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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A New Device for Stereotactic ct-Guided Biopsy of the Canine Brain: Design, Construction, and Needle Placement Accuracy

Giroux, Alain G. 19 June 2000 (has links)
Computed tomography (CT) is an imaging technique that uses x-ray and computers to create cross-sectional images of structures. Stereotactic CT-guided biopsy is defined as the use of a stable apparatus to direct and perform tissue biopsies under CT guidance. For the brain, the principal advantage of stereotactic CT guidance over other biopsy techniques is its high accuracy in getting a sample from deep-seated lesions. The objectives of this study were to create an inexpensive CT-guided stereotactic device adaptable to different canine head sizes and to test the accuracy of the device for needle placement in deep-seated brain targets. A biopsy device was created that consists of four main components: a CT table fixation device, a head fixture, a needle fixture , and motion control system. Accuracy was tested using 16 head and neck specimens obtained from dogs euthanitized for reasons unrelated to the brain. Deep-seated (caudate nucleus and pituitary gland) targets were identified on CT. After a 5 mm craniotomy, the biopsy needle, with CT monitoring, was progressively introduced into the target. The final needle track distance was measured on CT. The brain was removed and sliced to verify placement of the needle tip within the target and to measure the actual needle track distance. The total cost of materials and construction for the stereotactic CT-guided biopsy device was $785.00. No difference in needle placement accuracy was identified for caudate and pituitary targets. Based on assessments by 2 independent observers, the caudate target was successfully hit 75% of the time. Pituitary targets were successfully hit 96.8 % of the time. Actual needle track lengths were an average of 3.2 mm less that the track length measured on CT. This difference was most likely due to incomplete staining of the bevel part of the needle track on gross specimens. / Master of Science
2

Radiographer performed stereotactic needle core biopsy: Making a difference

Dixon A.M., Dearnley, Christine A. 05 November 2008 (has links)
No / This case study describes a qualitative investigation of the experiences of 14 experienced mammography radiographers who successfully undertook a formal programme of education and training in stereotactic needle core biopsy (SNCB) of the breast. They now routinely perform SNCB within symptomatic and screening breast services in a variety of NHS hospitals across the country. All 14 radiographers completed a semi-structured postal questionnaire approximately six months after the end of the course. A tentative theory derived from the data suggests that the professional challenge associated with radiographer-performed SNCB builds personal confidence and effects positive change. Three main categories emerging from the data e challenge, confidence and change are underpinned by two main themes e educational, professional and service drivers that promote the realisation of goals and vision; and personal, peer and external motivation sustained by respect, recognition and reward. SNCB role extension as explored in this study is having a positive and transformational impact on patient users of breast diagnostic clinical services and on the professional health carers providing them. The key drivers for this as identified in the study are a formal educational experience, professional role extension opportunities and the NHS modernisation process. The participants experienced positive change as individuals and as professional breast cancer multidisciplinary team members. Academic and financial rewards, respect and recognition from colleagues across professional disciplines and from patients, were key motivators that sustained the process. This study indicates that radiographer-performed SNCB can help deliver the NHS Plan and the NHS Cancer Plan and in doing so has the potential to improve the working lives of health care professionals and ultimately to improve the quality of care for patients.
3

<b>Using Minimally-Invasive </b><b><i>In vivo </i></b><b>Imaging to Map the Genomic Heterogeneity of Human Brain Tumors</b>

Mahsa Servati (18406212) 18 April 2024 (has links)
<p dir="ltr">Human brain tumors present significant challenges due to their heterogeneous nature, known as intra-tumoral heterogeneity (ITH), which evolves over space and time, leading to treatment resistance and poor patient outcomes. Current diagnostic methods rely on pre-surgical imaging and single biopsy samples, providing only a partial understanding of the tumor microenvironment (TME) and often resulting in incomplete targeting of tumor mutations, leaving residual disease vulnerable to recurrence. Our hypothesis proposes a novel approach: utilizing multimodal and multiparametric <i>in vivo</i> imaging to map the cellular and molecular characteristics of the TME. By correlating imaging signatures with underlying somatic and genomic aberrations, we aim to develop a predictive model guiding personalized targeted therapies to effectively address the heterogeneity of brain tumors.</p><p dir="ltr">To achieve this goal, we designed, tested, and validated a predictive model through a pilot study using clinical MRI scans and one stereotactic biopsy sample. Subsequently, we optimized a multimodal and multiparametric imaging protocol including MRI and PET scans, to acquire comprehensive morphological, functional, and molecular data from the TME. Additionally, we established a detailed pipeline for subject recruitment, data collection, and post-processing to ensure the robustness and reliability of our model.</p><p dir="ltr">This innovative approach has the potential to overcome the limitations of current diagnostic methods by providing a comprehensive understanding of the TME using minimally-invasive imaging techniques. By correlating imaging data with ground truth pathology and genomics, this model will enhance brain tumor diagnosis and facilitate the implementation of targeted therapies, ultimately improving treatment response and patient outcomes.</p>

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