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1.  Quantitative MRI of colonic mural enhancement: segmental differences exist in endoscopically proven normal colon 
The British Journal of Radiology  2012;85(1017):1314-1319.
Abnormal contrast enhancement on MRI is advocated as a biomarker for inflammation in colitis, although the enhancement kinetics of normal colon are poorly described. Our purpose was to quantitatively assess mural enhancement in normal colon and test for intersegmental differences.
Eight patients without prior history of inflammatory bowel disease underwent standard MRI colonography followed by normal same-day colonoscopy. Acquired sequences included a volumetric interpolated breath-hold examination (VIBE) to encompass the whole colonic volume, performed at 5°, 10° and 35° flip angles for T1 quantitation and then at a fixed 35° flip angle three times prior to and every 30 s following intravenous gadoterate meglumine for 220 s. Ascending colon, descending colon and rectal R1 (1/T1) was plotted against time. Mean pre-contrast R1, initial change of R1 (ΔR1), early and late “plateau phase” enhancement and the area under the R1–time (AUC–R1) curve were compared between segments using the Student's paired t-test.
There was no significant difference of pre-contrast R1 between segments (p=0.49 to 0.62). ΔR1 was higher for ascending colon compared with descending colon (0.0023±0.0012 ms−1 vs 0.0010±0.0011 ms−1, p=0.03). There was no significant difference for early or late plateau phase R1 between colonic segments (p=0.08 to 1.00). AUC–R1 was greater for ascending than descending colon (0.54±0.19 vs 0.30±0.14, p=0.03).
Intersegmental differences in colonic enhancement are present and should be considered when interpreting differential segmental enhancement.
PMCID: PMC3487064  PMID: 22919009
2.  MRI enterography: what is the clinical impact of unsuspected extra-enteric findings? 
The British Journal of Radiology  2012;85(1017):e766-e769.
To define the incidence and nature of incidental extra-enteric findings on magnetic resonance enterography (MRE) following the introduction of a new clinical service, to assess the volume of additional tests generated and to gauge the potential of MRE to reduce the need for subsequent abdominal imaging. The imaging and patient records of 500 consecutive patients undergoing MRE at a single institution were reviewed. Note was made of patient demographics, any extra-enteric findings reported on the MRE, whether additional tests were recommended by the reporting radiologists to clarify or follow up extra-enteric findings and whether the patients underwent additional abdominal or pelvic imaging in the 4 months after the MRE. 64% of the cohort was male. The mean age was 45 years (range 11–80 years). Overall 190 (38%) underwent MRE for assessment of known Crohn's disease and 310 (62%) for other indications, such as abdominal pain and anaemia. 26 non-bowel-related extra-enteric abnormalities were noted on the MRE report in just 15 patients (3%), and a total of 6 additional tests were recommended by the reporting radiologist. 13 patients (2.6%) underwent some form of abdominal imaging within 4 months of the MRE. None of these additional investigations revealed any abnormality missed on the MRE. Extra-enteric findings are unlikely to have a significant impact on healthcare resources after the introduction of an MRE service.
PMCID: PMC3487098  PMID: 22553300
3.  CT enterography: review of technique and practical tips 
The British Journal of Radiology  2012;85(1015):876-886.
CT enterography is a new non-invasive imaging technique that offers superior small bowel visualisation compared with standard abdomino-pelvic CT, and provides complementary diagnostic information to capsule endoscopy and MRI enterography. CT enterography is well tolerated by patients and enables accurate, efficient assessment of pathology arising from the small bowel wall or surrounding organs. This article reviews the clinical role of CT enterography, and offers practical tips for optimising technique and accurate interpretation.
PMCID: PMC3474054  PMID: 22553291
4.  Patient experiences of MR colonography and colonoscopy: a qualitative study 
The British Journal of Radiology  2012;85(1014):765-769.
The aim of this study was to apply qualitative techniques to assimilate data on patient experience and attitudes during MR colonography (MRC) and colonoscopy (CC).
18 patients (11 male, 8 female, median age 40.5 years), 10 of whom had known colonic inflammatory bowel disease (IBD) and 8 who were under investigation for suspected colonic neoplasia (non-IBD), underwent MRC and conventional CC. Semi-structured interviews were performed to assimilate test experiences and preferences, and themes were extracted using thematic analysis.
Thematic analysis identified three main themes: (i) physical experience, (ii) information provision and (iii) overall preference. Patients expressed mixed views about the physical experience of MRC but specifically identified water filling, breath holding and lying still as problematic. Anxiety was expressed regarding potential incontinence. Scanner noise interfered with the understanding of instructions, particularly amongst non-IBD patients. Non-IBD patients expressed greater anxiety over the delay in receiving the MRC report than IBD patients. In general MRI was considered as the more informative and safer investigation. Patients reported more physical discomfort during CC (notably IBD patients) related to air insufflation and colonoscopic manipulation but were more satisfied with the feedback they received. 10 patients (56%) stated an overall preference for MRC and 5 (28%) preferred CC. Reasons for preferences stated by the patients included discomfort, speed of the test, safety, perceived diagnostic ability and the ability to take biopsies.
Experiences of MRC and CC are complex and influenced by clinical indication. Individuals place different weightings on the relative importance of test attributes including discomfort, noise, immobility, feedback, safety and fear of incontinence and this defines overall preference.
PMCID: PMC3474127  PMID: 22010031
5.  Management of incidental findings during imaging research in “healthy” volunteers: current UK practice 
The British Journal of Radiology  2012;85(1009):11-21.
Incidental findings (IF) are becoming increasingly common due to the proliferation of imaging research. IFs can be life-changing for “healthy” volunteers. This study examined variation in IF management in UK research studies of healthy volunteers, including comparison with ethical and legal guidelines, thus providing baseline data and informing future practice.
Questionnaire of participant background [medical/non-medical; radiologist/non-radiologist; years as principal investigator (PI)], type of research (involving children or not), institutional policy, volunteer information, radiologist involvement in reporting scans and IF disclosure mechanisms. Investigator's current and perceived “ideal” practice was examined. Participants were PIs performing imaging research of healthy volunteers approved by UK ethics committees (2006–2009).
63/146 (43%) surveys completed. 54/61 (88.5%) had site-specific guidelines. Information commonly provided to volunteers should IF be found: personal data (51/62; 82%), contingency plans (54/62; 87%) and disclosure to general practitioner (GP)/treating physician (47/62; 76%). PIs used different strategies for image review. Commonest: radiologist reports research scans only when researcher suspicious of IF [15/57 (26%) compared with 5/28 (16%) in ideal practice]. Commonest ideal reporting strategy: routine reporting by specialist radiologists [9/28 (29%) compared with 8/57 (14%) in current practice]. 49/56 (87.5%) have a standardised disclosure contingency plan, usually involving GP. PIs most commonly disclosed IFs to volunteers when judged relevant (27/58; 47%), most commonly face to face (22/54; 41%), by volunteer's GP (26/60; 43%). Background of PI influenced consent, reporting and disclosure practice.
There is wide variation in handling IFs in UK imaging research. Much of the current practice contravenes the vague existing legal and ethical guidelines, and is unlikely to be in the best interests of volunteers or researchers.
PMCID: PMC3473920  PMID: 21937616
6.  Use of small bowel imaging for the diagnosis and staging of Crohn’s disease—a survey of current UK practice 
The British Journal of Radiology  2011;84(1002):508-517.
This study used a postal survey to assess the current use of small bowel imaging investigations for Crohn’s disease within National Health Service (NHS) radiological practice and to gauge gastroenterological referral patterns.
Similar questionnaires were posted to departments of radiology (n = 240) and gastroenterology (n = 254) identified, by the databases of the Royal College of Radiologists and British Society of Gastroenterologists. Questionnaires enquired about the use of small bowel imaging in the assessment of Crohn’s disease. In particular, questionnaires described clinical scenarios including first diagnosis, disease staging and assessment of suspected extraluminal complications, obstruction and disease flare. The data were stratified according to patient age.
63 (27%) departments of radiology (20 in teaching hospitals and 43 in district general hospitals (DGHs)) and 73 (29%) departments of gastroenterology replied. These departments were in 119 institutions. Of the 63 departments of radiology, 55 (90%) routinely performed barium follow-though (BaFT), 50 (80%) CT, 29 (46%) small bowel ultrasound (SbUS) and 24 (38%) small bowel MRI. BaFT was the most commonly used investigation across all age groups and indications. SbUS was used mostly for patients younger than 40 years of age with low index of clinical suspicion for Crohn’s disease (in 44% of radiology departments (28/63)). MRI was most frequently used in patients under 20 years of age for staging new disease (in 27% of radiology departments (17/63)) or in whom obstruction was suspected (in 29% of radiology departments (18/63)). CT was preferred for suspected extraluminal complications or obstruction (in 73% (46/63) and 46% (29/63) of radiology departments, respectively). Gastroenterological referrals largely concurred with the imaging modalities chosen by radiologists, although gastroenterologists were less likely to request SbUS and MRI.
BaFT remains the mainstay investigation for luminal small bowel Crohn’s disease, with CT dominating for suspected extraluminal complications. There has been only moderate dissemination of the use of MRI and SbUS.
PMCID: PMC3473626  PMID: 21081570
7.  CT colonography: computer-assisted detection of colorectal cancer 
The British Journal of Radiology  2011;84(1001):435-440.
Computer-aided detection (CAD) for CT colonography (CTC) has been developed to detect benign polyps in asymptomatic patients. We aimed to determine whether such a CAD system can also detect cancer in symptomatic patients.
CTC data from 137 symptomatic patients subsequently proven to have colorectal cancer were analysed by a CAD system at 4 different sphericity settings: 0, 50, 75 and 100. CAD prompts were classified by an observer as either true-positive if overlapping a cancer or false-positive if elsewhere. Colonoscopic data were used to aid matching.
Of 137 cancers, CAD identified 124 (90.5%), 122 (89.1%), 119 (86.9%) and 102 (74.5%) at a sphericity of 0, 50, 75 and 100, respectively. A substantial proportion of cancers were detected on either the prone or supine acquisition alone. Of 125 patients with prone and supine acquisitions, 39.3%, 38.3%, 43.2% and 50.5% of cancers were detected on a single acquisition at a sphericity of 0, 50, 75 and 100, respectively. CAD detected three cancers missed by radiologists at the original clinical interpretation. False-positive prompts decreased with increasing sphericity value (median 65, 57, 45, 24 per patient at values of 0, 50, 75, 100, respectively) but many patients were poorly prepared.
CAD can detect symptomatic colorectal cancer but must be applied to both prone and supine acquisitions for best performance.
PMCID: PMC3473653  PMID: 21081583
8.  Non-laxative CT colonography with barium-based faecal tagging: is additional phosphate enema beneficial and well tolerated? 
The British Journal of Radiology  2011;84(998):120-125.
The purpose of this study was to investigate the efficacy and tolerance of an additional phosphate enema prior to non-laxative CT colonography (CTC).
71 patients (mean age 80 years, 28 male, 43 female) underwent non-laxative CTC following 4 oral doses of diluted 2% w/w barium sulphate. Patients were invited to self-administer a phosphate enema 2 h before CTC. An experienced observer graded the volume of retained stool (1 (nil) to 4 (>75% bowel circumference coated)), retained fluid ((1 (nil) to 4 (>50% circumference obscured)), retained stool tagging quality (1 (untagged) to 5 (≥75% to 100%) tagged) and confidence a polyp ≥6 mm could be excluded (yes/no) for each of six colonic segments. Tolerance of the enema was assessed via questionnaire. Data were analysed between those using and not using the enema by Mann–Whitney and Fisher's exact test. 18/71 patients declined the enema.
There was no reduction in residual stool volume with enema use compared with non-use either overall (mean score 2.6 vs 2.7, p = 0.76) or in the left colon (mean 2.3 vs 2.4, p = 0.47). Overall tagging quality was no different (mean score 4.4 vs 4.3, p = 0.43). There was significantly more retained left colonic fluid post enema (mean score 1.9 vs 1.1, p<0.0001), and diagnostic confidence in excluding polyps was significantly reduced (exclusion not possible in 35% segments vs 21% without enema, p = 0.006). Of 53 patients, 30 (56%) found the enema straightforward to use, but 4 (8%) found it unpleasant.
Phosphate enema use prior to non-laxative CTC leads to greater retained fluid, reducing diagnostic confidence, and is not recommended.
PMCID: PMC3473848  PMID: 20959374
9.  Incidental findings found in “healthy” volunteers during imaging performed for research: current legal and ethical implications 
The British Journal of Radiology  2010;83(990):456-465.
Incidental findings found in “healthy” volunteers during research imaging are common and have important implications for study design and performance, particularly in the areas of informed consent, subjects' rights, clinical image analysis and disclosure. In this study, we aimed to determine current practice and regulations concerning information that should be given to research subjects when obtaining consent, reporting of research images, who should be informed about any incidental findings and the method of disclosure. We reviewed all UK, European and international humanitarian, legal and ethical agencies' guidance. We found that the guidance on what constitutes incidental pathology, how to recognise it and what to do about it is inconsistent between agencies, difficult to find and less complete in the UK than elsewhere. Where given, guidance states that volunteers should be informed during the consent process about how research images will be managed, whether a mechanism exists for identifying incidental findings, arrangements for their disclosure, the potential benefit or harm and therapeutic options. The effects of incidentally discovered pathology on the individual can be complex and far-reaching. Radiologist involvement in analysis of research images varies widely; many incidental findings might therefore go unrecognised. In conclusion, guidance on the management of research imaging is inconsistent, limited and does not address the interests of volunteers. Improved standards to guide management of research images and incidental findings are urgently required.
PMCID: PMC3473586  PMID: 20335427

Results 1-9 (9)