Die Diagnostik von Dünndarmerkrankungen stellt eine besondere Herausforderung dar, da dieser Darmabschnitt endoskopisch nur eingeschränkt zugänglich ist und die klinische Symptomatik häufig unspezifisch bleibt. Zudem wird die Beurteilung durch die Darmmotilität sowie die Abhängigkeit von einer Kontrastmittelgabe und einer luminalen Distension zusätzlich erschwert. Moderne Schnittbildverfahren, insbesondere die CT(Computertomographie)- und MR(Magnetresonanz)-Enterographie, haben die bildgebende Diagnostik von entzündlichen, neoplastischen und vaskulären Dünndarmerkrankungen revolutioniert. Die präzise Differenzierung der verschiedenen Pathologien des Dünndarms erfordert fundierte Kenntnisse charakteristischer Bildgebungsmuster. Wandverdickungen, deren Ausdehnung, Verteilung und Kontrastmittelaufnahmemuster, mesenteriale Gefäßveränderungen und begleitende extraintestinale Befunde liefern entscheidende diagnostische Hinweise. Die Integration klinischer Parameter mit morphologischen und funktionellen Bildgebungskriterien ermöglicht eine zeitnahe und zielgerichtete Therapieplanung.

The diagnostics of small bowel diseases represent a special challenge as this intestinal segment is not readily accessible endoscopically and the clinical symptoms are often nonspecific. The assessment is further complicated by the bowel motility and the dependency on contrast agent administration and luminal distension. Modern cross-sectional imaging techniques, particularly computed tomography (CT) and magnetic resonance (MR) enterography, have revolutionized the diagnostics of inflammatory, neoplastic and vascular small bowel diseases. The precise differentiation of the various small bowel pathologies requires thorough knowledge of characteristic imaging patterns. Bowel wall thickening, the extent, distribution and pattern of contrast enhancement uptake, mesenteric vascular changes and associated extraintestinal findings provide crucial diagnostic indications. The integration of clinical parameters with morphological and functional imaging criteria enables timely and targeted treatment planning.

Cross-sectional imaging procedures play a pivotal role in the assessment of the jejunum and ileum as these segments of the small intestine are less easily accessible to endoscopic evaluation compared to the stomach, duodenum and colon. The radiological diagnostics of the small bowel are, however, a special challenge as many small bowel diseases show similar imaging patterns making a differentiation difficult. Technical advances in imaging now enable a more precise characterization of the bowel wall, thereby providing the basis for increasingly more personalized medicine. An imaging pattern-based diagnostic approach can be helpful in narrowing down the spectrum of potential differential diagnoses and increasing the accuracy of radiological interpretation. The aim of this review article is to present the current diagnostic techniques, recent technological developments and characteristic radiological imaging features of small bowel diseases.

Schnittbildverfahren spielen eine zentrale Rolle bei der Untersuchung des Jejunums und des Ileums, da diese Abschnitte im Gegensatz zu Magen, Duodenum und Kolon endoskopisch weniger leicht zugänglich sind. Die radiologische Diagnostik des Dünndarms stellt jedoch eine besondere Herausforderung dar, da viele Dünndarmerkrankungen ähnliche Bildmuster aufweisen und sich daher nicht immer einfach voneinander unterscheiden lassen. Technische Fortschritte in der Bildgebung ermöglichen eine noch präzisere Charakterisierung der Darmwand und schaffen damit die Grundlage für eine zunehmend personalisierte Medizin. Ein bildmusterbasierter diagnostischer Ansatz hilft dabei, die Zahl möglicher Diagnosen einzugrenzen und die radiologische Beurteilung zu präzisieren. Ziel dieser Übersichtsarbeit ist es, aktuelle diagnostische Verfahren, neueste Entwicklungen und charakteristische radiologische Zeichen von Dünndarmerkrankungen darzustellen.

BACKGROUND:Computed tomography colonography (CTC) is a minimally invasive examination for radiologic imaging of the entire colon and rectum. It has replaced the now obsolete barium enemas and represents an important option to colonoscopy for the detection of colorectal neoplasia. OBJECTIVES:The aim of this article is to review the current status of CTC for detection of colorectal cancer (CRC) and its precursors. MATERIALS AND METHODS:Based on an extensive literature research, the current role of CTC in colorectal cancer imaging is summarized. This includes not only CRC detection but also the role of CTC in CRC screening and surveillance. RESULTS:CTC is a well-developed, minimally invasive examination for the identification of colorectal neoplasia. The diagnostic accuracy for colorectal adenomas and cancer is comparable to that of optical colonoscopy. Missed CRC cases are rare and typically result from perceptual or technical errors. In addition to the detection and characterization of carcinomas, CTC enables the visualization of prestenotic colonic segments and extracolonic structures. This allows for the preoperative detection of synchronous colonic neoplasms that are not endoscopically assessable as well as evaluation of abdominal tumor spread. Due to its ability to detect benign precancerous adenomas with high sensitivity, CTC can be used for opportunistic colorectal cancer screening. In CRC follow-up, CTC may be used to diagnose recurrence if colonoscopy is incomplete or not feasible. CONCLUSION:CTC is the radiological examination of choice for the detection of colorectal neoplasia. It is typically used in patients where colonoscopy is incomplete, contraindicated or refused. Moreover, CTC serves as a noninvasive option for opportunistic colorectal cancer screening.

Die Computertomographie-Kolonographie (CTK) ist eine minimal-invasive radiologische Untersuchung zur Darstellung des gesamten Kolons und Rektums. Sie ersetzt den mittlerweile obsoleten Kolonkontrasteinlauf und stellt eine wichtige Ergänzung zur Koloskopie in der Dickdarmkrebsdiagnostik dar. Ziel dieser Arbeit ist es, einen Überblick über den aktuellen Stellenwert und den Nutzen der CTK zur minimal-invasiven bildgebenden Diagnostik kolorektaler Karzinome (KRK) zu bieten. Mittels einer ausführlichen Literaturrecherche wird der aktuelle Wissensstand zur Rolle der CTK in der Dickdarmkrebsdiagnostik zusammengefasst. Dies umfasst neben der Bildgebung manifester Karzinome auch den Einsatz der CTK in der Vor- und Nachsorge des KRK. Die CTK ist eine ausgereifte, minimal-invasive Untersuchung zur Abklärung kolorektaler Neoplasien. Die Detektionsrate für gutartige Krebsvorstufen und manifeste Karzinome ist vergleichbar mit der Detektionsrate der optischen Koloskopie. Fehldiagnosen bei KRK sind selten und meist durch Perzeptionsfehler und technische Fehler bedingt. Durch die Möglichkeit bei stenosierenden Karzinomen auch endoskopisch nicht einsehbare Darmabschnitte und extrakolische Strukturen darzustellen, können zusätzlich zur Tumordetektion auch synchrone Dickdarmneoplasien erkannt und die abdominale Tumorausbreitung beurteilt werden. Neben der Diagnose manifester Karzinome kann die CTK durch das rechtzeitige Erkennen benigner Krebsvorstufen zur Dickdarmkrebsvorsorge eingesetzt werden. In der KRK-Nachsorge kann die CTK bei nicht erfolgreicher Koloskopie alternativ zur Rezidivdiagnostik eingesetzt werden. Die CT-Kolonographie ist die radiologische Untersuchung der Wahl zur Detektion kolorektaler Neoplasien. Sie kommt meistens bei Personen zum Einsatz, bei denen eine Koloskopie nicht möglich oder nur unvollständig ist, kann aber auch zur opportunistischen Dickdarmkrebsvorsorge eingesetzt werden.

Performing CTC according to current technical standards is prerequisite for high-quality examinations and is, thus, also a key factor to obtain a correct diagnosis. CTC is a noninvasive examination, capable of providing clinically relevant diagnoses for a wide range of indications.

Background In Crohn disease, differentiation between active intestinal inflammation and fibrosis has implications for treatment, but current imaging modalities are not reliably accurate. Purpose To evaluate the predictive value of gallium 68 (68Ga)-labeled fibroblast activation protein inhibitor (FAPI) PET/MR enterography for the assessment of bowel wall fibrosis in Crohn disease. Materials and Methods In this prospective single-center study, consecutive participants with Crohn disease and obstructive symptoms underwent preoperative 68Ga-FAPI PET/MR enterography from May 2021 to January 2022. Histopathologic analysis of resected bowel segments was performed to grade active inflammation (A0-A2) and fibrosis (F0-F2), which served as the reference standard. The fibroblast activation protein (FAP) expression in bowel wall layers was analyzed immunohistochemically for each layer. 68Ga-FAPI-derived maximum standardized uptake value (SUVmax) was compared with histopathologic results by using mixed-model analysis of variance and Bonferroni-corrected post hoc tests. Results In 14 participants (mean age, 45 years ± 9 [SD]; 10 men), fibrosis was diagnosed histopathologically in 28 of 51 bowel segments (grade F1, n = 14; grade F2, n = 14). Mean SUVmax was higher in segments with fibrosis than without (7.6 vs 2.0; P < .001). In severe fibrosis, mean SUVmax was higher than in mild to moderate fibrosis (8.9 ± 0.9 vs 6.2 ± 0.9; P = .045). Bowel segments with isolated active inflammation had lower mean 68Ga-FAPI uptake than segments with combined active inflammation and fibrosis (SUVmax, 3.2 ± 0.4 vs 8.1 ± 0.1; P = .005). With an SUVmax cutoff value of 3.5, the area under the receiver operating characteristic curve for the prediction of fibrosis was 0.94 (95% CI: 0.9, 1.0), with sensitivity of 26 of 28 segments (93%) and specificity of five of six segments (83%). 68Ga-FAPI-derived SUVmax correlated with FAP expression across all bowel layers (R2 = 0.50, P < .001). Conclusion Higher gallium 68 fibroblast activation protein inhibitor uptake at PET/MR enterography was associated with histopathologically assessed bowel wall fibrosis in participants with Crohn disease, suggesting diagnostic potential for treatment decisions. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by O'Shea in this issue.

Zusammenfassung Hintergrund Um mit der CT-Kolonographie (CTK) gute Ergebnisse zu erzielen, ist neben der spezifischen radiologischen Expertise eine hochqualitative Durchführung der Untersuchung und eine Indikationsstellung gemäß fachspezifischen Richtlinien erforderlich. Ziel der Arbeit Ziel dieser Arbeit ist es, einen Überblick über aktuelle Standards der Untersuchungstechnik sowie über Indikationen und Kontraindikationen der CTK in Anlehnung an rezente Empfehlungen und Richtlinien zu geben. Material und Methoden Mittels einer ausführlichen Literaturrecherche wird der aktuelle Wissensstand zur Untersuchungstechnik sowie zu den Einsatzgebieten und den Kontraindikationen zur CTK zusammengefasst. Ergebnisse Die CTK ist die radiologische Untersuchung der Wahl zur Detektion kolorektaler Neoplasien. Indikationen sind die unvollständige Koloskopie, Kontraindikationen oder Ablehnung der Koloskopie und die opportunistische Dickdarmkrebsvorsorge. Die Untersuchungstechnik umfasst eine den speziellen Erfordernissen der CTK angepasste Darmvorbereitung einschließlich „fecal tagging“, die Darmdistension, einen Niedrigdosis-CT-Scan in zwei Patientenpositionen sowie eine kombinierte 2D- und 3D-Auswertung. Diskussion Die Durchführung der CTK nach aktuellen technischen Standards ist Voraussetzung für hochqualitative und aussagekräftige Untersuchungen und damit auch ein Schlüsselfaktor zur korrekten Diagnosefindung. Als nichtinvasive Untersuchungsoption ermöglicht sie bei vielen Indikationen klinisch relevante Ergebnisse.

Background:Ultra-low-dose CT (ULDCT) examinations of the chest at only twice the radiation dose of a chest X-ray (CXR) now offer a valuable imaging alternative to CXR. This trial prospectively compares ULDCT and CXR for the detection rate of diagnoses and their clinical relevance in a low-prevalence cohort of non-traumatic emergency department patients. Methods:In this prospective crossover cohort trial, 294 non-traumatic emergency department patients with a clinically indicated CXR were included between May 2nd and November 26th of 2019 (www.clinicaltrials.gov: NCT03922516). All participants received both CXR and ULDCT, and were randomized into two arms with inverse reporting order. The detection rate of CXR was calculated from 'arm CXR' (n = 147; CXR first), and of ULDCT from 'arm ULDCT' (n = 147; ULDCT first). Additional information reported by the second exam in each arm was documented. From all available clinical and imaging data, expert radiologists and emergency physicians built a compound reference standard, including radiologically undetectable diagnoses, and assigned each finding to one of five clinical relevance categories for the respective patient. Findings:Detection rates for main diagnoses by CXR and ULDCT (mean effective dose: 0.22 mSv) were 9.1% (CI [5.2, 15.5]; 11/121) and 20.1% (CI [14.2, 27.7]; 27/134; P = 0.016), respectively. As an additional imaging modality, ULDCT added 9.1% (CI [5.2, 15.5]; 11/121) of main diagnoses to prior CXRs, whereas CXRs did not add a single main diagnosis (0/134; P < 0.001). Notably, ULDCT also offered higher detection rates than CXR for all other clinical relevance categories, including findings clinically irrelevant for the respective emergency department visit with 78.5% (CI [74.0, 82.5]; 278/354) vs. 16.2% (CI [12.7, 20.3]; 58/359) as a primary modality and 68.2% (CI [63.3, 72.8]; 245/359) vs. 2.5% (CI [1.3, 4.7]; 9/354) as an additional imaging modality. Interpretation:In non-traumatic emergency department patients, ULDCT of the chest offered more than twice the detection rate for main diagnoses compared to CXR. Funding:The Department of Biomedical Imaging and Image-guided Therapy of Medical University of Vienna received funding from Siemens Healthineers (Erlangen, Germany) to employ two research assistants for one year.

Background: In Crohn disease, differentiation between active intestinal inflammation and fibrosis has implications for treatment, but current imaging modalities are not reliably accurate. Purpose: To evaluate the predictive value of gallium 68 (Ga-68)-labeled fibroblast activation protein inhibitor (FAPI) PET/MR enterography for the assessment of bowel wall fibrosis in Crohn disease. Materials and Methods: In this prospective single-center study, consecutive participants with Crohn disease and obstructive symptoms underwent preoperative Ga-68-FAPI PET/MR enterography from May 2021 to January 2022. Histopathologic analysis of resected bowel segments was performed to grade active inflammation (A0-A2) and fibrosis (F0-F2), which served as the reference standard. The fibroblast activation protein (FAP) expression in bowel wall layers was analyzed immunohistochemically for each layer. Ga-68-FAPI-derived maximum standardized uptake value (SUVmax) was compared with histopathologic results by using mixed-model analysis of variance and Bonferroni-corrected post hoc tests. Results: In 14 participants (mean age, 45 years +/- 9 [SD]; 10 men), fibrosis was diagnosed histopathologically in 28 of 51 bowel segments (grade F1, n = 14; grade F2, n = 14). Mean SUVmax was higher in segments with fibrosis than without (7.6 vs 2.0; P <.001). In severe fibrosis, mean SUVmax was higher than in mild to moderate fibrosis (8.9 +/- 0.9 vs 6.2 +/- 0.9; P =.045). Bowel segments with isolated active inflammation had lower mean Ga-68-FAPI uptake than segments with combined active inflammation and fibrosis (SUVmax, 3.2 +/- 0.4 vs 8.1 +/- 0.1; P =.005). With an SUVmax cutoff value of 3.5, the area under the receiver operating characteristic curve for the prediction of fibrosis was 0.94 (95% CI: 0.9, 1.0), with sensitivity of 26 of 28 segments (93%) and specificity of five of six segments (83%). 68Ga-FAPI-derived SUVmax correlated with FAP expression across all bowel layers (R-2 = 0.50, P <.001). Conclusion: Higher gallium 68 fibroblast activation protein inhibitor uptake at PET/MR enterography was associated with histopathologically assessed bowel wall fibrosis in participants with Crohn disease, suggesting diagnostic potential for treatment decisions. (c) RSNA, 2023

Zusammenfassung Hintergrund Eine frühzeitige Diagnose von luminalen Dickdarmerkrankungen ist von wesentlicher klinischer Bedeutung, um eine rechtzeitige optimierte Therapie beginnen und Komplikationen frühzeitig erkennen zu können. Ziel der Arbeit Diese Arbeit soll einen Überblick über den Einsatz radiologischer Methoden bei der Diagnose neoplastischer und entzündlicher luminaler Erkrankungen des Kolons vermitteln. Dabei werden charakteristische morphologische Merkmale diskutiert und gegenübergestellt. Material und Methoden Anhand einer ausführlichen Literaturrecherche wird der aktuelle Wissensstand bezüglich der bildgebenden Diagnostik luminaler Pathologien des Dickdarms und ihrer Bedeutung im Patientenmanagement dargestellt. Ergebnisse Durch die technologischen Fortschritte in der Bildgebung ist die Diagnose von neoplastischen und entzündlichen Kolonerkrankungen mittels abdominaler Computertomographie (CT) und Magnetresonanztomographie (MRT) zum etablierten Standard geworden. Die Bildgebung erfolgt im Rahmen der Erstdiagnose bei klinisch symptomatischen Patienten, zum Ausschluss von Komplikationen, für eine Verlaufsbeurteilung unter Therapie sowie als optionale Screeningmethode bei asymptomatischen Personen. Diskussion Die genaue Kenntnis der radiologischen Erscheinungsformen der zahlreichen luminalen Krankheitsbilder, dem typischen Verteilungsmuster und den charakteristischen Darmwandveränderungen sind wesentlich, um die diagnostische Entscheidungsfähigkeit zu verbessern.

Eine frühzeitige Diagnose von luminalen Dickdarmerkrankungen ist von wesentlicher klinischer Bedeutung, um eine rechtzeitige optimierte Therapie beginnen und Komplikationen frühzeitig erkennen zu können. Diese Arbeit soll einen Überblick über den Einsatz radiologischer Methoden bei der Diagnose neoplastischer und entzündlicher luminaler Erkrankungen des Kolons vermitteln. Dabei werden charakteristische morphologische Merkmale diskutiert und gegenübergestellt. Anhand einer ausführlichen Literaturrecherche wird der aktuelle Wissensstand bezüglich der bildgebenden Diagnostik luminaler Pathologien des Dickdarms und ihrer Bedeutung im Patientenmanagement dargestellt. Durch die technologischen Fortschritte in der Bildgebung ist die Diagnose von neoplastischen und entzündlichen Kolonerkrankungen mittels abdominaler Computertomographie (CT) und Magnetresonanztomographie (MRT) zum etablierten Standard geworden. Die Bildgebung erfolgt im Rahmen der Erstdiagnose bei klinisch symptomatischen Patienten, zum Ausschluss von Komplikationen, für eine Verlaufsbeurteilung unter Therapie sowie als optionale Screeningmethode bei asymptomatischen Personen. Die genaue Kenntnis der radiologischen Erscheinungsformen der zahlreichen luminalen Krankheitsbilder, dem typischen Verteilungsmuster und den charakteristischen Darmwandveränderungen sind wesentlich, um die diagnostische Entscheidungsfähigkeit zu verbessern.

The potential of CT colonography for minimally invasive colorectal cancer screening has been discussed since its introduction more than 25 years ago. The strategy has gained support after being recommended as a potential screening test for colorectal cancer by the US Preventive Services Task Force in 2016.

Zusammenfassung Hintergrund Nikotin ist ein hochwirksames Suchtgift, das bei regelmäßiger Einnahme chronische oder unheilbare Erkrankungen und somit eine eingeschränkte Lebensqualität zur Folge haben kann. Fragestellung Das Ziel dieser Übersichtsarbeit besteht darin, mögliche gesundheitliche Folgen des Rauchens auf den Gastrointestinaltrakt aufzuzeigen und einen Überblick über raucherassoziierte neoplastische und nichtneoplastische gastrointestinale Erkrankungen zu geben. Material und Methode Anhand einer ausführlichen Literaturrecherche wird der aktuelle Wissensstand zu raucherassoziierten Folgen auf den Gastrointestinaltrakt dargestellt. Ergebnisse Rauchen ist ein wesentlicher Risikofaktor für die Entstehung neoplastischer und nichtneoplastischer Erkrankungen des gesamten Gastrointestinaltrakts. Diese weisen in der radiologischen Bildgebung allerdings keine spezifischen, raucherassoziierten Merkmale auf. Schlussfolgerung Die Kenntnis einer Raucheranamnese sowie möglicher Auswirkungen von Nikotin auf den Gastrointestinaltrakt können in der radiologischen Bildinterpretation hilfreich sein sowie die diagnostische Entscheidungsfähigkeit und Genauigkeit verbessern.

Authors Cristiano Spada*#, Cesare Hassan, Andrew Plumb, Cristina Carretero6, Andrea Laghi, Evelien Dekker, Jaap Stoker, Rami Eliakim7, Steve Halligan, Ignacio Fernandez Urien, Martina Morrin, Michael F. Kaminski3, Philippe Lefere, Anastasios Koulaouzidis, Thomas Mang, Deirdre McNamara2, Emanuele Neri, Mathieu Pioche1, David Burling, Manon CW Spaander5, Emanuele Rondonotti, Margriet de Haan, Sebastian Manuel Milluzzo*#, Giovanni Cappello, Silvia Pecere, Davide Bellini, Daniele Regge.

CT colonography (CTC) is the radiological examination of choice for the diagnosis of colorectal neoplasia. Faecal tagging is considered a mandatory part of bowel preparation. However, the colonic mucosa, obscured by tagged residue, is not accessible to endoluminal 3D views and requires time-consuming 2D evaluation. Electronic cleansing (EC) software algorithms can overcome this limitation by digitally subtracting tagged residue from the colonic lumen. Ideally, this enables a seamless 3D endoluminal evaluation. Despite this benefit, EC is a potential source of a wide range of artefacts. Accurate EC requires proper CTC examination technique and faecal tagging. The digital subtraction process has been shown to affect the relevant morphological features of both colonic anatomy and colonic lesions, if submerged under faecal residue. This article summarises the potential effects of EC on CTC imaging, the consequences for reporting and patient management, and strategies to avoid pitfalls. Furthermore, potentially negative effects on clinical reporting and patient management are shown, and problem-solving techniques, as well as recommendations for the appropriate use of EC techniques, are presented. Radiologists using EC should be familiar with EC-related effects on polyp size and also with correct measurement techniques.

Introduction: Congenital as well as acquired diseases may be responsible for the development of a megacolon. In adult patients, Clostridium difficile associated infection as well as late-onset of Morbus Hirschsprung disease are known to cause a megacolon. In addition, malignant as well as benign colorectal strictures may lead to intestinal dilatation. In case of an idiopathic megacolon, the underlying cause remains unclear. Case Presentation: We describe the case of a 44-year-old male patient suffering from a long history of chronic constipation. He presented himself with an obscurely dilated large intestine with bowel loops up to 17 centimeters in diameter. Radiological as well as endoscopic examination gave evidence of a spastic process in the sigmoid colon. The patient was treated with a subtotal colectomy and the intraoperative findings revealed a stenotic stricture in the sigmoid colon. Since the histological examination did not find a conclusive reason for the functional stenosis, an immunohistochemical staining was advised. This showed a decrease in interstitial cells of Cajal (ICC) in the stenotic part of the sigmoid colon. Discussion: This case report describes a patient with an idiopathic megacolon, where the underlying cause remained unclear until an immunohistochemical staining of the stenotic colon showed a substantial decrease of ICCs. Various pathologies leading to a megacolon are reviewed and discussed.

1. ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia. Strong recommendation, high quality evidence. ESGE/ESGAR do not recommend barium enema in this setting. Strong recommendation, high quality evidence. 2. ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. The timing depends on an interdisciplinary decision including endoscopic and radiological factors. Strong recommendation, low quality evidence. ESGE/ESGAR suggests that, in centers with expertise in and availability of colon capsule endoscopy (CCE), CCE preferably the same or the next day may be considered if colonoscopy is incomplete. Weak recommendation, low quality evidence. 3. When colonoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with alarm symptoms. Strong recommendation, high quality evidence. Because of lack of direct evidence, ESGE/ESGAR do not recommend CCE in this situation. Very low quality evidence. ESGE/ESGAR recommend CTC as an acceptable alternative to colonoscopy for patients with non-alarm symptoms. Strong recommendation, high quality evidence. In centers with availability, ESGE/ESGAR suggests that CCE may be considered in patients with non-alarm symptoms. Weak recommendation, low quality evidence. 4. Where there is no organized fecal immunochemical test (FIT)-based population colorectal screening program, ESGE/ESGAR recommend CTC as an option for colorectal cancer screening, providing the screenee is adequately informed about test characteristics, benefits, and risks, and depending on local service- and patient-related factors. Strong recommendation, high quality evidence. ESGE/ESGAR do not suggest CCE as a first-line screening test for colorectal cancer. Weak recommendation, low quality evidence. 5. ESGE/ESGAR recommend CTC in the case of a positive fecal occult blood test (FOBT) or FIT with incomplete or unfeasible colonoscopy, within organized population screening programs. Strong recommendation, moderate quality evidence. ESGE/ESGAR also suggest the use of CCE in this setting based on availability. Weak recommendation, moderate quality evidence. 6. ESGE/ESGAR suggest CTC with intravenous contrast medium injection for surveillance after curative-intent resection of colorectal cancer only in patients in whom colonoscopy is contraindicated or unfeasible. Weak recommendation, low quality evidence. There is insufficient evidence to recommend CCE in this setting. Very low quality evidence. 7. ESGE/ESGAR suggest CTC in patients with high risk polyps undergoing surveillance after polypectomy only when colonoscopy is unfeasible. Weak recommendation, low quality evidence. There is insufficient evidence to recommend CCE in post-polypectomy surveillance. Very low quality evidence. 8. ESGE/ESGAR recommend against CTC in patients with acute colonic inflammation and in those who have recently undergone colorectal surgery, pending a multidisciplinary evaluation. Strong recommendation, low quality evidence. 9. ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp ≥6 mm detected at CTC or CCE. Follow-up CTC may be clinically considered for 6–9-mm CTC-detected lesions if patients do not undergo polypectomy because of patient choice, comorbidity, and/or low risk profile for advanced neoplasia. Strong recommendation, moderate quality evidence.

Introduction/Purpose Weight regain and weight loss failure after bariatric surgery are important issues that may require a weight regain procedure. Three-dimensional-computed tomography (3D-CT) is a well-established method allowing exact measurements of pouch volume. The aims of this study were to prove the applicability of swallow MRI as a non-ionizing procedure and compare it to 3D-CT in patients after weight regain procedures following RYGB. Materials and Methods Twelve post-RYGB patients who had a follow-up operation for weight regain before 12/2017 were included in this prospective study. Swallow MRI and 3D-CT were performed in each patient to evaluate the size of the anastomosis, pouch volume, and intrathoracic pouch migration (ITM). Results Mean pouch volume in swallow MRI and 3D-CT were 40.4 ± 21.0 ml and 43.5 ± 30.2 ml, respectively ( p = 0.83), and pouch diameter at the maximal distention was 35.3 ± 5.9 ml (MRI) and 31.0 ± 10.0 ml (CT) ( p = 0.16). The rate of ITM was 75% in both examinations ( p = 1.0). Conclusion Swallow MRI is a valid method for the assessment of pouch volume in different phases of the swallowing process and is comparable to 3D-CT. The diagnosis of ITM using swallow MRI was equal to 3D-CT.