Adapting and testing a brief intervention to reduce maternal anxiety during pregnancy (ACORN): study protocol for a randomised controlled trial

BACKGROUND

National guidelines in the UK, United States of America, Canada, and Australia have recently stressed the importance of identifying and treating antenatal anxiety and depression. However, there is little research into the most effective and acceptable ways of helping women manage their symptoms of anxiety and stress during pregnancy. Research indicates the necessity to consider the unique needs and concerns of perinatal populations to ensure treatment engagement, highlighting the need to develop specialised treatments which could be integrated within routine antenatal healthcare services. This trial aims to develop a brief intervention for antenatal anxiety, with a focus on embedding the delivery of the treatment within routine antenatal care.

METHODS/DESIGN

This study is a two-phase feasibility trial. In phase 1 we will develop and pilot a brief intervention for antenatal anxiety, blended with group support, to be led by midwives. This intervention will draw on cognitive behavioural principles and wider learning from existing interventions that have been used to reduce anxiety in expectant mothers. The intervention will then be tested in a pilot randomised controlled trial in phase 2. The following outcomes will be assessed: (1) number of participants meeting eligibility criteria, (2) number of participants consenting to the study, (3) number of participants randomised, (4) number of sessions completed by those in the intervention arm, and (5) number of participants completing the post-intervention outcome measures. Secondary outcomes comprise: detailed feedback on acceptability, which will guide further development of the intervention; and outcome data on symptoms of maternal and paternal anxiety and depression, maternal quality of life, quality of couple relationship, mother-child bonding, infant temperament and infant sleep.

DISCUSSION

The study will provide important data to inform the design of a future full-scale randomised controlled trial of a brief intervention for anxiety during pregnancy. This will include information on its acceptability and feasibility regarding implementation within current antenatal services, which will inform whether ultimately this provision could be rolled out widely in healthcare settings.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN95282830 . Registered on 29 October 2014.

Comparative quantitative assessment of global small bowel motility using magnetic resonance imaging in chronic intestinal pseudo-obstruction and healthy controls

BACKGROUND

Chronic intestinal pseudo-obstruction (CIPO) is characterized by dilatation of the bowel lumen and abnormal motility. In this study, we aimed to quantify small bowel dysmotility in CIPO using a validated pan-intestinal motility assessment technique based on motion capture magnetic resonance imaging (MRI) compared to normal controls. In addition, we explored if motility responses of CIPO patients to neostigmine challenge differed from healthy volunteers.

METHODS

Twenty healthy volunteers (mean age 28, range 22-48) and 11 CIPO patients (mean age 47, range 19-90) underwent MRI enterography to capture global small bowel motility. Eleven controls and seven CIPO patients further underwent a randomized placebo-controlled crossover study of either intravenous neostigmine (0.5 mg) or saline with motility MRI repeated at a mean of 3 weeks. Motility was quantified in regions of interest placed to encompass the whole small bowel volume using a validated, postprocessing technique to give a global motility index in arbitrary units (AU). Baseline and stimulated motility was compared using Wilcoxon rank-sum paired T-tests.

KEY RESULTS

Baseline global small bowel motility was significantly lower in CIPO patients compared to controls (mean 0.25 AU vs 0.35 AU, p < 0.001). Motility in both groups increased significantly after neostigmine (0.06 AU increase, p = 0.016 in CIPO and 0.06 AU increase, p = 0.002 in controls). Three patients with scleroderma had a reduced response to neostigmine.

CONCLUSIONS & INFERENCES

Global small bowel motility in CIPO patients is significantly lower than controls and response to the pro-kinetic agent neostigmine may differ according to disease phenotype. Software-quantified bowel motility using cine MRI has potential as a future tool to investigate enteric dysmotility.

Evolution of multi-parametric MRI quantitative parameters following transrectal ultrasound-guided biopsy of the prostate

BACKGROUND

To determine the evolution of prostatic multi-parametric magnetic resonance imaging (mp-MRI) signal following transrectal ultrasound (TRUS)-guided biopsy.

METHODS

Local ethical permission and informed written consent was obtained from all the participants (n=14, aged 43-69, mean 64 years). Patients with a clinical suspicion of prostate cancer (PSA range 2.2-11.7, mean 6.2) and a negative (PIRAD 1-2/5) pre-biopsy mp-MRI (pre-contrast T1, T2, diffusion-weighted and dynamic-contrast-enhanced MRI) who underwent 10-core TRUS-guided biopsy were recruited for additional mp-MRI examinations performed at 1, 2 and 6 months post biopsy. We quantified mp-MRI peripheral zone (PZ) and transition zone (TZ) normalized T2 signal intensity (nT2-SI); T1 relaxation time (T10); diffusion-weighted MRI, apparent diffusion coefficient (ADC); dynamic contrast-enhanced MRI, maximum enhancement (ME); slope of enhancement (SoE) and area-under-the-contrast-enhancement-curve at 120 s (AUC120). Significant changes in mp-MRI parameters were identified by analysis of variance with Dunnett's post testing.

RESULTS

Diffuse signal changes were observed post-biopsy throughout the PZ. No significant signal change occurred following biopsy within the TZ. Left and right PZ mean nT2-SI (left PZ: 5.73, 5.16, 4.90 and 5.12; right PZ: 5.80, 5.10, 4.84 and 5.05 at pre-biopsy, 1, 2 and 6 months post biopsy, respectively) and mean T10 (left PZ: 1.02, 0.67, 0.78, 0.85; right PZ: 1.29, 0.64, 0.78, 0.87 at pre-biopsy, 1, 2 and 6 months post biopsy, respectively) were reduced significantly (P<0.05) from pre-biopsy values for up to 6 months post biopsy. Significant changes (P<0.05) of PZ-ME and AUC120 were observed at 1 month but resolved by 2 months post biopsy. PZ ADC did not change significantly following biopsy (P=0.23-1.0). There was no significant change of any TZ mp-MRI parameter at any time point following biopsy (P=0.1-1.0).

CONCLUSIONS

Significant PZ (but not TZ) T2 signal changes persist up to 6 months post biopsy, whereas PZ and TZ ADC is not significantly altered as early as 1 month post biopsy. Caution must be exercised when interpreting T1- and T2-weighted imaging early post biopsy, whereas ADC images are more likely to maintain clinical efficacy.

Autologous skeletal-muscle-derived cell injection for anal incontinence due to obstetric trauma: a 5-year follow-up of an initial study of 10 patients

AIM

Our aim was to determine whether the benefits of autologous skeletal-muscle-derived cell injection to treat obstetric anal incontinence are sustained at 5 years.

METHOD

An observational study was performed of 10 women suffering from obstetric anal incontinence refractory to non-surgical therapy. Autologous skeletal-muscle-derived cells were injected into the external sphincter defect under ultrasound guidance. Incontinence diaries and quality of life questionnaires were obtained pre-implantation and annually after implantation for 5 years. Anal physiology testing was performed before implantation and at 1, 2 and 5 years after implantation. The end-points included were adverse events, Wexner incontinence scores, incontinence episodes, anal squeeze pressures and quality of life over 5 years. An independent statistician used multilevel linear regression to analyse changes in repeated measures over time. Any skewed distributions were log transformed prior to analysis.

RESULTS

No procedure-related adverse events occurred and haematological and biochemical parameters were normal during the 5-year period. There were sustained significant improvements in the Wexner incontinence score and reduced frequency of defaecation and number of incontinence episodes (all comparisons P < 0.001). Anal resting and squeeze pressures showed sustained improvement (all P < 0.001) and quality of life improved overall (P < 0.001), including all submeasures studied (P < 0.001).

CONCLUSION

Autologous skeletal-muscle-derived cells to treat obstetric anal incontinence resulted in sustained improvement in incontinence episodes, physiological measurements of anal function and quality of life at 5 years.

Magnetic resonance imaging-quantified small bowel motility is a sensitive marker of response to medical therapy in Crohn's disease

BACKGROUND

Magnetic resonance enterography (MRE) can measure small bowel motility, reduction in which reflects inflammatory burden in Crohn's Disease (CD). However, it is unknown if motility improves with successful treatment.

AIM

To determine if changes in segmental small bowel motility reflect response to anti-TNFα therapy after induction and longer term.

METHODS

A total of 46 patients (median 29 years, 19 females) underwent MRE before anti-TNFα treatment; 35 identified retrospectively underwent repeat MRE after median 55 weeks of treatment and 11 recruited prospectively after median 12 weeks. Therapeutic response was defined by physician global assessment (retrospective group) or a ≥3 point drop in the Harvey-Bradshaw Index (prospective group), C-reactive protein (CRP) and the MaRIA score. Two independent radiologists measured motility using an MRE image-registration algorithm. We compared motility changes in responders and nonresponders using the Mann-Whitney test.

RESULTS

Anti-TNFα responders had significantly greater improvements in motility (median = 73.4% increase from baseline) than nonresponders (median = 25% reduction, P < 0.001). Improved MRI-measured motility was 93.1% sensitive (95%CI: 78.0-98.1%) and 76.5% specific (95% CI: 52.7-90.4%) for anti-TNFα response. Patients with CRP normalisation (<5 mg/L) had significantly greater improvements in motility (median = 73.4% increase) than those with persistently elevated CRP (median = 5.1%, P = 0.035). Individuals with post-treatment MaRIA scores of <11 had greater motility improvements (median = 94.7% increase) than those with post-treatment MaRIA score >11 (median 15.2% increase, P = 0.017).

CONCLUSIONS

Improved MRI-measured small bowel motility accurately detects response to anti-TNFα therapy for Crohn's disease, even as early as 12 weeks. Motility MRI may permit early identification of nonresponse to anti-TNFα agents, allowing personalised treatment.

Effect of faecal occult blood positivity on detection rates and positive predictive value of CT colonography when screening for colorectal neoplasia

AIM

To determine the detection rates and positive predictive value (PPV) of computed tomography (CT) colonography (CTC) according to the magnitude of faecal occult blood test (FOBt) positivity.

MATERIALS AND METHODS

Anonymised data from individuals undergoing CTC after a positive FOBt in the English Bowel Cancer Screening Programme were analysed. The detection of colorectal cancer (CRC), advanced neoplasia, and ≥ 6 mm polyps were stratified by the number of positive FOBt windows. The PPV was calculated by reference to subsequent endoscopy results. The influence of the FOBt result on detection rates was estimated with multilevel logistic regression. PPV, CRC stage, and location were compared across groups according to FOBt positivity.

RESULTS

Four thousand, six hundred and one individuals were included (mean = 66.7 years, 54.2% men). Detection rates of CRC and advanced neoplasia increased with greater numbers of positive FOBt windows (odds ratio [OR] for CRC = 1.41; 95% confidence interval [CI]: 1.31-1.52; OR for advanced neoplasia = 1.17; 95%CI: 1.12-1.23; both p < 0.0001). The PPV was significantly greater at higher FOBt levels (p = 0.020). The number of positive FOBt windows had no significant effect on stage (p = 0.30) or location (p = 0.20) of confirmed CRC.

CONCLUSIONS

The magnitude of FOBt positivity influences the PPV and detection rates when screening for colorectal neoplasia. CTC may be particularly useful for FOBt patients with few positive test windows.

Multiparametric MRI for detection of radiorecurrent prostate cancer: added value of apparent diffusion coefficient maps and dynamic contrast-enhanced images

BACKGROUND

Multiparametric magnetic resonance imaging (mp-MRI) is increasingly advocated for prostate cancer detection. There are limited reports of its use in the setting of radiorecurrent disease. Our aim was to assess mp-MRI for detection of radiorecurrent prostate cancer and examine the added value of its functional sequences.

METHODS

Thirty-seven men with mean age of 69.7 (interquartile range, 66-74) with biochemical failure after external beam radiotherapy underwent mp-MRI (T2-weighted, high b-value, multi-b-value apparent diffusion coefficient (ADC) and dynamic contrast-enhanced (DCE) imaging); then transperineal systematic template prostate mapping (TPM) biopsy. Using a locked sequential read paradigm (with the sequence order above), two experienced radiologists independently reported mp-MRI studies using score 1-5. Radiologist scores were matched with TPM histopathology at the hemigland level (n=74). Accuracy statistics were derived for each reader. Interobserver agreement was evaluated using kappa statistics.

RESULTS

Receiver-operator characteristic area under curve (AUC) for readers 1 and 2 increased from 0.67 (95% confidence interval (CI), 0.55-0.80) to 0.80 (95% CI, 0.69-0.91) and from 0.67 (95% CI, 0.55-0.80) to 0.84 (95% CI, 0.76-0.93), respectively, between T2-weighted imaging alone and full mp-MRI reads. Addition of ADC maps and DCE imaging to the examination did not significantly improve AUC for either reader (P=0.08 and 0.47 after adding ADC, P=0.90 and 0.27 after adding DCE imaging) compared with T2+high b-value review. Inter-reader agreement increased from k=0.39 to k=0.65 between T2 and full mp-MRI review.

CONCLUSIONS

mp-MRI can detect radiorecurrent prostate cancer. The optimal examination included T2-weighted imaging and high b-value DWI; adding ADC maps and DCE imaging did not significantly improve the diagnostic accuracy.

Making an effort to feel positive: insecure attachment in infancy predicts the neural underpinnings of emotion regulation in adulthood

BACKGROUND

Animal research indicates that the neural substrates of emotion regulation may be persistently altered by early environmental exposures. If similar processes operate in human development then this is significant, as the capacity to regulate emotional states is fundamental to human adaptation.

METHODS

We utilised a 22-year longitudinal study to examine the influence of early infant attachment to the mother, a key marker of early experience, on neural regulation of emotional states in young adults. Infant attachment status was measured via objective assessment at 18-months, and the neural underpinnings of the active regulation of affect were studied using fMRI at age 22 years.

RESULTS

Infant attachment status at 18-months predicted neural responding during the regulation of positive affect 20-years later. Specifically, while attempting to up-regulate positive emotions, adults who had been insecurely versus securely attached as infants showed greater activation in prefrontal regions involved in cognitive control and reduced co-activation of nucleus accumbens with prefrontal cortex, consistent with relative inefficiency in the neural regulation of positive affect.

CONCLUSIONS

Disturbances in the mother-infant relationship may persistently alter the neural circuitry of emotion regulation, with potential implications for adjustment in adulthood.

Abdominal computed tomography, colonography and radiation exposure: what the surgeon needs to know

AIM

Abdominal computed tomography (CT) improves the accuracy of clinical diagnosis and facilitates patient management. Radiation exposure must be considered by requesting clinicians and is especially relevant owing to the increasing use of CT colonography for diagnosis and screening of colorectal disorders. This review describes the radiation dose of abdominopelvic CT and colonography and attempts to quantify the risk for the clinician.

METHOD

Articles were searched in the PubMed and Medline databases using combinations of the MeSH terms 'radiation', 'abdominal computed tomography' and 'colonography'. Electronic English language abstracts were read by two reviewers and the full article was retrieved if relevant to the review.

RESULTS

Abdominopelvic CT and CT colonography convey significant radiation dose to the patient but also have considerable diagnostic potential. In the right clinical context, the radiation risk should not be overestimated. Techniques to reduce the dose should be used. Repeated imaging in certain patients is a concern and should be monitored.

CONCLUSION

Radiation risk can be quantified and presented simply in a manner that both patients and doctors can comprehend and evaluate. This approach will diminish misconceptions and allow a rational choice of diagnostic test.

Towards a framework for analysis of eye-tracking studies in the three dimensional environment: a study of visual search by experienced readers of endoluminal CT colonography

OBJECTIVE

Eye tracking in three dimensions is novel, but established descriptors derived from two-dimensional (2D) studies are not transferable. We aimed to develop metrics suitable for statistical comparison of eye-tracking data obtained from readers of three-dimensional (3D) "virtual" medical imaging, using CT colonography (CTC) as a typical example.

METHODS

Ten experienced radiologists were eye tracked while observing eight 3D endoluminal CTC videos. Subsequently, we developed metrics that described their visual search patterns based on concepts derived from 2D gaze studies. Statistical methods were developed to allow analysis of the metrics.

RESULTS

Eye tracking was possible for all readers. Visual dwell on the moving region of interest (ROI) was defined as pursuit of the moving object across multiple frames. Using this concept of pursuit, five categories of metrics were defined that allowed characterization of reader gaze behaviour. These were time to first pursuit, identification and assessment time, pursuit duration, ROI size and pursuit frequency. Additional subcategories allowed us to further characterize visual search between readers in the test population.

CONCLUSION

We propose metrics for the characterization of visual search of 3D moving medical images. These metrics can be used to compare readers' visual search patterns and provide a reproducible framework for the analysis of gaze tracking in the 3D environment.

ADVANCES IN KNOWLEDGE

This article describes a novel set of metrics that can be used to describe gaze behaviour when eye tracking readers during interpretation of 3D medical images. These metrics build on those established for 2D eye tracking and are applicable to increasingly common 3D medical image displays.

Small bowel strictures in Crohn's disease: a quantitative investigation of intestinal motility using MR enterography

BACKGROUND

Intestinal stricturing and aberrant small bowel motility are common complications in patients with Crohn's disease (CD) leading to significant morbidity. A retrospective study was performed quantifying small bowel motility within and upstream of strictures in CD patients using magnetic resonance enterography (MRE).

METHODS

A total of 91 subjects with stricturing CD (mean age 36 range 18-88) and undergoing MRE with dynamic motility imaging were identified. Of this cohort, 84 subjects were scanned at 1.5 T field strength with the remainder at 3 T. Linear regions of interest (ROI) were placed at the stricture, immediately upstream of the stricture, and in a proximal normal segment of bowel. Maximum bowel calibre (mm) and motility (Arbitrary units) at each ROI were calculated using previously validated software. Diameters and motility were compared using repeat measures anova and diameter correlated with motility score. In 21 subjects with follow-up MRE, ROIs were duplicated and percentage diameter and motility change across the two time points correlated.

KEY RESULTS

Mean diameter within the normal, prestricture and strictured bowel was 20, 30, and 15 mm (p < 0.001) with motility score 0.43, 0.28, and 0.15 AU, respectively (p < 0.001). There was a negative correlation between prestricture bowel diameter and motility (Pearson's R = -0.47, p < 0.001). For patients with follow-up MRE, there was a negative correlation between percentage change in prestricture diameter and motility, Spearman's Rho -0.6 p = 0.007.

CONCLUSIONS & INFERENCES

Quantified small bowel motility during MRE differs significantly between normal, prestricture, and strictured bowel. As prestricture bowel dilates, motility decreases, although this appears reversible in some.

Imaging techniques for assessment of inflammatory bowel disease: joint ECCO and ESGAR evidence-based consensus guidelines

The management of patients with IBD requires evaluation with objective tools, both at the time of diagnosis and throughout the course of the disease, to determine the location, extension, activity and severity of inflammatory lesions, as well as, the potential existence of complications. Whereas endoscopy is a well-established and uniformly performed diagnostic examination, the implementation of radiologic techniques for assessment of IBD is still heterogeneous; variations in technical aspects and the degrees of experience and preferences exist across countries in Europe. ECCO and ESGAR scientific societies jointly elaborated a consensus to establish standards for imaging in IBD using magnetic resonance imaging, computed tomography, ultrasonography, and including also other radiologic procedures such as conventional radiology or nuclear medicine examinations for different clinical situations that include general principles, upper GI tract, colon and rectum, perineum, liver and biliary tract, emergency situation, and the postoperative setting. The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas such as the comparison of diagnostic accuracy between different techniques, the value for therapeutic monitoring, and the prognostic implications of particular findings.

Diffusion weighted MRI: overview and implications for rectal cancer management

Diffusion weighted imaging (DWI) is an MRI technique that quantifies the movement of water molecules at a cellular level. As the diffusion properties of water vary in areas of necrosis, high cellularity, inflammation and fibrosis, this technique is inherently sensitive to different pathologies. Having become a well-established adjunct to standard sequences during neurological MRI, technological advances have enabled extrapolation to abdominopelvic imaging, including staging of rectal cancer. Scan acquisitions can be performed rapidly using widely available equipment and consequently there has been rapid dissemination into routine practice. However, while DWI shows promise for detecting, staging and monitoring rectal cancer response to therapy, the evidence base remains scant with no current consensus for technical protocols, interpretation or integration into rectal cancer management. Moreover, those studies available to date have a small sample size and few observers, and their results may not be generalizable to daily practice. This article outlines the physical principles of DWI, reviews the literature and suggests avenues for future research into this important technical development.

CT colonography for investigation of patients with symptoms potentially suggestive of colorectal cancer: a review of the UK SIGGAR trials

This paper argues for the use of CT colonography (CTC) to investigate patients with symptoms potentially suggestive of colorectal cancer. It describes the rationale for the UK Special Interest Group in Gastrointestinal and Abdominal Radiology (SIGGAR) randomised controlled trials that compared CTC with barium enema (BE) or colonoscopy for diagnosis of colorectal cancer or large polyps in symptomatic patients. Diagnostic outcomes from the trials are detailed for both intra- and extracolonic disease, along with psychological reactions of patients to the tests, and cost-effectiveness of the different diagnostic strategies. The author concludes that BE should be replaced by CTC immediately and that CTC is a sensitive, acceptable and equally cost-effective alternative to colonoscopy in patients in whom colonoscopy is contraindicated or undesirable.

An interview study analysing patients' experiences and perceptions of non-laxative or full-laxative preparation with faecal tagging prior to CT colonography

AIM

To compare patients' experiences of either non- or full-laxative bowel preparation with additional faecal tagging and subsequent computed tomographic (CT) colonography using in-depth interviews to elicit detailed responses.

MATERIALS AND METHODS

Patients who received CT colonography after non- (n = 9) or full-laxative (n = 9) preparation participated in a semi-structured telephone interview at least 2 days after the investigation. Full-laxative preparation consisted of magnesium citrate and sodium picosulphate administered at home (or polyethylene glycol, if contraindicated), followed by hospital-based faecal tagging with iohexol. Non-laxative preparation was home-based barium sulphate for faecal tagging. Interviews were transcribed and thematically analysed to identify recurrent themes on patients' perceptions and experiences.

RESULTS

Experiences of full-laxative preparation were usually negative and characterized by pre-test diarrhoea that caused significant interference with daily routine. Post-test flatus was common. Non-laxative preparation was well-tolerated; patients reported no or minimal changes to bowel habit and rapid return to daily routine. Patients reported worry and uncertainty about the purpose of faecal tagging. For iohexol, this also added burden from waiting before testing.

CONCLUSION

Patients' responses supported previous findings that non-laxative preparation is more acceptable than full-laxative preparation but both can be improved. Faecal tagging used in combination with laxative preparation is poorly understood, adding burden and worry. Home-based non-laxative preparation is also poorly understood and patients require better information on the purpose and mechanism in order to give fully informed consent. This may also optimize adherence to instructions. Allowing home-based self-administration of all types of preparation would prevent waiting before testing.

CT colonography in the English Bowel Cancer Screening Programme: national survey of current practice

AIM

To obtain information regarding the provision of computed tomography colonography (CTC) services to the National Health Service (NHS) Bowel Cancer Screening Programme (BCSP).

MATERIALS AND METHODS

Specialist screening practitioners at the 58 BCSP screening centres and lead BCSP radiologists at 110 hospitals performing CTC for the Programme were contacted and completed a semi-structured questionnaire administered by telephone. Responses were collated and descriptive statistics derived.

RESULTS

One hundred and seven (98%) SSPs and 103 (94%) radiologists were surveyed. All screening centres had access to CTC at 110 hospital sites. All sites used CTC for failed or contraindicated colonoscopy, 24% used it for patients taking anticoagulants, and 17% for those with fear of colonoscopy. Patient preference was not an indication at any site. Multidetector CT (100%), carbon dioxide insufflators (94%), and CTC software (95%) were almost universal. Ninety-one percent of radiographers and 98% of radiologists were trained in CTC image acquisition and interpretation, respectively. Seventy-five percent of the radiologists were gastrointestinal subspecialists and two-thirds had interpreted more than 300 examinations in clinical practice, although 5% had interpreted fewer than 100. Eighty-one percent of radiologists favoured some form of accreditation for CTC interpretation.

CONCLUSIONS

CTC is widely available to the BCSP. Appropriate hardware and software is almost ubiquitous. Most radiographers and radiologists offering CTC to the BCSP have received specific training. Formal service evaluation is patchy. The majority of radiologists would welcome national accreditation for CTC.

Quantitative MRI of colonic mural enhancement: segmental differences exist in endoscopically proven normal colon

OBJECTIVES

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.

METHODS

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 T(1) 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 R(1) (1/T(1)) was plotted against time. Mean pre-contrast R(1), initial change of R(1) (ΔR(1)), early and late "plateau phase" enhancement and the area under the R(1)-time (AUC-R(1)) curve were compared between segments using the Student's paired t-test.

RESULTS

There was no significant difference of pre-contrast R(1) between segments (p=0.49 to 0.62). ΔR(1) 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 R(1) between colonic segments (p=0.08 to 1.00). AUC-R(1) was greater for ascending than descending colon (0.54±0.19 vs 0.30±0.14, p=0.03).

CONCLUSIONS

Intersegmental differences in colonic enhancement are present and should be considered when interpreting differential segmental enhancement.

WE-E-213CD-03: Inverse-Consistent Symmetric Registration of Inner Colon Surfaces Derived from Prone and Supine CT Colonography

PURPOSE

Robust registration of prone and supine colonie surfaces acquired during CT colonography may lead to faster and more accurate detection of colorectal cancer and polyps. Any directional bias when registering one surface to the other could precipitate incorrect anatomical correspondence and engender reader error. Despite this, non-rigid registration methods are often implemented asymmetrically, which could negatively influence the registration. We aimed to reduce directional bias and so increase robustness by adapting a cylindrical registration algorithm to be both symmetric and inverse-consistent.

METHODS

The registration task can be simplified by mapping both prone and supine colonie surfaces onto regular cylinders. Spatial correspondence can then be established in cylindrical space using the original surfaces' local shape indices. We implemented a symmetric formulation of the popular non-rigid B-spline image registration method in cylindrical space. A symmetric similarity measure computes the sum of squared differences between both cylindrical representations of prone-to-supine and supine-to-prone directions simultaneously. Inverse consistency of the transformation is enforced by adding an appropriately weighted penalty term to the optimisation function.

RESULTS

We selected 8 CT colonography patient cases with marked variation in luminal distension and surface morphology. We randomly allocated 4 of these for tuning an optimal set of registration parameters and 4 for validation. The mean inverse-consistency error was reduced by 32% from 4.8mm to 3.2mm by the new symmetric formulation. The mean registration error improved from 8.2mm to 7.3mm for 330 manually chosen reference points on the 4 validation sets.

CONCLUSIONS

A symmetric formulation of prone and supine surface registration improves the quality of registration. Information from both prone-to-supine and supine-to-prone directions helps enforce convergence towards a more accurate solution due to reduced directional bias. A more robust and accurate registration will facilitate interpretation of CT colonography and has the potential to improve existing computer-aided detection methods. The authors gratefully acknowledge financial support for this work from the NIHR program: “Imaging diagnosis of colorectal cancer: Interventions for efficient and acceptable diagnosis in symptomatic and screening populationsâ€.

MRI enterography: what is the clinical impact of unsuspected extra-enteric findings?

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.

Patient experiences of MR colonography and colonoscopy: a qualitative study

OBJECTIVES

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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.