Damian Tolan

MR Enterographic Manifestations of Small Bowel Crohn Disease

Magnetic resonance (MR) enterography is a clinically useful technique for the evaluation of both intraluminal and extraluminal small bowel disease, particularly in younger patients with Crohn disease. MR enterography offers the advantages of multiplanar capability and lack of ionizing radiation. It allows evaluation of bowel wall contrast enhancement, wall thickening, and edema, findings useful for the assessment of Crohn disease activity. MR enterography can also depict other pathologic findings such as lymphadenopathy, fistula and sinus formation, abscesses, and abnormal fold patterns. Even subtle disease manifestations may be detected when adequate distention of the small bowel is achieved, although endoscopic and double-contrast barium small bowel techniques remain superior in the depiction of changes in early Crohn disease (eg, aphthoid ulceration). Further research will be needed to determine whether MR imaging enhancement patterns may reliably help discriminate between active and inactive disease.

Effects of infliximab therapy on transmural lesions as assessed by magnetic resonance enteroclysis in patients with ileal Crohn's disease☆ , ☆☆ , ★

BACKGROUND AND AIMSnAnti TNF therapy induces mucosal healing in patients with Crohns disease, but the effects on transmural inflammation in the ileum are not well understood. Magnetic resonance-enteroclysis (MRE) offers excellent imaging of transmural and peri-enteric lesions in Crohns ileitis and we aimed to study its responsiveness to anti TNF therapy.nnnMETHODSnIn this multi-center prospective trial, anti TNF naïve patients with ileal Crohns disease and with increased CRP and contrast enhanced wall thickening received infliximab 5 mg/kg at weeks 0, 2 and 6, and q8 weeks maintenance MRE was performed at baseline, 2 weeks and 6 months and assessed based on a predefined MRE score of severity in ileal Crohns Disease.nnnRESULTSnTwenty patients were included; of those, 18 patients underwent MRE at week 2 and 15 patients at weeks 2 and 26 as scheduled. Inflammatory components of the MRE index decreased by ≥2 points and by ≥50% at week 26 (primary endpoint) in 40% and 32% of patients (per protocol and intention to treat analysis, respectively). The MRE index improved in 44% at week 2 and in 80% at week 26. Complete absence of inflammatory lesions was observed in 0/18 at week 2 and 13% (2/15) at week 26. The obstructive elements did not change. Clinical and CRP improvement occurred as early as wk 2, but only CDAI correlated with the MRE index.nnnCONCLUSIONnImprovement of MRE occurs from 2 weeks after infliximab therapy onwards and correlates with clinical response but normalization of MRE is rare.

Anastomotic Leakage after Esophagectomy for Cancer: A Mortality-Free Experience

BACKGROUNDnLeakage is a serious complication of esophagectomy and is historically associated with high mortality. This study aimed to describe the morphology and strategies for clinical management of leakage after esophagectomy.nnnSTUDY DESIGNnA database prospectively maintained from July 2002 to July 2005 at a referral unit for foregut cancer was used to identify patients with leakage of saliva or gastrointestinal contents after esophagectomy and reconstruction with stomach. Contrast swallow was routinely performed on postoperative day 7. Leakage was diagnosed and classified by well-defined criteria.nnnRESULTSnThere were 99 men and 27 women, yielding an institutional volume of 42 esophagectomies per year. There was no in-hospital mortality from any cause. Actual 1-year survival was 87%. An Ivor Lewis operation was performed on 103 patients (82%); 4 patients had leakage within 5 days of operation and all had immediate rethoracotomy. An additional 8 patients with Ivor Lewis operation had leakage after day 5, and this was detected by contrast swallow in only 3 patients; 2 patients had no intervention, 4 patients had radiology-guided drainage, 1 had thoracoscopy, and 1 had rethoracotomy. Leakage was from the actual esophagogastric anastomosis in eight patients, from the linear gastric staple line in three patients, or from gastric necrosis in one patient. Twenty-three patients had a transhiatal or three-stage operation; leakage was from the actual anastomosis in five patients or gastric necrosis in one patient.nnnCONCLUSIONSnAfter Ivor Lewis esophagectomy, leakage was from the actual anastomosis in two-thirds of patients or from the gastric conduit in the remaining one-third. Prompt reoperation is recommended for early postoperative leakage. Most patients with leakage after day 5 can be treated nonoperatively.

Replacing Barium Enema with CT Colonography in Patients Older Than 70 Years: The Importance of Detecting Extracolonic Abnormalities

OBJECTIVEnThe objective of our study was to evaluate the significance of extracolonic abnormalities in patients older than 70 years referred for CT colonography (CTC).nnnMATERIALS AND METHODSnWe performed a retrospective analysis of 400 consecutive patients older than 70 years undergoing CTC over a 14-month period. All patients presented with weight loss, alteration of bowel habits, rectal blood loss, abdominal pain, or anemia; these symptoms led to clinical suspicion of lower gastrointestinal abnormalities.nnnRESULTSnFive hundred five separate extracolonic abnormalities were detected in 268 of 400 patients (67%). One hundred thirty-nine pathologic processes were deemed significant in 116 patients. Of these, 110 lesions (79%) were previously unknown in 96 of the 400 patients (24.0%). Forty-nine of the 400 patients (12.3%) had at least one malignancy, including 23 extracolonic malignancies and 29 colorectal malignancies. Thirteen patients had early cancers (T1N0M0 or T2N0M0). Twenty of the colon cancer patients had significant previously unknown extracolonic abnormalities, half of which were related to the primary tumor and half of which were unrelated extracolonic abnormalities.nnnCONCLUSIONnIn patients older than 70 years being examined because of lower gastrointestinal symptoms, CTC findings yield a high number of new significant extracolonic abnormalities. This finding makes a compelling case for targeting this group of patients for a CTC service.

The first joint ESGAR/ ESPR consensus statement on the technical performance of cross-sectional small bowel and colonic imaging

AbstractObjectivesTo develop guidelines describing a standardised approach to patient preparation and acquisition protocols for magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) of the small bowel and colon, with an emphasis on imaging inflammatory bowel disease.MethodsAn expert consensus committee of 13 members from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) and European Society of Paediatric Radiology (ESPR) undertook a six-stage modified Delphi process, including a detailed literature review, to create a series of consensus statements concerning patient preparation, imaging hardware and image acquisition protocols.ResultsOne hundred and fifty-seven statements were scored for agreement by the panel of which 129 statements (82xa0%) achieved immediate consensus with a further 19 (12xa0%) achieving consensus after appropriate modification. Nine (6xa0%) statements were rejected as consensus could not be reached.ConclusionsThese expert consensus recommendations can be used to help guide cross-sectional radiological practice for imaging the small bowel and colon.Key points• Cross-sectional imaging is increasingly used to evaluate the boweln • Image quality is paramount to achieving high diagnostic accuracyn • Guidelines concerning patient preparation and image acquisition protocols are provided

Precautions to be taken by radiologists and radiographers when prescribing hyoscine-N-butylbromide

Hyoscine-N-butylbromide (Buscopan, Boehringer Ingelheim) is a widely used antispasmodic in radiological practice. There seems to be no consensus as to best practice within radiology regarding the precautions that need to be taken when prescribing Buscopan. We have performed a thorough review of the available literature and make the following recommendations to those administering Buscopan: (1) enquire whether there is an allergic history; (2) ensure patient literature warns that in the rare event that following the examination you develop painful, blurred vision in one or both eyes, you must attend hospital immediately for assessment; (3) warn patients to expect blurred vision and not to drive until this has worn off; (4) remind clinicians that special consideration needs to be given as to the method of investigating patients with cardiac instability, such as those recently admitted with acute coronary syndrome, recurrent cardiac pain at rest, uncontrolled left ventricular failure and recent ventricular arrhythmias.

Influence of Computer-Aided Detection False-Positives on Reader Performance and Diagnostic Confidence for CT Colonography

OBJECTIVEnThe objective of our study was to investigate whether an increasing number of computer-aided detection (CAD) false-positives decreases reader sensitivity, specificity, and confidence for nonexpert readers of CT colonography (CTC).nnnMATERIALS AND METHODSnFifty CTC data sets (29 men; mean age, 65 years), 25 of which contained 35 polyps > or = 5 mm, were selected in which CAD had 100% polyp sensitivity at two sphericity settings (0 and 75) but differed in the number of false-positives. The data sets were read by five readers twice: once at each sphericity setting. Sensitivity, specificity, report time, and confidence before and after second-read CAD were compared using the paired exact and Students t test, respectively. Receiver operating characteristic (ROC) curves were generated using reader confidence (1-100) in correct case classification (normal or abnormal).nnnRESULTSnCAD generated a mean of 42 (range, 3-118) and 15 (range, 1-36) false-positives at a sphericity of 0 and 75, respectively. CAD at both settings increased per-patient sensitivity from 82% to 87% (p = 0.03) and per-polyp sensitivity by 8% and 10% for a sphericity of 0 and 75, respectively (p < 0.001). Specificity decreased from 84% to 79% (sphericity 0 and 75, p = 0.03 and 0.07). There was no difference in sensitivity, specificity, or reader confidence between sphericity settings (p = 1.0, 1.0, 0.11, respectively). The area under the ROC curve was 0.78 (95% CI, 0.70-0.86) and 0.77 (0.68-0.85) for a sphericity of 0 and 75, respectively. CAD added a median of 4.4 minutes (interquartile range [IQR], 2.7-6.5 minutes) and 2.2 minutes (IQR, 1.2-4.0 minutes) for a sphericity of 0 and 75, respectively (p < 0.001). CONCLUSION. CAD has the potential to increase the sensitivity of readers inexperienced with CTC, although specificity may be reduced. An increased number of CAD-generated false-positives does not negate any beneficial effect but does reduce efficiency.

Quantitative assessment of colonic movement between prone and supine patient positions during CT colonography.

This paper aims to quantify changes in colonic length and positional change between supine and prone CT colonography (CTC) studies in order to aid development of image registration techniques. CTC studies in 20 patients (10 men and 10 women) with technically adequate distension were analysed using an image analysis workstation. Spatial co-ordinates of colonic landmarks were determined in both prone and supine orientations using a three-dimensional colon model view and centreline positions. Change in the co-ordinate position of colonic segments between supine and prone scans was calculated using the superior mesenteric artery as a fixed point of reference. There was no significant difference in total colonic length for subjects between prone and supine positions, nor any significant difference overall when men were compared with women. However, significant differences between sexes for individual segments were found; the ascending colon, descending colon and rectum were significantly longer in men and the sigmoid colon was longer in women. The transverse colon was the most mobile segment during positional change, with an average displacement between supine and prone scans of 4.6 cm (standard deviation, 0.48 cm) for men and 4.1 cm (standard deviation, 0.4 cm) for women. Consistent patterns of colonic positional change between supine and prone orientations were present and were thought to be most likely the result of abdominal compression. We concluded that there is minimal variation in colonic length between prone and supine orientations. Consistent patterns of colonic displacement with patient position suggest that predictable forces act upon the colon. Understanding these forces will facilitate image registration for CT colonography.

METRIC (MREnterography or ulTRasound in Crohn's disease): a study protocol for a multicentre, non-randomised, single-arm, prospective comparison study of magnetic resonance enterography and small bowel ultrasound compared to a reference standard in those aged 16 and over.

BackgroundCrohn’s disease (CD) is a lifelong, relapsing and remitting inflammatory condition of the intestine. Medical imaging is crucial for diagnosis, phenotyping, activity assessment and detecting complications. Diverse small bowel imaging tests are available but a standard algorithm for deployment is lacking. Many hospitals employ tests that impart ionising radiation, of particular concern to this young patient population. Magnetic resonance enterography (MRE) and small bowel ultrasound (USS) are attractive options, as they do not use ionising radiation. However, their comparative diagnostic accuracy has not been compared in large head to head trials. METRIC aims to compare the diagnostic efficacy, therapeutic impact and cost effectiveness of MRE and USS in newly diagnosed and relapsing CD.MethodsMETRIC (ISRCTN03982913) is a multicentre, non-randomised, single-arm, prospective comparison study. Two patient cohorts will be recruited; those newly diagnosed with CD, and those with suspected relapse. Both will undergo MRE and USS in addition to other imaging tests performed as part of clinical care. Strict blinding protocols will be enforced for those interpreting MRE and USS. The Harvey Bradshaw index, C-reactive protein and faecal calprotectin will be collected at recruitment and 3xa0months, and patient experience will be assessed via questionnaires. A multidisciplinary consensus panel will assess all available clinical and imaging data up to 6xa0months after recruitment of each patient and will define the standard of reference for the presence, localisation and activity of disease against which the diagnostic accuracy of MRE and USS will be judged. Diagnostic impact of MRE and USS will be evaluated and cost effectiveness will be assessed. The primary outcome measure is the difference in per patient sensitivity between MRE and USS for the correct identification and localisation of small bowel CD.DiscussionThe trial is open at 5 centres with 46 patients recruited. We highlight the importance of stringent blinding protocols in order to delineate the true diagnostic accuracy of both imaging tests and discuss the difficulties of diagnostic accuracy studies in the absence of a single standard of reference, describing our approach utilising a consensus panel whilst minimising incorporation bias.Trial registrationMETRIC - ISRCTN03982913 – 05.11.13.

CT assessment of right colonic arterial anatomy pre and post cancer resection – a potential marker for quality and extent of surgery?

Background There is conflicting opinion as to the optimum extent of resection for right-sided colonic cancer, which is currently graded by pathological analysis of the resected specimen. It is not known if computed tomography (CT) analysis of residual post-resection arterial stump length could be used as an alternative in vivo marker for extent of mesenteric resection. Ileocolic artery stumps have been demonstrated previously on CT after right hemicolectomy, but only in the early postoperative period. Purpose To analyze preoperative right colonic arterial anatomy using portal venous colorectal cancer staging CT and subsequently determine if post-resection arterial stumps (a potential in vivo marker of surgical resection) could be consistently identified using routine follow-up CT scans many months after cancer resection. Material and Methods A retrospective analysis of routine staging and follow-up CT scans for 151 patients with right-sided colorectal cancer was performed. Preoperative right colonic arterial anatomy and postoperative arterial stumps were analyzed and measured. Results Preoperative ileocolic (98.8%), middle (94.7%), and right colic artery (23.8%) identification was comparable to catheter angiogram studies. Postoperative ileocolic stumps were consistently demonstrated (88.3%) many months (average, 2 years and 42 days) after resection and were significantly longer than expected for a standard D2 resection (paired t-test, t(127)u2009=u2009−11.45, Pu2009≤u20090.001). Conclusion This is the first study to successfully demonstrate ileocolic arterial stumps many months (and years) after cancer resection using routine portal venous CT. Further prospective research should assess whether arterial stumps can be used as an in vivo marker of surgical quality and extent.