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 20 of 20 for “"phantom study"”.
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Moving Phantom Study of Stereotactic Body Radiation Therapy for Lung Cancer
… we performed a systematic evaluation using phantoms that simulated motions from real patients (irregular motions) as well as sinusoidal motions (regular motions). The irregular patterns investigated in this study were of two types: small range irregular breathing motions (=10mm) and large …
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Assessment of fetoscopic tracheal occlusion using ultrasound images in phantom study
Congenital Diaphragmatic Hernia (CDH) is a birth defect that affects approximately 1 in 2000-5000 neonates. Most of the CDH cases are isolated, which means that affected individuals have no other major malformations. The diaphragm is a muscle that separates the chest from the abdomen. Incomplete …
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The Advantage of Digital Tomosynthesis for Pulmonary Nodule Detection concerning Influence of Nodule Location and Size: Phantom Study
… were inserted into 8 different area of lung phantom classified as danger or non-danger zone. All 96 cases in which SPNs were inserted underwent examinations of 3 modalities at the same time. Additional 96 examinations were done to serve as a normal control using the same thoracic phantom. …
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Application of a High‑Resolution Computed Radiography System in Detecting an Iodinated X‑ray Contrast Agent: Small Animal Phantom Study
… Omnipaque‑240, an iodinated contrast agent, in a phantom mimicking small animal tumor model.</p> <p>The first phase of the project was dedicated to a comprehensive assessment of CR image quality by measuring presampled Modulation Transfer Function (MTF), Noise Power Spectrum (NPS), Relative …
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A Phantom Study for Attenuation Change and Detection of Calcification in Lung Nodules According to Variation of Examination Techniques in Low Dose CT
… standard-dose CT. Material and Methods : A chest phantom containing artificial nodules was scanned with 64-detector-row and 128-detector-row CT scanners using a standard and various low-dose settings with iterative reconstruction. Mean attenuation of nodules and image noise were compared between …
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Evaluation of the effect of breast implants on the accuracy of the CT attenuation Correction (CTAC) map for SPECT/CT myocardial perfusion imaging: a phantom study
… and without three sizes of breast implant, ina phantom study. The first experiment used a diagnostic CT scanner to design the method. Thesecond experiment was carried out in a clinical centre using the CT components of a SPECT/CTscanner to assess the impact of three different breast implants on …
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Assessment of the Measurement Repeatability and Sensitivity of a Noninvasive Blood Perfusion Measuring Probe
… blood perfusion probe by testing the probe on phantom tissue, such that the effects of physiologic or pathologic conditions on the blood perfusion could be eliminated. Another objective was to conduct a preliminary in vivo study using rats for the purpose of establishing proper experimental …
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DEVELOPMENT OF ENHANCED CALIBRATION SYSTEM AND MEASUREMENT PROGRAM FOR RADIOSTEREOMETRIC ANALYSIS
… by using numerical and image simulations. The phantom study showed that the novel cage has significant improvement of accuracy and precision over two widely used cages. By implementing and modifying existing algorithms, a new measurement program for RSA radiographs was also developed. The …
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Evaluation of image receptor angulation during mediolateral oblique positioning for optimised pressure and area distribution in mammography
… in two phases. Phase one was an anthropomorphic phantom study to establish a structured and reproducible method of using the angle of the sternum to measure the correct angle of the IR for MLO projection. An inclinometer was used to measure the sternal angle of phantom model used. Six sets of …
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Evaluating Bone by Ultrasound
… unfortunately utilizes ionizing radiation. This study proposes the application of a reflection ultrasound method to evaluate non-BMD properties of cancellous bone, including porosity and the microstructure of the trabecular network, all of which are directly related to bone morphological changes …
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Feasibility of Using Virtual Unenhanced Images to Replace Pre-Contrast Images In Multiphase Renal Ct Examinations
… clinical efficiency.</p> <p>A retrospective study was conducted for 60 consecutively selected patient exams. VUE and TUE images were compared qualitatively and the differences were tested using a Bayesian Hierarchical model. VUE images were found to be inferior to TUE images for visualization …
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Dynamic Magnetic Resonance Imaging for Tumor Prognosis
… tumor physiological characteristics. In order to study the BOLD mechanism, I designed a phantom system and built it for in-vitro study. Since inhalation of oxygen could cause variation in the blood flow and oxygenation, and BOLD MRI is sensitive to both these factors, it becomes very important to …
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Influential Factors and Predicting Dose Delivery Accuracy for Imaging and Radiation Oncology Core’s Phantom Program using Machine Learning
… clinical trials. To obtain this mission, IROC’s phantom program provides a third-party end-to-end check of the clinical workflow of a patient receiving radiotherapy. The goal of the phantom audit is to compare the dose delivered to the dose planned by the treatment system ensuring dose delivery …
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Optimization of Image Guided Radiation Therapy for Lung Cancer Using Limited-angle Projections
… using the extended cardiac torso (XCAT) digital phantom, the phase-matched DTS technique localizes the 3D target position with an localization error of 1.07 mm (± 0.57 mm) (average ± standard deviation (S.D.)). Similarly, for the total 60 scenarios evaluated using the computerized imaging …
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Evaluation of yttrium-90 positron emission tomography dosimetry
… and Methods:</strong> PET acquisitions of a phantom containing <sup>90</sup>Y filled cylindrical inserts were acquired to determine quantitative accuracy of the PET images to measure <sup>90</sup>Y activity. Numerous reconstruction algorithms were used to determine the optimal protocol to …
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Estimating Target Vessel Location on Robot-Assisted CABG using Feature-based CT to US Registration
… validated via both an in vitro and a clinical study, and predicted the position of the peri-operative target vessel location with ~ 3.5 mm RMS accuracy in the in vitro study while it yielded ~ 5.0 mm accuracy for the clinical validation. As the desired clinical accuracy imposed by this …
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Evaluation of external ventricular drain complications and the use of a procedure-targeted image-guidance system
… Board-approved retrospective cross-sectional study was conducted at the Brigham and Women's Hospital (BWH) to characterize the practice of external ventricular drain placements using data from the patient electronic medical record. Post-procedure catheter location was measured on …
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Establishing an evidence-base for erect pelvis radiography : positioning, radiation dose and image quality
… (Diers) and an inclinometer.Phase Two was a phantom study evaluating the potential changes to radiation dose and image quality when moving between supine and erect imaging. Phase two was undertaken using three experiments (experiment #1, experiment #2 and experiment #3). Experiment #1 …
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Myocardial Perfusion Imaging With Rb-82 PET
… imaging (MPI) is an effective technique used to study the left ventricular ejection function (LVEF), myocardial perfusion, wall motion, and wall thickening. Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are two modalities that can be used to quantify …
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Metaboloptics: In Vivo Optical Imaging to Enable Simultaneous Measurement of Glucose Uptake, Mitochondrial Membrane Potential, and Vascular Features in Cancer
… new chemical species. </p><p>We also performed a phantom study on the hyperspectral imaging system, used for all animal imaging in Aim 1 and Aim 2, to estimate the range of 2-NBDG and TMRE concentrations that are seen at the tissue level in normal and tumor window chambers. We created a new …