Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 12 of 12 for “"4DCT"”.
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Discrete spring–mass system inversion of lung stiffness from 4DCT with adjoint regularization and graph convolutional network
… lung stiffness from four dimensional CT (4DCT) without requiring elastography labels. At its core is a discrete spring–mass system (SMS) formulation that approximates small strain linear elasticity on a tetrahedral mesh. Each respiratory phase is modeled as a quasi static equilibrium …
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Moving Phantom Study of Stereotactic Body Radiation Therapy for Lung Cancer
… (=20mm). Four-dimensional computed tomography (4DCT) and cone beam computed tomography (CBCT) are important methodologies for SBRT, but previously have only been used to evaluate regular patterns. For targets moving regularly or irregularly within a small range (7.0 ± 1.8 mm, n = 6), we observed …
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Analysis of 3D and 4D proton treatment planning for hepatic tumors
… of gating on radiation dose to normal tissue. 4DCT scans are collected for 25 patients with hepatic tumors treated by proton radiotherapy. The 4D treatment planning process explicitly takes into account respiratory motion of abdominal organs. A 4DCT scan consists of 10 3D anatomical states, …
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Improving Dose-Response Correlations For Locally Advanced Nsclc Patients Treated With Imrt Or Pspt
… using deformable registration of weekly 4DCT images acquired over the course or radiotherapy and (b) the incorporation of variable relative biological effectiveness (RBE), would lead to statistically and clinically significant improvement in the correlation of RP with biologically …
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Comparison of Tumor Shrinkage and Cumulative Dose Distribution For Lung Cancers
… repeated 4-dimensional computed tomography (4DCT) scans during the course of radiation treatments. The original GTVp contours were propagated to T50 of weekly 4DCT images using deformable image registration and their absolute volumes were measured. Statistical analysis was performed to …
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Detecting and Evaluating Therapy Induced Changes In Radiomics Features Measured From Non-Small Cell Lung Cancer to Predict Patient Outcomes
… from weekly 4-dimensional computed tomography (4DCT) images of non-small cell lung cancers (NSCLC) change during treatment and if those changes are prognostic for patient outcomes or dependent on treatment modality. Radiomics features are quantitative metrics designed to evaluate tumor …
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Investigation of Radiation Injury In The Esophagus From Definitive Chemoradiation Therapy Using Novel Imaging Biomarkers
… using 4-dimensional computed tomography (4DCT) and <sup>18</sup>fluorodeoxyglucose positron emission tomography (FDG-PET), separately. These imaging biomarkers were then compare with radiation esophagitis grade, using traditional and machine learning techniques, and shown to objectively …
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Towards Intelligent Tumor Tracking and Setup Verification in Radiation Therapy For Lung Cancer
… patient verification. We propose to register 4DCT and 2D x-ray images taken before treatment to derive the couch shifts necessary for precise radiotherapy. The proposed technique leads to improved patient care.
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A Patient-Specific Multiscale Model of Mechanical Ventilation of COVID-19-afflicted Lungs
… using four-dimensional computed tomography (4DCT) imaging data from COVID-19 patients. Models presented in this thesis were designed to provide insight into airflow redistribution and volume and pressure differentials on a regional basis. One model was developed as a patient-specific …
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Four-Dimensional Imaging of Respiratory Motion in the Radiotherapy Treatment Room Using a Gantry Mounted Flat Panel Imaging Device
… <super/> 4D DTS, 360<super> o <super/> CBCT and 4DCT, respectively. Motion artifacts for 4D DTS were found to be substantially less than those seen in 4DCT, which is the current clinical standard in 4D imaging. </p><p>We then developed a comprehensive framework for relating patient respiratory …
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IMAGE-BASED RESPIRATORY MOTION EXTRACTION AND RESPIRATION-CORRELATED CONE BEAM CT (4D-CBCT) RECONSTRUCTION
… Respiration-correlated or four-dimensional CT (4DCT) imaging techniques have been recently integrated into imaging systems for verifying tumor position during treatment and managing respiration-induced tissue motion. The quality of the 4D reconstructed volumes is highly affected by the …
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Advances in real-time thoracic guidance systems
… are modeled via respiratory correlated imaging: 4DCT) coupled with a breathing surrogate representative of the patient's respiratory phase/amplitude. Once the target position is known with respect to the surrogate, intervention can be performed when the target is in the correct location. The …