Medicine and Health Sciences Commons^™

Grid-Based Fourier Transform Phase Contrast Imaging, Sajjad Tahir

Legacy Theses & Dissertations (2009 - 2024)

Low contrast in x-ray attenuation imaging between different materials of low electron density is a limitation of traditional x-ray radiography. Phase contrast imaging offers the potential to improve the contrast between such materials, but due to the requirements on the spatial coherence of the x-ray beam, practical implementation of such systems with tabletop (i.e. non-synchrotron) sources has been limited. One recently developed phase imaging technique employs multiple fine-pitched gratings. However, the strict manufacturing tolerances and precise alignment requirements have limited the widespread adoption of grating-based techniques. In this work, we have investigated a technique recently demonstrated by Bennett et al.1 …

Plasmablastic Lymphoma Of The Oral Cavity With Breast Recurrence: A Case Report, Zarka Samoon, Romana Idrees, Nehal Masood, Tayyaba Zehra Ansari

Department of Radiation Oncology

Background: Plasmablastic lymphoma is an aggressive variant of diffuse large B cell lymphoma, mostly found in the oral cavity and associated with human immunodeficiency virus. There are no clear guidelines for its treatment. Therapies more intensive than cyclophosphamide, doxorubicin, vincristine, and prednisone are not associated with a prolonged survival. Lymphomas of the breast are rare, in one series representing 0.14% of all female breast malignancies, with diffuse large B cell lymphoma comprising up to 55% of all cases. Only one case of plasmablastic lymphoma involving the breast has been reported in the literature.CASE PRESENTATION: A 30 year old Pakistani woman, …

Radionuclide Imaging: Past, Present And Future Outlook In The Diagnosis Of Infected Prosthetic Joints, L. Brammen, C. Palestro, H. Sinzinger

Journal Articles

Objective: A serious complication of joint replacement surgery is infection, which results in prolonged invalidity as well as removal and subsequent re-implantation after lengthy antibiotic therapy. In terms of diagnostic imaging, nuclear medicine has presented several tracers and imaging modalities over the years to be used in prosthetic joint infection. The PubMed/MEDLINE literature database was systematically examined for publications on infection, arthroplasty, joint replacement, prosthetic joint, gallium, labeled leukocytes, sulfur colloid, antimicrobial peptides, Fluorine-18-fluorodeoxyglucose (F-18-FDG), positron emission tomography/computed tomography (PET-CT), and single-photon emission (SPET-CT). This was determined to be a comprehensive review, not a meta-analysis of prosthetic joint infection and …

Detection Of Symptomatic Carotid Plaque Using Source Data From Mr And Ct Angiography: A Correlative Study, A. Gupta, H. Baradaran, E. E. Mtui, H. Kamel, A. Pandya, A. Giambrone, C. Iadecola, P. C. Sanelli

Journal Articles

BACKGROUND: Carotid plaque MRI has been a useful method to characterize vulnerable atherosclerotic plaque elements. Recent investigations have suggested that source images from CT angiography (CTA) and MR angiography (MRA) can identify the simple high-risk features of symptom-producing carotid artery plaque. We studied the correlation and relative diagnostic accuracies of CTA and MRA source images in detecting symptomatic carotid artery plaque. METHODS: Subjects were eligible if they had carotid stenosis between 50 and 99% and had MRA and CTA exams performed within 10 days of one another. We measured the soft (non-calcified) plaque and hard (calcified) plaque thickness on CTA …

Evaluating Blood-Brain Barrier Permeability In Delayed Cerebral Infarction After Aneurysmal Subarachnoid Hemorrhage, J. Ivanidze, K. Kesavabhotla, O. N. Kallas, D. Mir, H. Baradaran, A. Gupta, A. Z. Segal, J. Claassen, P. C. Sanelli

Journal Articles

BACKGROUND AND PURPOSE: Patients with SAH are at increased risk of delayed infarction. Early detection and treatment of delayed infarction remain challenging. We assessed blood-brain barrier permeability, measured as permeability surface area product, by using CTP in patients with SAH with delayed infarction. MATERIALS AND METHODS: We performed a retrospective study of patients with SAH with delayed infarction on follow-up NCCT. CTP was performed before the development of delayed infarction. CTP data were postprocessed into permeability surface area product, CBF, and MTT maps. Coregistration was performed to align the infarcted region on the follow-up NCCT with the corresponding location on …

Emphysematous Pyelonephritis, N. Kim, S. Machnicki

Journal Articles

No abstract provided.

Comparison Of Multiparametric Mri Scoring Systems And The Impact On Cancer Detection In Patients Undergoing Mr Us Fusion Guided Prostate Biopsies, A. R. Rastinehad, N. Waingankar, B. Turkbey, O. Yaskiv, A. M. Sonstegard, M. Fakhoury, C. A. Olsson, D. N. Siegel, P. L. Choyke, E. Ben-Levi, R. Villani

Journal Articles

INTRODUCTION: Multiple scoring systems have been proposed for prostate MRI reporting. We sought to review the clinical impact of the new Prostate Imaging Reporting and Data System v2 (PI-RADS) and compare those results to our proposed Simplified Qualitative System (SQS) score with respect to detection of prostate cancers and clinically significant prostate cancers. METHODS: All patients who underwent multiparametric prostate MRI (mpMRI) had their images interpreted using PI-RADS v1 and SQS score. PI-RADS v2 was calculated from prospectively collected data points. Patients with positive mpMRIs were then referred by their urologists for enrollment in an IRB-approved prospective phase III trial …

Computer Aided Detection Of Oral Lesions On Ct Images, Shaikat Mahmood Galib

Masters Theses

"Oral lesions are important findings on computed tomography images. They are difficult to detect on CT images because of low contrast, arbitrary orientation of objects, complicated topology and lack of clear lines indicating lesions. In this thesis, a fully automatic method to detect oral lesions from dental CT images is proposed to identify (1) Closed boundary lesions and (2) Bone deformation lesions. Two algorithms were developed to recognize these two types of lesions, which cover most of the lesion types that can be found on CT images. The results were validated using a dataset of 52 patients. Using non training …

Metastatic Pancreatic Carcinoma And Experience With Folfirinox - A Cross Sectional Analysis From A Developing Country, Muhammad Nauman Zahir, Adnan Abdul Jabbar

Department of Radiation Oncology

Background: Pancreatic cancer is the fourth leading cause of cancer related death with median survival ranging from 3 to 6 months for metastatic disease. Palliative chemotherapy has been the backbone of treatment in advanced stage and has evolved over time. Data pertaining to the disease are scarce from our part of the world where treatment poses a significant challenge due to lack of resources.MATERIALS AND Methods: A retrospective chart review was performed for all patients presenting with stage IV pancreatic carcinoma at a tertiary care hospital in Karachi, Pakistan between January 2008 and December 2012. Data were collected using a …

Computer Aided Diagnosis Of Oral Cancer: Using Time-Step Ct Images, Jonathan T. Scott

Masters Theses

"In medical imaging it is a very common practice to use a technique known as Time-Step imaging in patients who might develop cancer. Time-Step imaging it a very powerful technique, however it can lead to unmanageable amounts of image data. Previously the only way to search all of this data was to manually look through all of the files. This had to be done by trained professionals who knew what to look for within the images and make a judgment about the patient based on the images. This paper discusses the development of an algorithm to have a computer search …

Promoting Comfort During Ct-Coronary Angiogram, Margo Archer, Dawn Arevalo, Kelly Vazquez

All Publications

No abstract provided.

The Multimodal Brain Tumor Image Segmentation Benchmark (Brats), Bjoern H. Menze, Andras Jakab, Stefan Bauer, Jayashree Kalpathy-Cramer, Khan M. Iftekharuddin, Syed M.S. Reza

Electrical & Computer Engineering Faculty Publications

In this paper we report the set-up and results of the Multimodal Brain Tumor Image Segmentation Benchmark (BRATS) organized in conjunction with the MICCAI 2012 and 2013 conferences. Twenty state-of-the-art tumor segmentation algorithms were applied to a set of 65 multi-contrast MR scans of low-and high-grade glioma patients-manually annotated by up to four raters-and to 65 comparable scans generated using tumor image simulation software. Quantitative evaluations revealed considerable disagreement between the human raters in segmenting various tumor sub-regions (Dice scores in the range 74%-85%), illustrating the difficulty of this task. We found that different algorithms worked best for different sub-regions …

Temporal Trends In Results Of 9170 Myocardial Perfusion Imaging Studies (2004 To 2013)., Nosheen Fatima

Department of Surgery

Abstract

BACKGROUND:

To assess the frequency of normal and abnormal myocardial perfusion imaging (MPI) in a consecutive cohort of patients from Pakistan over a period of 8.5 years.

MATERIAL AND METHODS:

We assessed 9170 patients who had undergone stress-rest MPI between January 2004 and June 2013. Patients were assessed for change in demographics, risk factors, and frequency of abnormal and normal MPI.

RESULTS:

Overall mean age and male predominance of studied cohort was ≈ 55 years and ≈ 55:45 (M:F), respectively, with no appreciable decline or rise. Marked decline in exercise as mode of stress (from 71% to 35%, p …

Outcome And Cost Effectiveness Of Autobiographically Guided Surgical Clip Placement For Tumor Localization In Patients Undergoing Neo-Adjuvant Chemotherapy For Breast Cancer., Imrana Masroor, Sana Zeeshan, Shaista Afzal Saeed, Saira Naz, Madeeha Ali, Khabir Ahmad, Shaista Khan

Department of Surgery

Abstract

BACKGROUND:

To determine the outcome and cost saving by placing ultrasound guided surgical clips for tumor localization in patientsundergoing neo-adjuvant chemotherapy for breast cancer.

MATERIALS AND METHODS:

This retrospective cross sectional analytical study was conducted at the Department of Diagnostic Radiology, Aga Khan University Hospital, Karachi, Pakistan from January to December 2014. A sample of 25 women fulfilling our selection criteria was taken. All patients came to our department for ultrasound guided core biopsy of suspicious breast lesions and clip placement in the index lesion prior to neo-adjuvant chemotherapy. All the selected patients had biopsy proven breast cancer.

RESULTS: …

Hyperpolarization Methods For Mrs, Boyd M. Goodson, Nicholas Whiting, Aaron M. Coffey, Panayiotis Nikolaou, Fan Shi, Brogan M. Gust, Maxwell E. Gemeinhardt, Roman Shchepin, Jason G. Skinner, Jonathan R. Birchall, Michael J. Barlow, Eduard Y. Chekmenev

Nicholas Whiting