Liver perfusion MRI in a rodent model of cirrhosis: Agreement with bulk-flow phase-contrast MRI and noninvasive evaluation of inflammation in chronic liver disease using flow-sensitive alternating inversion recovery arterial spin labelling and tissue T1.

Noninvasive measurements of liver perfusion and fibrosis in cirrhotic small animals can help develop treatments for haemodynamic complications of liver disease. Here, we measure liver perfusion in cirrhotic rodents using flow-sensitive alternating inversion recovery arterial spin labelling (FAIR ASL), evaluating agreement with previously validated caval subtraction phase-contrast magnetic resonance imaging (PCMRI) total liver blood flow (TLBF). Baseline differences in cirrhotic rodents and the haemodynamic effects of acute inflammation were investigated using FAIR ASL and tissue T1. Sprague-Dawley rats (nine bile duct ligated [BDL] and ten sham surgery controls) underwent baseline hepatic FAIR ASL with T1 measurement and caval subtraction PCMRI (with two-dimensional infra-/supra-hepatic inferior vena caval studies), induction of inflammation with intravenous lipopolysaccharide (LPS) and repeat liver FAIR ASL with T1 measurement after ~90 minutes. The mean difference between FAIR ASL hepatic perfusion and caval subtraction PCMRI TLBF was -51 ± 30 ml/min/100 g (Bland-Altman 95% limits-of-agreement ±258 ml/min/100 g). The FAIR ASL coefficient of variation was smaller than for caval subtraction PCMRI (29.3% vs 50.1%; P = .03). At baseline, FAIR ASL liver perfusion was lower in BDL rats (199 ± 32 ml/min/100 g vs sham 316 ± 24 ml/min/100 g; P = .01) but liver T1 was higher (BDL 1533 ± 50 vs sham 1256 ± 18 ms; P = .0004). Post-LPS FAIR ASL liver perfusion response differences were observed between sham/BDL rats (P = .02), approaching significance in sham (+78 ± 33 ml/min/100 g; P = .06) but not BDL rats (-49 ± 40 ml/min/100 g; P = .47). Post-LPS differences in liver tissue T1 were nonsignificant (P = .35). FAIR ASL hepatic perfusion and caval subtraction PCMRI TLBF agreement was modest, with significant baseline FAIR ASL liver perfusion and tissue T1 differences in rodents with advanced cirrhosis compared with controls. Following inflammatory stress, differences in hepatic perfusion response were detected between cirrhotic/control animals, but liver T1 was unaffected. Findings underline the potential of FAIR ASL in the assessment of vasoactive treatments for patients with chronic liver disease and inflammation.

Monitoring Crohn's disease during anti-TNF-α therapy: validation of the magnetic resonance enterography global score (MEGS) against a combined clinical reference standard.

OBJECTIVES: To assess the ability of magnetic resonance enterography global score (MEGS) to characterise Crohn's disease (CD) response to anti-TNF-α therapy. METHODS: Thirty-six CD patients (median age 26 years, 20 males) commencing anti-TNF-α therapy with concomitant baseline MRI enterography (MRE) were identified retrospectively. Patients' clinical course was followed and correlated with subsequent MREs. Scan order was randomised and MEGS (a global activity score) was applied by two blinded radiologists. A physician's global assessment of the disease activity (remission, mild, moderate or severe) at the time of MRE was assigned. The cohort was divided into clinical responders and non-responders and MEGS compared according to activity status and treatment response. Interobserver agreement was assessed. RESULTS: Median MEGS decreased significantly between baseline and first follow-up in responders (28 versus 6, P < 0.001) but was unchanged in non-responders (26 versus 18, P = 0.28). The median MEGS was significantly lower in clinical remission (9) than in moderate (14) or severe (29) activity (P < 0.001). MEGS correlated significantly with clinical activity (r = 0.53; P < 0.001). Interobserver Bland-Altman limits of agreement (BA LoA) were -19.7 to 18.5. CONCLUSIONS: MEGS decreases significantly in clinical responders to anti-TNF-α therapy but not in non-responders, demonstrates good interobserver agreement and moderate correlation with clinical disease activity. KEY POINTS: • MRI scores of Crohn's activity are used increasingly in clinical practice and therapeutic trials. • Such scores have been advocated as biomarkers of therapeutic response. • MEGS reflects clinical response to anti-TNF-α therapy and the clinical classification of disease activity. • MEGS demonstrates good interobserver agreement.

Imaging features for the prediction of clinical endpoints in chronic liver disease: a scoping review protocol.

INTRODUCTION: Chronic liver disease is a growing cause of morbidity and mortality in the UK. Acute presentation with advanced disease is common and prioritisation of resources to those at highest risk at earlier disease stages is essential to improving patient outcomes. Existing prognostic tools are of limited accuracy and to date no imaging-based tools are used in clinical practice, despite multiple anatomical imaging features that worsen with disease severity.In this paper, we outline our scoping review protocol that aims to provide an overview of existing prognostic factors and models that link anatomical imaging features with clinical endpoints in chronic liver disease. This will provide a summary of the number, type and methods used by existing imaging feature-based prognostic studies and indicate if there are sufficient studies to justify future systematic reviews. METHODS AND ANALYSIS: The protocol was developed in accordance with existing scoping review guidelines. Searches of MEDLINE and Embase will be conducted using titles, abstracts and Medical Subject Headings restricted to publications after 1980 to ensure imaging method relevance on OvidSP. Initial screening will be undertaken by two independent reviewers. Full-text data extraction will be undertaken by three pretrained reviewers who have participated in a group data extraction session to ensure reviewer consensus and reduce inter-rater variability. Where needed, data extraction queries will be resolved by reviewer team discussion. Reporting of results will be based on grouping of related factors and their cumulative frequencies. Prognostic anatomical imaging features and clinical endpoints will be reported using descriptive statistics to summarise the number of studies, study characteristics and the statistical methods used. ETHICS AND DISSEMINATION: Ethical approval is not required as this study is based on previously published work. Findings will be disseminated by peer-reviewed publication and/or conference presentations.

METRIC-EF: magnetic resonance enterography to predict disabling disease in newly diagnosed Crohn's disease-protocol for a multicentre, non-randomised, single-arm, prospective study.

INTRODUCTION: Crohn's disease (CD) is characterised by discontinuous, relapsing enteric inflammation. Instituting advanced therapies at an early stage to suppress inflammation aims to prevent future complications such as stricturing or penetrating disease, and subsequent surgical resection. Therapeutics are effective but associated with certain side-effects and relatively expensive. There is therefore an urgent need for robust methods to predict which newly diagnosed patients will develop disabling disease, to identify patients who are most likely to benefit from early, advanced therapies. We aim to determine if magnetic resonance enterography (MRE) features at diagnosis improve prediction of disabling CD within 5 years of diagnosis. METHODS AND ANALYSIS: We describe the protocol for a multicentre, non-randomised, single-arm, prospective study of adult patients with newly diagnosed CD. We will use patients already recruited to the METRIC study and extend their clinical follow-up, as well as a separate group of newly diagnosed patients who were not part of the METRIC trial (MRE within 3 months of diagnosis), to ensure an adequate sample size. Follow-up will extend for at least 4 years. The primary outcome is to evaluate the comparative predictive ability of prognostic models incorporating MRE severity scores (Magnetic resonance Enterography Global Score (MEGS), simplified MAgnetic Resonance Index of Activity (sMaRIA) and Lémann Index) versus models using standard characteristics alone to predict disabling CD (modified Beaugerie definition) within 5 years of new diagnosis. ETHICS AND DISSEMINATION: This study protocol achieved National Health Service Research Ethics Committee (NHS REC), London-Hampstead Research Ethics Committee approval (IRAS 217422). Our findings will be disseminated via conference presentations and peer-reviewed publications. TRIAL REGISTRATION NUMBER: ISRCTN76899103.

Assessment of body composition and association with clinical outcomes in patients with lung and colorectal cancer.

Objectives: To assess body composition in patients with non-small cell lung cancer (NSCLC) and colorectal cancer using whole-body MRI and relate this to clinical outcomes. Methods: 53 patients with NSCLC (28 males, 25 females; mean age 66.9) and 74 patients with colorectal cancer (42 males, 32 females; mean age 62.9) underwent staging whole-body MRI scans, which were post-processed to derive fat mass (FM), fat free mass (FFM) and skeletal muscle (SM) indices and SM fat fraction (FF). These were compared between the two cancer cohorts using two-sided t-tests and the chi-squared test. Measurements of body composition were correlated with outcomes including length of hospital stay, metastatic status and mortality. Results: Patients with NSCLC had significantly lower FFM (p = 0.0071) and SM (p = 0.0084) indices. Mean SM FF was greater in patients with NSCLC (p = 0.0124) and was associated with longer hospital stay (p = 0.035). There was no significant relationship between FM, FFM and SM indices and length of hospital stay, metastatic status or mortality. Conclusions: Patients with NSCLC had lower FFM and SM indices than patients with colorectal cancer and greater SMFF, indicating lower SM mass with fatty infiltration. These findings reflect differences in the phenotype of the two groups and suggest patients with lung cancer are more likely to require additional nutritional support. Advances in knowledge: Body composition differs between NSCLC and colorectal cancer. Patients with NSCLC have both a reduced SM mass and greater SM FF suggesting that they are more nutritionally deplete than patients with colorectal cancer.

Relationship between MRI quantified small bowel motility and abdominal symptoms in Crohn's disease patients-a validation study.

OBJECTIVE: Previous single-centre MRI data suggests an inverse correlation between normal small bowel motility variance and abdominal symptoms in Crohn's disease (CD) patients. The current work prospectively assesses this observation in a larger, two-centre study. METHODS: MR enterography datasets were analysed from 82 patients (38 male, aged 16-68), who completed a contemporaneous Harvey-Bradshaw index (HBI) questionnaire. Dynamic "cine motility" breath-hold balanced steady-state free precession sequences were acquired through the whole small bowel (SB) volume. Regions of interest (ROIs) were manually applied to encompass all morphologically normal SB (i.e. excluding Crohn's affected bowel) and a validated registration technique used to produce motility maps. Mean and variance motility metrics were correlated with HBI and symptom components (well-being, pain and diarrhoea) using Spearman's correlation statistics. RESULTS: Overall, motility variance was non-significantly negatively correlated with the total HBI score, (r = -0.17, p = 0.12), but for subjects with a HBI score over 10, the negative correlation was significant (r = -0.633, p = 0.027). Motility variance was negatively correlated with diarrhoea (r = -0.29, p < 0.01). No significant correlation was found between mean motility and HBI (r = -0.02, p = 0.84). CONCLUSION: An inverse association between morphologically normal small bowel motility variance and patient symptoms has been prospectively confirmed in patients with HBI scores above 10. This association is particularly apparent for the symptom of diarrhoea. Advances in knowledge: This study builds on preliminary work by confirming in a large, well-controlled prospective multicentre study a relationship between normal bowel motility variance and patient reported symptoms which may have implications for drug development and clinical management.