Doug Altman, medical statistician par excellence: What can radiologists learn from his legacy?

This narrative review describes our experience of working with Doug Altman, the most highly cited medical statistician in the world. Doug was particularly interested in diagnostics, and imaging studies in particular. We describe how his insights helped improve our own radiological research studies and we provide advice for other researchers hoping to improve their own research practice.

Has maternal sensitivity been comprehensively investigated in sub-Saharan Africa? A narrative scoping review.

Child development is strongly influenced by maternal characteristics. Maternal sensitivity, as well as risks to and outcomes of sensitive maternal style, are well studied in industrialised western contexts, but it is unclear if this is the case for other contexts. Sub-Saharan Africa has been subjected to and continues to negotiate socio-economic and psychological sequelae of colonial and race-based politics: exploring the nature and outcomes of early caregiver input in such challenging conditions is imperative. This scoping review thus aims to 1) evaluate the nature and extent of quantified observational assessments of dyadic interactions, with a focus on maternal sensitivity, in Sub-Saharan Africa and 2) ascertain which risk and outcome factors have been examined in relation to maternal sensitivity. Study quality and cross-cultural appropriateness will also be considered. The search using expanded search terms yielded 20 papers -four characterizing maternal sensitivity or style, eight examining maternal sensitivity in relation to risks and outcomes, and eight intervention studies examining efforts to improve maternal sensitivity. Most research was conducted in South Africa - only seven studies were conducted in four other countries. Researchers used a wide array of coding schemes, mostly developed in the west. Ten studies made some adaptations to measures. Language issues and cultural considerations were often not explicitly addressed. Taken together, very limited research on this important topic exists. For the work that does exist, questions around westernized assumptions, language, and appropriateness of measures remain. Substantially more research, informed by both culturally flexible conceptualizations and methodological rigour, is required.

Access to statistical support for medical imaging research: questionnaire survey of UK radiology trainees.

AIM: To investigate the level of statistical support available to UK radiology trainees, and to gather opinions regarding how support may affect their current and future research aspirations. MATERIALS AND METHODS: An online survey was developed, piloted, and distributed to radiology trainees via the UK Radiology Academic Network for Trainees and training programme directors. Research experience, research aspirations, available and desired statistical support, and attitudes to statistics were surveyed and responses were collated. RESULTS: Seventy-nine responses were received, only two (3%) of whom had allocated time for research. Only three (4%) respondents were content with their statistical support whereas 25 (32%) reported insufficient statistical support; 13 (52%) of these believed this impacted "considerably" on research aspirations. Sixty-six (84%) respondents desired dedicated statistical support, 40 (61%) of whom stated the amount required would likely be "moderate" and 26 (39%) "significant". Respondents believed support would be most helpful to analyse data already collected (41 responses, 54%) rather than research planning (25, 33%). Most respondents (60, 76%) had used self-help methods to learn research statistics but only 21 (35%) found this useful. CONCLUSION: Training schemes must improve the provision, access to, and awareness of statistical support so that any research efforts are performed to a high standard. Trainees should not be expected to participate in research without sufficient time, mentorship, and statistical support.

Change in prevalence of post-traumatic stress disorder in the two years following trauma: a meta-analytic study.

Background: Understanding the course of post-traumatic stress disorder (PTSD) and the factors that impact this is essential to inform decisions about when and for whom screening and intervention are likely to be beneficial. Objective: To provide meta-analytic evidence of the course of recovery from PTSD in the first year following trauma, and the factors that influence that recovery. Method: We conducted a meta-analysis of observational studies of adult PTSD prevalence which included at least two assessments within the first 12 months following trauma exposure, examining prevalence statistics through to 2 years post-trauma. We examined trauma intentionality (intentional or non-intentional), PTSD assessment method (clinician or self-report), sample sex distribution, and age as moderators of PTSD prevalence over time. Results: We identified 78 eligible studies including 16,484 participants. Pooled prevalence statistics indicated that over a quarter of individuals presented with PTSD at 1 month post-trauma, with this proportion reducing by a third between 1 and 3 months. Beyond 3 months, any prevalence changes were detected over longer intervals and were small in magnitude. Intentional trauma, younger age, and female sex were associated with higher PTSD prevalence at 1 month. In addition, higher proportions of females, intentional trauma exposure, and higher baseline PTSD prevalence were each associated with larger reductions in prevalence over time. Conclusions: Recovery from PTSD following acute trauma exposure primarily occurs in the first 3 months post-trauma. Screening measures and intervention approaches offered at 3 months may better target persistent symptoms than those conducted prior to this point. HIGHLIGHTS: PTSD rates in the immediate aftermath of trauma exposure decline from 27% at 1 month to 18% at 3 months post-trauma, showing significant spontaneous recovery.Problems appear to stabilize after 3 months.Screening/intervention for PTSD at 3 months post-trauma is indicated.

Reporting guideline for interventional trials of primary and incisional ventral hernia repair.

BACKGROUND: Primary and incisional ventral hernia trials collect unstandardized inconsistent data, limiting data interpretation and comparison. This study aimed to create two minimum data sets for primary and incisional ventral hernia interventional trials to standardize data collection and improve trial comparison. To support these data sets, standardized patient-reported outcome measures and trial methodology criteria were created. METHODS: To construct these data sets, nominal group technique methodology was employed, involving 15 internationally recognized abdominal wall surgeons and two patient representatives. Initially a maximum data set was created from previous systematic and panellist reviews. Thereafter, three stages of voting took place: stage 1, selection of the number of variables for data set inclusion; stage 2, selection of variables to be included; and stage 3, selection of variable definitions and detection methods. A steering committee interpreted and analysed the data. RESULTS: The maximum data set contained 245 variables. The three stages of voting commenced in October 2019 and had been completed by July 2020. The final primary ventral hernia data set included 32 variables, the incisional ventral hernia data set included 40 variables, the patient-reported outcome measures tool contained 25 questions, and 40 methodological criteria were chosen. The best known variable definitions were selected for accurate variable description. CT was selected as the optimal preoperative descriptor of hernia morphology. Standardized follow-up at 30 days, 1 year, and 5 years was selected. CONCLUSION: These minimum data sets, patient-reported outcome measures, and methodological criteria have allowed creation of a manual for investigators aiming to undertake primary ventral hernia or incisional ventral hernia interventional trials. Adopting these data sets will improve trial methods and comparisons.

Identifying predictors of ventral hernia recurrence: systematic review and meta-analysis.

BACKGROUND: Ventra hernias are increasing in prevalence and many recur despite attempted repair. To date, much of the literature is underpowered and divergent. As a result there is limited high quality evidence to inform surgeons succinctly which perioperative variables influence postoperative recurrence. This systematic review aimed to identify predictors of ventral hernia recurrence. METHODS: PubMed was searched for studies reporting prognostic data of ventral hernia recurrence between 1 January 1995 and 1 January 2018. Extracted data described hernia type (primary/incisional), definitions of recurrence, methods used to detect recurrence, duration of follow-up, and co-morbidity. Data were extracted for all potential predictors, estimates and thresholds described. Random-effects meta-analysis was used. Bias was assessed with a modified PROBAST (Prediction model Risk Of Bias ASsessment Tool). RESULTS: Screening of 18 214 abstracts yielded 274 individual studies for inclusion. Hernia recurrence was defined in 66 studies (24.1 per cent), using 41 different unstandardized definitions. Three patient variables (female sex, age 65 years or less, and BMI greater than 25, 30, 35 or 40 kg/m2), five patient co-morbidities (smoking, diabetes, chronic obstructive pulmonary disease, ASA grade III-IV, steroid use), two hernia-related variables (incisional/primary, recurrent/primary), six intraoperative variables (biological mesh, bridged repair, open versus laparoscopic surgery, suture versus mesh repair, onlay/retrorectus, intraperitoneal/retrorectus), and six postoperative variables (any complication, surgical-site occurrence, wound infection, seroma, haematoma, wound dehiscence) were identified as significant prognostic factors for hernia recurrence. CONCLUSION: This study summarized the current evidence base for predicting ventral hernia recurrence. Results should inform best practice and future research.

ESGAR consensus statement on the imaging of fistula-in-ano and other causes of anal sepsis.

OBJECTIVES: To develop imaging guidelines for patients with fistula-in-ano and other causes of anal sepsis. METHODS: An expert group of 13 members of the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) used a modified Delphi process to vote on a series of consensus statements relating to the imaging of patients with potential anal sepsis. Participants first completed a questionnaire to gather practice information and to help frame the statements posed. RESULTS: In the first round of voting, the expert group scored 51 statements of which 45 (88%) achieved immediate consensus. The remaining 6 statements were redrafted following input from the expert group and consensus achieved for all during a second round of voting, including an additional statement drafted. No statement was rejected due to a lack of consensus. After redrafting to improve clarity, 53 individual statements were presented. CONCLUSION: These expert consensus statements can be used to guide appropriate indication, acquisition, interpretation and reporting of medical imaging for patients with potential fistula-in-ano and other causes of anal sepsis. KEY POINTS: • Medical imaging, notably magnetic resonance imaging, is used widely for the diagnosis and monitoring of fistula-in-ano and other causes of anal and perianal sepsis. • While the indexed medical literature is clear that diagnostic accuracy is potentially excellent, this depends on competent image acquisition and interpretation. • In order to facilitate this, the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) has produced expert consensus guidelines regarding the imaging of fistula-in-ano and related conditions.

Do radiological research articles apply the term "pilot study" correctly? Systematic review.

AIM: To determine what proportion of radiological studies used the term "pilot" correctly. MATERIAL AND METHODS: Indexed studies describing themselves as a "pilot" in their title were identified from four indexed radiological journals. The aim was to identify 20 consecutive, eligible studies from each journal, as this sample size was deemed sufficient to be representative as to how this methodological description was employed by authors of radiological articles. Data were extracted relating to study design and data presented. The review was reported according to PRISMA guidelines. RESULTS: The search string used identified 658 records across the four targeted journals. Ultimately, 78 reviews describing 5,572 patients were selected for systematic review. Median sample size was just 20 patients. No individual study qualified as a genuine pilot study when assessed against the a priori criteria. In reality, the large majority (66 studies, 84.6%) were framed as studies of diagnostic test accuracy. A significant proportion (21 studies, 26.9%) was retrospective, and the overwhelming majority were conducted in single centres (76 centres, 94.7%). Most (55 studies, 70.5%) stated no rationale for their sample size, and no study presented a formal power calculation. CONCLUSION: Radiological "pilot" studies are mostly underpowered studies of diagnostic test accuracy. In order to have scientific credibility, authors, reviewers, and editors of radiological journals are encouraged to familiarise themselves with different methodological study designs and their precise implications.

International classification of abdominal wall planes (ICAP) to describe mesh insertion for ventral hernia repair.

BACKGROUND: Nomenclature for mesh insertion during ventral hernia repair is inconsistent and confusing. Several terms, including 'inlay', 'sublay' and 'underlay', can refer to the same anatomical planes in the indexed literature. This frustrates comparisons of surgical practice and may invalidate meta-analyses comparing surgical outcomes. The aim of this study was to establish an international classification of abdominal wall planes. METHODS: A Delphi study was conducted involving 20 internationally recognized abdominal wall surgeons. Different terms describing anterior abdominal wall planes were identified via literature review and expert consensus. The initial list comprised 59 possible terms. Panellists completed a questionnaire that suggested a list of options for individual abdominal wall planes. Consensus on a term was predefined as occurring if selected by at least 80 per cent of panellists. Terms scoring less than 20 per cent were removed. RESULTS: Voting started August 2018 and was completed by January 2019. In round 1, 43 terms (73 per cent) were selected by less than 20 per cent of panellists and 37 new terms were suggested, leaving 53 terms for round 2. Four planes reached consensus in round 2, with the terms 'onlay', 'inlay', 'preperitoneal' and 'intraperitoneal'. Thirty-five terms (66 per cent) were selected by less than 20 per cent of panellists and were removed. After round 3, consensus was achieved for 'anterectus', 'interoblique', 'retro-oblique' and 'retromuscular'. Default consensus was achieved for the 'retrorectus' and 'transversalis fascial' planes. CONCLUSION: Consensus concerning abdominal wall planes was agreed by 20 internationally recognized surgeons. Adoption should improve communication and comparison among surgeons and research studies.

ANTECEDENTES: La nomenclatura de la inserción de una malla para la reparación de una hernia incisional ventral (ventral hernia, VH) es inconsistente y confusa. En la literatura indexada se usan varios términos, tales como 'inlay', 'sublay', y 'underlay' que pueden referirse a los mismos planos anatómicos. Este hecho frustra las comparaciones de técnicas quirúrgicas e invalida los metaanálisis que comparan resultados quirúrgicos en función del plano de inserción de la malla. En consecuencia, el objetivo de este estudio fue establecer una clasificación internacional de los planos de la pared abdominal (International Classification of Abdominal Wall Planes, ICAP). MÉTODOS: Se realizó un estudio Delphi, en el que participaron 20 cirujanos de pared abdominal reconocidos internacionalmente. Se identificaron diferentes términos que describían los planos de la pared abdominal anterior mediante la revisión de la literatura y el consenso de expertos. La lista inicial incluía 59 términos posibles. Los panelistas completaron un cuestionario que sugería una lista de opciones para los planos individuales de la pared abdominal. El consenso sobre un término fue predefinido cuando dicho término había sido seleccionado por ≥ 80% de panelistas. Se eliminaron los términos con una puntuación < 20%. RESULTADOS: La votación comenzó en agosto de 2018 y se completó en enero de 2019. Durante la Ronda 1, 43 (73%) términos fueron seleccionados por < 20% de los panelistas y se sugirieron 37 términos nuevos, dejando 53 términos para la Ronda 2. Cuatro planos alcanzaron un consenso en la Ronda 2 con los términos 'onlay', 'inlay', 'pre-peritoneal' e 'intra-peritoneal'. Treinta y cinco (66%) términos fueron seleccionados por < 20% de los panelistas y fueron eliminados. Después de la Ronda 3, se logró un consenso para 'anterectus' (ante-recto), 'interoblique' (inter-oblicuo), 'retrooblique' (retro-oblicuo) y 'retromuscular'. Se alcanzó un consenso por defecto para los planos 'retrorectus' (retro-recto) y 'transversalis fascial' (fascial transverso). CONCLUSIÓN: La ICAP ha sido desarrollada por el consenso de 20 cirujanos reconocidos internacionalmente. Su implementación debería mejorar la comunicación y la comparación entre cirujanos y estudios de investigación.

A systematic methodological review of non-randomised interventional studies of elective ventral hernia repair: clear definitions and a standardised minimum dataset are needed.

BACKGROUND: Ventral hernias (VHs) often recur after surgical repair and subsequent attempts at repair are especially challenging. Rigorous research to reduce recurrence is required but such studies must be well-designed and report representative and comprehensive outcomes. OBJECTIVE: We aimed to assesses methodological quality of non-randomised interventional studies of VH repair by systematic review. METHODS: We searched the indexed literature for non-randomised studies of interventions for VH repair, January 1995 to December 2017 inclusive. Each prospective study was coupled with a corresponding retrospective study using pre-specified criteria to provide matched, comparable groups. We applied a bespoke methodological tool for hernia trials by combining relevant items from existing published tools. Study introduction and rationale, design, participant inclusion criteria, reported outcomes, and statistical methods were assessed. RESULTS: Fifty studies (17,608 patients) were identified: 25 prospective and 25 retrospective. Overall, prospective studies scored marginally higher than retrospective studies for methodological quality, median score 17 (IQR: 14-18) versus 15 (IQR 12-18), respectively. For the sub-categories investigated, prospective studies achieved higher median scores for their, 'introduction', 'study design' and 'participants'. Surprisingly, no study stated that a protocol had been written in advance. Only 18 (36%) studies defined a primary outcome, and only 2 studies (4%) described a power calculation. No study referenced a standardised definition for VH recurrence and detection methods for recurrence varied widely. Methodological quality did not improve with publication year or increasing journal impact factor. CONCLUSION: Currently, non-randomised interventional studies of VH repair are methodologically poor. Clear outcome definitions and a standardised minimum dataset are needed.

What Exactly is Meant by "Loss of Domain" for Ventral Hernia? Systematic Review of Definitions.

Large ventral hernias are a significant surgical challenge. "Loss of domain" (LOD) expresses the relationship between hernia and abdominal volume, and is used to predict operative difficulty and success. This systematic review assessed whether different definitions of LOD are used in the literature. The PubMed database was searched for articles reporting large hernia repairs that explicitly described LOD. Two reviewers screened citations and extracted data from selected articles, focusing on the definitions used for LOD, study demographics, study design, and reporting surgical specialty. One hundred and seven articles were identified, 93 full-texts examined, and 77 were included in the systematic review. Sixty-seven articles were from the primary literature, and 10 articles were from the secondary literature. Twenty-eight articles (36%) gave a written definition for loss of domain. These varied and divided into six broad groupings; four described the loss of the right of domain, six described abdominal strap muscle contraction, five described the "second abdomen", five describing large irreducible hernias. Six gave miscellaneous definitions. Two articles gave multiple definitions. Twenty articles (26%) gave volumetric definitions; eight used the Tanaka method [hernia sac volume (HSV)/abdominal cavity volume] and five used the Sabbagh method [(HSV)/total peritoneal volume]. The definitions used for loss of domain were not dependent on the reporting specialty. Our systematic review revealed that multiple definitions of loss of domain are being used. These vary and are not interchangeable. Expert consensus on this matter is necessary to standardise this important concept for hernia surgeons.

A systematic methodological review of reported perioperative variables, postoperative outcomes and hernia recurrence from randomised controlled trials of elective ventral hernia repair: clear definitions and standardised datasets are needed.

BACKGROUND: This systematic review assesses the perioperative variables and post-operative outcomes reported by randomised controlled trials (RCTs) of VH repair. This review focuses particularly on definitions of hernia recurrence and techniques used for detection. OBJECTIVE: Our aim is to identify and quantify the inconsistencies in perioperative variable and postoperative outcome reporting, so as to justify future development of clear definitions of hernia recurrence and a standardised dataset of such variables. METHODS: The PubMed database was searched for elective VH repair RCTs reported January 1995 to March 2016 inclusive. Three independent reviewers performed article screening, and two reviewers independently extracted data. Hernia recurrence, recurrence rate, timing and definitions of recurrence, and techniques used to detect recurrence were extracted. We also assessed reported post-operative complications, standardised operative outcomes, patient reported outcomes, pre-operative CT scan hernia dimensions, intra-operative variables, patient co-morbidity, and hernia morphology. RESULTS: 31 RCTs (3367 patients) were identified. Only 6 (19.3%) defined hernia recurrence and methods to detect recurrence were inconsistent. Sixty-four different clinical outcomes were reported across the RCTs, with wound infection (30 trials, 96.7%), hernia recurrence (30, 96.7%), seroma (29, 93.5%), length of hospital stay (22, 71%) and haematoma (21, 67.7%) reported most frequently. Fourteen (45%), 11 (35%) and 0 trials reported CT measurements of hernia defect area, width and loss of domain, respectively. No trial graded hernias using generally accepted scales. CONCLUSION: VH RCTs report peri- and post-operative variables inconsistently, and with poor definitions. A standardised minimum dataset, including definitions of recurrence, is required.

Diffusion-weighted imaging for evaluating inflammatory activity in Crohn's disease: comparison with histopathology, conventional MRI activity scores, and faecal calprotectin.

PURPOSE: To evaluate whether the extent of enteric diffusion-weighted imaging (DWI) signal abnormality reflects inflammatory burden in Crohn's disease (CD), and to compare qualitative and quantitative grading. METHODS: 69 CD patients (35 male, age 16-78) undergoing MR enterography with DWI (MRE-D) and the same-day faecal calprotectin (cohort 1) were supplemented by 29 patients (19 male, age 16-70) undergoing MRE-D and terminal ileal biopsy (cohort 2). Global (cohort 1) and terminal ileal (cohort 2) DWI signal was graded (0 to 3) by 2 radiologists and segmental apparent diffusion coefficient (ADC) calculated. Data were compared to calprotectin and a validated MRI activity score [MEGS] (cohort 1), and a histopathological activity score (eAIS) (cohort 2) using nonparametric testing and rank correlation. RESULTS: Patients with normal (grades 0 and 1) DWI signal had lower calprotectin and MEGS than those with abnormal signal (grades 2 and 3) (160 vs. 492 µg/l, p = 0.0004, and 3.3 vs. 21, p < 0.0001), respectively. Calprotectin was lower if abnormal DWI affected <10 cm of small bowel compared to diffuse small and large bowel abnormality (236 vs. 571 µg, p = 0.009). The sensitivity and specificity for active disease (calprotectin > 120 µg/l) were 83% and 52%, respectively. There was a negative correlation between ileal MEGS and ADC (r = -0.41, p = 0.017). There was no significant difference in eAIS between qualitative DWI scores (p = 0.42). Mean ADC was not different in those with and without histological inflammation (2077 vs. 1622 × 10-6mm2/s, p = 0.10) CONCLUSIONS: Qualitative grading of DWI signal has utility in defining the burden of CD activity. Quantitative ADC measurements have poor discriminatory ability for segmental disease activity.

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.

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.

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.

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.