Radiology Commons^™

Overview Of The Role Of Duplex Ultrasound For Treatment And Surveillance Of Peripheral Arterial Disease, John H. Fish Iii, Peter Klein-Weigel, Gustav Fraedrich

Journal of Patient-Centered Research and Reviews

Imaging strategies for preinterventional planning in symptomatic peripheral artery disease have employed various modalities ranging from duplex ultrasound to noninvasive angiography with computed tomography (CT) or magnetic resonance (MRA). These methods have classically been compared to the gold standard of digital subtraction angiography and are reviewed here in detail through the work of relevant published studies and meta-analyses between 1996 and 2014. In particular, we focus on the diagnostic performance, reproducibility and cost-effectiveness of these aforementioned modalities with respect to mapping the lower extremity arterial tree for planning vascular intervention and surveillance. The data presented suggests comparable sensitivity and specificity …

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 …

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.

Performance Evaluation Of Material Decomposition Using Rapid Kvp-Switching Dual-Energy Ct For Assessing Bone Mineral Density, John M. Wait

Dissertations and Theses (Open Access)

Osteoporosis is diagnosed by assessing the bone mineral density (BMD) of the trabecular bone, and has previously been characterized with dual-energy x-ray absorptiometry (DXA) or single-energy computed tomography (SECT). Dual-energy computed tomography (DECT) is able to create two three-dimensional sets of images representing the densities of two materials in a given basis pair. DECT is theoretically capable of providing a true density measurement of trabecular bone material with the proper material basis pair.

Using the rapid kVp-switching GE HD750 scanner, the concentrations of various solutes were assessed in two-material syringe-phantoms in different experimental conditions with DECT material density images, SECT …

Scanned Ion Beam Therapy For Thoracic Tumors, John Gordon Eley

Dissertations and Theses (Open Access)

Although frequently cured of Hodgkin lymphoma, adolescents and young adults can develop radiation induced second cancers. These patients could potentially benefit from scanned ion radiotherapy yet likely would require motion mitigation strategies. In theory, four-dimensional (4D) optimization of ion beam fields for individual motion states of respiration can enable superior sparing of healthy tissue near moving targets, compared to other motion mitigation strategies. Furthermore, carbon-ion therapy can sometimes provide greater relative biological effectiveness (RBE) for cell sterilization in a target but nearly equivalent RBE in tissue upstream of the target, compared to proton therapy. Thus, we expected that for some …

Ultrasound Based Evaluation Of Hepatic Steatosis And Fibrosis In Hepatitis C Non-Responders, Saba Sohail, Sina Aziz, Talat Mirza

Department of Radiology

Objective: To determine the accuracy of ultrasound in the diagnosis and grading of steatosis and fibrosis in Hepatitis C (HCV) patients not responding to ribavarin-interferon therapy.
Study design: A cross-sectional, analytical study.
Place and duration of study: Radiology Department, Civil Hospital, Karachi, from March 2008 to August 2010.
Methodology: Patients with positive HCV RNA despite 24 weeks ribavarin-interferon therapy (non-responders) were subjected to ultrasound and biopsy prior to institution of pegylated interferon therapy for detection and grading of steatosis and fibrosis. Using histopathology as the gold standard, sensitivity, specificity, negative and positive predictive values for ultrasound were determined.
Results: The …

A Descriptive Study To Find Possible Correlation Between Mri Findings Of Pituitary Gland And Serum Prolactin Level, Muhammad Azeemuddin, Rohana Naqi, Mohammad Wasay

Department of Medicine

Objective: To explore equation, if any, between findings of magnetic resonance imaging of pituitary gland and serum prolactin level.

Methods: The retrospective, descriptive study was conducted at the Department of Radiology, Aga Khan University Hospital, Karachi, and related to patients\' records from April 19, 2006 to April 23, 2009. Seventy patients underwent magnetic resonance imaging of brain for pituitary gland. Inclusion criteria were all patients referred with relevant clinical symptoms or deranged serum prolactin level. Patients who were claustrophobic or had a pacemaker, aneurysm clip, metallic foreign body in the orbit or with no laboratory investigation were excluded from the …

Physical Activity And Exercise During Adolescence And Young Adulthood Can Act As Preventative Measures Against The Development Of Osteoporosis In Elderly People, Christine C. Center

Honors College Theses

Osteoporosis, “the silent killer,” is responsible for 8.9 million annual fractures. Although not bound to these factors, osteoporosis typically targets females that are post-menopausal and have a family history of the disease. Osteoporosis is caused by a decrease in bone mass density. Physical activity and exercise and often spoken about when the topic of osteoporosis is discussed because of the impact they have on maintaining bone mass density in an effort to delay osteoporosis. This paper first provides an overview of osteoporosis, explanation of methods of diagnosing osteoporosis, risk factors, complications and treatment for osteoporosis. Topics covered include, bone mass …

Feasibility Of Tomotherapy-Based Image-Guided Radiotherapy To Reduce Aspiration Risk In Patients With Non-Laryngeal And Non-Pharyngeal Head And Neck Cancer, Nam P. Nguyen, Lexie Smith-Raymond, Vincent Vinh-Hung, Paul Vos, Rick Davis, Anand Desai, Thomas Sroka

Dartmouth Scholarship

Purpose: The study aims to assess the feasibility of Tomotherapy-based image-guided radiotherapy (IGRT) to reduce the aspiration risk in patients with non-laryngeal and non-hypopharyngeal cancer. A retrospective review of 48 patients undergoing radiation for non-laryngeal and non-hypopharyngeal head and neck cancers was conducted. All patients had a modified barium swallow (MBS) prior to treatment, which was repeated one month following radiotherapy. Mean middle and inferior pharyngeal dose was recorded and correlated with the MBS results to determine aspiration risk.

Diffusion Weighted Mr Imaging Of Ring Enhancing Brain Lesions, Muhammad Shahbaz Alam, Zafar Sajjad, Muhammad Azeemuddin, Zahid Anwar Khan, Fatima Mubarak, Waseem Akhtar

Department of Radiology

Objective: To evaluate the role of diffusion weighted imaging in differentiating the cause of ring enhancing brain lesions.

Study Design: Analytical, descriptive study.

Place and Duration of Study: Department of Radiology, The Aga Khan University Hospital, Karachi, from March 2007 to July 2011. Methodology: Diffusion weighted imaging (DWI) was performed on 37 patients having ring enhancing lesions on their post-contrast brain MRI scans. These lesions were characterized into neoplastic and abscess cavity on the basis of diffusion restriction. Correlation of all these findings was done with histopathology obtained in all these patients. Sensitivity, specificity, positive and negative predictive values and …

Infectious Intracranial Aneurysms: Collaboration For Treatment Success, Erin M. Conahan Rn, Bsn, Cnrn

Patient Care Services / Nursing

No abstract provided.

Correlates Of Morbidity And Mortality In Severe Necrotizing Pancreatitis, K. M. Pal, Pashtoon Murtaza Kasi, Mohammad Tayyeb, S. M. Faisal Mosharraf, Zafar Fatmi

Community Health Sciences

Acute severe pancreatitis is associated with a high morbidity and mortality and frequently is accompanied by underlying pancreatic parenchymal necrosis. Patients with pancreatic necrosis must be identified, because the morbidity and mortality rate in this subgroup is much higher. Our objective was to compare the clinical outcomes of these patients based on the degree of pancreatic necrosis. A total of 35 patients were noted to have pancreatic necrosis. These were divided into 2 groups based on extent of necrosis: group A had less than 50% necrosis and group B had more than 50% necrosis. The rate of mortality (5% versus …

Cerebral Toxoplasmosis In A Patient With Acquired Immunodeficiency Syndrome, Rohana Naqi, Muhammad Azeemuddin, Humera Ahsan

Department of Radiology

Cerebral toxoplasmosis commonly affects patients with advanced HIV immunodeficiency. Toxoplasmosis in patients who are immunocompromised can be severe and debilitating in patients with Central Nervous System (CNS) involvement and the condition may be fatal. We report the case of a 40-year-old man who was a known case of HIV and presented with cerebral toxoplasmosis. His Magnetic Resonance Imaging (MRI) scan showed multiple ring enhancing lesions with extensive surrounding oedema in supratentorial as well as infratentorial region. Lesions were mainly located in the periventricular region as well as at the grey-white matter junction and showed enhancement in the periphery as well …

A Doppler-Based Evaluation Of Peripheral Lower Limb Arterial Insufficiency In Diabetes Mellitus, Riffat Shaheen, Saba Sohail

Department of Radiology

Objective: To determine the frequency, level and flow patterns of lower limb arterial insufficiency in diabetic patients on Doppler ultrasound study.
Study Design: Cross-sectional study.
Place and Duration of Study: Radiology Department, Civil Hospital, Karachi, from February 2007 to September 2008.
Methodology: One hundred adult diabetic patients with suspected peripheral vascular insufficiency irrespective of gender were included. Demographic data, presenting complaints, treatment history, and level of HbA1c were recorded. Doppler evaluated arterial status and ankle brachial index (ABI) were recorded on proforma. Statical analysis were done on SPSS version 12.
Results: The mean HbA1c was 8.4 ± 1.4gm/dl, a majority …

Primary Cutaneous B Cell Lymphoma--Leg Type (New Eortc--Who Classification), With Nasal Sinuses Involvement, Asim Jamal Shaikh, Nehal Masood, Aamir Ahsan, Wasim Memon

Department of Radiation Oncology

Primary Cutaneous lymphomas of B cell origin are rare, there remains a controversy in truly classifying these lymphomas and an updated EORTC classification divides them on the basis of their distinct histopthological grounds rather than on the basis of their anatomic location as in WHO classification, while the new WHO- EORTC joint classification maintains some characteristics of both systems, We report an elderly gentleman who primarily had a typical Leg dominant Cutaneous lymphoma of B cell origin uniquely with involvement of nasal Sinusues, bearing the Immunohistochemical staining features of "Cutaneous lymphoma - Leg Type" befitting the new joint WHO-EORTC classification …

Repeatability Of Serial Carotid Intima Media Thickness Scanning On Individual Subjects, Judi Nightingale

Loma Linda University Electronic Theses, Dissertations & Projects

Background. Heart disease affects millions of Americans each year. In order to improve primary prevention, early risk identification is essential. B-mode ultrasound of the common carotid artery (CCA) intima-media thickness (IMT) assesses risk of a coronary event early in the process of plaque development. Because IMT changes are so small over time, in order to determine clinically significant versus clinically insignificant changes in IMT over a 12 month time period, a protocol is needed which can detect the least significant difference (LSD) of at least 0.030 mm.

Purpose. The purpose of this study was to develop and test a well-defined …

Mechanism Of Neuronal Injury In Cerebral Venous Thrombosis, Uzma Usman, Mohammad Wasay

Department of Medicine

The impact of CVT on the brain is wide spectrum, ranging from completely normal parenchyma to brain oedema and/or haemorrhage. Multiple factors relate to neuronal injury in CVT including; dural sinus pressure, increased venous flow velocities, collateralization of venous channels, rate of occlusion, development of cytotoxic and vasogenic oedema, recanalization and accelerated myelination. It is suggested that recanalization of occluded vein, as well as, the presence or absence and the efficiency of intracranial venous collaterals, may have an impact on the extent of brain tissue damage and hence the prognosis of acute CVT.

Near-Infrared Characterization Of Breast Tumors In Vivo Using Spectrally-Constrained Reconstruction, Subhadra Srinivasan, Brian W. Pogue, Ben Brooksby, Shudong Jiang, Hamid Dehghani, Christine Kogel, Wendy A. Wells, Steven P. Poplack, Keith D. Paulsen

Dartmouth Scholarship

Multi-wavelength Near-Infrared (NIR) Tomography was utilized in this study to non-invasively quantify physiological parameters of breast tumors using direct spectral reconstruction. Frequency domain NIR measurements were incorporated with a new spectrally constrained direct chromophore and scattering image reconstruction algorithm, which was validated in simulations and experimental phantoms. Images of total hemoglobin, oxygen saturation, water, and scatter parameters were obtained with higher accuracy than previously reported. Using this spectral approach, in vivo NIR images are presented and interpreted through a series of case studies (n=6 subjects) having differing abnormalities. The corresponding mammograms and ultrasound images are also evaluated. Three of six …

Socio-Economic And Diagnostic Aspects Of Tuberculosis In Pakistan, Saba Sohail

Department of Radiology

No abstract provided.

Outbreak Of Sars, Ambreen Shakil, Muhammad Imran Omar, Saba Sohail

Department of Radiology

No abstract provided.

Development Of Periapical Lesions In Immunosuppressed Rats, Phillip A. Waterman Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

The pathogenesis of periapical lesions is the interaction of the oral flora with the existing host defenses. The role of bacteria has been established in endodontic disease but the contribution of the host defenses in periapical lesion formation is less clear. The purpose of this study was to compare periapical lesion development in immunosuppressed rats with that in normal rats. Thirty-five, eight-week old Sprague-Dawley rats were equally divided into seven groups. Groups 1, 2, and 3 were given weekly injections of Cytoxan, an immunosuppressive agent. Groups 4, 5, and 6 received no immunosuppressive therapy. Group 7 served as a control, …

Magnetic Resonance Imaging Of Oromandibular Limb Hypogenesis Syndrome (Olhs) : Type 1a Congenital Hypoglossia With Micrognathia, Edmond H. Henken

Loma Linda University Electronic Theses, Dissertations & Projects

An eighteen-year old female with Oromandibular Limb Hypogenesis Syndrome Type 1A was imaged with Magnetic Resonance in the sagittal, coronal, and transverse planes with the jaws closed. The intrinsic muscles of the tongue, genioglossus, geniohyoid, mylohyoid, medial and lateral pterygoid muscles were identified and compared with a control of the same age and sex. All the muscles in question were present. Combined with the intrinsic muscles of the tongue, the genioglossus were approximately one-half the size of the control in the sagittal plane. The geniohyoid of the OLHS subject was enlarged most probably due to the hyperactivity of the floor …