Medicine and Health Sciences Commons^™

Numerical Chromosomal Instability Mediates Susceptibility To Radiation Treatment, Samuel F. Bakhoum, Lilian Kabeche, Matthew D. Wood, Christopher D. Laucius

Dartmouth Scholarship

The exquisite sensitivity of mitotic cancer cells to ionizing radiation (IR) underlies an important rationale for the widely used fractionated radiation therapy. However, the mechanism for this cell cycle-dependent vulnerability is unknown. Here we show that treatment with IR leads to mitotic chromosome segregation errors in vivo and long-lasting aneuploidy in tumour-derived cell lines. These mitotic errors generate an abundance of micronuclei that predispose chromosomes to subsequent catastrophic pulverization thereby independently amplifying radiation-induced genome damage. Experimentally suppressing whole-chromosome missegregation reduces downstream chromosomal defects and significantly increases the viability of irradiated mitotic cells. Further, orthotopically transplanted human glioblastoma tumours in which …

Magnetic Resonance Imaging Compatible Remote Catheter Navigation System, Mohammad Ali Tavallaei

Electronic Thesis and Dissertation Repository

Many vascular and cardiac diseases are diagnosed and treated using a medical technique known as percutaneous transluminal catheter intervention (PTC). In PTC, the interventionalist inserts a catheter into the vasculature, and using the vessel as the guiding passageway, the catheter is navigated to desired anatomical targets where it would be used for various purposes such as catheter ablation for the treatment/management of cardiac arrhythmias. The catheterization procedure is conventionally guided with x-ray fluoroscopic imaging and more recently, but rarely, with Magnetic Resonance Imaging (MRI). X-ray imaging irradiates the patient directly during the procedure, and the staff and interventionalists indirectly through …

Characteristics Of A Novel Treatment System For Linear Accelerator–Based Stereotactic Radiosurgery, Ning Wen, Haisen Li, Kwang Song, Karen Chin-Snyder, Yujiao Qin, Jinkoo Kim, Maria Bellon, Misbah Gulam, Stephen Gardner, Anthony Doemer, Suneetha Devpura, James Gordon, Indrin Cherry, Farzan Siddiqui, Munther Ajlouni, Robert Pompa, Zane Hammoud, Michael Simoff, Steven Kalkanis, Benjamin Movsas, M. Salim Siddiqui

Internal Medicine Faculty Publications

The purpose of this study is to characterize the dosimetric properties and accuracy of a novel treatment platform (Edge radiosurgery system) for localizing and treating patients with frameless, image-guided stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT). Initial measurements of various components of the system, such as a comprehensive assessment of the dosimetric properties of the flattening filter-free (FFF) beams for both high definition (HD120) MLC and conical cone-based treatment, positioning accuracy and beam attenuation of a six degree of freedom (6DoF) couch, treatment head leakage test, and integrated end-to-end accuracy tests, have been performed. The end-to-end test of the …

Disruption Of White Matter Integrity In Adult Survivors Of Childhood Brain Tumors: Correlates With Long-Term Intellectual Outcomes, Tricia Z. King, Liya Wang, Hui Mao

Psychology Faculty Publications

Background

Although chemotherapy and radiation treatment have contributed to increased survivorship, treatment-induced brain injury has been a concern when examining long-term intellectual outcomes of survivors. Specifically, disruption of brain white matter integrity and its relationship to intellectual outcomes in adult survivors of childhood brain tumors needs to be better understood.

Methods

Fifty-four participants underwent diffusion tensor imaging in addition to structural MRI and an intelligence test (IQ). Voxel-wise group comparisons of fractional anisotropy calculated from DTI data were performed using Tract Based Spatial Statistics (TBSS) on 27 survivors (14 treated with radiation with and without chemotherapy and 13 treated without …

Labrad : Vol 41, Issue 2 - July 2015, Aga Khan Universiity Hospital, Karachi

LABRAD

• An Overview of Immunoglobulin G4-Related Disease
• Plasma Neutrophil Gelatinase Associated Lipocalin (NGAL) a Marker of Acute Kidney Injury
• Celiac Disease: Biomarkers for Diagnosis and Monitoring
• Pathophysiology of Paroxysmal Nocturnal Haemoglobinuria and Diagnosis by Flowcytommetry
• Pathological Changes in Renal Transplant Biopsies not Related to Allo-Immune Mechanisms
• Myelodysplastic Syndromes
• Fluorescent Optical Method for Platelet Estimation: An Advanced Clinical Parameter in Laboratory Hematology
• Introduction of Beta-D-Glucan and Galactomannan - Testing for Diagnosis of Invasive Fungal Infections
• Basic Concepts in Hematopoietic Stem Cell Transplantation

Radiobiological Evaluation Of Intensity Modulated Radiation Therapy Treatments Of Patients With Head And Neck Cancer: A Dual-Institutional Study, G. Narayanasamy, A. P. Pyakuryal, S. Pandit, J. Vincent, C. Lee, P. Mavroidis, N. Papanikolaou, Mahesh Kudrimoti, T. T. Sio

Radiation Medicine Faculty Publications

In clinical practice, evaluation of clinical efficacy of treatment planning stems from the radiation oncologist's experience in accurately targeting tumors, while keeping minimal toxicity to various organs at risk (OAR) involved. A more objective, quantitative method may be raised by using radiobiological models. The purpose of this work is to evaluate the potential correlation of OAR-related toxicities to its radiobiologically estimated parameters in simultaneously integrated boost (SIB) intensity modulated radiation therapy (IMRT) plans of patients with head and neck tumors at two institutions. Lyman model for normal tissue complication probability (NTCP) and the Poisson model for tumor control probability (TCP) …

The Utilization Of The Anatomage Virtual Dissection Table In The Education Of Imaging Science Students, Tanya M. Custer, Kim Michael

Posters and Presentations: Medical Imaging & Therapeutic Sciences

Objectives: The purpose of this research was to investigate the use of the Anatomage Virtual Dissection Table in the education of imaging science students and to assess the beliefs and perceptions of the students in regard to using the Table for teaching imaging-based anatomy & pathology.

Subjects & Methods: Study participants included 17 medical imaging students to include 9 Diagnostic Medical Sonography students, 2 Magnetic Resonance Imaging students, 2 Nuclear Medicine Technology students, 2 Radiation Therapy students and 2 Cardiovascular Interventional Technology students. Data was collected through focus groups and course/instructor evaluations. The researchers followed Creswell’s procedure for data analysis …

Functional Neuroimaging Distinguishes Posttraumatic Stress Disorder From Traumatic Brain Injury In Focused And Large Community Datasets., Daniel G Amen, Cyrus A Raji, Kristen Willeumier, Derek Taylor, Robert Tarzwell, Andrew B. Newberg, Md, Theodore A Henderson

Department of Radiology Faculty Papers

BACKGROUND: Traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) are highly heterogeneous and often present with overlapping symptomology, providing challenges in reliable classification and treatment. Single photon emission computed tomography (SPECT) may be advantageous in the diagnostic separation of these disorders when comorbid or clinically indistinct.

METHODS: Subjects were selected from a multisite database, where rest and on-task SPECT scans were obtained on a large group of neuropsychiatric patients. Two groups were analyzed: Group 1 with TBI (n=104), PTSD (n=104) or both (n=73) closely matched for demographics and comorbidity, compared to each other and healthy controls (N=116); Group 2 …

In Ovo Serial Skeletal Muscle Diffusion Tractography Of The Developing Chick Embryo Using Dti: Feasibility And Correlation With Histology, Zien Zhou, Zachary Delproposto, Lianming Wu, Jianrong Xu, Jia Hua, Yan Zhou, Yongquan Ye, Zishu Zhang, Jiani Hu, E Mark Haacke

Yan Zhou 周彦文档

Abstract Background Magnetic resonance imaging is a noninvasive method of evaluating embryonic development. Diffusion tensor imaging (DTI), based on the directional diffusivity of water molecules, is an established method of evaluating tissue structure. Yet embryonic motion degrades the in vivo acquisition of long-duration DTI. We used a dual-cooling technique to avoid motion artifact and aimed to investigate whether DTI can be used to monitor chick embryonic skeletal muscle development in ovo, and to investigate the correlation between quantitative DTI parameters fractional anisotropy (FA) and fiber length and quantitative histologic parameters fiber area percentage (FiberArea%) and limb length. Results From 84 …

Obesity-Induced Adipokine Imbalance Impairs Mouse Pulmonary Vascular Endothelial Function And Primes The Lung For Injury., Dilip Shah, Freddy Romero, Michelle Duong, Nadan Wang, Bishnuhari Paudyal, Benjamin T Suratt, Caleb B Kallen, Jianxin Sun, Ying Zhu, Kenneth Walsh, Ross Summer

Center for Translational Medicine Faculty Papers

Obesity is a risk factor for the development of acute respiratory distress syndrome (ARDS) but mechanisms mediating this association are unknown. While obesity is known to impair systemic blood vessel function, and predisposes to systemic vascular diseases, its effects on the pulmonary circulation are largely unknown. We hypothesized that the chronic low grade inflammation of obesity impairs pulmonary vascular homeostasis and primes the lung for acute injury. The lung endothelium from obese mice expressed higher levels of leukocyte adhesion markers and lower levels of cell-cell junctional proteins when compared to lean mice. We tested whether systemic factors are responsible for …

Parametric Mapping Of Contrasted Ovarian Transvaginal Sonography., Katrina Korhonen, Ryan Moore, Andrej Lyshchik, Arthur C. Fleischer

Department of Radiology Faculty Papers

The purpose of this study was to assess the accuracy of parametric analysis of transvaginal contrast-enhanced ultrasound (TV-CEUS) for distinguishing benign versus malignant ovarian masses. A total of 48 ovarian masses (37 benign and 11 borderline/malignant) were examined with TV-CEUS (Definity; Lantheus, North Billerica, MA; Philips iU22; Philips Medical Systems, Bothell, WA). Parametric images were created offline with a quantification software (Bracco Suisse SA, Geneva, Switzerland) with map color scales adjusted such that abnormal hemodynamics were represented by the color red and the presence of any red color could be used to differentiate benign and malignant tumors. Using these map …

Multiparametric Mr Enterography Without The Use Of Antiperistaltic Agents: Performance And Interpretation, Amelia M. Wnorowski, Md, Flavius Guglielmo, Md, Robert Ford, Md, Donald G. Mitchell, Md

Department of Radiology Faculty Papers

Purpose

To describe how to perform and interpret MR enterography (MRE) without using antiperistaltic agents.

Thyroxine Replacement In Patients On Parenteral Nutrition: A Clinical Conundrum, Abdul Rehman, Noor Ul-Ain Baloch, Muhammad Awais

Department of Biological & Biomedical Sciences

No abstract provided.

Quantifying Unnecessary Normal Tissue Complication Risks Due To Suboptimal Planning: A Secondary Study Of Rtog 0126., Kevin L. Moore, Rachel Schmidt, Vitali Moiseenko, Lindsey A. Olsen, Jun Tan, Ying Xiao, James Galvin, Stephanie Pugh, Michael J Seider, Adam P. Dicker, Walter Bosch, Jeff Michalski, Sasa Mutic

Department of Radiation Oncology Faculty Papers

PURPOSE: The purpose of this study was to quantify the frequency and clinical severity of quality deficiencies in intensity modulated radiation therapy (IMRT) planning in the Radiation Therapy Oncology Group 0126 protocol.

METHODS AND MATERIALS: A total of 219 IMRT patients from the high-dose arm (79.2 Gy) of RTOG 0126 were analyzed. To quantify plan quality, we used established knowledge-based methods for patient-specific dose-volume histogram (DVH) prediction of organs at risk and a Lyman-Kutcher-Burman (LKB) model for grade ≥2 rectal complications to convert DVHs into normal tissue complication probabilities (NTCPs). The LKB model was validated by fitting dose-response parameters relative …

Salvage Brachytherapy In Combination With Interstitial Hyperthermia For Locally Recurrent Prostate Carcinoma Following External Beam Radiation Therapy: A Prospective Phase Ii Study., Andrzej M Kukiełka, Vratislav Strnad, Paul R. Stauffer, Tomasz Dąbrowski, Marcin Hetnał, Damian Nahajowski, Tomasz Walasek, Piotr Brandys, Robert Matys

Department of Radiation Oncology Faculty Papers

Optimal treatment for patients with only local prostate cancer recurrence after external beam radiation therapy (EBRT) failure remains unclear. Possible curative treatments are radical prostatectomy, cryosurgery, and brachytherapy. Several single institution series proved that high-dose-rate brachytherapy (HDRBT) and pulsed-dose-rate brachytherapy (PDRBT) are reasonable options for this group of patients with acceptable levels of genitourinary and gastrointestinal toxicity. A standard dose prescription and scheme have not been established yet, and the literature presents a wide range of fractionation protocols. Furthermore, hyperthermia has shown the potential to enhance the efficacy of re-irradiation. Consequently, a prospective trial is urgently needed to attain clear …

Ultrasound Evaluation Of Umbilical Coiling Index In Second Trimester Of Gestation And Its Association With Small For Gestational Age Status At Birth, Josephine Mwikali Ndolo

Theses & Dissertations

Introduction: The degree of coiling of the umbilical cord, referred to as umbilical coiling index, has been shown to have an effect on perinatal adverse outcomes such as small for gestational age neonates, interventional delivery, meconium staining, low fetal pH and low Apgar score. This study proposes that the antenatal umbilical coiling index performed in the second trimester of pregnancy has a correlation with the gestation-specific birth weight and can therefore be used as a marker to predict small for gestational age neonates.

Objective: To determine the association between antenatal umbilical coiling index (aUCI) in the second trimester and small …

Comparison Of Quantitative Analysis To Qualitative Analysis For Interpretation Of Lower Limb Lymphoscintigraphy, Edward Chege Nganga

Theses & Dissertations

Background: Lymphoscintigraphy is now the primary imaging modality used in determining a diagnosis in patients with suspected extremity lymphedema. However, analysis is mainly by visual qualitative analysis which is subjective and has a wide inter-observer variability. Subtle differences in ilioinguinal uptake between normal and abnormal limbs may be missed with visual qualitative analysis. This study seeks to compare quantitative analysis to qualitative analysis by computing percentage ilioinguinal nodes uptake at 1.5 hours.

Objectives: To compare quantitative analysis to qualitative analysis of lower limb lymphoscintigraphy in the diagnosis of lymphedema.

To determine the diagnostic accuracy of quantitative lymphoscintigraphy analysis.

Methodology: 52 …

Prevalence Of Suspicious Ultrasound Findings In Patients With Mammographic Focal Asymmetry At Aga Khan University Hospital, Nairobi, Jacqueline Ndunge Mavuti

Theses & Dissertations

Background: Breast cancer has become the leading cancer in women in both economically developed and developing countries, accounting for 25% of all cancers diagnosed worldwide in 2012. The cornerstone of breast cancer control remains early detection in order to improve outcomes and survival. Thus far the only breast cancer screening method that has proved to be effective is mammography. Although mammography is the mainstay of early detection, a fundamental limitation is its low inherent contrast difference between the soft tissue structures in the breast. Mammographic specificity relies on the ability to distinguish benign from malignant breast lesions based on their …

Characterization Of Low Density Intracranial Lesions Using Dual-Energy Computed Tomography, Jessica L. Nute

Dissertations & Theses (Open Access)

Calcific and hemorrhagic foci of susceptibility are frequently encountered on routine brain MR studies. Both etiologies cause variations in local magnetic field strength, leading to dark regions on the MR images that cannot be classified. Single-energy CT (SECT) can be used to identify lesions with attenuation over 100 HU as calcific, however lesions with lower attenuation cannot be reliably identified. While calcific lesions are unlikely to cause harm, hemorrhagic lesions carry a risk of subsequent intracranial bleeding; as such, identification of hemorrhage is vital in preventing the inappropriate use of anticoagulant medications in patients with hemorrhagic lesions.

Given there currently …

Comparison Between Coated Vs. Uncoated Suture Middle Cerebral Artery Occlusion In The Rat As Assessed By Perfusion/Diffusion Weighted Imaging, James Bouley, Marc Fisher, Nils Henninger

Nils Henninger

Differences among models in the temporal evolution of ischemia after middle cerebral artery occlusion (MCAO) in rats may considerably influence the results of experimental treatment studies. Using diffusion and perfusion imaging, we compared the spatiotemporal evolution of ischemia in Sprague-Dawley rats after permanent MCAO (pMCAO) with different types of sutures. Male Sprague-Dawley rats were randomly assigned to pMCAO produced with either 4-0 silicone coated (n=8), or 3-0 uncoated monofilaments (n=8). Serial determination of quantitative cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) maps were performed up to 3 h after pMCAO. Lesion volumes were calculated by using previously validated …

Re-Expansion Pulmonary Edema, Talal Alzahrani, Nawaf Abaalkhail, Mayssam Nehme, Jalil Ahari

GW Research Days 2015

Re-expansion pulmonary edema (RPE) is a rare complication of therapeutic thoracentesis. Unfortunately, there is no definitive treatment modality for RPE. The high mortality rate, reported up to 21%, presses the issue for finding adequate prevention and treatment. Here we report a new management modality that is very useful for a patient with RPE.

Case Report: An 80-year-old man with a history of hypertension, atrial fibrillation, congestive heart failure with preserved ejection fraction, and sacral decubitus ulcer, who was admitted for surgical debridement of his ulcer. He developed hospital-acquired pneumonia and was resolved with antibiotics and aggressive hydration. He became hypoxic, …

Image Enhancement Of Cancerous Tissue In Mammography Images, Richard Thomas Richardson

CCE Theses and Dissertations

This research presents a framework for enhancing and analyzing time-sequenced mammographic images for detection of cancerous tissue, specifically designed to assist radiologists and physicians with the detection of breast cancer. By using computer aided diagnosis (CAD) systems as a tool to help in the detection of breast cancer in computed tomography (CT) mammography images, previous CT mammography images will enhance the interpretation of the next series of images. The first stage of this dissertation applies image subtraction to images from the same patient over time. Image types are defined as temporal subtraction, dual-energy subtraction, and Digital Database for Screening Mammography …

Knee Morphometric Risk Factors For Acute Anterior Cruciate Ligament Injury In Skeletally Immature Patients, Kenneth Aaron Shaw, Brian S. Dunoski, Neil J. Mardis, Donna M. Pacicca

Manuscripts, Articles, Book Chapters and Other Papers

© 2015, The Author(s).

Study design: Retrospective, case–control.

Purpose: Knee morphometric risk factors for noncontact anterior cruciate ligament (ACL) injury have been a popular topic with skeletally mature patients. Little research has focused on the skeletally immature, with conflicting conclusions. This study performs a comprehensive analysis of identified parameters thought to predispose to ACL injury in a skeletally immature cohort.

Methods: A retrospective review of pediatric patients undergoing knee magnetic resonance imaging (MRI) was performed over a 4-year period. Inclusionary criteria included mid-substance ACL disruption, skeletal immaturity, noncontact injury, without associated ligamentous disruption, and no medical condition associated with ligamentous …

Focused Ultrasound For Treatment Of Bone Tumours., Dario B. Rodrigues, Paul R. Stauffer, David Vrba, Mark Hurwitz, Md

Department of Radiation Oncology Faculty Papers

PURPOSE: Focused ultrasound (FUS) is a modality with rapidly expanding applications across the field of medicine. Treatment of bone lesions with FUS including both benign and malignant tumours has been an active area of investigation. Recently, as a result of a successful phase III trial, magnetic resonance-guided FUS is now a standardised option for treatment of painful bone metastases. This report reviews the clinical applications amenable to treatment with FUS and provides background on FUS and image guidance techniques, results of clinical studies, and future directions.

METHODS: A comprehensive literature search and review of abstracts presented at the recently completed …

Cost-Effectiveness Of Coronary Artery Calcium Testing For Coronary Heart And Cardiovascular Disease Risk Prediction To Guide Statin Allocation: The Multi-Ethnic Study Of Atherosclerosis (Mesa), Khurram Nasir

All Publications

BACKGROUND: The Multi-Ethnic Study of Atherosclerosis (MESA) showed that the addition of coronary artery calcium (CAC) to traditional risk factors improves risk classification, particularly in intermediate risk asymptomatic patients with LDL cholesterol levels /dL. However, the cost-effectiveness of incorporating CAC into treatment decision rules has yet to be clearly delineated.OBJECTIVE: To model the cost-effectiveness of CAC for cardiovascular risk stratification in asymptomatic, intermediate risk patients not taking a statin. Treatment based on CAC was compared to (1) treatment of all intermediate-risk patients, and (2) treatment on the basis of United States guidelines.METHODS: We developed a Markov model of first coronary …

Is Metabolic Syndrome Predictive Of Prevalence, Extent, And Risk Of Coronary Artery Disease Beyond Its Components? Results From The Multinational Coronary Ct Angiography Evaluation For Clinical Outcome: An International Multicenter Registry (Confirm), Ricardo Cury

All Publications

No abstract provided.

Labrad : Vol 41, Issue 1 - March 2015, Aga Khan University Hospital, Karachi

LABRAD

• An Overview of Proficiency Testing
• Sources of Pre-analytical Variations
• Five Q-Framework for Implementing Total Quality Management in Laboratory
• Delta Check in Clinical Laboratory
• Indicators of Quality Improvement in Surgical Pathology
• Types of Analytical Errors
• Method Validation for Quantitative Tests: CAP Recommendations
• Levey Jenning Chart and a Guide to Use Westgard Rules
• Quality Control of Vitek-2 System
• Establishing Quality Control Values for Haematology Parameters

Radiation Therapy After Radical Prostatectomy For Prostate Cancer: Evaluation Of Complications And Influence Of Radiation Timing On Outcomes In A Large, Population-Based Cohort., Sarah E Hegarty, Terry Hyslop, Adam Dicker Md, Phd, Timothy Showalter Md

Department of Radiation Oncology Faculty Papers

PURPOSE: To evaluate the influence of timing of salvage and adjuvant radiation therapy on outcomes after prostatectomy for prostate cancer.

METHODS: Using the Surveillance, Epidemiology, and End Results-Medicare linked database, we identified prostate cancer patients diagnosed during 1995-2007 who had one or more adverse pathological features after prostatectomy. The final cohort of 6,137 eligible patients included men who received prostatectomy alone (n = 4,509) or with adjuvant (n = 894) or salvage (n = 734) radiation therapy. Primary outcomes were genitourinary, gastrointestinal, and erectile dysfunction events and survival after treatment(s).

RESULTS: Radiation therapy after prostatectomy was associated with higher rates …

Active Brain Regions During Sleep Using Electroencephalography-Functional Magnetic Resonance Imaging, Grace Duan '15, Sameeksha Malhotra '15, Todd B. Parrish

Student Publications & Research

Purpose: To determine the differences in functional connectivity among brain regions during the different stages of the human sleep cycle.

The Artificial Divide Between Biomedical Sciences And Clinical Medicine In Undergraduate Medical Education, Abdul Rehman, Noor Ul-Ain Baloch, Muhammad Awais

Department of Biological & Biomedical Sciences

No abstract provided.