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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.
11

Corpus callosum morphology in children on mid-sagittal MR imaging

Raubenheimer, Lauren 19 February 2019 (has links)
Background: There is little published research on the wide variation of corpus callosum (CC) morphology in children, the assessment of which is made difficult by the complex alteration of its appearance in childhood. Objective: The purpose of our study was to assess the morphology of the CC on mid-sagittal T1- weighted magnetic resonance imaging (MRI) in a large number of children and correlate the findings with demographic and clinical criteria. Materials and methods: We reviewed all brain mid-sagittal T1-weighted MRI’s performed from July to December 2015 and obtained relevant demographic and clinical information from the accompanying report and laboratory system. The CC morphology was analysed by three radiologists and compared using cross tabulation with the chi-square test and ANOVA. Interobserver correlation was assessed using Kappa coefficient of conformance. Results: 257 patients with mean age 72±60 months were included, 142 were male (55%). In abnormal MRI’s the CC was less likely to have an identifiable isthmus and was more likely to be convex, thin and have separation of the fornix insertion (all p<0.01). In young children (< 5 years) the CC was also less likely to have an identifiable isthmus (p=0.01) and was more likely to be convex (p=0.04) but the fornix was more likely to insert normally (p<0.01). Children with tuberous sclerosis had significantly thinner splenia (p=0.02). Conclusion: There is a distinct pathological appearance of the CC. The immature appearance of the corpus callosum can mirror this but is distinguished by normal insertion of the fornix and normal quantitative measurements. Splenial thinning in children with tuberous sclerosis warrants further investigation.
12

Evaluating the yield of brain CT examinations in patients presenting with first onset seizures at the Groote Schuur Hospital, Cape Town

Ncube, Innocent Vusumusi 06 May 2020 (has links)
Background: Seizures are a frequent and potentially significant presenting complaint to the emergency department (ED). Determining the underlying cause for seizures is important in guiding further clinical management of patients. ED physicians at Groote Schuur Hospital, Cape Town, South Africa routinely request Computed Tomography (CT) brain scans in the work-up of patients presenting with first onset seizures. Objectives: To determine the number and proportion of CT scan examinations with abnormal findings in patients presenting with first onset seizures at the Groote Schuur Hospital ED, Cape Town, South Africa and to identify the range of CT abnormalities. Method: A retrospective study was carried out in the Division of Radiology, Groote Schuur Hospital. Patients who presented to the ED with first onset seizures and who underwent brain CT examination as part of their work up between 1 January 2013 and 31 December 2016 were enrolled. All patients presenting to the ED with first onset focal or grand mal seizures were included. Patients with recent trauma and those with previously diagnosed epilepsy were excluded. Results: A total of 200 patients were eligible for the study. Of these, 92 (46%) patients with first onset seizures had an abnormality or abnormalities on brain CT scan. Of those patients whose HIV status was known, 50% of HIV positive and 53% of HIV negative patients had abnormal CT scans. 54% of patients with focal seizures and 38% with generalised seizures had an abnormality on CT scan. Abnormalities found on CT scans included chronic cerebral infarction (7.5%), acute or subacute cerebral infarction (4.5%), neurocysticercosis (7.0%), other infections (6.5%), haemorrhage and other vascular lesions (6.5%), post-traumatic encephalomalacia (6.5%), primary brain tumours and metastases (based on CT characteristics) (7.0%). Conclusion: Forty-six (46%) of patients presenting to the Groote Schuur Hospital ED, Cape Town, South Africa with first onset seizures had an abnormality on their brain CT scans. Brain CT scan is therefore recommended in patients presenting to the ED department with first-onset seizures, irrespective of their HIV/ neurological status.
13

Value of follow-up CT in head injury assessment

Owen, Jeannine Margaret January 2015 (has links)
INTRODUCTION: The question of when and if to perform follow- up CT scanning of the brain in a patient with a proven head injury remains pertinent, and the answer is not clear cut. This is even more so compounded when one tries to compare and equate what happens in a developed country with that of a developing country such as South Africa. AIM: To evaluate referral patterns, associated time-delays and findings of follow-up CT as well as patient outcomes in patients with head injury at Groote Schuur Hospital. METHOD: A retrospective review, over a 6 month time period, of the CT scans and folders belonging to patients who underwent follow-up CT scanning of the brain after blunt trauma to the head. RESULTS: There were 313 follow-up studies performed in 212 patients, of which the majority, 135 /313 (43.1%) were referred for neurological reasons, whilst 103/313 (32.9%) were referred for conservative management reasons and 75/313 (24%) were referred as part of their post-surgical check-up. There were significant time delays from arrival of patients in casualty to their initial CT scan (mean 18.74 hours) as well as between the initial CT and the first follow-up scan (mean 121.78 hours). There was a significant amount of data missing regarding the time of actual injury for many patients. There were 74 neurosurgical interventions that took place as a result of CT scans performed. Of these, 54 (73%) took place after the initial CT scan, whilst only 20 (27%) occurred after a follow-up CT. Of those surgical interventions performed after a follow- up study, 6 (30%) were performed as a result of a scan performed for post-surgical check- up. 12 (60%) were performed as a result of a scan performed for neurological reasons. Two (10%) neurosurgical interventions occurred as a result of a scan performed for conservative management reasons (thus routine follow-up imaging). CONCLUSIONS: A routine single follow-up CT may be a reasonable approach with further follow-up imaging reserved for patients who have undergone surgery, those with possibly surgically manageable findings on initial CT (that do not undergo surgery) and those with new neurology. The routine use of follow-up CT beyond the first follow-up CT is unlikely to lead to a change in management when the above clinical, and prior CT findings are absent. However, the time delays across all aspects of imaging traumatic brain injuries in our setting are unpredictable and represent a major problem in standardising when CT scans are performed.
14

Diagnostic yield of ultrasound-guided fine needle aspiration biopsy (US-guided FNAB) and post-surgical histopathological correlation of thyroid nodules in the Department of Radiology, Groote Schuur Hospital, Cape Town, South Africa over a two-year period

Matimati, Bornaventure 29 March 2023 (has links) (PDF)
Background: Nodular thyroid disease is common worldwide, and the incidence of thyroid nodules is increasing globally. Ultrasound (US)-guided thyroid nodule fine needle aspiration biopsy (FNAB) is a reliable and cost-effective method of distinguishing between benign and malignant nodules before major surgery is performed. Aims: The study aimed to establish the diagnostic yield of US-guided thyroid FNAB's done at Groote Schuur Hospital over two years and to correlate findings with histopathological results in those patients that underwent thyroidectomy. Objectives: The objectives were to establish the number of US-guided FNABs performed, the number of repeat FNABs and the number of patients who subsequently had thyroidectomy over two years. A further objective was to evaluate the diagnostic yield by comparing the cytology and histology results for patients that underwent thyroidectomy. Methods: This was a retrospective study of all patients referred for US-guided FNAB from 1 January 2018 to 31 December 2019. All patients with cytology results after FNAB and histology results after thyroidectomy, were included in the study. US-guided FNAB data was collected from the Picture Archiving and Communication System (PACS) and Radiology Information System (RIS), while cytology and histology data were obtained from the National Health Laboratory Services (NHLS). Results: A total of 236 patients were included in the study (220 females and 16 males), with ages ranging from 19 to 82 years. The diagnostic yield was 34-% on the first, 36-% on the second and 48-% on the third FNAB. Most of the US-guided FNABs were non-diagnostic (66- % on the first, 64-% on the second and 52-% on the third FNAB). A total of 107 patients (45 %) had a repeat FNAB, while 23 patients (9.7-%) had a second repeat FNAB. A total of 48 patients (20.3-%) underwent thyroidectomy. Cancer was detected in 29/236 (12.3-%), of which 17/29 (59-%) were papillary thyroid carcinomas. There was no significant correlation between FNAB results and post-surgical histopathological results in patients who underwent thyroidectomy, with a p value of .15. Conclusion: The overall cancer rate of 12.3-% was comparable with that of other institutions. 66-% of US-guided FNABs were non-diagnostic, while 34-% were diagnostic on the first FNAB with 45-% requiring a repeat second FNAB. The assistance of a cytopathologist during the biopsy has been known to result in fewer non-diagnostic results, avoiding repeat attempts. Further diagnostic and cost-effective analysis of cytopathology assistance in the US-guided FNAB for characterising thyroid nodules is advised.
15

Endovascular treatment of post-traumatic carotid-cavernous fistulae with latex detachable balloons

Szkup, Piotr 05 September 2023 (has links) (PDF)
Carotid cavernous fistula (CCF) is an abnormal connection between the carotid artery and the cavernous sinus. The CCF's are usually classified in three ways: 1. Pathologically, as spontaneous or traumatic; 2. Hemodynamically, into high-flow or low-flow; or 3. Angiographically, as direct or indirect. The Barrow angiographic classification is most commonly used. It is based on the pattern of arterial supply and has therapeutic implications.
16

The spectrum of radiological appearances in bronchoscopically proven pneumocystis pneumonia in HIV positive adults: a retrospective analysis from Helen Joseph Hospital

Rubin, Grace 21 February 2012 (has links)
M.Med. (Diagnostic Radiology), Faculty of Health Sciences, University of the Witwatersrand, 2011 / Pneumocystis jirovecci pneumonia (PJP) in HIV/AIDS is a significant opportunistic infection. As CD4 counts decrease, so does specificity of chest X-ray (CXR). AIM: To determine the proportion of bronchoscopically proven PJP in HIV infected adults, CD4 counts, CXR signs and compare PJP to TB. METHODS: The proportion of bronchoscopically proven PJP and co-infection was determined. Sensitivity and specificity of CXR for the diagnosis of PJP and TB, and frequency of CXR signs were determined. RESULTS: PJP was present in 26.6% and co-infection 19%. Median CD4 (13 cell/mm3) was significantly lower for PJP patients (p = 0.0089). CXR sensitivity for PJP was 33% and specificity was 100%. Bilateral, multilobar and diffuse disease, bronchopneumonia, nodules and cavitation overlapped for PJP and TB. Unilateral and unilobar disease indicated TB over PJP. Effusions and lymphadenpopathy were not seen with PJP. CONCLUSION: PJP makes up a quarter of indeterminate diagnoses in HIV infected adults. Sensitivity of diagnosis on CXR is low. The CXR diagnosis of TB is made more confidently, but is overcalled. In patients with low CD4 levels, a diagnosis of PJP should be considered as important as TB.
17

Magnetic Resonance Imaging of the Hepatobiliary System Using Hepatocyte-Specific Contrast Media / Magnetresonanstomografi av lever och gallvägar med levercellsspecifika kontrastmedel

Dahlström, Nils January 2009 (has links)
<p>There are two Gadolinium-based liver-specific contrast media for Magnetic Resonance Imaging on the market, Gd-BOPTA (MultiHance®, Bracco Imaging, Milan, Italy) and Gd-EOB-DTPA (Primovist®, Bayer Schering Pharma, Berlin, Germany). The aim of this study in two parts was to evaluate the dynamics of biliary, parenchymal and vascular enhancement using these contrast media in healthy subjects. Ten healthy volunteers were examined in a 1.5 T magnetic resonance system using three-dimensional Volumetric Interpolated Breath-Hold (VIBE) sequences for dynamic imaging with both contrast media – at two different occasions – until five hours after injection. The doses given were 0.025 mmol/kg for Gd-EOB-DTPA and 0.1 mmol/kg for Gd-BOPTA. The enhancement over time of the common biliary duct in contrast to the liver parenchyma was analyzed in the first study. This was followed by a study of the image contrasts of the hepatic artery, portal vein and middle hepatic vein versus the liver parenchyma.While Gd-EOB-DTPA gave an earlier and more prolonged enhancement of the biliary duct, Gd-BOPTA achieved higher image contrast for all vessels studied, during the arterial and portal venous phases. There was no significant difference in the maximal enhancement obtained in the liver parenchyma.At the obtained time-points and at the dosage used, the high contrast between the common biliary duct and liver parenchyma had an earlier onset and longer duration for Gd-EOB-DTPA, while Gd-BOPTA achieved higher maximal enhancement of the hepatic artery, portal vein and middle hepatic vein than Gd-EOB-DTPA. Diseases of the liver and biliary system may affect the vasculature, parenchyma, biliary excretion or a combination of these. The clinical context regarding the relative importance of vascular, hepatic parenchymal and biliary processes should determine the choice of contrast media for each patient and examination.</p><p> </p>
18

Perfusion measurements by dynamic susceptibility MRI

Morell, Arvid January 2010 (has links)
No description available.
19

Magnetic Resonance Imaging of the Hepatobiliary System Using Hepatocyte-Specific Contrast Media / Magnetresonanstomografi av lever och gallvägar med levercellsspecifika kontrastmedel

Dahlström, Nils January 2009 (has links)
There are two Gadolinium-based liver-specific contrast media for Magnetic Resonance Imaging on the market, Gd-BOPTA (MultiHance®, Bracco Imaging, Milan, Italy) and Gd-EOB-DTPA (Primovist®, Bayer Schering Pharma, Berlin, Germany). The aim of this study in two parts was to evaluate the dynamics of biliary, parenchymal and vascular enhancement using these contrast media in healthy subjects. Ten healthy volunteers were examined in a 1.5 T magnetic resonance system using three-dimensional Volumetric Interpolated Breath-Hold (VIBE) sequences for dynamic imaging with both contrast media – at two different occasions – until five hours after injection. The doses given were 0.025 mmol/kg for Gd-EOB-DTPA and 0.1 mmol/kg for Gd-BOPTA. The enhancement over time of the common biliary duct in contrast to the liver parenchyma was analyzed in the first study. This was followed by a study of the image contrasts of the hepatic artery, portal vein and middle hepatic vein versus the liver parenchyma.While Gd-EOB-DTPA gave an earlier and more prolonged enhancement of the biliary duct, Gd-BOPTA achieved higher image contrast for all vessels studied, during the arterial and portal venous phases. There was no significant difference in the maximal enhancement obtained in the liver parenchyma.At the obtained time-points and at the dosage used, the high contrast between the common biliary duct and liver parenchyma had an earlier onset and longer duration for Gd-EOB-DTPA, while Gd-BOPTA achieved higher maximal enhancement of the hepatic artery, portal vein and middle hepatic vein than Gd-EOB-DTPA. Diseases of the liver and biliary system may affect the vasculature, parenchyma, biliary excretion or a combination of these. The clinical context regarding the relative importance of vascular, hepatic parenchymal and biliary processes should determine the choice of contrast media for each patient and examination.
20

Två metoder för att påvisa lungemboli : En litteraturstudie

Ådemark, Belisa January 2012 (has links)
Sammanfattning I Sverige drabbas ca 10000 personer årligen av lungemboli (LE). En vanlig bakomliggande orsak till LE är djup ventrombos. Tromboserna brukar vanligen sitta i benets eller bäckenets djupa vener. För att påvisa LE krävs att patienten genomgår olika radiologiska metoder såsom t.ex. datortomografi (DT) eller lungscintigrafi. Syftet med denna studie är att beskriva radiologiska metodval vid utredning av LE, för- och nackdelar med de olika metoderna och i vilka fall respektive metod föredras.  I databasen Pubmed söktes vetenskapliga artiklar som analyserar vilken av de radiologiska metoderna som föredras vid LE. Åtta artiklar valdes ut. Båda metoderna, DT och lungscintigrafi, är viktiga för att ställa diagnos vid misstänkt LE.  DT är den metod som väljs som förstahandsmetod, detta på grund av stor tillgänglighet och snabbhet, vilket är en stor fördel. Lungscintigrafiteknik bör dock inte uteslutas eftersom de båda metoderna kan komplettera varandra.

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