Medical Specialties Commons^™

Social-Ecological Factors Affecting Patient Shield Use Among Radiologic And Computed Tomography Technologists, Megan Housenick-Lee

Electronic Theses and Dissertations

Medical radiation is estimated to contribute to over 200,000 deaths annually. Recent increases in the use of radiation-producing medical imaging examinations have led to increasing cumulative radiation dose to the general public. Multiple measures have been taken to address this alarming trend, including physician education, technologist education on dose reduction, and equipment-facilitated dose reduction techniques. Shield use can reduce the primary beam by up to 95%. Medical imaging technologists are the primary individuals responsible for applying shielding during an examination. Currently, literature shows that technologists are not shielding individuals as often as they should.

After pilot testing, medical imaging technologists …

Correlation Between Ovarian Volume And Polycystic Ovarian Syndrome Using Ultrasound., Ndecho Muriuki Guandaru

Theses & Dissertations

Background: Polycystic ovarian syndrome (PCOS) is the most common endocrine abnormality in women of reproductive age with a prevalence of 5-10% in different populations. The prevalence of PCOM in patients with PCOS has been shown to be ≥ 90% in different populations. Diagnostic evaluation accounts for a relatively minor part of the total costs of providing care and evaluating women with PCOS. Hence more widespread and liberal screening for the disorder appears be a cost-effective strategy in susceptible patients. PCOM on ultrasound is diagnosed if one of the following is present in one or both of the ovaries; Ovarian volume …

Association Between Calcaneal Spurs And Plantar Fasciitis: A Study Comparing Heel Plain Radiography And Sonography, Micah Silaba Ominde

Theses & Dissertations

Background: Heel pain is a common clinical entity that requires appropriate diagnostic evaluation. Multiple clinical conditions are known to cause heel pain but plantar fasciitis is the most common. Calcaneal spurs are thought to be associated with heel pain and plantar fasciitis but conclusive studies to prove this are sparse. Plain radiography is usually the first line imaging modality for imaging patients with heel pain. Magnetic Resonance Imaging is the gold standard for diagnosing plantar fasciitis but studies have shown ultrasound to be comparable in sensitivity and specificity. The aim is to establish whether a relationship exists between calcaneal spurs …

Diagnostic Value Of Complementary Strain Elastography In The Classification Of Breast Masses, Sarah Muthoni Wambui

Theses & Dissertations

Background: Breast cancer is the commonest cancer in women. Ultrasound has a high sensitivity but low specificity in the classification of benign and malignant breast masses. Strain elastography has the potential of increasing the specificity of breast ultrasound in classifying malignant and benign breast masses and reducing the number of benign breast biopsies performed. The diagnostic value of breast elastography in African women is not known.

Objective: The aim of this study was to evaluate the additive diagnostic value of strain elastography to conventional ultrasound in the classification of malignant and benign breast masses in an African population.

Materials …

Comparison Of Image Quality In High Pitch Free Breathing Versus Standard Pitch Breath-Holding Computed Tomographic Pulmonary Angiography., Kevin Onyinkwa Ombati

Theses & Dissertations

Background: Pulmonary embolism (PE) is the third most common acute cardiovascular disease. Missed diagnosis is responsible for most preventable deaths associated with PE. Artefacts from cardiac and breathing motion are a main pitfall. Advances in Computed Tomographic imaging have enabled rapid imaging in an attempt to overcome these pitfalls.

Objective: To compare image quality when using high pitch free breathing versus standard pitch breath holding Computed Tomographic Pulmonary Angiography (CTPA) using a dual source scanner.

Methods: This was a randomised control trial whereby patients referred to the radiology department for CTPA examination for suspected pulmonary embolism were randomly selected into …

Sensitivity Of Diffuse Reflectance Spectroscopy To Dose- And Depth-Dependent Changes In Tumor Oxygenation After Radiation Therapy, Daria Semeniak

Graduate Theses and Dissertations

Along with chemotherapy, immunotherapy, and surgery, radiotherapy is one of the most common treatments used against cancer. Around 50% of all cancer patients undergo radiation therapy. While for some patients radiotherapy works efficiently and lead to a complete cancer disappearance, for others treatment outcome may be less favorable due to radioresistance processes happening within a tumor on the molecular level. Radioresistance remains a big challenge for modern oncology. The ability to identify radioresistance at the early stage of radiotherapy would help physicians to improve therapy efficiency. At the current moment, despite the rapid progress in cancer understanding and diagnostic modalities, …

Mammogram And Tomosynthesis Classification Using Convolutional Neural Networks, Xiaofei Zhang

Theses and Dissertations--Computer Science

Mammography is the most widely used method of screening for breast cancer. Traditional mammography produces two-dimensional X-ray images, while advanced tomosynthesis mammography produces reconstructed three-dimensional images. Due to high variability in tumor size and shape, and the low signal-to-noise ratio inherent to mammography, manual classification yields a significant number of false positives, thereby contributing to an unnecessarily large number of biopsies performed to reduce the risk of misdiagnosis. Achieving high diagnostic accuracy requires expertise acquired over many years of experience as a radiologist.

The convolutional neural network (CNN) is a popular deep-learning construct used in image classification. The convolutional process …

Validation, Optimization, And Image Processing Of Spiral Cine Dense Magnetic Resonance Imaging For The Quantification Of Left And Right Ventricular Mechanics, Gregory J. Wehner

Theses and Dissertations--Biomedical Engineering

Recent evidence suggests that cardiac mechanics (e.g. cardiac strains) are better measures of heart function compared to common clinical metrics like ejection fraction. However, commonly-used parameters of cardiac mechanics remain limited to just a few measurements averaged over the whole left ventricle. We hypothesized that recent advances in cardiac magnetic resonance imaging (MRI) could be extended to provide measures of cardiac mechanics throughout the left and right ventricles (LV and RV, respectively).

Displacement Encoding with Stimulated Echoes (DENSE) is a cardiac MRI technique that has been validated for measuring LV mechanics at a magnetic field strength of 1.5 T but …

Properties And Optimization Of Respiratory Navigator Gating For Spiral Cine Dense Cardiac Mri, Sean Michael Hamlet

Theses and Dissertations--Electrical and Computer Engineering

Cardiac magnetic resonance (MR) imaging can non-invasively assess heart function. Displacement encoding with stimulated echoes (DENSE) is an advanced cardiac MR imaging technique that measures tissue displacement and can be used to quantify cardiac mechanics (e.g. strain and torsion). When combined with clinical risk factors, cardiac mechanics have been shown to be better predictors of mortality than traditional measures of heart function.

End-expiratory breath-holds are typically used to minimize respiratory motion artifacts. Unfortunately, requiring subjects to breath-hold introduces limitations with the duration of image acquisition and quality of data acquired, especially in patients with limited ability to hold their breath. …

From Gd2o3suspension To Nanocomposite: Synthesis, Properties And Radiation Protection, Ly B. T. La

Theses: Doctorates and Masters

This study provides details for the design, preparation of an environmentally friendly, clinically safe and lightweight radiation protective shield made ofGd2O3/epoxy nanocomposite (Gd-nanocomposite) which is proposed as an alternative to traditional toxic lead (Pb)-based aprons for diagnostic X-ray protection. In theory, this particulate nanocomposite can possess significant features of both inorganic particles and organic polymeric matrices. However, in practice, its performance does not simply depend on the sum of the individual contributions of characteristics of the constituent phases but on the interaction of their inner interfaces and the homogeneous dispersion of inorganic particles in the polymer matrix.

The miniaturization of …