scholarly journals Construction of patient‐specific computational models for organ dose estimation in radiological imaging

2019 ◽  
Vol 46 (5) ◽  
pp. 2403-2411 ◽  
Author(s):  
Tianwu Xie ◽  
Azadeh Akhavanallaf ◽  
Habib Zaidi
Author(s):  
Wanyi Fu ◽  
William P. Segars ◽  
Ehsan Abadi ◽  
Shobhit Sharma ◽  
Anuj J. Kapadia ◽  
...  

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 898
Author(s):  
Marta Saiz-Vivó ◽  
Adrián Colomer ◽  
Carles Fonfría ◽  
Luis Martí-Bonmatí ◽  
Valery Naranjo

Atrial fibrillation (AF) is the most common cardiac arrhythmia. At present, cardiac ablation is the main treatment procedure for AF. To guide and plan this procedure, it is essential for clinicians to obtain patient-specific 3D geometrical models of the atria. For this, there is an interest in automatic image segmentation algorithms, such as deep learning (DL) methods, as opposed to manual segmentation, an error-prone and time-consuming method. However, to optimize DL algorithms, many annotated examples are required, increasing acquisition costs. The aim of this work is to develop automatic and high-performance computational models for left and right atrium (LA and RA) segmentation from a few labelled MRI volumetric images with a 3D Dual U-Net algorithm. For this, a supervised domain adaptation (SDA) method is introduced to infer knowledge from late gadolinium enhanced (LGE) MRI volumetric training samples (80 LA annotated samples) to a network trained with balanced steady-state free precession (bSSFP) MR images of limited number of annotations (19 RA and LA annotated samples). The resulting knowledge-transferred model SDA outperformed the same network trained from scratch in both RA (Dice equals 0.9160) and LA (Dice equals 0.8813) segmentation tasks.


2021 ◽  
Vol 216 (3) ◽  
pp. 824-834
Author(s):  
Wanyi Fu ◽  
Francesco Ria ◽  
William Paul Segars ◽  
Kingshuk Roy Choudhury ◽  
Joshua M. Wilson ◽  
...  

Author(s):  
Justin Raudabaugh ◽  
Giao Nguyen ◽  
Carolyn Lowry ◽  
Natalie Januzis ◽  
James Colsher ◽  
...  

Author(s):  
Andrew E. Anderson ◽  
Benjamin J. Ellis ◽  
Christopher L. Peters ◽  
Jeffrey A. Weiss

Segmentation of medical image data is often used for the construction of computational models to study the mechanics of diarthrodial joints such as the hip and knee. The analyst must demonstrate that the reconstructed geometry is an accurate representation of the true continuum to ensure model validity. This becomes especially important for computational modeling of joint contact, which requires accurate reconstruction of articular cartilage. Although volumetric computed tomography (CT) is often used to image diarthrodial joints, the lower bounds for detecting articular cartilage thickness and the influence of imaging parameters on the ability to image cartilage have not been reported. The use of contrast agent (CT arthrography) is necessary to visualize the surface of articular cartilage in live patients. Thus, it is of primary interest to quantify the accuracy of CT arthrography to demonstrate the feasibility of patient-specific modeling. The objectives of this study were to assess the accuracy and detection limits of CT for measuring simulated cartilage thickness using a phantom and to quantify changes in accuracy due to alterations in contrast agent concentration, imaging plane direction, spatial resolution and joint spacing.


Author(s):  
Jean-Pierre Rabbah ◽  
Neelakantan Saikrishnan ◽  
Ajit P. Yoganathan

Patient specific mitral valve computational models are being actively developed to facilitate surgical planning. These numerical models increasingly employ more realistic geometries, kinematics, and mechanical properties, which in turn requires rigorous experimental validation [1]. However, to date, native mitral flow dynamics have not been accurately and comprehensively characterized. In this study, we used Stereoscopic Particle Image Velocimetry (SPIV) to characterize the ventricular flow field proximal to a native mitral valve in a pulsatile experimental flow loop.


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