension was achieved in other bowel segments. Distension was maintained up to 75 min from the start of oral ingestion. Water enema and spasmolytics significantly and independently improved distension of the small bowel. Distension of the cecum after spasmolytics was decreased. Gastric content, age, gender and body mass had no significant influence of bowel distension. ConclusionsMREC enables diagnostic distension of the colon and ileum (including terminal segment) in CD patients and healthy volunteers and diagnostically acceptable distension of the jejunum.

Gadolinium-Loaded Solid Lipid Nanoparticles for Colorectal Tumor in MR Colonography.

The current study aims to investigate the possibility of using solid lipid nanoparticles (SLNs)-enhanced magnetic resonance (MR) colonography to diagnose colorectal cancer. Gd-FITC-SLNs were synthesized by loading gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and fluorescein isothiocyanate (FITC) simultaneously. Twenty mice received azoxymethane/dextran sulfate sodium (AOM/DSS) to induce adenocarcinoma of the colon and were divided into 4 groups, and 5 in per group. MR colonography were performed at different time periods before and after enema or intravenous injection of Gd-FITC-SLNs or Gd-DTPA. The results demonstrated SNR (signal-to-noise ratio) significantly increased from 1.56- to 1.76-fold within the colorectal tumors after the enema of Gd-FITC-SLNs (p < 0.001). No differences in SNR were observed after the enema of Gd-DTPA (p > 0.05). Besides, SNR increased from 1.54- to 1.72-fold within the colorectal tumors after the intravenous injection of Gd-FITC-SLNs (p < 0.001) while SNR increased from 1.39to 1.57-fold within the colorectal tumors after the injection of Gd-DTPA (p < 0.001). In addition, SNR within colorectal tumors significantly increased ranging from 20th to 140th min, and lasted for about 120 min (p < 0.05) after the enema of Gd-FITC-SLNs and SNR within colorectal tumors also significantly increased ranging from 0th hour to 8th hour, lasted for about 8 hour (p < 0.05) after the injection of Gd-FITC-SLNs. However, after the injection of Gd-DTPA, SNR within colorectal tumors significantly increased only ranging from 0th min to 20th min after administration (p < 0.01). Furthermore, hematoxylin and eosin (H&E) staining revealed that all mice developed adenocarcinoma of the colon. In summary, it is feasible by using Gd-FITC-SLNs in MR colonography to diagnose colorectal cancer. Enema of Gd-FITC-SLNs can provide marked enhancement of colorectal tumors quickly, and safer while intravenous injection of Gd-FITC-SLNs can provide a long-lasting enhancement of colorectal tumors in MR colonography. These findings present a potential clinical application of Gd-FITC-SLNs on MR colonography.

Diagnostic value of magnetic resonance and computed tomography colonography for the diagnosis of colorectal cancer: A systematic review and meta-analysis.

Background:Surgical resection is the recommended procedure for colorectal cancer (CRC), but majority of the patients were diagnosed with advanced or metastatic CRC. Currently, there were inconsistent results about the diagnostic value of magnetic resonance colonography (MRC) and computed tomography colonography (CTC) in early CRC diagnosis. Our study conducted this meta-analysis to investigate the diagnostic value of MRC and CTC for CRC surveillance.Methods:A comprehensive literature search was conducted in PubMed, Embase, and the Cochrane library to select relevant studies. The summary sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under the receiver operating characteristic curves (AUC) were calculated to evaluate the diagnostic value of MRC and CTC, respectively.Result:Twenty-five studies including 2985 individuals were selected in the final analysis. Eight studies evaluated the diagnostic value of MRC, and 17 studies assessed CTC. The summary sensitivity, specificity, PLR, NLR, DOR, and AUC in MRC for early detection of CRC were 0.98 (95% confidence interval, CI: 0.80–1.00), 0.94 (95% CI: 0.85–0.97), 15.48 (95% CI: 6.30–38.04), 0.02 (95% CI: 0.00–0.25), 115.09 (95% CI: 15.37–862.01), and 0.98 (95% CI: 0.97–0.99), respectively. In addition, the sensitivity, specificity, PLR, NLR, DOR, and AUC of CTC for diagnosing CRC were 0.97 (95% CI: 0.88–0.99), 0.99 (95% CI: 0.99–1.00), 154.11 (95% CI: 67.81–350.22), 0.03 (95% CI: 0.01–0.13), 642.51 (95% CI: 145.05–2846.02), and 1.00 (95% CI: 0.99–1.00). No significant differences were found between MRC and CTC for DOR in all the subsets.Conclusion:The findings of meta-analysis indicated that MRC and CTC have higher diagnostic values for early CRC diagnosis. However, the DOR for diagnosing CRC between MRC and CTC showed no significance.

A prospective comparative study of detection of colonic polyposis by magnetic resonance colonography versus conventional colonoscopy

Background: Colorectal cancer mostly arises from adenomatous polyp and the transition time to convert into carcinoma is around ten years. As the progress to adenocarcinoma is a slow process so, early detection and endoscope resection is claimed to be effective in decreasing incidence and mortality by colorectal cancer. MR colonography is a non-invasive method for evaluating entire colon. It can detect precancerous lesion, cancer and staging. It is non-invasive tool for screening. Acceptability of the patient is better for MR colonography.Methods: Present study is a prospective comparative evaluation of magnetic resonance colonography verses colonoscopy conducted in the Department of Radiology, Konaseema Institute of Medical Science, and other establishments from August 2015 to January 2018. The sample size was calculated to be 112. Specificity, sensitivity and predictive value were calculated by medical statistical software.Results: For all size of tumours, sensitivity was 85.71%, specificity was 92.85%, positive predictive value was 92.30%, negative predictive value was 86.66% and accuracy was 94.34%. The positive predictive value was 90.00% negative predictive value was 92.68% and accuracy was 92.16%. For 1 mm to 4 mm size of polyp the sensitive was 28.57%, specificity was 92.31%, positive predictive value was 66.67%, negative predictive value was 70.59% and accuracy was 70%.Conclusions: In present study we have found that there was male predominance in patient and gastrointestinal bleeding was common clinical presentation. We have also observed that all size of poly MR colonography as having sensitivity and specificity around 90% but MR colonography is highly sensitive and specific for polyp size above 8mm but it is less sensitive for size below 4 mm.

Magnetic Resonance Colonography Enables the Efficacy Assessment of Immune Checkpoint Inhibitors in an Orthotopic Colorectal Cancer Mouse Model

Immune checkpoint inhibitors (ICIs) have become an effective therapeutic option for colorectal cancer and studies on these drugs have therefore increased greatly. Efficacy assessments of ICIs in preclinical orthotopic colorectal cancer using MRI have not been reported however due to the difficulties in conducting colorectal imaging. The purpose of this present study was to investigate the feasibility of using magnetic resonance colonography (MRC) to evaluate the efficacy of an ICI, an anti-PD-L1 antibody, in an orthotopic colorectal cancer mouse model. The mouse model was generated by the engraftment of colorectal cancer cells into the submucosal layer of the colon. Anti-cancer efficacy was assessed by tumor volume and metastatic tumor number analyses, and these values were significantly lower in the PD-L1 antibody-treated group compared to the controls. Histological analyses using H&E and Ki-67 immunohistochemical staining confirmed a highly efficacious tumor growth inhibition and enhanced infiltration by CD4+ and CD8+ lymphocytes in the PD-L1 antibody-treated group. We conclude that MRC has the potential to be used for ICI efficacy assessments against orthotopic colorectal cancer mouse model.

Comparison of subjective and objective measures of constipation – Employing a new method for categorizing gastrointestinal symptoms

IntroductionCorrelations between subjective and objective measures of constipation have seldom been demonstrated. This could be due to multiple confounding factors in clinical studies and the broad span of symptoms represented in questionnaires used to assess constipation. We developed a new method for categorizing gastrointestinal (GI) symptoms into relevant symptom groups, and used this in a controlled experimental study aimed to investigate whether GI transit times and colonic volumes were correlated to self-reported GI symptoms. MethodsTwenty-five healthy male participants were enrolled in a randomized, double-blinded, placebo-controlled, five-day crossover study with the treatments oxycodone and placebo. Objective measures of GI transit times and colonic volumes were obtained by the means of the 3D-Transit System and magnetic resonance colonography, whereas subjective GI symptoms were measures via three validated questionnaires. The symptoms were then categorized into five groups; “abdominal symptoms”, “defecation difficulties”, “incomplete bowel evacuation”, “reduced bowel movement frequency”, and “stool symptoms”. Spearman's rank order correlation was used to determine correlations between the five groups of symptoms and the objective measures. ResultsNo correlations between the GI symptoms and transit times or colonic volumes were found (all P > 0.05). DiscussionGI transit times and colonic volumes were not correlated to self-reported GI symptoms even in a controlled experimental study and when symptoms were categorized into relevant symptom groups. Thus, both subjective and objective measures must be considered relevant when assessing constipation in clinical and research settings, ensuring that both physiological aspects as well as the severity and impact of symptoms experienced by patients can be assessed.

Diagnostic value of magnetic resonance versus computed tomography colonography for colorectal cancer: A PRISMA-compliant systematic review and meta-analysis.

Background:Advanced colorectal cancers were associated with poor prognosis, and early diagnosis was important for high-risk patients. Colonography is commonly used for diagnosing colorectal cancer. However, a few studies reported the diagnostic value of magnetic resonance colonography (MRC) versus computed tomography colonography (CTC). This study aimed to compare the diagnostic value of MRC versus CTC for colorectal cancer.Methods:Twenty-three studies on the diagnosis of colorectal cancer using MRC or CTC were obtained from PubMed, Embase, and the Cochrane Library databases until July 2017. The ratios of sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and receiver operating characteristic (ROC) curve were calculated to compare the diagnostic value of MRC versus CTC.Results:The summary sensitivity, specificity, PLR, NLR, and area under the ROC for MRC were 0.97 (0.81–1.00), 0.92 (0.80–0.97), 11.71 (4.46–30.73), 0.03 (0.00–0.24), and 0.98 (0.97–0.99), respectively, for diagnosing colorectal cancer. The pooled estimates for CTC in diagnosing colorectal cancer were as follows: sensitivity, 0.96 (0.90–0.98); specificity, 1.00 (0.99–1.00); PLR, 197.32 (73.21–531.85); NLR, 0.04 (0.02–0.11); and area under the ROC, 1.00 (0.99–1.00). No significant differences were found between MRC and CTC for sensitivity, specificity, and NLR. MRC was associated with lower PLR and area under the ROC for diagnosing colorectal cancer compared with CTC.Conclusion:This study demonstrated MRC and CTC as potential diagnostic approaches for colorectal cancer. CTC had a higher diagnostic value of PLR and area under the ROC for colorectal cancer.

Assessing Mucosal Inflammation in a DSS-Induced Colitis Mouse Model by MR Colonography.

Inflammatory bowel disease (IBD) is characterized by a chronic flaring inflammation of the gastrointestinal tract. To determine disease activity, the inflammatory state of the colon should be assessed. Endoscopy in patients with IBD aids visualization of mucosal inflammation. However, because the mucosa is fragile, there is a significant risk of perforation. In addition, the technique is based on grading of the entire colon, which is highly operator-dependent. An improved, noninvasive, objective magnetic resonance imaging (MRI) technique will effectively assess pathologies in the small intestinal mucosa, more specifically, along the colon, and the bowel wall and surrounding structures. Here, dextran sodium sulfate polymer induced acute colitis in mice that was subsequently characterized by multisection magnetic resonance colonography. This study aimed to develop a noninvasive, objective, quantitative MRI technique for detecting mucosal inflammation in a dextran sodium sulfate–induced colitis mouse model. MRI results were correlated with endoscopic and histopathological evaluations.

Magnetic Resonance Colonography May Predict the Need for Bowel Resection in Colorectal Endometriosis.

Purpose To define if MRI findings in patients with deep pelvic endometriosis (DPE) may be predictive for the need of bowel resection. Material and Methods A retrospective survey of 196 pelvic MRIs of women who received laparoscopic procedures for DPE was carried out. A pelvic MRI was performed in all patients: it consisted in T2w-TSE sequences in axial, sagittal, and coronal planes and T1w and THRIVE sequences in the axial plane; the exam was completed by MR-Colonography. Intestinal lesions were measured in short and long axis and the degree of stenosis was established. A multivariate logistic regression was used to identify the predictors of intestinal resection. Results 57/196 patients received an intestinal resection. Multivariate logistic regression demonstrated a predictive value of short axis (Odds-Ratio = 2.29, p = 0.011) and stenosis (Odds-Ratio = 1.20, p = 0.003). ROC analysis showed that a cut-off value of 11 mm for the short axis and 30% for the stenosis may correctly classify, respectively, 96,94% (sensitivity 92,9% and specificity 98,56%) and 97,96% (sensitivity 94,74% and specificity 99,3%) of the cases. Conclusion The presence of an endometriotic rectal nodule > 11 mm in short axis causing a stenosis > 30% in pelvic MRI reliably predicts the need of a rectal resection.

Accuracy of Diffusion-weighted Magnetic Resonance Colonography in Assessing Mucosal Healing and the Treatment Response in Patients with Ulcerative Colitis

Using sigmoidoscopy as the gold standard, we assessed the accuracy, and the responsiveness to change, of diffusion-weighted magnetic resonance colonography in ulcerative colitis, using the Nancy score. A total of 29 ulcerative colitis patients, having undergone at least two diffusion-weighted magnetic resonance colonographies, were included. Disease activity was evaluated using the Mayo endoscopic subscore and the Nancy score. We determined the accuracy of the Nancy score in the diagnosis of mucosal healing. We also assessed its responsiveness to change in 17 patients with a Mayo endoscopic subscore of 2 or 3 at treatment initiation. A total Nancy score < 7 had a sensitivity of 0.75 and a specificity of 0.67 (area under the curve: 0.72; 95% confidence interval: [0.56-0.88]; p = 0.0063) in the diagnosis of mucosal healing. The total Nancy score was sensitive to change in ulcerative colitis [Guyatt's responsiveness index: 1.8; standardised effect size ratio: 1.36]. The Nancy score was reliable [intra-class correlation coefficient: 0.63; p = 0.01]. The mean Mayo endoscopic subscore and the mean Nancy score both fell significantly in patients who achieved mucosal healing (mean ± standard deviation [SD] Mayo endoscopic subscore: 2.4 ± 0.55 at baseline and 0.6 ± 0.55 at reassessment, p = 0.02; mean Nancy score: 18.2 ± 9.1 at baseline and 3 ± 1.6 at reassessment, p = 0.006). No significant changes in Nancy score were observed in active patients at reassessment. The Nancy score is a highly responsive, reliable tool for assessing treatment response in patients with ulcerative colitis. The Nancy score accurately detects mucosal healing.

MR colonography with a fecal tagging technique and water-based enema for the assessment of inflammatory bowel disease.

To assess the usefulness of MR colonography (MRC) with a fecal tagging technique and water-based enema in patients with inflammatory bowel disease (IBD). Twenty-two patients with suspected or known IBD underwent MRC with a 1.5-T MR system (Siemens Symphony) using a phased-array coil. A fecal tagging technique was performed by oral administration of dense barium sulfate (200ml) at major meals starting 2days before the MRI. After a water enema (2000-2500ml), the MR protocol was carried out, starting with HASTE and true-FISP sequences. Coronal T1w 3D VIBE (2.0mm thick) was obtained before and 60s after intravenous administration of Gd chelate. MR images were evaluated by consensus agreement of two observers in terms of image quality and by searching for bowel abnormalities. MRC findings were correlated with our gold standard-conventional colonoscopy (incomplete in 6/22 patients) with histopathological analysis, and surgery (performed in 8/22 subjects). The MR imaging protocol was completed in all of the investigated subjects. In terms of image quality, 128 out of 132 colon segments (97%) were considered diagnostic on MR examinations by the two reviewers; signs of bowel inflammation were identified in 74 and 72% of colon segments of patients with ulcerative colitis (n=6) and Crohn's disease (n=15), respectively. In 13/15 patients with Crohn's disease, involvement of both the large and small bowel was demonstrated on MR imaging; perianal abscesses and fistulas were also identified in 2 and 3 of these patients, respectively. In one patient with normal MRC, a diagnosis of IBD could not be confirmed. MRC with a fecal tagging technique and water-based enema is a promising minimally invasive technique for evaluating the bowel in patients with a suspected or established diagnosis of IBD.

The potential of imaging techniques as a screening tool for colorectal cancer: a cost-effectiveness analysis.

Imaging may be promising for colorectal cancer (CRC) screening, since it has test characteristics comparable with colonoscopy but is less invasive. We aimed to assess the potential of CT colonography (CTC) and MR colonography (MRC) in terms of (cost-effectiveness) using the Adenoma and Serrated pathway to Colorectal CAncer model. We compared several CTC and MRC strategies with 5- or 10-yearly screening intervals with no screening, 10-yearly colonoscopy screening and biennial faecal immunochemical test (FIT) screening. We assumed trial-based participation rates in the base-case analyses and varied the rates in sensitivity analyses. Incremental lifetime costs and health effects were estimated from a healthcare perspective. The health gain of CTC and MRC was similar and ranged from 0.031 to 0.048 life-year gained compared with no screening, for 2-5 screening rounds. Lifetime costs per person for MRC strategies were €60-110 higher than those for CTC strategies with an equal number of screening rounds. All imaging-based strategies were cost-effective compared with no screening. FIT screening was the dominant screening strategy, leading to most LYG and highest cost-savings. Compared with three rounds of colonoscopy screening, CTC with five rounds was found to be cost-effective in an incremental analysis of imaging strategies. Assumptions on screening participation have a major influence on the ordering of strategies in terms of costs and effects. CTC and MRC have potential for CRC screening, compared with no screening and compared with three rounds of 10-yearly colonoscopy screening. When taking FIT screening as the reference, imaging is not cost-effective. Participation is an important driver of effectiveness and cost estimates. This is the first study to assess the cost-effectiveness of MRC screening for CRC.