scholarly journals Enabling 3D-Liver Perfusion Mapping from MR-DCE Imaging Using Distributed Computing

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Benjamin Leporq ◽  
Sorina Camarasu-Pop ◽  
Eduardo E. Davila-Serrano ◽  
Frank Pilleul ◽  
Olivier Beuf
Keyword(s):  
Distributed Computing ◽  
Liver Perfusion ◽  
Reference Method ◽  
Free Breathing ◽  
Blood Pool ◽  
Average Value ◽  
Contrast Enhanced ◽  
Healthy Control ◽  
Speed Up ◽  
Dynamic Acquisition

An MR acquisition protocol and a processing method using distributed computing on the European Grid Infrastructure (EGI) to allow 3D liver perfusion parametric mapping after Magnetic Resonance Dynamic Contrast Enhanced (MR-DCE) imaging are presented. Seven patients (one healthy control and six with chronic liver diseases) were prospectively enrolled after liver biopsy. MR-dynamic acquisition was continuously performed in free-breathing during two minutes after simultaneous intravascular contrast agent (MS-325 blood pool agent) injection. Hepatic capillary system was modeled by a 3-parameters one-compartment pharmacokinetic model. The processing step was parallelized and executed on the EGI. It was modeled and implemented as a grid workflow using the Gwendia language and the MOTEUR workflow engine. Results showed good reproducibility in repeated processing on the grid. The results obtained from the grid were well correlated with ROI-based reference method ran locally on a personal computer. The speed-up range was 71 to 242 with an average value of 126. In conclusion, distributed computing applied to perfusion mapping brings significant speed-up to quantification step to be used for further clinical studies in a research context. Accuracy would be improved with higher image SNR accessible on the latest 3T MR systems available today.

scholarly journals Prevalence of Failure of Passive Transfer of Immunity in Dairy Calves in the Czech Republic

2019 ◽  
Vol 67 (1) ◽  
pp. 163-172 ◽  
Author(s):  
Stanislav Staněk ◽  
Eliška Nejedlá ◽  
Petr Fleischer ◽  
Alena Pechová ◽  
Soňa Šlosárková
Keyword(s):  
Reference Method ◽  
Herd Size ◽  
Passive Transfer ◽  
Dairy Calves ◽  
Dairy Herds ◽  
Serum Samples ◽  
Average Value ◽  
Holstein Breed ◽  
Newborn Calves ◽  
Autumn And Winter

Prevalence of failure of passive transfer (FPT) of immunity remains relatively high worldwide. The aim of this study was to estimate the FPT prevalence in Czech dairy calves and to evaluate the selected factors – breed, herd size, sex of calves, single versus twin births and the influence of the season of birth. A total of 1,175 serum samples were taken from calves of Czech Fleckvieh and Holstein breed from 33 herds between October 2015 and October 2017. Serum IgG concentration was determined by reference method for IgG determination – radial immunodiffusion. Statistical evaluation was performed by Kruskal‑Wallis test. The concentration of IgG ranged from 1.5 to 46.6 g/L with average value 13.7 g/L and was significantly influenced by breed, size of the herd and season. Using the criterion IgG < 10 g/L, it was found that 34.6 % of calves had FPT. The prevalence of FPT by breed was 42.9 % vs. 24.2 % (Czech Fleckvieh vs. Holstein), by size of the herd 45.0, 44.4, 25.5 and 22.0 % (< 200, 200–399, 400–599 and ≥ 600 cows per herd, respectively) and by season 25.3, 34.6, 29.9 and 52.5 % (spring, summer, autumn and winter, respectively). The sex of calves was not found to be a statistically significant factor. The study in newborn calves showed that FPT is still an important problem in Czech dairy herds, especially in the Czech Fleckvieh breed. In smaller herds and especially in the winter, the prevalence of FPT was very high.

PARTICLE FILTER OPTIMIZATION TOOLS FOR DYNAMICAL SYSTEMS PROBABILISTIC MODELS

2021 ◽  
pp. 4-10
Author(s):  
П.В. Полухин
Keyword(s):  
Dynamical Systems ◽  
Distributed Computing ◽  
Particle Filter ◽  
Dynamic Systems ◽  
Probabilistic Models ◽  
Sufficient Statistics ◽  
Voice Synthesis ◽  
Sample Decomposition ◽  
Speed Up ◽  
Filtering Procedure

В работе предложены математические инструменты на основе достаточных статистик и декомпозиции выборок в сочетании с алгоритмами распределенных вычислений, позволяющие существенно повысить эффективность процедуры фильтрации. Filtering algorithms are used to assess the state of dynamic systems when solving various practical problems, such as voice synthesis and determining the geo-position and monitoring the movement of objects. In the case of complex hierarchical dynamic systems with a large number of time slices, the process of calculating probabilistic characteristics becomes very time-consuming due to the need to generate a large number of samples. The essence of optimization is to reduce the number of samples generated by the filter, increase their consistency and speed up computational operations. The paper offers mathematical tools based on sufficient statistics and sample decomposition in combination with distributed computing algorithms that can significantly improve the efficiency of the filtering procedure.

scholarly journals A Deep Learning Segmentation Approach in Free-Breathing Real-Time Cardiac Magnetic Resonance Imaging

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Fan Yang ◽  
Yan Zhang ◽  
Pinggui Lei ◽  
Lihui Wang ◽  
Yuehong Miao ◽  
...  
Keyword(s):  
Deep Learning ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Cardiac Function ◽  
Data Augmentation ◽  
Function Analysis ◽  
Free Breathing ◽  
Blood Pool ◽  
Training Time ◽  
Segmentation Approach

Objectives. The purpose of this study was to segment the left ventricle (LV) blood pool, LV myocardium, and right ventricle (RV) blood pool of end-diastole and end-systole frames in free-breathing cardiac magnetic resonance (CMR) imaging. Automatic and accurate segmentation of cardiac structures could reduce the postprocessing time of cardiac function analysis. Method. We proposed a novel deep learning network using a residual block for the segmentation of the heart and a random data augmentation strategy to reduce the training time and the problem of overfitting. Automated cardiac diagnosis challenge (ACDC) data were used for training, and the free-breathing CMR data were used for validation and testing. Results. The average Dice was 0.919 (LV), 0.806 (myocardium), and 0.818 (RV). The average IoU was 0.860 (LV), 0.699 (myocardium), and 0.761 (RV). Conclusions. The proposed method may aid in the segmentation of cardiac images and improves the postprocessing efficiency of cardiac function analysis.

scholarly journals Nanoparticle Contrast-enhanced T1-Mapping Enables Estimation of Placental Fractional Blood Volume in a Pregnant Mouse Model

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrew A. Badachhape ◽  
Laxman Devkota ◽  
Igor V. Stupin ◽  
Poonam Sarkar ◽  
Mayank Srivastava ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Blood Volume ◽  
Placental Tissue ◽  
Blood Pool ◽  
Pregnant Mouse ◽  
Gadolinium Contrast ◽  
Vascular Perfusion ◽  
Post Contrast ◽  
Placental Perfusion ◽  
Contrast Enhanced

AbstractNon-invasive methods for estimating placental fractional blood volume (FBV) are of great interest for characterization of vascular perfusion in placentae during pregnancy to identify placental insufficiency that may be indicative of local ischemia or fetal growth restriction (FGR). Nanoparticle contrast-enhanced magnetic resonance imaging (CE-MRI) may enable direct placental FBV estimation and may provide a reliable, 3D alternative to assess maternal-side placental perfusion. In this pre-clinical study, we investigated if placental FBV at 14, 16, and 18 days of gestation could be estimated through contrast-enhanced MRI using a long circulating blood-pool liposomal gadolinium contrast agent that does not penetrate the placental barrier. Placental FBV estimates of 0.47 ± 0.06 (E14.5), 0.50 ± 0.04 (E16.5), and 0.52 ± 0.04 (E18.5) were found through fitting pre-contrast and post-contrast T1 values in placental tissue using a variable flip angle method. MRI-derived placental FBV was validated against nanoparticle contrast-enhanced computed tomography (CE-CT) derived placental FBV, where signal is directly proportional to the concentration of iodine contrast agent. The results demonstrate successful estimation of the placental FBV, with values statistically indistinguishable from the CT derived values.

scholarly journals Contrast-Enhanced Ultrasound (CEUS) for the Evaluation of Bosniak III Complex Renal Cystic Lesions—A 10-Year Specialized European Single-Center Experience with Histopathological Validation

Medicina ◽  
2020 ◽  
Vol 56 (12) ◽  
pp. 692
Author(s):  
Vincent Schwarze ◽  
Johannes Rübenthaler ◽  
Saša Čečatka ◽  
Constantin Marschner ◽  
Matthias Frank Froelich ◽  
...  
Keyword(s):  
Imaging Modality ◽  
Color Doppler ◽  
Blood Pool ◽  
Histopathological Analysis ◽  
Cystic Lesions ◽  
Contrast Enhanced Ultrasound ◽  
Single Center ◽  
Renal Lesions ◽  
Experienced Radiologist ◽  
Contrast Enhanced

Background and objectives: The aim of the present retrospective single-center study is to evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) for assessing Bosniak III complex renal cystic lesions with histopathological validation. Materials and Methods: 49 patients with CEUS-categorized Bosniak III renal cystic lesions were included in this retrospective study. All patients underwent native B-mode, Color Doppler, contrast-enhanced ultrasound (CEUS) between 2010–2020. Eight and five patients underwent computed tomography (CT) and magnetic resonance imaging (MRI), respectively. Twenty-nine underwent (partial) nephrectomy allowing for histopathological analysis. The applied contrast agent for CEUS was a second-generation blood pool agent. Ultrasonography examinations were performed and interpreted by a single experienced radiologist with more than 15 years of experience (EFSUMB Level 3). Results: CEUS examinations were successfully performed in all included patients without registering any adverse effects. The malignancy rate of CEUS-categorized Bosniak III renal lesions accounted for 66%. Initially, cystic complexity was visualized in native B-mode. In none of the renal lesions hypervascularization was detected in Color Doppler. CEUS allowed for detection of contrast enhancement patterns in all included Bosniak III renal lesions. Delayed wash-out could be detected in 6/29 renal lesions. In two cases of histopathologically confirmed clear-cell RCC, appropriate up-grading from Bosniak IIF to III was achieved by CEUS. Conclusions: CEUS depicts a promising imaging modality for the precise diagnostic workup and stratification of renal cystic lesions according to the Bosniak classification system, thereby helping guidance of adequate clinical management in the future.

scholarly journals PO-0921: Free-breathing dynamic contrast enhanced MRI of lung cancer

2016 ◽  
Vol 119 ◽  
pp. S446
Author(s):  
S. Kumar ◽  
G. Liney ◽  
R. Rai ◽  
D. Moses ◽  
C. Choong ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Free Breathing ◽  
Dynamic Contrast Enhanced Mri ◽  
Dynamic Contrast Enhanced ◽  
Enhanced Mri ◽  
Contrast Enhanced ◽  
Contrast Enhanced Mri
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