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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

CT angiographic detection of cerebral aneurysms in patients with subarachnoid haemorrhage in a South African institution

Chisha, Mike 19 January 2021 (has links)
Study rationale The incidence, location, morphology and size characteristics of cerebral aneurysms in patients presenting to Groote Schuur hospital with either subarachnoid haemorrhage or 3 rd nerve palsy have not been established by a formal audit. Objectives To determine the patient demographics, frequency of CT angiographic detection of cerebral aneurysms and aneurysmal characteristics in patients presenting to Groote Schuur Hospital with sub-arachnoid haemorrhage and /or 3 rd nerve palsy Materials and methods Computed tomographic angiographic reports of cerebral vessels of patients who presented either with subarachnoid haemorrhage or 3 rd nerve palsy to Groote Schuur hospital were reviewed over a 19-month period from January 2018 – July 2019. The data obtained were coded, entered and analysed using IBM SPSS version 25 software. Descriptive statistics was used to report the means, modes and frequencies. Demographic and aneurysmal data were compared with a similar period 5 years previously. Results One hundred and twenty-one aneurysms (121) were analysed in 2018 -2019 and 124 in 2013-2014. The large majority were solitary (92% in both groups), small (94% and 90%) and saccular (96% and 87%) respectively. Significantly more fusiform aneurysms (13% vs 6%) were seen in the earlier group. 8 % of patients had multiple aneurysms. Less than 1% were ‘giant' ( >20mm). The mean age of the patients was the same for both periods (47 years). The mean aneurysm body size was 5.7mm and 7.1mm and the mean body: neck ratio was 6 2.1 vs 1.8b). Themost frequent locations were the posterior communicating artery (31.4% [2018/2019], 35% [2013- 2014]), anterior communicating artery (29% [2018/2019], 18.5% [2013/2014]) and the middle Cerebral Arteries (13.2% [2018/2019], 13.7% [2013/2014]). The least common sites were the Superior Cerebellar artery (SCA) [2018/2019] and the Vertebral artery (0.8%) [2013/2014]. Conclusion This study has compared the demographics of patients presenting to Groote Schuur Hospital with CT angiographically confirmed symptomatic intracranial aneurysms over two periods (January to July) 5 years apart. Both the patient demographics and the aneurysmal architecture were consistent over these time periods. Further our findings conform to that described previously both in Southern Africa and abroad i.e aneurysms which have bled are most commonly related to the posterior communicating, anterior communicating and the middle cerebral arteries and most aneurysms are small and saccular in shape. Over the periods studied, there was no change in the number of patients presenting to Groote Schuur Hospital for CT cerebral angiography and Interventional treatment post aneurysm rupture. These data represent a baseline for future statistical comparison and the information extrapolated from this study will be useful for interventive planning and resource mobilization at our institution and within the Western Cape Department of Health.
2

The Impact of Time to Major Intervention and Delayed Care for Patients with Traumatic Hemorrhage

Lamb, Tyler 25 September 2023 (has links)
Background: The specific clinical impact of delays to hemostatic intervention in trauma is under-explored. Objectives: Investigate the current understanding of the impact of increasing time to hemostasis and assess its relationship with clinical outcomes. Methods: We conducted a systematic review to characterize existing definitions of delayed hemostasis and its clinical sequelae. We conducted a cohort study of 147 trauma patients to investigate the impact of increased time to hemostasis. Results: Most studies demonstrated significant relationships between time to hemostasis and mortality, despite heterogeneity. The cohort study failed to demonstrate a significant association between time to hemostasis and mortality. Discussion: The thesis has taken steps to investigate time to hemostasis with appropriate methodology. The findings are limited by sample size and confounding by indication. Conclusions: There remains a substantial gap in the literature with respect to understanding the impact of increasing time to hemostasis in trauma and larger studies are needed.
3

Technique for Repeatable Hyperosmotic Blood-Brain Barrier Disruption in the Dog

Culver, Britt Wayne 09 July 1997 (has links)
Reversible hyperosmotic blood-brain barrier disruption (BBBD) has been used in pharmaceutical research as well as human medicine to enhance drug delivery across the blood-brain barrier. However a technique for repeatable BBBD in the canine has not been described. This study describes a repeatable technique for BBBD in the dog and evaluates the clinical and morphological effects of BBBD. Using fluoroscopic guidance, an arterial catheter was directed into the internal carotid artery via the femoral artery in ten dogs. BBBD was achieved in 5 dogs using 25% mannitol while 5 control dogs received only saline. Following recovery, dogs were monitored for clinical signs before a second, non-survival procedure was performed 2-3 weeks later. BBBD was estimated using CT densitometry as well as Evan's blue staining on post-mortem exam. Histopathological evaluation of the brain was performed on all dogs. Seven dogs completed the study. Two treatment dogs were lost after the first infusion with deteriorating neurologic function attributed to CNS edema and increased intracranial pressure. One control dog was lost due to vessel wall damage during catheterization. The remaining dogs exhibited only transient neurologic, ocular, and vasculature injury. Successful BBBD was demonstrated in all treatment dogs as evidenced by CT and Evan's blue staining. Histopathological evaluation revealed multifocal areas of infarction in all dogs indicating refinement of the technique is needed. This study shows that repeatable disruption the BBB in the dog is possible and opens the way for further investigations of BBBD using the dog as a model. / Master of Science
4

Strålskydd för personal som arbetar inom Interventionell Radiologi

Lindgren, Johanna, Gustavsson, Erika January 2014 (has links)
Bakgrund: Trots en snabb utveckling av undersökningsmetoderna inom IR har inte strålskydden utvecklats i samma takt. Den joniserande strålning som förekommer på modaliteten kan medföra en hälsorisk för personalen därav finns det stråldosgränser att hålla sig inom för att minimera risken för yrkesrelaterade strålskador. För att förebygga risken för strålningsrelaterade skador är det viktigt att undersöka olika metoder av skydd för att optimera personalens strålsäkerhet.Syfte: Syftet med studien var att belysa metoder för att reducera stråldosen för personal verksam vid interventionell radiologi.Metod: Sökningarna av artiklarna genomfördes i databaserna CINAHL, PubMed och Scopus varav 13 studier valdes ut, kvalitetsgranskades samt analyserades kritiskt med utgångspunkt från en innehållsanalys.Resultat: Resultatet visade på 11 strålskyddsmetoder för personalen: blyförkläde med thyroideablyskydd, Suspended Personal Radiation Protection System, blyglasögon, blyhandskar, takfäst blyglas, golvbaserade blyglas, patientblyskydd, direktdigital dosimeter, avstånd till patienten genom automatisk kontrastspruta, vismut-bariumöverdrag samt erfarenhet och information.Konklusion: Trots att metoderna enskild reducerade stråldosen till personalen skulle det kunna vara mer effektivt att kombinera olika strålskydd för bättre reduceringseffekt. Genom resultatet anser författarna att fortsatt forskning krävs inom utvecklandet av nya strålskydd som är mer ergonomiska mot personalen samt hur strålskydden påverkar patienterna både fysiskt och psykiskt. / Background: Despite the fast development of examination methods in IR, the development of the radiation protections has not been as rapid. Ionizing radiation that occurs in the modality can be a threat to the personnel of which there are radiation dose limits to keep within in order to minimize the risk of occupational radiation damage. In order to minimize the risk of occupational radiation damage, it is of importance to explore different methods to optimize the radiation protection for the personnel.Purpose: The aim of this study was to illuminate methods to reduce the radiation dose to personnel working in interventional radiology.Method: Searches were conducted in the databases CINAHL, PubMed and Scopus from which 13 studies were selected, viewed and analyzed with basis from a content analysis.Results: The results showed 11 different radiation protection methods for the staff were identified and those were: lead apron with a thyroid lead shield, Suspended Personal Radiation Protection System, leaded eyeglasses, leaded gloves, ceiling suspended leaded shield, rolling leaded shield, patient lead shield, real-time dosimeter, distance to the patient through an automatic power injector, bismuth - barium shielding and experience and information.Conclusion: Although the methods individual reduced radiation dose to the personnel, it might be more efficient to combine the various radiation protections for better reduction effect. The authors recommend that further research is required in the development of new radiation protection that is more ergonomic to the personnel and how the radiation shields affects patients both physically and psychologically.
5

Radiation Dose Optimization For Critical Organs

January 2013 (has links)
abstract: Ionizing radiation used in the patient diagnosis or therapy has negative effects on the patient body in short term and long term depending on the amount of exposure. More than 700,000 examinations are everyday performed on Interventional Radiology modalities [1], however; there is no patient-centric information available to the patient or the Quality Assurance for the amount of organ dose received. In this study, we are exploring the methodologies to systematically reduce the absorbed radiation dose in the Fluoroscopically Guided Interventional Radiology procedures. In the first part of this study, we developed a mathematical model which determines a set of geometry settings for the equipment and a level for the energy during a patient exam. The goal is to minimize the amount of absorbed dose in the critical organs while maintaining image quality required for the diagnosis. The model is a large-scale mixed integer program. We performed polyhedral analysis and derived several sets of strong inequalities to improve the computational speed and quality of the solution. Results present the amount of absorbed dose in the critical organ can be reduced up to 99% for a specific set of angles. In the second part, we apply an approximate gradient method to simultaneously optimize angle and table location while minimizing dose in the critical organs with respect to the image quality. In each iteration, we solve a sub-problem as a MIP to determine the radiation field size and corresponding X-ray tube energy. In the computational experiments, results show further reduction (up to 80%) of the absorbed dose in compare with previous method. Last, there are uncertainties in the medical procedures resulting imprecision of the absorbed dose. We propose a robust formulation to hedge from the worst case absorbed dose while ensuring feasibility. In this part, we investigate a robust approach for the organ motions within a radiology procedure. We minimize the absorbed dose for the critical organs across all input data scenarios which are corresponding to the positioning and size of the organs. The computational results indicate up to 26% increase in the absorbed dose calculated for the robust approach which ensures the feasibility across scenarios. / Dissertation/Thesis / Ph.D. Industrial Engineering 2013
6

Imaging of Acute Appendicitis in Children

Ferguson, Mark R., Wright, Jason N., Ngo, Anh-Vu, Desoky, Sarah M., Iyer, Ramesh S. 03 1900 (has links)
Acute appendicitis is a common cause of abdominal surgery in children, and is the result of appendiceal luminal obstruction and subsequent inflammation. The clinical presentation is often variable, allowing imaging to play a central role in disease identification and characterization. Ultrasound is often the modality of choice for diagnosis of appendicitis in children. Ready availability and lack of ionizing radiation are attractive features of sonography, though operator dependence is a potential barrier. Computed tomography (CT) was historically the preferred modality in children, as in adults, but recent awareness of the risks of radiation has reduced its usage. The purpose of this article is to detail the imaging findings of appendicitis in children. The discussion will focus on typical signs of appendicitis seen on ultrasound, CT, and magnetic resonance imaging. Considerations for percutaneous drainage by interventional radiology will also be presented. Finally, the evolution of imaging algorithms for appendicitis will be discussed.
7

The role of interventional radiology in the interdisciplinary management of abdominopelvic trauma in the United States

Louis, Emily 24 February 2021 (has links)
Trauma care across the globe has evolved greatly over the years. However, trauma remains a major contributor to morbidity and mortality as the third leading cause of death in the United States. It also accounts for a considerable portion of healthcare costs. In light of this, and in order to reduce its adverse impacts, appropriate and effective management is necessary. Emergency Medicine, Trauma Surgery, Interventional Radiology and many other specialties contribute to the acute care of patients in the setting of trauma. Other areas of medicine have shown that a clearly outlined multidisciplinary approach to management can lead to better outcomes and shorter hospital stays, specifically where it pertains to rapid response situations. Interventional Radiology has been found to be effective in managing trauma patients presenting with abdominopelvic injury but a clear approach to when they should be involved has yet to be developed. In fact, studies have shown that precise decision making regarding surgical versus non-operative management of trauma patients is essential to providing appropriate care and improving patient outcomes. In order to accomplish this, Interventional Radiology and Trauma Surgery need to have a prompt, active and collaborative dialogue when patients present with such injuries. A description and analysis of the current approach to management of patients with abdominopelvic trauma and subsequent outcomes at a Level 1 Trauma Center will provide valuable insight into how to establish a protocol that could lead to better selection of minimally invasive interventions and in turn improved patient outcomes. / 2022-02-24T00:00:00Z
8

Examination of the Informed Consent Process as Experienced by Patients Who Underwent a De Novo Transjugular Intrahepatic Portosystemic Shunt, Chemoembolization or Radioembolization Procedure

Hughes-Gay, Marsha A. 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this study is to examine the informed consent (IC) procedure as it was experienced by patients who had undergone a de novo transjugular intrahepatic portosystemic shunt (TIPS), chemoembolization (TACE), or radioembolization (TARE) procedure in an Interventional Radiology (IR) Department. The three main study aims and a fourth exploratory aim are as follows: (1) Describe how patients who underwent a de novo TIPS, TACE, or TARE procedure in an IR Department described the IC procedure; (2) Describe what information patients who underwent a de novo TIPS, TACE, or TARE procedure in an IR Department recalled being told during the IC procedure; (3) Describe the satisfaction of patients who underwent a de novo TIPS, TACE, or TARE procedure in an IR Department with the IC procedure; and (4) Explore how the IC experiences of patients who underwent a de novo TIPS, TACE, or TARE procedure in an IR Department differed according to their levels of health literacy. Using a qualitative descriptive design, participants were recruited from an IR department that performed these procedures. A total of 14 participants were interviewed about their IC experiences and the Newest Vital Sign (NVS) Health Literacy assessment was administered. The participants described the IC procedure by discussing the staff they encountered, their feelings during the visit, the support persons who accompanied them, and the decisions they made about the procedure. The participants recalled being told about how their procedure would be performed, the care they would need, and the benefits and risks of the procedure. Most were satisfied with the information received during the IC procedure and found the information consistent with how they experienced the procedure. A few participants would have liked more visual materials, addition details about the procedure, simpler language, or more explanation of the medical terminology. No apparent differences in the IC experience could be attributed to health literacy. These findings suggest that persons’ experiences during the IC process are multi-faceted and affected by their emotions and concerns and the nature of their encounters with their healthcare providers.
9

Resultados da vertebroplastia percutânea na doença vertebral cervical / Results of percutaneous vertebroplasty in the cervical spine

Mont'Alverne, Francisco José Arruda 17 November 2008 (has links)
A vertebroplastia percutânea (VP) consiste na injeção de polimetilmetacrilato (PMMA) no corpo vertebral para alívio da dor e estabilização vertebral, porém seu uso na região cervical é restrito. No intuito de avaliar a efetividade e a segurança da VP na região cervical (VPC), foram avaliados 75 pacientes que se submeteram à VPC (n=101) por doença maligna (n=69) ou hemangioma vertebral (n=6) no período de janeiro de 1994 a outubro de 2007. A VPC foi realizada por uma abordagem ântero-lateral guiada por fluoroscopia. A dor foi graduada por uma escala variando de 0 a 10. O seguimento clinico (período médio de 8,8 meses) foi obtido em 57 (76%) pacientes: 48 tiveram a VPC indicada para controle da dor e nove para estabilização vertebral. Os dados foram analisados de forma univariada e multivariada. A efetividade analgésica foi obtida em 37 (77,1%) dos 48 pacientes seguidos, tendo sido associada ao volume de cimento injetado (P=0,011) e ao preenchimento vertebral (P=0,007) na análise multivariada. A estabilidade vertebral foi observada em 55 (96,5%) dos 57 pacientes, não se correlacionando com as variáveis estudadas. A curva de ROC identificou o preenchimento vertebral como preditor da efetividade analgésica (P=0,008), sendo 50% o melhor ponto de corte para discriminar a maior probabilidade de efetividade analgésica (sensibilidade de 78,0% e especificidade de 62,5%). O extravasamento de cimento foi identificado em 83 (82,2%) das 101 vértebras tratadas não se correlacionando com as variáveis estudadas. As complicações clínicas foram detectadas em 13 (17,3 %) pacientes: complicações locais em 10 (13,3%) e sistêmicas em três (4%) pacientes. As complicações clínicas foram estatisticamente relacionadas à ruptura do muro posterior (P=0,026) e ao extravasamento de PMMA no plexo venoso transverso (P=0,023). A taxa de mortalidade e morbidade a longo termo foi de 1,3% (um paciente) e 1,3% (um paciente). Pode se inferir que a VPC é um procedimento efetivo e seguro, sem se negligenciar os riscos potenciais de complicações. O preenchimento vertebral e o volume de cimento foram associados à efetividade analgésica, mas não à estabilidade vertebral. O preenchimento vertebral teve o maior poder discriminatório da efetividade analgésica, tendo sido obtido com o ponto de corte de 50 % o melhor equilíbrio entre sensibilidade e especificidade para se determinar a efetividade analgésica / Percutaneous vertebroplasty (PV) consists of an injection of polymethylmethacrylate (PMMA) into the vertebral body for pain relief and spinal stabilization, however reports of PV in the cervical spine (CPV) are scarce in the literature. To evaluate the effectiveness and security of CPV, we evaluated 75 patients (mean age, 51.3 years) who underwent CPV (n=101) for malignancies (n=69) and vertebral hemangiomas (n=6) between January 1994 and October 2007. CPV was performed via an antero-lateral approach, using fluoroscopic guidance. Pain intensity was scored with a scale ranging from 0 to 10. Follow-up (mean time of 8.8 months) was avaible in 57 (76 %) patients: 48 of them had CPV indicated for pain control and nine for spinal stabilization. Data were analysed by means of univariate and multivariate analysis. Pain improvement was observed in 37 (77.1%) out of 48 followed patients and was correlated in multivariate analysis with cement volume (P=0.011) and with vertebral filling (P=0.007). Spinal stabilization was observed in 55 (96.5%) of 57 followed patients and was related with none of the evaluated variables. The ROC curve identified the vertebral filling as a good predictor of pain improvement (P=0.008). The best cut-off point to discriminate pain improvement was 50% of vertebral filling (78.0% sensitivity and 62.5% specificity). In 83 (82.2%) of the 101 treated vertebral levels, at least one type of PMMA leakage was found. None of the evaluated factors were related significantly to PMMA leakage. Clinical complications were detected in 13 (17.3%) patients: local complications in 10 (13.3%) patients and systemic clinical complications in three (4.0%) patients. Posterior wall disruption (P=0.026) and transverse venous PMMA leakage (P=0.023) were significantly associated with clinical complications. Long-term morbidity and mortality rate was 1.3% (one patient) and 1.3% (one patient). CPV is a safe and efficacious procedure, but the potential for local and systemic complications must be considered. Cement volume and vertebral filling were associated with pain improvement but not with spinal stability. Vertebral filling has a good performance to predict pain improvement and a cut-off of 50% of vertebral filing obtained the best compromise between sensitivity and specificity to discriminate pain improvement
10

Resultados da vertebroplastia percutânea na doença vertebral cervical / Results of percutaneous vertebroplasty in the cervical spine

Francisco José Arruda Mont'Alverne 17 November 2008 (has links)
A vertebroplastia percutânea (VP) consiste na injeção de polimetilmetacrilato (PMMA) no corpo vertebral para alívio da dor e estabilização vertebral, porém seu uso na região cervical é restrito. No intuito de avaliar a efetividade e a segurança da VP na região cervical (VPC), foram avaliados 75 pacientes que se submeteram à VPC (n=101) por doença maligna (n=69) ou hemangioma vertebral (n=6) no período de janeiro de 1994 a outubro de 2007. A VPC foi realizada por uma abordagem ântero-lateral guiada por fluoroscopia. A dor foi graduada por uma escala variando de 0 a 10. O seguimento clinico (período médio de 8,8 meses) foi obtido em 57 (76%) pacientes: 48 tiveram a VPC indicada para controle da dor e nove para estabilização vertebral. Os dados foram analisados de forma univariada e multivariada. A efetividade analgésica foi obtida em 37 (77,1%) dos 48 pacientes seguidos, tendo sido associada ao volume de cimento injetado (P=0,011) e ao preenchimento vertebral (P=0,007) na análise multivariada. A estabilidade vertebral foi observada em 55 (96,5%) dos 57 pacientes, não se correlacionando com as variáveis estudadas. A curva de ROC identificou o preenchimento vertebral como preditor da efetividade analgésica (P=0,008), sendo 50% o melhor ponto de corte para discriminar a maior probabilidade de efetividade analgésica (sensibilidade de 78,0% e especificidade de 62,5%). O extravasamento de cimento foi identificado em 83 (82,2%) das 101 vértebras tratadas não se correlacionando com as variáveis estudadas. As complicações clínicas foram detectadas em 13 (17,3 %) pacientes: complicações locais em 10 (13,3%) e sistêmicas em três (4%) pacientes. As complicações clínicas foram estatisticamente relacionadas à ruptura do muro posterior (P=0,026) e ao extravasamento de PMMA no plexo venoso transverso (P=0,023). A taxa de mortalidade e morbidade a longo termo foi de 1,3% (um paciente) e 1,3% (um paciente). Pode se inferir que a VPC é um procedimento efetivo e seguro, sem se negligenciar os riscos potenciais de complicações. O preenchimento vertebral e o volume de cimento foram associados à efetividade analgésica, mas não à estabilidade vertebral. O preenchimento vertebral teve o maior poder discriminatório da efetividade analgésica, tendo sido obtido com o ponto de corte de 50 % o melhor equilíbrio entre sensibilidade e especificidade para se determinar a efetividade analgésica / Percutaneous vertebroplasty (PV) consists of an injection of polymethylmethacrylate (PMMA) into the vertebral body for pain relief and spinal stabilization, however reports of PV in the cervical spine (CPV) are scarce in the literature. To evaluate the effectiveness and security of CPV, we evaluated 75 patients (mean age, 51.3 years) who underwent CPV (n=101) for malignancies (n=69) and vertebral hemangiomas (n=6) between January 1994 and October 2007. CPV was performed via an antero-lateral approach, using fluoroscopic guidance. Pain intensity was scored with a scale ranging from 0 to 10. Follow-up (mean time of 8.8 months) was avaible in 57 (76 %) patients: 48 of them had CPV indicated for pain control and nine for spinal stabilization. Data were analysed by means of univariate and multivariate analysis. Pain improvement was observed in 37 (77.1%) out of 48 followed patients and was correlated in multivariate analysis with cement volume (P=0.011) and with vertebral filling (P=0.007). Spinal stabilization was observed in 55 (96.5%) of 57 followed patients and was related with none of the evaluated variables. The ROC curve identified the vertebral filling as a good predictor of pain improvement (P=0.008). The best cut-off point to discriminate pain improvement was 50% of vertebral filling (78.0% sensitivity and 62.5% specificity). In 83 (82.2%) of the 101 treated vertebral levels, at least one type of PMMA leakage was found. None of the evaluated factors were related significantly to PMMA leakage. Clinical complications were detected in 13 (17.3%) patients: local complications in 10 (13.3%) patients and systemic clinical complications in three (4.0%) patients. Posterior wall disruption (P=0.026) and transverse venous PMMA leakage (P=0.023) were significantly associated with clinical complications. Long-term morbidity and mortality rate was 1.3% (one patient) and 1.3% (one patient). CPV is a safe and efficacious procedure, but the potential for local and systemic complications must be considered. Cement volume and vertebral filling were associated with pain improvement but not with spinal stability. Vertebral filling has a good performance to predict pain improvement and a cut-off of 50% of vertebral filing obtained the best compromise between sensitivity and specificity to discriminate pain improvement

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