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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

The role of Technetium-99m Sestamibi scintimammography to evaluate palpable breast lesions : a comparison with mammography and histological results

Nizami, Mohammad Athar Farooq January 1999 (has links)
This study was conducted with the support of the Combined Breast Clinic at our institution which consists of the Departments of Surgery, Radiology and Radiation Oncology. The work was done in three parts. The literature showed somewhat lengthy imaging procedure for scintimammography which were not whole suitable to the setting of the Combined Breast Clinic. Initially a Pilot Study was conducted to determine the practicality of the imaging procedure. The results of this study were promising but the imaging procedure was time consuming. Certain modifications were subsequently done in the imaging method of the Formal Study to accommodate more number of patients into the study without jeopardizing the quality of the images. This study, however, had a shortcoming in that the way this study was structured one could not demonstrate lesion by lesion analysis of each breast lesion detected on clinical examination, mammography and scintimammography with their respective biopsy results. Our Formal Study and the literature suggested that scintimammography is of value in patients with indeterminate mammograms due to its high negative predictive value. Therefore, a separate Additional Study, with the same scintigraphic method, was conducted on patients with clinical breast lumps with indeterminate mammographic lesions. Special emphasis was placed on lesion by lesion comparison of each breast lesion detected by clinical examination or scintimammography or both with the biopsy results of that particular lesion.
2

Relationship between ¹²³l-metaiodobenzylguanidine (¹²³l-MIBG) imaging findings and outcome in patients with neuroblastoma at the Red Cross War Memorial Children's Hospital

Amoako, Yaw Ampem January 2017 (has links)
Background: In neuroblastoma, the presence of distant metastases is associated with a poor prognosis. Aim: To assess the relationship between the findings on ¹²³I-MIBG scan and outcome in patients with neuroblastoma at the Red Cross War Memorial Children's Hospital (RCWMCH). Methods: A single observer reviewed the ¹²³I-MIBG scans and clinical data of patients who had a histologically confirmed diagnosis of neuroblastoma and a baseline ¹²³I-MIBG scan and at least one follow up scan after chemotherapy cycles 4 or 7 between January 2001 and May 2015. Follow up extended to June 2016. Disease burden was assessed using the Curie scoring (CS) method. Results: Thirty four stage 4 patients were included in the analysis. Twenty nine (85%) were older than 12 months, with a median age at diagnosis of 32.5 months (range 6 - 93 months). 62% of primary tumours were located in the adrenal gland and half were NMYC amplified. Twenty (59%) patients died, 90% of deaths occurring in patients older than 12 months. No deaths were recorded in the 13 months after recruitment ended. The baseline CS did not predict outcome (alive or dead) or duration of survival. Patients with CS >2 (n = 5) on the cycle 4 scan had a median survival of 19.5 months compared with 29 months for those with a score ≤ 2 (n = 17, p = 0.88). Patients with a CS > 2 on the cycle 7 scan (n = 7) had a median survival of 28 months compared with 35 months for those with CS ≤ 2 (n = 14, p = 0.93). There was no relationship between the magnitude of the decrease in CS between the baseline and post cycle 4 or 7 scans and outcome. Conclusion: In these 34 high risk patients, the baseline CS and CS at cycle 4 or cycle 7 were not significantly indicative of survival. This is similar to other studies that did not find the pre-treatment score or the post treatment MIBG scan to be a predictor of outcome.
3

Renogram Image Characteristics and the Reproducibility of Differential Renal Function Measurement

Brink, Anita 22 April 2020 (has links)
Aim The reproducibility of differential renal function (DRF) estimates on 99mTc-mercaptoacetyltriglycine (99m Tc-MAG3) is good in the majority of children. There is however a small but important group with poor reproducibility which, if not recognized, could affect clinical decision making. Some factors, such as age and glomerular filtration rate (GFR), have been implicated as causes for poor reproducibility. The aim of this study is to formally investigate image characteristics associated with the reproducibility of DRF measurements. Patients and methods The image characteristics and reproducibility of the DRF estimates of the 127 patients in cohort 1 was used to identify the characteristics associated with reproducibility. The associations between these image characteristics and reproducibility were then tested in a second cohort of 227 patients. The DRF measurements were calculated using two internationally accepted methods for calculating DRF, the HERMES area under the curve (HAUC) method and the HERMES Rutland Patlak (HRP) method. The images were visually inspected to categorise the categorical variables and processed to obtain the values of the continuous variables. The variables investigated included two nonimaging variables, age (in months) and GFR which included measured or estimated GFR values. The association between each variable and the reproducibility of DRF measurement for both the HAUC and the HRP methods was tested with univariate linear regression. The results of the univariate linear regression were used to plan the multiple linear regression combinations. All possible combinations were tested with multiple linear regression. Results The goodness-to-fit for the multiple regression models were much higher for all the combinations analysed in cohort 1 than in cohort 2. In cohort 1 the R2 -values ranged from 0.3510 to 0.4906 for log MAXMINHAUC and 0.3284 to 0.4500 for log MAXMINHRP. In cohort 2, they ranged from 0.1675 to 0.2163 for log MAXMINHAUC, and 0.1706 to 0.2191 for log MAXMINHRP. The combinations with the highest R2 -value for multiple linear regression analyses were similar in cohort 1 and 2. The only individual variable which was significant in all the multiple linear regression combinations for cohort 1 and 2 for both log MAXMINHAUC and log MAXMINHRP was LEFT KIDNEY TO BACKGROUND RATIO. RIGHT KIDNEY TO BACKGROUND RATIO, RIGHT RENAL MARGINS WELL DEFINED, RIGHT RENAL MARGINS POORLY VISUALISED and TIME VISUALISATION RIGHT CALYCES were significant in most of the combinations analysed. A high kidney to background ratio, RIGHT RENAL MARGINS WELL DEFINED and higher AGE predicted a good reproducibility. A low kidney to background ratio and later TIME VISUALISATION RIGHT CALYCES predicted poor reproducibility. The variables LEFT RENAL AREA, LEFT BACKGROUND AREA, BOTH RENAL MARGINS SMOOTH and RIGHT RENAL MARGINS IRREGULAR were not-significant in any combinations analysed cohort 1 and 2 for both log MAXMINHAUC and log MAXMINHRP. The remaining variables inconsistently predicted reproducibility in log MAXMINHAUC and log MAXMINHRP for both cohort 1 and 2. Conclusion: The only variables which consistently predicted good and poor reproducibility for the measurement of DRF on 99mTc-MAG3 renograms performed according to the EANM guidelines for both log MAXMINHAUC and log MAXMINHRP were AGE, LEFT KIDNEY TO BACKGROUND RATIO, RIGHT KIDNEY TO BACKGROUND RATIO, RIGHT RENAL MARGINS WELL DEFINED and TIME VISUALISATION RIGHT CALYCES. Consideration should be given to incorporating the kidney to background ratio into the renal processing screen display as a valuable quality control step. The DRF values should be interpreted with caution if the kidney to background ratio is < 2.0.
4

Renal Cortical Transit time as a predictor for pyeloplasty in paediatric patients with unilateral hydronephrosis at the Red Cross War Memorial Children's Hospital

More, Stuart Setjhaba 17 May 2019 (has links)
Background: Majority of patients with unilateral hydronephrosis (HN) detected on ultrasound (US) do not require pyeloplasty. Indications for pyeloplasty are in patients with symptomatic obstruction (recurrent flank pain), complications such as urinary tract infection, a drop in differential renal function (DRF) of more than 10% and a progressive increase in the anterior posterior diameter (APD) in subsequent studies. Schlotmann et al, Piepsz et al and Harper et al have demonstrated the measurement of the cortical transit time (CTT) to predict the need for patient who may require pyeloplasty. Objectives: To assess if the CTT would have predicted a drop in DRF in patients with unilateral HN on the affected side. In addition to assess whether the CTT would differ on the first renogram between those patients who had a pyeloplasty and those who did not have a pyeloplasty at the Red Cross War Memorial Children’s Hospital (RCWMCH). Methods: Sixty eight (68) patients with at least two renograms with unilateral HN with a normal contralateral kidney were observed retrospectively between December 2000 and May 2015. The CTT was recorded for the upper, middle and lower third of each kidney and the mean used as the CTT of the kidney. Each renogram was processed three times to measure the DRF using the Rutland Patlak and Integral methods. The mean of the three DRF measurements was used for analysis. Results: The mean CTT of the left and right hydronephrotic kidneys were 6.0minutes and 6.7minutes respectively. A significant relationship was demonstrated in the CTT and DRF as well as CTT and APD in the first renogram of those patients who did not have a pyeloplasty (p < 0.05). There was no difference between the DRF of the first and second renograms in those patients who did not have a pyeloplasty. In the 20 patients who had a pyeloplasty, there was a drop of more than 10% in the DRF of 3 patients. No difference was seen in the DRF or in the CTT between the first and second renogram. The CTT was shorter in the second renogram in 9 of the 20 patients who had a pyeloplasty. No significant difference was found in the CTT or DRF when comparing the group who had surgery against the group who did not have surgery. Conclusion: The current study was unable to demonstrate in our series of patients that CTT can predict those patients who would require pyeloplasty. This may be owing to the retrospective nature of the study and the reliance on the clinical notes for the US data and surgical notes. In future, a prospective study evaluating the relationship between CTT and a drop in the DRF should be undertaken in this unit.
5

The conclusions drawn from ventilation/perfusion single photon emission computed tomography (SPECT) compared to lung perfusion SPECT and a chest x-ray (CXR) in patients with suspected pulmonary pulmonary thromboembolism

Abubakar, Sofiullah 18 February 2019 (has links)
Purpose: There are conflicting results from studies on whether the ventilation (V) scintigraphy can be safely omitted or replaced by a chest x-ray. These studies were based on planar ventilation perfusion (V/Q) scintigraphy. We evaluated the value of the V single photon emission computed tomography (SPECT) on the final conclusion drawn from a V/Q SPECT and the possible role of the chest x-ray as a surrogate for the V SPECT. Methods Raw data of V/Q SPECT images and chest x-ray acquired within 48 hours over 18 months period were retrieved, reprocessed and reviewed in batches. The V SPECT, Q SPECT and chest x-ray were reviewed separately and in combination. Data on the presence and character of defects and chest x-ray abnormalities were recorded. The V/Q SPECT images were interpreted using the criteria in the EANM guideline and the Q SPECT and chest x-ray images were interpreted using the PISAPED criteria. Agreement between the diagnosis on the V/Q SPECT review and the Q SPECT and chest x-ray review was analysed. Results 21.1% of the patients were classified as 'PE present’ on the V/Q SPECT review whereas 48.9% were classified as 'PE present’ on the Q SPECT and chest x-ray review. Only 5.4% of defects seen on V SPECT had matched chest x-ray lung field opacity. Conclusion Our study showed that the omission of a V SPECT led to a high rate of false positive diagnoses and that the ventilation scan cannot be replaced by a chest x-ray.
6

Assessment of the impact of the application single photon emission computerized tomography and SPECT-CT on lesion catergorization

Yunusa, Garba Haruna January 2015 (has links)
Includes bibliographical references / Objectives: To assess initial experience with the use of a new SPECT-CT in the evaluation of lesions. Methods: The folder number, radiopharmaceutical used and type of scan of patients examined with a new Siemens T6 SPECT-CT between 2 April and 31 December 2013 were retrieved. The number of 99m Tc -MDP bone scans was sufficient for a detailed analysis. The scans were re-processed and reported by the observer before he was given any clinical information. Whole body planar, whole body planar plus SPECT and whole body planar plus SPECT-CT images were assessed successively in three separate sessions at least two weeks apart. At each session, the certainties of detection, localisation, and categorisation of each lesion were recorded. Results: A total of 539 lesions were seen on the whole body, SPECT and CT images in 133 patients. The whole body images showed no lesions in three patients and 378 lesions in 130 patients, 117(31%) lesions in areas not covered by the SPECT. SPECT detected 122 additional lesions in 79 patients. Thirty-nine (12.2%) lesions were seen only on CT in 32 (24.1%) patients. F or the 261 lesions seen on the planar images in the SPECT FOV, lesion detection was definite in 233 (89.3%), localisation definite in 151(57.9%) and categorisation definite in 123 (47.1%) lesions. On the SPECT, definite lesion detection, localisation and categorisation were recorded respectively for 259 (99.2%), 228 (87.4%) and 176 (67.4%) of the 261 lesions. Lesion detection, localisation and categorisation certainties were definite for 100%, 99.1% and 94.7% of the SPECT-CT lesions respectively. Conclusion: Whole body planar scintigraphy is essential in lesion detection. SPECT markedly improves lesion detection and localisation and CT enhances lesion categorisation.
7

The use of lymphoscintigraphy to localise the sentinel lymph node

Korowlay, Nisaar Ahmed January 2005 (has links)
Includes bibliographical references (leaves 72-90). / Sentinel lymph node (SLN) biopsy is being used increasingly for staging early breast carcinoma in place of complete axillary lymph node dissection. The optimal method to identify the SLN and has not been clearly elucidated in the literature. A number of techniques have been proposed for identifying SLN/s. The main debate centres on whether to use a blue dye or radiopharmaceutical method either singly or in combination.
8

Comparison of estimates of left ventricular ejection fraction using gated blood imagining

Steyn,Rachelle 01 September 2022 (has links) (PDF)
Serial measurement of left ventricular ejection fraction (L VEF) using GBP imaging is an established technique for monitoring L VEF in patients undergoing chemotherapy with cardio-toxic medication and in patients after heart transplants. Oncologists at our institution decide that cardio-toxic chemotherapy should be discontinued if the L VEF decreases by 10%, or if a value of 50% is reached. In patients with baseline L VEFs of less than 50% but greater than 30% therapy will be discontinued if the L VEF decreases by 10% or if a value of less than 30% is reached. This is in accordance with the guidelines set out by the Oxford Textbook ofOncology.3 In patients who have had heart transplants, GBP studies are used to monitor L VEF. If there is a decrease in L VEF, cardiologists may decide to start glucocoricosteroids for rejection. It is therefore imperative that serial studies on an individual patient are comparable. There are two software systems used in our nuclear medicine department; the Siemens system and the Hermes system. In a pilot study we found large differences between the L VEFs calculated by the two systems. This is consistent with the consensus in the literature that different software programs for processing GBP studies cannot be used interchangeably.
9

The use of factor methods in the analysis of dynamic radionuclide studies

Martel, Anne L. January 1992 (has links)
No description available.
10

Microautoradiography in radiopharmaceutical research

Puncher, M. January 1994 (has links)
No description available.

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