Myocardial Infarction Quantification From Late Gadolinium Enhancement MRI Using Top-hat Transforms and Neural Networks

Significance: Late gadolinium enhanced magnetic resonance imaging (LGE-MRI) is the gold standard technique for myocardial viability assessment. Although the technique accurately reflects the damaged tissue, there is no clinical standard for quantifying myocardial infarction (MI), demanding most algorithms to be expert dependent. Objectives and Methods: In this work a new automatic method for MI quantification from LGE-MRI is proposed. Our novel segmentation approach is devised for accurately detecting not only hyper-enhanced lesions, but also microvascular-obstructed areas. Moreover, it includes a myocardial disease detection step which extends the algorithm for working under healthy scans. The method is based on a cascade approach where firstly, diseased slices are identified by a convolutional neural network (CNN). Secondly, by means of morphological operations a fast coarse scar segmentation is obtained. Thirdly, the segmentation is refined by a boundary-voxel reclassification strategy using an ensemble of CNNs. For its validation, reproducibility and further comparison against other methods, we tested the method on a big multi-field expert annotated LGE-MRI database including healthy and diseased cases. Results and Conclusion: In an exhaustive comparison against nine reference algorithms, the proposal achieved state-of-the-art segmentation performances and showed to be the only method agreeing in volumetric scar quantification with the expert delineations. Moreover, the method was able to reproduce the intra- and inter-observer variability ranges. It is concluded that the method could suitably be transferred to clinical scenarios.Comment: Submitted to IEE

Patterns of Bone Failure in Localized Prostate Cancer Previously Irradiated: The Preventive Role of External Radiotherapy on Pelvic Bone Metastases

Introduction: External beam radiation therapy (EBRT) can cure localized prostate cancer (PCa) by sterilizing cancer cells in the prostate gland and surrounding tissues at risk of microscopic dissemination. We hypothesized that pelvic EBRT for localized PCa might have an unexpected prophylactic impact on the occurrence of pelvic bone metastases.Material and Methods: We reviewed the data of 332 metastatic PCa patients. We examined associations between the number (≤5 vs. >5) and the location of bone metastases (in-field vs. out-of-field), which occurred at first relapse, and a previous history of EBRT for PCa (EBRT vs. No-EBRT).Results: One hundred and ten patients M0 at baseline were eligible. Fifty-six patients (51%) were in the No-EBRT group, and 54 patients (49%) in the EBRT group. The proportion of patients who developed >5 bone metastases in the bony pelvis was higher in the No-EBRT group vs. the EBRT group: 10 patients (18%) vs. 2 patients (4%), respectively (p = 0.02). By multivariate analysis EBRT was associated with a lesser occurrence of patients who had >5 bone metastases in the bony pelvis (OR = 0.17 [95%CI, 0.04–0.87], p = 0.03). Time to occurrence of bone metastases ≥5 years (OR = 0.10 [95%CI, 0.05–0.19], p < 0.01), prior curative prostate treatment (OR = 0.58 [95%CI, 0.36–0.91], p = 0.02), >5 bone metastases in bony pelvis (OR = 2.61 [95%CI, 1.28–5.31], p < 0.01), >5 bone metastases out of bony pelvis (OR = 1.73 [95%CI, 1.09–2.76], p = 0.02) were all predictive of overall survival.Conclusion: Previous pelvic EBRT for PCa is associated with a lower number of pelvic bone metastases, which is associated with better overall survival

ABCG2 Is Overexpressed on Red Blood Cells in Ph-Negative Myeloproliferative Neoplasms and Potentiates Ruxolitinib-Induced Apoptosis

Acknowledgments: The authors would like to thank Dominique Gien, Sirandou Tounkara, and Eliane Véra at Centre National de Référence pour les Groupes Sanguins for the management of blood samples. Funding: The work was supported by Institut National de la Santé et de la Recherche Médicale (Inserm), Institut National de la Transfusion Sanguine (INTS), the University of Paris, and grants from Laboratory of Excellence (Labex) GR-Ex, reference No. ANR-11-LABX-0051. The Labex GR-Ex is funded by the IdEx program “Investissements d’avenir” of the French National Research Agency, reference No. ANR-18-IDEX-0001. R.B. was funded by the European Union’s Horizon 2020 Research and Innovation Program under grant agreement No. 675115-RELEVANCE-H2020-MSCA-ITN-2015. M.B. was funded by Ministère de l’Enseignement Supérieur et de la Recherche at the BioSPC Doctoral School. R.B. and M.B. also received financial support from Société Française d’Hématologie (SFH) and Club du Globule Rouge et du Fer (CGRF).Peer reviewedPublisher PD

Nonsupervised Ranking of Different Segmentation Approaches: Application to the Estimation of the Left Ventricular Ejection Fraction From Cardiac Cine MRI Sequences

International audienceA statistical methodology is proposed to rank several estimation methods of a relevant clinical parameter when no gold standard is available. Based on a regression without truth method, the proposed approach was applied to rank eightmethods without using any a priori information regarding the reliability of each method and its degree of automation. It was only based on a prior concerning the statistical distribution of the parameter of interest in the database. The ranking of the methods relies on figures of merit derived from the regression and computed using a bootstrap process. The methodology was applied to the estimation of the left ventricular ejection fraction derived from cardiac magnetic resonance images segmented using eight approaches with different degrees of automation: three segmentations were entirely manually performed and the others were variously automated. The ranking of methods was consistent with the expected performance of the estimation methods: the most accurate estimates of the ejection fraction were obtained using manual segmentations. The robustness of the ranking was demonstrated when at least three methods were compared. These results suggest that the proposed statistical approach might be helpful to assess the performance of estimation methods on clinical data for which no gold standard is available

Comparison of different segmentation approaches without using gold standard. Application to the estimation of the left ventricle ejection fraction from cardiac cine MRI sequences.

International audienceA statistical method is proposed to compare several estimates of a relevant clinical parameter when no gold standard is available. The method is illustrated by considering the left ventricle ejection fraction derived from cardiac magnetic resonance images and computed using seven approaches with different degrees of automation. The proposed method did not use any a priori regarding with the reliability of each method and its degree of automation. The results showed that the most accurate estimates of the ejection fraction were obtained using manual segmentations, followed by the semiautomatic methods, while the methods with the least user input yielded the least accurate ejection fraction estimates. These results were consistent with the expected performance of the estimation methods, suggesting that the proposed statistical approach might be helpful to assess the performance of estimation methods on clinical data for which no gold standard is available

Improved estimation of the left ventricular ejection fraction using a combination of independent automated segmentation results in cardiovascular magnetic resonance imaging

—This work aimed at combining different segmenta-tion approaches to produce a robust and accurate segmentation result. Three to five segmentation results of the left ventricle were combined using the STAPLE algorithm and the reliability of the resulting segmentation was evaluated in comparison with the result of each individual segmentation method. This comparison was performed using a supervised approach based on a reference method. Then, we used an unsupervised statistical evaluation, the extended Regression Without Truth (eRWT) that ranks different methods according to their accuracy in estimating a specific biomarker in a population. The segmentation accuracy was evaluated by focusing on the left ventricular ejection fraction (LVEF) estimate resulting from the LV contour delineation using a public cardiac cine MRI database. Eight different segmentation methods, including three expert delineations, were studied, and sixteen combinations of the five automated methods were investigated. The supervised and unsupervised evaluations demonstrated that in most cases, STAPLE results provided better estimates of the LVEF than individual automated segmentation methods. In addition, LVEF obtained with STAPLE were within inter-expert variability. Overall, combining different automated segmentation methods improved the reliability of the segmenta-tion result compared to that obtained using an individual metho

Utility of Cardiac Magnetic Resonance to assess association between admission hyperglycemia and myocardial damage in patients with reperfused ST-Segment Elevation Myocardial Infarction

International audienceAbstract: Aims: to investigate the association between admission hyperglycemia and myocardial damage in patients with ST-segment elevation myocardial infarction (STEMI) using Cardiac Magnetic Resonance (CMR). Methods: We analyzed 113 patients with STEMI treated with successful primary percutaneous coronary intervention. Admission hyperglycemia was defined as a glucose level >= 7.8 mmol/l. Contrast-enhanced CMR was performed between 3 and 7 days after reperfusion to evaluate left ventricular function and perfusion data after injection of gadolinium-DTPA. First-pass images (FP), providing assessment of microvascular obstruction and Late Gadolinium Enhanced images (DE), reflecting the extent of infarction, were investigated and the extent of transmural tissue damage was determined by visual scores. Results: Patients with a supramedian FP and DE scores more frequently had left anterior descending culprit artery (p = 0.02 and < 0.001), multivessel disease (p = 0.02 for both) and hyperglycemia (p < 0.001). Moreover, they were characterized by higher levels of HbA(1c) (p = 0.01 and 0.04), peak plasma Creatine Kinase (p < 0.001), left ventricular end-systolic volume (p = 0.005 and < 0.001), and lower left ventricular ejection fraction (p = 0.001 and < 0.001). In a multivariate model, admission hyperglycemia remains independently associated with increased FP and DE scores. Conclusion: Our results show the existence of a strong relationship between glucose metabolism impairment and myocardial damage in patients with STEMI. Further studies are needed to show if aggressive glucose control improves myocardial perfusion, which could be assessed using CMR

Analyse quantitative de la prostate en TEP/TDM à la F-Fluorocholine guidée par l'IRM multimodale lors de la récidive biochimique du cancer prostatique

Objectif : Décrire le comportement métabolique en TEP à la 18F-Fluorocholine (FCH) des territoires prostatiques identifiés par l'IRM (zone périphérique, zone centrale, tumeur) et évaluer les relations entre le métabolisme prostatique et les paramètres IRM. Matériel et méthodes : Trente et un patients présentant une récidive biochimique d un cancer de la prostate après traitement par radiothérapie (PSA médian : 3,5 ng/ml) furent inclus rétrospectivement. Chaque patient bénéficia d un examen TEP/TDM (Philips Gemini TF) consistant en une acquisition dynamique de 8 minutes centrée sur le pelvis immédiatement après injection de 4 MBq/Kg de FCH suivie d'une acquisition corps entier, et d une IRM multimodalités (séquences T1, T2, diffusion, perfusion et spectroscopie multivoxels) centrée sur le pelvis (Siemens TrioTIM). Les images TDM furent utilisées comme référence pour un recalage rigide avec l'IRM. A partir des images IRM, les régions d intérêt suivantes furent définies dans chaque prostate : zone centrale (ZC), zone périphérique (ZP) et zone tumorale (ZT), définie selon les critères de la Société Européenne d Urologie (ESUR). Résultats : Une récidive tumorale intra-prostatique (ZT) fut identifiée chez 16 patients sur l IRM. La ZT présentait un métabolisme (SUVmoy) significativement supérieur à la ZP (2,65 vs 1,52 ; p0,05). La ZC présentait également un métabolisme supérieur à la ZP (2,07 vs 1,52 ; p<0,001). Il n'y avait pas de différence significative entre les 3 zones concernant la cinétique précoce d accumulation de la FCH (pente initiale 1-2 min et finale 2-8 minutes). Les paramètres IRM n'étaient pas significativement corrélés avec le métabolisme. Conclusion : En cas de récidive locale de cancer prostatique après radiothérapie initiale, il ne semble pas exister de différence métabolique entre la tumeur et la zone centrale saine. La sensibilité de détection de la récidive en zone centrale apparaît donc plus limitée, sans retrouver d'apport supplémentaire des acquisitions TEP dynamiques.DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

Facteurs prédictifs de cardiotoxicité induite par le trastuzumab (intérêt de l'analyse de la fonction diastolique en ventriculographie isotopique)

DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF