Coprophagia in early life tunes expression of immune genes after weaning in rabbit ileum

Coprophagia by suckling rabbits, i.e. ingestion of feces from their mother, reduces mortality after weaning. We hypothesized that this beneficial effect of coprophagia is immune-mediated at the intestinal level. Therefore, this study investigated immune development after weaning by analyzing the ileal transcriptome at day 35 and 49 in rabbits with differential access to coprophagia in early life. Rabbit pups had access between day 1 and 15 to (i) no feces (NF) or (ii) feces from unrelated does (Foreign Feces, FF) or (iii) feces from unrelated does treated with antibiotics (FFab). 350 genes were differentially expressed between day 35 and day 49 in suckling rabbits with access to coprophagia. These genes coded for antimicrobial peptides, a mucin, cytokines and chemokines, pattern recognition receptors, proteins involved in immunoglobulin A secretion and in interferon signaling pathway. Strikingly, prevention of coprophagia or access to feces from antibiotic-treated does in early life blunted immune development between day 35 et 49 in the ileum of rabbits. Thus, coprophagia might be crucial for the maturation of intestinal immunity in rabbits and could explain why this behavior improves survival.

Evaluation of utero-placental vascularization using contrast-enhanced ultrasound: Early first trimester maternal perfusion of the intervillous space is confirmed

INTRODUCTION

The objective was to confirm and semiquantify the maternal perfusion of the intervillous space between 8 and 13 + 6 gestational weeks (GW).

METHODS

We conducted a prospective, multicenter, and nonrandomized open study. Women undergoing voluntary termination of pregnancy at three different gestational ages (Group 8 GW: 8 to 8 + 6 GW, Group 11GW: 11 to 11 + 6 GW and Group 13GW: 13 to 13 + 6 GW) were included, with 14 subjects per group. Women presenting with a personal risk of preeclampsia and/or intrauterine growth restriction were excluded. Contrast-enhanced ultrasound (CEUS) was performed with an intravenous bolus administration of 2.4 mL of microbubbles. The region of interest (ROI) was the entire placenta. The perfusion curves and kinetic parameters, including wash-in perfusion index, peak enhancement and mean transit time, were calculated.

RESULTS

Of the 42 women initially included, interpretable perfusion curves could be obtained for 33. Regardless of the gestational age, contrast was observed in the entire placenta. No significant difference in perfusion parameters was observed between groups. There was an association between signal intensity and both maternal heart frequency and placental location. Signal intensity was decreased when the heart frequency increased (p < 0.05) and when the placenta was in a nonanterior position (p > 0.005).

DISCUSSION

We confirmed the presence of maternal perfusion of the intervillous space as early as 8 GW. No significant increase in perfusion parameters was observed between 8 and 13 + 6 GW. Our observations, in accordance with the previous experiment published by Roberts et al.1, strongly challenge the classic trophoblastic plug theory.

Role of aldosterone in mid- and long-term left ventricular remodelling after acute myocardial infarction: The REMI study

AIMS

Whether aldosterone levels after myocardial infarction (MI) are associated with mid- and long-term left ventricular (LV) remodelling in the era of systematic use of renin-angiotensin system inhibitors is uncertain. We prospectively investigated the relationship between aldosterone levels and mid- and long-term LV remodelling in patients with acute MI.

METHODS AND RESULTS

Plasma aldosterone was measured in 119 patients successfully treated by primary percutaneous coronary angioplasty for a first acute ST-elevation MI (STEMI) 2-4 days after the acute event. LV volumes were assessed by cardiac magnetic resonance (CMR) and transthoracic echocardiography (TTE) in the same timeframe and 6 months later. LV assessment was repeated by TTE 3-9 years after MI (n = 80). The median aldosterone level at baseline was 23.1 [16.8; 33.1] pg/ml. In the multivariable model, higher post-MI aldosterone concentration was significantly associated with more pronounced increase in LV end-diastolic volume index (TTE: β ± standard error [SE]: 0.113 ± 0.046, p = 0.015; CMR: β ± SE: 0.098 ± 0.040, p = 0.015) and LV end-systolic volume index (TTE: β ± SE: 0.083 ± 0.030, p = 0.008; CMR: β ± SE: 0.064 ± 0.032, p = 0.048) at 6-month follow-up, regardless of the method of assessment. This result was consistent also in patients with a LV ejection fraction (LVEF) >40%. The association between baseline plasma aldosterone and adverse LV remodelling did not persist at the 3-9-year follow-up evaluation.

CONCLUSION

Aldosterone concentration in the acute phase was associated with adverse LV remodelling in the medium term, even in the subgroup of patients with LVEF >40%, suggesting a potential role of the mineralocorticoid system in post-MI adverse remodelling. Plasma aldosterone was no longer associated with LV remodelling in the long term (NCT01109225).

Machine Learning-Based Phenogrouping in MVP Identifies Profiles Associated With Myocardial Fibrosis and Cardiovascular Events

BACKGROUND

Structural changes and myocardial fibrosis quantification by cardiac imaging have become increasingly important to predict cardiovascular events in patients with mitral valve prolapse (MVP). In this setting, it is likely that an unsupervised approach using machine learning may improve their risk assessment.

OBJECTIVES

This study used machine learning to improve the risk assessment of patients with MVP by identifying echocardiographic phenotypes and their respective association with myocardial fibrosis and prognosis.

METHODS

Clusters were constructed using echocardiographic variables in a bicentric cohort of patients with MVP (n = 429, age 54 ± 15 years) and subsequently investigated for their association with myocardial fibrosis (assessed by cardiac magnetic resonance) and cardiovascular outcomes.

RESULTS

Mitral regurgitation (MR) was severe in 195 (45%) patients. Four clusters were identified: cluster 1 comprised no remodeling with mainly mild MR, cluster 2 was a transitional cluster, cluster 3 included significant left ventricular (LV) and left atrial (LA) remodeling with severe MR, and cluster 4 included remodeling with a drop in LV systolic strain. Clusters 3 and 4 featured more myocardial fibrosis than clusters 1 and 2 (P < 0.0001) and were associated with higher rates of cardiovascular events. Cluster analysis significantly improved diagnostic accuracy over conventional analysis. The decision tree identified the severity of MR along with LV systolic strain <21% and indexed LA volume >42 mL/m2 as the 3 most relevant variables to correctly classify participants into 1 of the echocardiographic profiles.

CONCLUSIONS

Clustering enabled the identification of 4 clusters with distinct echocardiographic LV and LA remodeling profiles associated with myocardial fibrosis and clinical outcomes. Our findings suggest that a simple algorithm based on only 3 key variables (severity of MR, LV systolic strain, and indexed LA volume) may help risk stratification and decision making in patients with MVP. (Genetic and Phenotypic Characteristics of Mitral Valve Prolapse, NCT03884426; Myocardial Characterization of Arrhythmogenic Mitral Valve Prolapse [MVP STAMP], NCT02879825).

Contribution of contrast-enhanced ultrasound in the diagnosis of adnexal torsion (AGATA): protocol for a prospective comparative study

INTRODUCTION

Adnexal torsion is a surgical emergency and its prognosis depends on the time elapsed prior to treatment. The diagnosis relies on pelvic ultrasound in which sensitivity remains low and may lead to misdiagnosis.The primary objective is to evaluate the diagnostic performance of contrast-enhanced ultrasound for the diagnosis of adnexal torsion in women with suspected adnexal torsion. The secondary objectives are: (1) to describe the perfusion parameters of the ovaries by contrast-enhanced ultrasound, (2) to compare diagnostic performance of contrast ultrasound with bidimensional (2D) Doppler for the detection of adnexal torsion, (3) to describe the perfusion parameters of the ovarian as a function of the degree of adnexal torsion, (4) to compare perfusion parameters before and after ovarian detorsion and (5) to describe perfusion parameters of the ovarian by using MicroVascular Flow technique.

METHODS AND ANALYSIS

This is a monocentric, prospective comparative, non-randomised, open and interventional study. We hypothesise to include 30 women: 20 positive cases compared with 10 control cases. Women are informed and recruited in the emergency ward, over a period of 36 months.The primary endpoint is the signal intensity measurement to assess sensitivity, specificity, positive and negative predictive values of contrast-enhanced ultrasound for detection of adnexal torsion in women with suspected adnexal torsion. The presence or absence of adnexal torsion is confirmed during the surgical intervention.

ETHICS AND DISSEMINATION

The study was approved by the French Ethics Committee, the CPP (Comité de Protection des Personnes) OUEST I on 3 July 2020 with reference number 2020T1-16. The results of this study will be published in a peer-reviewed journal and will be presented at relevant conferences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov registry (NCT04522219); EudraCT registry (2020-000993-27).

[The role of the physiotherapist in the assessment and management of dyspnea]

The role of the physiotherapist in the assessment and management of dyspnea. Dyspnea is the most common symptom in cardio-respiratory diseases. Recently improved comprehension of dyspnea mechanisms have underlined the need for three-faceted assessment. The three key aspects correspond to the "breathing, thinking, functioning" clinical model, which proposes a multidimensional - respiratory, emotional and functional - approach. Before initiating treatment, it is essential for several reasons to assess each specific case, determining the type of dyspnea affecting the patient, appraising the impact of shortness of breath, and estimating the effectiveness of the treatment applied. The physiotherapist has a major role to assume in the care of dyspneic patients, not only in assessment followed by treatment but also as a major collaborator in a multidisciplinary team, especially with regard to pulmonary rehabilitation. The aim of this review is to inventory the existing assessment tools and the possible physiotherapies for dyspnea, using a holistic approach designed to facilitate the choice of techniques and to improve quality of care by fully addressing the patient's needs.

Multi-tracer and multiparametric PET imaging to detect the IDH mutation in glioma: a preclinical translational in vitro, in vivo, and ex vivo study

Background

This translational study explores multi-tracer PET imaging for the non-invasive detection of the IDH1 mutation which is a positive prognostic factor in glioma.

Methods

U87 human high-grade glioma (HGG) isogenic cell lines with or without the IDH1 mutation (CRISP/Cas9 method) were stereotactically grafted into rat brains, and examined, in vitro, in vivo and ex vivo. PET imaging sessions, with radiotracers specific for glycolytic metabolism ([¹⁸F]FDG), amino acid metabolism ([¹⁸F]FDopa), and inflammation ([¹⁸F]DPA-714), were performed sequentially during 3–4 days. The in vitro radiotracer uptake was expressed as percent per million cells. For each radiotracer examined in vivo, static analyses included the maximal and mean tumor-to-background ratio (TBR_max and TBR_mean) and metabolic tumor volume (MTV). Dynamic analyses included the distribution volume ratio (DVR) and the relative residence time (RRT) extracted from a reference Logan model. Ex vivo analyses consisted of immunological analyses.

Results

In vitro, IDH1+ cells (i.e. cells expressing the IDH1 mutation) showed lower levels of [¹⁸F]DPA-714 uptake compared to IDH1- cells (p < 0.01). These results were confirmed in vivo with lower [¹⁸F]DPA-714 uptake in IDH+ tumors (3.90 versus 5.52 for TBR_max, p = 0.03). Different values of [¹⁸F]DPA-714 and [¹⁸F] FDopa RRT (respectively 11.07 versus 22.33 and 2.69 versus − 1.81 for IDH+ and IDH- tumors, p < 0.02) were also observed between the two types of tumors. RRT [¹⁸F]DPA-714 provided the best diagnostic performance to discriminate between the two cell lines (AUC of 100%, p < 0.01). Immuno-histological analyses revealed lower expression of Iba-1 and TSPO antibodies in IDH1+ tumors.

Conclusions

[18F]DPA-714 and [18F] FDopa both correlate with the presence of the IDH1 mutation in HGG. These radiotracers are therefore good candidates for translational studies investigating their clinical applications in patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-022-00454-6.

Relationship Between Left Ventricular Ejection Fraction Variation and Systemic Vascular Resistance: A Prospective Cardiovascular Magnetic Resonance Study

Introduction: This cardiovascular magnetic resonance (CMR) study aims to determine whether changes in systemic vascular resistance (SVR), obtained from CMR flow sequences, might explain the significant long-term changes in left ventricular (LV) ejection fraction (EF) observed in subjects with no cardiac disease history. Methods: Cohort subjects without any known cardiac disease but with high rates of hypertension and obesity, underwent CMR with phase-contrast sequences both at baseline and at a median follow-up of 5.2 years. Longitudinal changes in EF were analyzed for any concomitant changes in blood pressure and vascular function, notably the indexed SVR given by the formula: mean brachial blood pressure / cardiac output x body surface area. Results: A total of 118 subjects (53 ± 12 years, 52% women) were included, 26% had hypertension, and 52% were obese. Eighteen (15%) had significant EF variations between baseline and follow-up (7 increased EF and 11 decreased EF). Longitudinal changes in EF were inversely related to concomitant changes in mean and diastolic blood pressures (p = 0.030 and p = 0.027, respectively) and much more significantly to SVR (p < 0.001). On average, these SVR changes were -8.08 ± 9.21 and +8.14 ± 8.28 mmHg.min.m².L^-1, respectively, in subjects with significant increases and decreases in EF, and 3.32 ± 7.53 mmHg.min.m².L^-1 in subjects with a stable EF (overall p < 0.001). Conclusions: Significant EF variations are not uncommon during the long-term CMR follow-up of populations with no evident health issues except for uncomplicated hypertension and obesity. However, most of these variations are linked to SVR changes and may therefore be unrelated to any intrinsic change in LV contractility. This underscores the benefits of specifically assessing LV afterload when EF is monitored in populations at risk of vascular dysfunction. Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT01716819 and NCT02430805.

MRI Angiography of normal and pathological pregnancy PLacentas Ex vivo (MAPLE): protocol for a prospective pilot study. (Preprint)

Background

Preeclampsia (PE) and intrauterine growth restriction (IUGR) are 2 major pregnancy complications due to abnormal placental vasculogenesis. Data on whole fetoplacental vasculature are still missing; hence, these pathologies are not well understood. Ex vivo magnetic resonance imaging (MRI) angiography has been developed to characterize the human placental vasculature by injecting a contrast agent within the umbilical cord.

Objective

The primary objective of this study is to compare the placental vascular architecture between normal and pathological pregnancies. This study’s secondary objectives are to (1) compare texture features on MRI between groups (normal and pathological), (2) quantitatively compare the vascular architecture between both pathological groups (pathological IUGR, and pathological PE), (3) evaluate the quality of the histological examination in injected placentas, and (4) compare vascularization indices to histological characteristics.

Methods

This is a prospective controlled study. We expect to include 100 placentas: 40 from normal pregnancies and 60 from pathological pregnancies (30 for IUGR and 30 for PE). Ex vivo MR image acquisition will be performed shortly after delivery and with preparation by injection of a contrast agent in the umbilical cord. The vascular architecture will be quantitatively described by vascularization indices measured from ex vivo MRI angiography data. Comparisons of vascularization indices and texture features in accordance with the group and within comparable gestational age will be also performed. After MR image acquisition, placental histopathological analysis will be performed.

Results

The enrollment of women began in November 2019. In view of the recruitment capacity of our institution and the availability of the MRI, recruitment should be completed by March 2022. As of November 2021, we enrolled 70% of the intended study population.

Conclusions

This study protocol aims to provide information about the fetal side of placental vascular architecture in normal and pathological placenta through MRI.

Trial Registration

Clinicaltrials.gov NCT04389099; https://clinicaltrials.gov/ct2/show/NCT04389099

International Registered Report Identifier (IRRID)

DERR1-10.2196/35051

New insights into human functional ultrasound imaging

Ultrasound imaging is a vital tool for exploring in vivo the placental function which is essential to understand pathological phenomena such as preeclampsia or intrauterine growth restriction. As technology advances including ready availability of three-dimensional (3D) probes and novel software, new markers of placental function become possible. The objective of this review was to provide an overview of the new ultrasound markers of placental function with a focus on the potential clinical application of three-dimensional power Doppler (3DPD). A broad-free text literature search was undertaken based on human placental studies and sixty full-text studies were included in this review. Three-dimensional power Doppler is a promising technique to predict preeclampsia in the first trimester. However, the influence of external factors such as body mass index, parameter standardisation and machine settings still need to be addressed. Contrast-enhanced ultrasound is currently reserved for research, because the required injected contrast mediums are not currently approved for use in pregnancy, although the safety data is reassuring.

In vivo characterization of physiological and metabolic changes related to isocitrate dehydrogenase 1 mutation expcression by multiparametric MRI and MRS in a rat model with orthotopically grafted human-derived glioblastoma cell lines

The physiological mechanism induced by the isocitrate dehydrogenase 1 (IDH1) mutation, associated with better treatment response in gliomas, remains unknown. The aim of this preclinical study was to characterize the IDH1 mutation through in vivo multiparametric MRI and MRS. Multiparametric MRI, including the measurement of blood flow, vascularity, oxygenation, permeability, and in vivo MRS, was performed on a 4.7 T animal MRI system in rat brains grafted with human-derived glioblastoma U87 cell lines expressing or not the IDH1 mutation by the CRISPR/Cas9 method, and secondarily characterized with additional ex vivo HR-MAS and histological analyses. In univariate analyses, compared with IDH1-, IDH1+ tumors exhibited higher vascular density (p < 0.01) and better perfusion (p = 0.02 for cerebral blood flow), but lower vessel permeability (p < 0.01 for time to peak (TTP), p = 0.04 for contrast enhancement) and decreased T1 map values (p = 0.02). Using linear discriminant analysis, vascular density and TTP values were found to be independent MRI parameters for characterizing the IDH1 mutation (p < 0.01). In vivo MRS and ex vivo HR-MAS analysis showed lower metabolites of tumor aggressiveness for IDH1+ tumors (p < 0.01). Overall, the IDH1 mutation exhibited a higher vascularity on MRI, a lower permeability, and a less aggressive metabolic profile. These MRI features may prove helpful to better pinpoint the physiological mechanisms induced by this mutation.

[Inspiratory muscle training during pulmonary rehabilitation]

INTRODUCTION

Inspiratory muscle training (IMT) is part of the management of patients with pulmonary diseases during rehabilitation. Since the last recommendations of the Société de pneumologie de langue française, several studies have focused on the role of inspiratory muscle training during pulmonary rehabilitation.

BACKGROUND

IMT, in comparison to standard care or sham-IMT, improves the strength and endurance of the inspiratory muscles, decreases dyspnoea during the activities of daily living, improves walking distance and quality of life. However, the different studies did not show an additional effect of IMT during a pulmonary rehabilitation program compared to a rehabilitation program without IMT, with regard to improvement of exercise capacity and quality of life.

OUTLOOK

One study showed an improvement in dyspnoea of effort, but these results are yet to be confirmed. Finally, it seems appropriate to associate IMT with an exercise-training program before chest or abdominal surgery, even if further studies are necessary.

CONCLUSION

During a pulmonary rehabilitation program, IMT does not provide additional benefits. However, when patients cannot perform a global exercise training, IMT has shown benefit. IMT provides additional benefits in pre-operative programs.

Replacement Myocardial Fibrosis in Patients With Mitral Valve Prolapse: Relation to Mitral Regurgitation, Ventricular Remodeling, and Arrhythmia

BACKGROUND

Mitral valve prolapse (MVP) is a frequent disease that can be complicated by mitral regurgitation (MR), heart failure, arterial embolism, rhythm disorders, and death. Left ventricular (LV) replacement myocardial fibrosis, a marker of maladaptive remodeling, has been described in patients with MVP, but the implications of this finding remain scarcely explored. We aimed at assessing the prevalence, pathophysiological and prognostic significance of LV replacement myocardial fibrosis through late gadolinium enhancement (LGE) by cardiac magnetic resonance in patients with MVP.

METHODS

Four hundred patients (53±15 years of age, 55% male) with MVP (trace to severe MR by echocardiography) from 2 centers, who underwent a comprehensive echocardiography and LGE cardiac magnetic resonance, were included. Correlates of replacement myocardial fibrosis (LGE+), influence of MR degree, and ventricular arrhythmia were assessed. The primary outcome was a composite of cardiovascular events (cardiac death, heart failure, new-onset atrial fibrillation, arterial embolism, and life-threatening ventricular arrhythmia).

RESULTS

Replacement myocardial fibrosis (LGE+) was observed in 110 patients (28%; 91 with myocardial wall including 71 with basal inferolateral wall, 29 with papillary muscle). LGE+ prevalence was 13% in trace-mild MR, 28% in moderate MR, and 37% in severe MR, and was associated with specific features of mitral valve apparatus, more dilated LV and more frequent ventricular arrhythmias (45% versus 26%, P<0.0001). In trace-mild MR, despite the absence of significant volume overload, abnormal LV dilatation was observed in 16% of patients and ventricular arrhythmia in 25%. Correlates of LGE+ in multivariable analysis were LV mass (odds ratio, 1.01 [95% CI, 1.002-1.017], P=0.009) and moderate-severe MR (odds ratio, 2.28 [95% CI, 1.21-4.31], P=0.011). LGE+ was associated with worse 4-year cardiovascular event-free survival (49.6±11.7 in LGE+ versus 73.3±6.5% in LGE-, P<0.0001). In a stepwise multivariable Cox model, MR volume and LGE+ (hazard ratio, 2.6 [1.4-4.9], P=0.002) were associated with poor outcome.

CONCLUSIONS

LV replacement myocardial fibrosis is frequent in patients with MVP; is associated with mitral valve apparatus alteration, more dilated LV, MR grade, and ventricular arrhythmia; and is independently associated with cardiovascular events. These findings suggest an MVP-related myocardial disease. Last, cardiac magnetic resonance provides additional information to echocardiography in MVP.

Birth experience during COVID-19 confinement (CONFINE): protocol for a multicentre prospective study

INTRODUCTION

The absence of companionship during childbirth is known to be responsible for negative emotional birth experience, which can increase the risk of postpartum depression and post-traumatic stress disorder. The context of COVID-19 epidemic and the related confinement could increase the rate of negative experience and mental disorders. The main objective is to compare, in immediate post partum, the maternal sense of control during childbirth between a group of women who gave birth during confinement ('confinement' group) versus a group of women who gave birth after confinement but in the context of epidemic ('epidemic' group) versus a group of control women ('control' group; excluding confinement and epidemic context).

METHODS AND ANALYSIS

This is a national multicentre prospective cohort study conducted in four French maternity units. We expect to include 927 women in a period of 16 months. Women will be recruited immediately in post partum during three different periods constituting the three groups: 'confinement'; 'epidemic' and 'control' group. The maternal sense of control will be evaluated by the Labour Agentry Scale questionnaire completed immediately in post partum. Postnatal depression (Edinburgh Postnatal Depression Scale), post-traumatic stress disorder (Impact of Event Scale-Revised) and breast feeding (evaluative statement) will be evaluated at 2 months post partum.

ETHICS AND DISSEMINATION

The study was approved by the French Ethics Committee, the CPP (Comité de Protection des Personnes) SUD OUEST ET OUTRE-MER IV on 16th of April 2020 with reference number CPP2020-04-040. The results of this study will be published in a peer-reviewed journal and will be presented at relevant conferences.

TRIAL REGISTRATION NUMBER

NCT04348929.

Design and evaluation of an abbreviated pixelwise dynamic contrast enhancement analysis protocol for early extracellular volume fraction estimation

INTRODUCTION

T1-based method is considered as the gold standard for extracellular volume fraction (ECV) mapping. This technique requires at least a 10 min delay after injection to acquire the post injection T1 map. Quantitative analysis of Dynamic Contrast Enhancement (DCE) images could lead to an earlier estimation of an ECV like parameter (2 min). The purpose of this study was to design a quantitative pixel-wise DCE analysis workflow to assess the feasibility of an early estimation of ECV.

METHODS

Fourteen patients with mitral valve prolapse were included in this study. The MR protocol, performed on a 3 T MR scanner, included MOLLI sequences for T1 maps acquisition and a standard SR-turboFlash sequence for dynamic acquisition. DCE data were acquired for at least 120 s. We implemented a full DCE analysis pipeline with a pre-processing step using an innovative motion correction algorithm (RC-REG algorithm) and a post-processing step using the extended Tofts Model (ECV_ETM). Estimated ECV_ETM maps were compared to standard T1-based ECV maps (ECV_T1) with both a Pearson correlation analysis and a group-wise analysis.

RESULTS

Image and map quality assessment showed systematic improvements using the proposed workflow. Strong correlation was found between ECV_ETM, and ECV_T1 values (r-square = 0.87).

CONCLUSION

A DCE analysis workflow based on RC-REG algorithm and ETM analysis can provide good quality parametric maps. Therefore, it is possible to extract ECV values from a 2 min-long DCE acquisition that are strongly correlated with ECV values from the T1 based method.

First trimester screening for pre-eclampsia and intrauterine growth restriction using three-dimensional Doppler angiography (SPIRIT): protocol for a multicentre prospective study in nulliparous pregnant women

INTRODUCTION

Pre-eclampsia (PE) and intrauterine growth restriction (IUGR) are two major pregnancy complications, related to chronic uteroplacental hypoperfusion. Nowadays, there is no screening or diagnostic test for uteroplacental vascularisation deficiency in pregnant women. Since 2004, 3 three-imensional power Doppler (3DPD) angiography has been used for the evaluation of uteroplacental vascularisation and three vascular indices are usually calculated: Vascularisation Index (VI), Flow Index (FI) and vascularisation-FI (VFI). A high intraobserver and interobserver reproducibility and a potential interest for placental function study were reported by our team and others.The main objective of our study is to determine differences in 3DPD indices at first trimester between pregnancies defined at their outcome as uncomplicated pregnancy, PE (mild and severe) and IUGR in nulliparous women.

METHODS AND ANALYSIS

This is a national multicentre prospective cohort study conducted in four French maternity units. We expect to include 2200 women in a period of 36 months. The nulliparous pregnant women will be recruited during their first trimester consultation (11-13+6 gestation week (GW)).The 3DPD and uterine artery Doppler acquisition will be included in the current routine 11-13+6 GW ultrasound. Also, additional blood samples will be taken for biomarker analysis (PAPP-A and P1GF) and biological collection. Uteroplacental VIs (FI and VFI) will be measured. For each subgroup (uncomplicated pregnancy, PE and IUGR), mean values in 3DPD indices will be computed and compared using a pairwise t test with a Bonferroni correction p value adjustment.

ETHICS AND DISSEMINATION

The study was approved by the French Ethics Committee, the Comité de Protection des Personnes SUD MEDITERRANEE IV on 13 February 2018 with reference number 17 12 03. The results of this study will be published in a peer-reviewed journal and will be presented at relevant conferences.

TRIAL REGISTRATION NUMBER

NCT03342014; Pre-results. PHRCN-16-0567.

Assessing the neuroanatomy knowledge and spatial ability of radiotherapy technologist undergraduates using an interactive volumetric simulation tool-the RadioLOG project

OBJECTIVE

To assess the use of a volumetric image display simulation tool (VDST) for the evaluation of applied radiological neuroanatomy knowledge and spatial understanding of radiotherapy technologist (RTT) undergraduates.

METHODS

Ninety-two third-year RTT students from three French RTT schools took an examination using software that allows visualization of multiple volumetric image series. To serve as a reference, 77 first- and second-year undergraduates, as well as ten senior neuroradiologists, took the same examination. The test included 13 very-short-answer questions (VSAQ) and 21 exercises in which examinees positioned markers onto preloaded brain MR images from a healthy volunteer. The response time was limited. Each correct answer scored 100 points, with a maximum possible test score of 3,400 (VSAQ = 1,300; marker exercise = 2,100). Answers were marked automatically for the marker positioning exercise and semi-automatically for the VSAQs against prerecorded expected answers.

RESULTS

Overall, the mean test score was 1,787 (150-3,300) and the standard deviation was 781. Scores were highly significantly different between all evaluated groups (p < 0.001). The interoperator reproducibility was 0.90. All the evaluated groups could be discriminated by VSAQ, marker, and overall total scores independently (p ≤ 0.0001 to 0.001). The test was able to discriminate between the three schools either by VSAQ scores (p < 0.001 to 0.02) or by overall total score (p < 0.001 to 0.05).

CONCLUSION

This software is a high-quality evaluation tool for the assessment of radiological neuroanatomy knowledge and spatial understanding in RTT undergraduates.

KEY POINTS

• This VDST allows volumetric image analysis of MR studies. • A high reliability test could be created with this tool. • Test scores were strongly associated with the examinee expertise level.

FRI0653-HPR AN OLEUROPEIN-BASED DIETARY SUPPLEMENT IMPROVES JOINT FUNCTIONALITY IN OLDER PEOPLE WITH HIGH KNEE JOINT PAIN

Background:

OLE provides oleuropein the most prevalent phenolic component in olive leaves and has been shown to have potent anti-inflammatory and anti-oxidant effects potentially interesting for joint health (1).

Objectives:

The aim of this study was to investigate the effects of a 6-month intervention with an Olive Leaf Extract (OLE) standardized for oleuropein content on knee functionality and biomarkers of bone/cartilage metabolism and inflammation.

Methods:

The study was a randomized, double-blind, placebo-controlled, multi-centric trial of 124 subjects with mild knee pain or mobility issues. Subjects were randomized equally to receive twice a day one capsule of either maltodextrin (control treatment, CT) or 125-mg OLE (BonoliveTM, an Olive Leaf Extract containing 50 mg of Oleuropein) for 6 months. The co-primary endpoints were Knee injury and Osteoarthritis Outcome Score (KOOS) using a self-administered questionnaire and serum Coll2-1NO2 specific biomarker of cartilage degradation. The secondary endpoints were each of the five sub-scales of the KOOS questionnaire, Knee pain VAS score at rest and at walking, OARSI core set of performance-based tests and serum biomarkers (Coll2-1, MPO, CTX1, osteocalcin, PGE2 and Vplex cytokines assay in serum) and concentration of Oleuropein’s metabolites in urine.

Results:

Primary (global KOOS score, biomarker Coll2-1 NO2) and secondary endpoints (the five subscales of the KOOS score) improved time dependently in both groups. OLE treatment showed significantly elevated urinary oleuropein metabolites (oleuropein aglycone, hydroxytyrosol, homovanillyl alcohol and isomer of homovanillyl alcohol), and was well tolerated without significant differences in number of subjects with adverse events. At 6 months, OLE group showed a higher global KOOS score compared to placebo (treatment difference = 3.73; 95% CI = [-4.08;11.54]; p = 0.34), without significant changes of inflammatory and cartilage remodeling biomarkers. Subgroup analyses demonstrated a large and significant treatment effect of OLE in subjects with high walking pain at baseline (14.4; 95% CI = [1.19;27.63], p=0.03). This was observed at 6 months for the global KOOS score and each different subscale and for pain at walking (-23.07;95% CI = [-41.8;-4.2];p=0.02). These treatment effects at 6 months were significant for KOOS score as well as for the subscales Pain and QoL and the pain at walking.

Conclusion:

OLE was not effective on joint discomfort in people with low to moderate pain at baseline but significantly benefited subjects with high pain at treatment initiation. As oleuropein is well-tolerated, OLE can be used to relieve knee joint pain and enhance mobility in subjects with articular pain the most painful subjects.

References:

[1] Horcajada MN, Sanchez C, Membrez Scalfo F, Drion P, Comblain F, Taralla S, Donneau AF, Offord EA, Henrotin Y. Oleuropein or rutin consumption decreases the spontaneous development of osteoarthritis in the Hartley guinea pig. Osteoarthritis Cartilage. 2015 Jan;23(1):94-102

Disclosure of Interests:

Marie-Noelle Horcajada Employee of: nestlé, Maurice Beaumont Employee of: nestle, Nicolas Sauvageot Employee of: Nestlé, Laure Poquet Employee of: Nestlé, Madleen Saboudjian Employee of: Nestlé, Anne-Christine Hick Employee of: Artialis SA, Berenice Costes Employee of: Artialis SA, Laetitia Garcia Employee of: Artialis, Yves Henrotin Grant/research support from: HEEL, TILMAN

Optimization of Fetal Biometry With 3D Ultrasound and Image Recognition (EPICEA): protocol for a prospective cross-sectional study

CONTEXT

Variability in 2D ultrasound (US) is related to the acquisition of planes of reference and the positioning of callipers and could be reduced in combining US volume acquisitions and anatomical structures recognition.

OBJECTIVES

The primary objective is to assess the consistency between 3D measurements (automated and manual) extracted from a fetal US volume with standard 2D US measurements (I). Secondary objectives are to evaluate the feasibility of the use of software to obtain automated measurements of the fetal head, abdomen and femur from US acquisitions (II) and to assess the impact of automation on intraobserver and interobserver reproducibility (III).

METHODS AND ANALYSIS

225 fetuses will be measured at 16-30 weeks of gestation. For each fetus, six volumes (two for head, abdomen and thigh, respectively) will be prospectively acquired after performing standard 2D biometry measurements (head and abdominal circumference, femoral length). Each volume will be processed later by both a software and an operator to extract the reference planes and to perform the corresponding measurements. The different sets of measurements will be compared using Bland-Altman plots to assess the agreement between the different processes (I). The feasibility of using the software in clinical practice will be assessed through the failure rate of processing and the score of quality of measurements (II). Interclass correlation coefficients will be used to evaluate the intraobserver and interobserver reproducibility (III).

ETHICS AND DISSEMINATION

The study and related consent forms were approved by an institutional review board (CPP SUD-EST 3) on 2 October 2018, under reference number 2018-033 B. The study has been registered in https://clinicaltrials.gov registry on 23 January 2019, under the number NCT03812471. This study will enable an improved understanding and dissemination of the potential benefits of 3D automated measurements and is a prerequisite for the design of intention to treat randomised studies assessing their impact.

TRIAL REGISTRATION NUMBER

NCT03812471; Pre-results.

Mediation of the Relationship Between Endovascular Therapy and Functional Outcome by Follow-up Infarct Volume in Patients With Acute Ischemic Stroke

Importance

The positive treatment effect of endovascular therapy (EVT) is assumed to be caused by the preservation of brain tissue. It remains unclear to what extent the treatment-related reduction in follow-up infarct volume (FIV) explains the improved functional outcome after EVT in patients with acute ischemic stroke.

Objective

To study whether FIV mediates the relationship between EVT and functional outcome in patients with acute ischemic stroke.

Design, Setting, and Participants

Patient data from 7 randomized multicenter trials were pooled. These trials were conducted between December 2010 and April 2015 and included 1764 patients randomly assigned to receive either EVT or standard care (control). Follow-up infarct volume was assessed on computed tomography or magnetic resonance imaging after stroke onset. Mediation analysis was performed to examine the potential causal chain in which FIV may mediate the relationship between EVT and functional outcome. A total of 1690 patients met the inclusion criteria. Twenty-five additional patients were excluded, resulting in a total of 1665 patients, including 821 (49.3%) in the EVT group and 844 (50.7%) in the control group. Data were analyzed from January to June 2017.

Main Outcome and Measure

The 90-day functional outcome via the modified Rankin Scale (mRS).

Results

Among 1665 patients, the median (interquartile range [IQR]) age was 68 (57-76) years, and 781 (46.9%) were female. The median (IQR) time to FIV measurement was 30 (24-237) hours. The median (IQR) FIV was 41 (14-120) mL. Patients in the EVT group had significantly smaller FIVs compared with patients in the control group (median [IQR] FIV, 33 [11-99] vs 51 [18-134] mL; P = .007) and lower mRS scores at 90 days (median [IQR] score, 3 [1-4] vs 4 [2-5]). Follow-up infarct volume was a predictor of functional outcome (adjusted common odds ratio, 0.46; 95% CI, 0.39-0.54; P < .001). Follow-up infarct volume partially mediated the relationship between treatment type with mRS score, as EVT was still significantly associated with functional outcome after adjustment for FIV (adjusted common odds ratio, 2.22; 95% CI, 1.52-3.21; P < .001). Treatment-reduced FIV explained 12% (95% CI, 1-19) of the relationship between EVT and functional outcome.

Conclusions and Relevance

In this analysis, follow-up infarct volume predicted functional outcome; however, a reduced infarct volume after treatment with EVT only explained 12% of the treatment benefit. Follow-up infarct volume as measured on computed tomography and magnetic resonance imaging is not a valid proxy for estimating treatment effect in phase II and III trials of acute ischemic stroke.

Validation of overestimation ratio and TL-SVS as imaging biomarker of cardioembolic stroke and time from onset to MRI

OBJECTIVE

We aimed to determine in the "THRACE" trial, the clinical and MRI technical parameters associated with the two-layered susceptibility vessel sign (TL-SVS) and the overestimation ratio (overR).

MATERIALS AND METHODS

Patients with pre-treatment brain gradient echo (GRE) sequence and an etiological work-up were identified. Two readers reviewed TL-SVS, i.e., a SVS with a linear low-intense signal core surrounded by a higher intensity and measured the overR as the width of SVS divided by the width of the artery. Binomial and ordinal logistic regression respectively tested the association between TL-SVS and quartiles of overR with patient characteristics, cardioembolic stroke (CES), time from onset to imaging, and GRE sequence parameters (inter slice gap, slice thickness, echo time, flip angle, voxel size, and field strength).

RESULTS

Among 258 included patients, 102 patients were examined by 3 Tesla MRI and 156 by 1.5 Tesla MRI. Intra- and inter-reader agreements for quartiles of overR and TL-SVS were good to excellent. The median overR was 1.59 (IQR, 1.30 to 1.86). TL-SVS was present in 101 patients (39.2%, 95%CI, 33.1 to 45.1%). In multivariate analysis, only CES was associated with overR quartiles (OR, 1.83; 95%CI, 1.11 to 2.99), and every 60 min increase from onset to MRI time was associated with TL-SVS (OR, 1.72; 95%CI, 1.10 to 2.67). MRI technical parameters were statistically associated with neither overR nor TL-SVS.

CONCLUSION

Independent of GRE sequence parameters, an increased overR was associated to CES, while the TL-SVS is independently related to a longer time from onset to MRI.

KEY POINTS

• An imaging biomarker would be useful to predict the etiology of stroke in order to adapt secondary prevention of stroke. • The two-layered susceptibility vessel sign and the overestimation ratio are paramagnetic effect derived markers that vary according to the MRI machines and sequence parameters. • Independent of sequence parameters, an increased overestimation ratio was associated to cardioembolic stroke, while the two-layered susceptibility vessel sign is independently related to a longer time from onset to MRI.

[Follow-up and evaluation of plans developed during pulmonary rehabilitation]

BACKGROUND

Pulmonary rehabilitation inevitably contains two essential components: therapeutic education and exercise training. The principal aim of this study was to evaluate the evolution over a year of the realization of plans determined during a pulmonary rehabilitation program (PRP).

METHODS

At the end of a PRP the patient made plans in accordance with his health condition. A telephone enquiry was undertaken at 3, 7 and 12 months to evaluate the progress of the plans, the motivation to perform them, dyspnoea and quality of life.

RESULTS

The data of 65 patients were analyzed (87 inclusions). Fifty-seven percent of the plans continued for one year. Walking had an adherence rating of 71%. Loss of motivation appeared to be the main cause for stopping (20%). Quality of life remained stable (p=0.39) and an increase in dyspnoea, though statistically significant (p<0.01), was of no clinical relevance.

CONCLUSION

The majority of plans were maintained but without clinical effect on the quality of life or the level of dyspnoea. Decreased motivation was the major limitation to realization or continuation of the plans. New studies will have to be implemented to analyze the factors which lead to this decrease.

Susceptibility Vessel Sign and Cardioembolic Etiology in the THRACE Trial

PURPOSE

The susceptibility vessel sign (SVS) has been described on gradient echo (GRE) magnetic resonance imaging (MRI) in acute ischemic stroke patients by large vessel occlusion. The presence of SVS (SVS+) was associated with treatment outcome and stroke etiology with conflicting results. Based on multicenter data from the THRombectomie des Artères CErebrales (THRACE) study, we aimed to determine if the association between SVS and cardioembolic etiology (CE) was independent of GRE sequence parameters.

MATERIAL AND METHODS

Patients with a pretreatment brain GRE sequence were identified. Logistic regression tested the association between SVS+, CE, time from onset to imaging and GRE sequence parameters (e.g. echo time, voxel size, field strength). We calculated the sensitivity, specificity, positive and negative predictive values (PPV and NPV) for the SVS to predict a stroke from a CE.

RESULTS

An SVS+ was observed in 237 out of 287 (83%) patients. In the univariate analysis, there was a significant association between SVS+ and a CE with an odds ratio (OR) and 95% confidence interval (95% CI) of 2.10 (1.02-4.29), respectively (p = 0.04) but not with GRE sequence parameters. In multivariate analysis, there was an independent relationship between SVS+ and CE (OR [95% CI]: 2.14 [1.02-4.45], p = 0.04). Sensitivity and specificity of SVS+ to predict CE were 0.89 and 0.21, respectively. The PPV and NPV of SVS+ were 0.44 and 0.78, respectively.

CONCLUSION

The presence of SVS is associated to CE, independent of GRE sequence parameters. While the specificity and the PPV of the sign were low, CE seems less likely in the absence of an SVS.

Association of follow-up infarct volume with functional outcome in acute ischemic stroke: a pooled analysis of seven randomized trials

Background

Follow-up infarct volume (FIV) has been recommended as an early indicator of treatment efficacy in patients with acute ischemic stroke. Questions remain about the optimal imaging approach for FIV measurement.

Objective

To examine the association of FIV with 90-day modified Rankin Scale (mRS) score and investigate its dependency on acquisition time and modality.

Methods

Data of seven trials were pooled. FIV was assessed on follow-up (12 hours to 2 weeks) CT or MRI. Infarct location was defined as laterality and involvement of the Alberta Stroke Program Early CT Score regions. Relative quality and strength of multivariable regression models of the association between FIV and functional outcome were assessed. Dependency of imaging modality and acquisition time (≤48 hours vs >48 hours) was evaluated.

Results

Of 1665 included patients, 83% were imaged with CT. Median FIV was 41 mL (IQR 14–120). A large FIV was associated with worse functional outcome (OR=0.88(95% CI 0.87 to 0.89) per 10 mL) in adjusted analysis. A model including FIV, location, and hemorrhage type best predicted mRS score. FIV of ≥133 mL was highly specific for unfavorable outcome. FIV was equally strongly associated with mRS score for assessment on CT and MRI, even though large differences in volume were present (48 mL (IQR 15–131) vs 22 mL (IQR 8–71), respectively). Associations of both early and late FIV assessments with outcome were similar in strength (ρ=0.60(95% CI 0.56 to 0.64) and ρ=0.55(95% CI 0.50 to 0.60), respectively).

Conclusions

In patients with an acute ischemic stroke due to a proximal intracranial occlusion of the anterior circulation, FIV is a strong independent predictor of functional outcome and can be assessed before 48 hours, oneither CT or MRI.

Ex vivo magnetic resonance angiography to explore placental vascular anatomy

INTRODUCTION

A normal placenta development is crucial for a successful pregnancy. In case of major obstetric complications such as intra-uterine growth restriction, the placental vascularization morphological alteration at macroscopic level is less known than that at microscopic scale. Ex vivo MRA has the potential to visualize whole fresh human placental vasculature fast and efficiently but can be hampered by contrast agent extravasation problem. This study aimed to provide an optimized ex vivo MRA protocol to acquire understanding of global human placenta vasculature morphology.

METHODS

Six fresh normal human placentas were imaged with two contrast agents (i.e. Gd-chelate and pump oil) using different imaging parameters on a 3T clinical MR scanner (GE). The contrast to noise ratio, signal to noise ratio and enhancement efficiency were assessed in order to decide which contrast agent and imaging protocol was better. In the end, morphology indices were measured based on the 3D vasculature models reconstructed from the placentas imaged with the optimized protocol.

RESULTS

With the same imaging parameters, the CNR and the enhancement efficiency of images enhanced with pump oil were superior to those using Gd-chelate. Enhanced by pump oil, an optimized ex vivo MRA protocol was determined, leading to a clear 3D visualization and reconstruction of human placenta vascularization.

DISCUSSION

The proposed ex vivo MRA method is easy to manipulate, and can be used to investigate the human placental vasculature morphology. The acquired data are of good quality and can be used for characterization of placenta vascularization morphology.

Impact of denoising on precision and accuracy of saturation-recovery-based myocardial T1 mapping

PURPOSE

To evaluate the impact of a novel postprocessing denoising technique on accuracy and precision in myocardial T₁ mapping.

MATERIALS AND METHODS

This study introduces a fast and robust denoising method developed for magnetic resonance T₁ mapping. The technique imposes edge-preserving regularity and exploits the co-occurence of spatial gradients in the acquired T₁ -weighted images. The proposed approach was assessed in simulations, ex vivo data and in vivo imaging on a cohort of 16 healthy volunteers (12 males, average age 39 ± 8 years, 62 ± 9 bpm) both in pre- and postcontrast injection. The method was evaluated in myocardial T₁ mapping at 3T with a saturation-recovery technique that is accurate but sensitive to noise. ROIs in the myocardium and left-ventricle blood pool were analyzed by an experienced reader. Mean T₁ values and standard deviation were extracted and compared in all studies.

RESULTS

Simulations on synthetic phantom showed signal-to-noise ratio and sharpness improvement with the proposed method in comparison with conventional denoising. In vivo results demonstrated that our method preserves accuracy, as no difference in mean T₁ values was observed in the myocardium (precontrast: 1433/1426 msec, 95%CI: [-40.7, 55.9], p = 0.75, postcontrast: 766/759 msec, 95%CI: [-60.7, 77.2], p = 0.8). Meanwhile, precision was improved with standard deviations of T₁ values being significantly decreased (precontrast: 223/151 msec, 95%CI: [27.3, 116.5], p = 0.003, postcontrast: 176/135 msec, 95%CI: [5.5, 77.1], p = 0.03).

CONCLUSION

The proposed denoising method preserves accuracy and improves precision in myocardial T₁ mapping, with the potential to offer better map visualization and analysis.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1377-1388.

Untangling the relationship between diet and visceral fat mass through blood metabolomics and gut microbiome profiling

BACKGROUND/OBJECTIVES

Higher visceral fat mass (VFM) is associated with an increased risk for developing cardio-metabolic diseases. The mechanisms by which an unhealthy diet pattern may influence visceral fat (VF) development has yet to be examined through cutting-edge multi-omic methods. Therefore, our objective was to examine the dietary influences on VFM and identify gut microbiome and metabolite profiles that link food intakes to VFM.

SUBJECTS/METHODS

In 2218 twins with VFM, food intake and metabolomics data available we identified food intakes most strongly associated with VFM in 50% of the sample, then constructed and tested the 'VFM diet score' in the remainder of the sample. Using linear regression (adjusted for covariates, including body mass index and total fat mass), we investigated associations between the VFM diet score, the blood metabolomics profile and the fecal microbiome (n=889), and confirmed these associations with VFM. We replicated top findings in monozygotic (MZ) twins discordant (⩾1 s.d. apart) for VFM, matched for age, sex and the baseline genetic sequence.

RESULTS

Four metabolites were associated with the VFM diet score and VFM: hippurate, alpha-hydroxyisovalerate, bilirubin (Z,Z) and butyrylcarnitine. We replicated associations between VFM and the diet score (beta (s.e.): 0.281 (0.091); P=0.002), butyrylcarnitine (0.199 (0.087); P=0.023) and hippurate (-0.297 (0.095); P=0.002) in VFM-discordant MZ twins. We identified a single species, Eubacterium dolichum to be associated with the VFM diet score (0.042 (0.011), P=8.47 × 10^-5), VFM (0.057 (0.019), P=2.73 × 10^-3) and hippurate (-0.075 (0.032), P=0.021). Moreover, higher blood hippurate was associated with elevated adipose tissue expression neuroglobin, with roles in cellular oxygen homeostasis (0.016 (0.004), P=9.82x10^-6).

CONCLUSIONS

We linked a dietary VFM score and VFM to E. dolichum and four metabolites in the blood. In particular, the relationship between hippurate, a metabolite derived from microbial metabolism of dietary polyphenols, and reduced VFM, the microbiome and increased adipose tissue expression of neuroglobin provides potential mechanistic insight into the influence of diet on VFM.

Cardiac remodeling following reperfused acute myocardial infarction is linked to the concomitant evolution of vascular function as assessed by cardiovascular magnetic resonance

BACKGROUND

Left ventricular (LV) remodeling following acute myocardial infarction (MI) is difficult to predict at an individual level although a possible interfering role of vascular function has yet to be considered to date. This study aimed to determine the extent to which this LV remodeling is influenced by the concomitant evolution of vascular function and LV loading conditions, as assessed by phase-contrast Cardiovascular Magnetic Resonance (CMR) of the ascending aorta.

METHODS

CMR was performed in 121 patients, 2-4 days after reperfusion of a first ST-segment elevation myocardial infarction and 6 months thereafter. LV remodeling was: (i) assessed by the 6-month increase in end-diastolic volume (EDV) and/or ejection fraction (EF) and (ii) correlated with the indexed aortic stroke volume (mL.m-2), determined by a CMR phase-contrast sequence, along with derived functional vascular parameters (total peripheral vascular resistance (TPVR), total arterial compliance index, effective arterial elastance).

RESULTS

At 6 months, most patients were under angiotensin enzyme converting inhibitors (86%) and beta-blockers (84%) and, on average, all functional vascular parameters were improved whereas blood pressure levels were not. An increase in EDV only (EDV+/EF-) was documented in 17% of patients at 6 months, in EF only (EDV-/EF+) in 31%, in both EDV and EF (EDV+/EF+) in 12% and neither EDV nor EF (EDV-/EF-) in 40%. The increase in EF was mainly and independently linked to a concomitant decline in TPVR (6-month change in mmHg.min.m2.L-1, EDV-/EF-: +1 ± 8, EDV+/EF-: +3 ± 9, EDV-/EF+: -7 ± 6, EDV+/EF+: -15 ± 20, p < 0.001) while the absence of any EF improvement was associated with high persisting rates of abnormally high TPVR at 6 months (EDV-/EF-: 31%, EDV+/EF-: 38%, EDV-/EF+: 5%, EDV+/EF+: 13%, p = 0.007). By contrast, the 6-month increase in EDV was mainly dependent on cardiac as opposed to vascular parameters and particularly on the presence of microvascular obstruction at baseline (EDV-/EF-: 37%, EDV+/EF-: 76%, EDV-/EF+: 38%, EDV+/EF+: 73%, p = 0.003).

CONCLUSION

LV remodeling following reperfused MI is strongly influenced by the variable decrease in systemic vascular resistance under standard care vasodilating medication. The CMR monitoring of vascular resistance may help to tailor these medications for improving vascular resistance and consequently, LV ejection fraction.

TRIAL REGISTRATION

NCT01109225 on ClinicalTrials.gov site (April, 2010).

Non-invasive evaluation of placental blood flow: lessons from animal models

In human obstetrics, placental vascularisation impairment is frequent as well as linked to severe pathological events (preeclampsia and intrauterine growth restriction), and there is a need for reliable methods allowing non-invasive evaluation of placental blood flow. Uteroplacental vascularisation is complex, and animal models are essential for the technical development and safety assessment of these imaging tools for human clinical use; however, these techniques can also be applied in the veterinary context. This paper reviews how ultrasound-based imaging methods such as 2D and 3D Doppler can provide valuable insight for the exploration of placental blood flow both in humans and animals and how new approaches such as the use of ultrasound contrast agents or ultrafast Doppler may allow to discriminate between maternal (non-pulsatile) and foetal (pulsatile) blood flow in the placenta. Finally, functional magnetic resonance imaging could also be used to evaluate placental blood flow, as indicated by studies in animal models, but its safety in human pregnancy still requires to be confirmed.

Myocardial infarct sizing by late gadolinium-enhanced MRI: Comparison of manual, full-width at half-maximum, and n-standard deviation methods

PURPOSE

To compare three widely used methods for myocardial infarct (MI) sizing on late gadolinium-enhanced (LGE) magnetic resonance (MR) images: manual delineation and two semiautomated techniques (full-width at half-maximum [FWHM] and n-standard deviation [SD]).

MATERIALS AND METHODS

3T phase-sensitive inversion-recovery (PSIR) LGE images of 114 patients after an acute MI (2-4 days and 6 months) were analyzed by two independent observers to determine both total and core infarct sizes (TIS/CIS). Manual delineation served as the reference for determination of optimal thresholds for semiautomated methods after thresholding at multiple values. Reproducibility and accuracy were expressed as overall bias ± 95% limits of agreement.

RESULTS

Mean infarct sizes by manual methods were 39.0%/24.4% for the acute MI group (TIS/CIS) and 29.7%/17.3% for the chronic MI group. The optimal thresholds (ie, providing the closest mean value to the manual method) were FWHM30% and 3SD for the TIS measurement and FWHM45% and 6SD for the CIS measurement (paired t-test; all P > 0.05). The best reproducibility was obtained using FWHM. For TIS measurement in the acute MI group, intra-/interobserver agreements, from Bland-Altman analysis, with FWHM30%, 3SD, and manual were -0.02 ± 7.74%/-0.74 ± 5.52%, 0.31 ± 9.78%/2.96 ± 16.62% and -2.12 ± 8.86%/0.18 ± 16.12, respectively; in the chronic MI group, the corresponding values were 0.23 ± 3.5%/-2.28 ± 15.06, -0.29 ± 10.46%/3.12 ± 13.06% and 1.68 ± 6.52%/-2.88 ± 9.62%, respectively. A similar trend for reproducibility was obtained for CIS measurement. However, semiautomated methods produced inconsistent results (variabilities of 24-46%) compared to manual delineation.

CONCLUSION

The FWHM technique was the most reproducible method for infarct sizing both in acute and chronic MI. However, both FWHM and n-SD methods showed limited accuracy compared to manual delineation. J. Magn. Reson. Imaging 2016;44:1206-1217.

Joint Reconstruction of Multiple Images and Motion in MRI: Application to Free-Breathing Myocardial T₂Quantification

Exploiting redundancies between multiple images of an MRI examination can be formalized as the joint reconstruction of these images. The anatomy is preserved indeed so that specific constraints can be implemented (e.g. most of the features or spatial gradients should be in the same place in all these images) and only the contrast changes from one image to another need to be encoded. The application of this concept is particularly challenging in cardiovascular and body imaging due to the complex organ deformations, especially with the patient breathing. In this study a joint optimization framework is proposed for reconstructing multiple MR images together with a nonrigid motion model. The motion model takes into account both intra-image and inter-image motion and therefore can correct for most ghosting/blurring artifacts and misregistration between images. The framework was validated with free-breathing myocardial T2 mapping experiments from nine heart transplant patients at 1.5 T. Results showed improved image quality and excellent image alignment with the multi-image reconstruction compared to the independent reconstruction of each image. Segment-wise myocardial T2 values were in good agreement with the reference values obtained from multiple breath-holds (62.5 ± 11.1 ms against 62.2 ± 11.2 ms which was not significant with p=0.49).

Assessment of Left Ventricular Ejection Fraction Calculation on Long-axis Views From Cardiac Magnetic Resonance Imaging in Patients With Acute Myocardial Infarction

To assess left ventricular ejection fraction (LVEF) accurately, cardiac magnetic resonance (CMR) can be indicated and lays on the evaluation of multiple slices of the left ventricle in short axis (CMRSAX). The objective of this study was to assess another method consisting of the evaluation of 2 long-axis slices (CMRLAX) for LVEF determination in acute myocardial infarction.One hundred patients underwent CMR 2 to 4 days after acute myocardial infarction. LVEF was computed by the area-length method on horizontal and vertical CMRLAX images. Those results were compared to reference values obtained on contiguous CMRSAX images in one hand, and to values obtained from transthoracic echocardiography (TTE) in the other hand. For CMRSAX and TTE, LVEF was computed with Simpson method. Reproducibility of LVEF measurements was additionally determined. The accuracy of volume measurements was assessed against reference aortic stroke volumes obtained by phase-contrast MR imaging.LVEF from CMRLAX had a mean value of 47 ± 8% and were on average 5% higher than reference LVEF from CMRSAX (42 ± 8%), closer to routine values from TTELAX (49 ± 8%), much better correlated with the reference LVEF from CMRSAX (R = 0.88) than that from TTE (R = 0.58), obtained with a higher reproducibility than with the 2 other techniques (% of interobserver variability: CMRLAX 5%, CMRSAX 11%, and TTE 13%), and obtained with 4-fold lower recording and calculation times than for CMRSAX. Apart from this, CMRLAX stroke volume was well correlated with phase-contrast values (R = 0.81).In patients with predominantly regional contractility abnormalities, the determination of LVEF by CMRLAX is twice more reproducible than the reference CMRSAX method, even though the LVEF is consistently overestimated compared with CMRSAX. However, the CMRLAX LVEF determination provides values closer to TTE measurements, the most available and commonly used method in clinical practice, clinical trials, and guidelines in ischemic cardiomyopathy. Moreover, LVEF determination by CMRLAX allows a 63% gain of acquisition/reading time compared with CMRSAX. Thus, despite the fact that LVEF obtained from CMRSAX remains the gold standard, CMRLAX should be considered to shorten the overall imaging acquisition and reading time as a putative replacement.