Radiology Commons^™

Dysembryoplastic Neuroepithelial Tumor With Atypical Presentation: Mri And Diffusion Tensorcharacteristics, Kalyan Paudel, Samuel Borofsky, Robert V. Jones, Lucien M. Levy

Radiology Faculty Publications

We report the neuroimaging findings of a 26-year-old female patient with a biopsy-proven dysembryoplastic neuroepithelial tumor (DNET). DNETs are an uncommon, usually benign, glial-neural cortical neoplasm of children and young adults who typically present with intractable seizures. DNETs may occur in any region of the supratentorial cortex, but have a predilection for the temporal lobes. Accurate neuroimaging diagnosis is essential since patients with DNET benefit from complete resection. However, accurate differentiation from other cortical lesions may be challenging. Typical conventional Magnetic Resonance Imaging (MRI) features can help in the differentiation from other similar cortical tumors. Diffusion tensor imaging can also …

Stereotactic Localization And Targeting Accuracy For Experimental Proton Radiosurgery, Yin Chen

Theses Digitization Project

The purpose of this study was to improve an existing experimental proton radiosurgery system at Loma Linda University Medical Center to reach sub-millimeter accuracy before proton radiosurgery with narrow beams can be used in a clinical trial. Protons, different from photons (i.e., x-rays or gamma rays), are charged with particles that slow down in matter and release a burst of energy near the end of their range (maximum depth of penetration), which is called the Bragg peak, named after the physicist William Henry Bragg who discovered it in 1903. Photon beams deliver most doses over a large area near the …

Alternative Hull Detection Techniques For Preprocessing In Proton Computed Tomography Reconstruction, Blake Edward Schultze

Theses Digitization Project

The purpose of this study was to develop computationally efficient hull detection techniques appropriate for image reconstruction using sparse matrices. The hull detection techniques investigated were space carving (SC), modified space carving (MSC), and space modeling (SM) and these were compared to the cone-beam version of filtered back projection (FBP) algorithm in terms of their computation time and the quality of the object hull they produced.

Fiducial-Free Alignment Verification Techniques For Intracranial Radiosurgery, Kenneth Matthew Williams

Theses Digitization Project

This thesis serves as the basis for a method using image registration to automate patient alignment in an effort to eliminate the dependency on the fiducial markers as well as improve the accuracy efficiency of the alignment process. Proton beams are an external beam modality of radiation therapy that can be used effectively for radiosurgical applications due to the dosimetry advantage of the Bragg peak. The Bragg peak is a phenomenon exploited by proton beam therapy to concentrate the effect of the beams on the tumor while minimizing damage to critical structures and other health tissues within the patient.

Impact Of Varied Low Resolution Phantoms On Intensity Modulated Proton Therapy Dose Distributions, Aarohi Shyam Padhye

Theses Digitization Project

The primary purpose of this thesis is to discuss the usefulness of image segmentation techniques in creating accurate proton dose distribution plans. The calculation of the proton dose distribution has to take into account the material (tissue, bone, brain) in the treatment area of the patients body.

A New Phantom And Gradient Isocenter Estimation For Magnetic Resonance Imaging Distortion Correction, Zongqi Cai

Theses Digitization Project

The purpose of this study was to develop and implement a numerical software based method that can accurately correct the distortion of MR images generated by 3T MRI scanner. To accomplish this, a new phantom has been designed from scratch to capture the distortions inside 3T MRI scanner. An algorithm has been developed, based on the unique geometric feature of the new phantom, to estimate the location of gradient isocenter of the magnetic field inside 3T MRI scanner for the first time.

Ovarian Masses: Is Multi-Detector Computed Tomography A Reliable Imaging Modality?, Yasir Jamil, Saima Hafeez, Tariq Alam, Madiha Beg, Mohammad Awais, Imrana Masroor

Department of Radiology

Background: Ovarian cancer continues to pose a major challenge to physicians and radiologists. It is the third most common gynecologic malignancy and estimated to be fifth leading cancer cause of death in women, constituting 23% of all gynecological malignancies. Multi-detector computed tomography (MDCT) appears to offer an excellent modality in diagnosing ovarian cancer based on combination of its availability, meticulous technique, efficacy and familiarity of radiologists and physicians. The aim of this study was to compute sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of 64- slice MDCT in classifying ovarian masses; 95% confidence intervals were reported.MATERIALS AND …

Uterine Fibroid Embolization For Symptomatic Fibroids; Correlation Of Mid-Term Changes In Disease-Specific Symptoms And Magnetic Resonance Imaging Results At A Teaching Hospital In Kenya, John Kiprop Mutai

Theses & Dissertations

Background: Uterine fibroid embolization, though a widely available option in high income countries in managing symptomatic fibroids is relatively new in the East African region. It is currently offered at only one tertiary facility for the past three years. The symptom and radiological response in these patients, who literature suggests may have bigger fibroid burden and worse symptoms, is the subject of this study.

Objective: Characterization of MRI imaging features in women undergoing uterine fibroid embolization and identification of clinical correlates in an African population.

Methods: Patients with symptomatic fibroids who are selected to undergo UFE at the hospital formed …

Embolization With Histoacryl Glue Of An Anastomotic Pseudoaneurysm Following Surgical Repair Of Abdominal Aortic Aneurysm, Ayesha Walid, Tanveer Ul Haq, Raza Sayani, Zia Ur Rehman

Department of Radiology

We report a 62-year-old female who had surgical repair of abdominal aortic aneurysm with a bifurcated graft 2 years ago. She presented with a distal anastomotic pseudoaneurysm which was successfully embolized with histoacryl glue. Only one such similar case has been reported in the literature so far (Yamagami et al. (2006)).

Plan Dose Evaluation Of Three Dimensional Conformal Radiotherapy Planning (3d-Crt) Of Nasopharyngeal Carcinoma (Npc): Experience Of A Tertiary Care University Hospital In Pakistan, Ahmed Nadeem Abbasi, Asim Hafiz, Nasir Ali, Khurshid Ahmed Khan

Department of Radiation Oncology

Background: Radiation therapy is the mainstay of treatment for nasopharyngeal carcinoma. Importance of tumor coverage and challenges posed by its unique and critical location are well evident. Therefore we aimed to evaluate our radiation treatment plan through dose volume histograms (DVHs) to find planning target volume (PTV) dose coverage and factors affecting it.MATERIALS AND Methods: This retrospective study covered 45 histologically proven nasopharyngeal cancer patients who were treated with definitive 3D-CRT and chemotherapy between Feb 2006 to March 2013 at the Department of Oncology, Section Radiation Oncology ,Aga Khan University Hospital, Karachi, Pakistan. DVH was evaluated to find numbers of …

Using The Theory Of Planned Behavior As A Predictor Of Radiologic Technologists' Use Of Patient Radiation Protection Best Practices: A Regional Study, Brenda L. Boyd

Dissertations

Problem. A growing concern exists that patients are receiving an increase in radiation exposure while undergoing medical imaging exams. According to a March 2009 report by the National Council on Radiation Protection and Measurements (NCRP), the U.S. population's total exposure to ionizing radiation has nearly doubled over the past two decades. With the introduction of new digital radiology equipment, patient dose is on the rise. Possible reasons for a radiologic technologist's behavior include: influence by availability or lack of equipment, policies, social pressure, attitudes, and a safety culture. Little research has been done in this area, specifically with applying a …

Potential For High Resolution Microscintigraphy Using Polycapillary Optics, Patrick Richard Conlon

Legacy Theses & Dissertations (2009 - 2024)

Scintigraphy, also known as nuclear imaging, is the process of imaging an object that has been labeled with a radioactive material. A novel technique employing polycapillary optics for very high - resolution scintigraphy is presented. The small channel size and angular selectivity of polycapillary optics allow them to act as multiple-hole collimators and be used with high - resolution detectors. The ability of the optics to work with high resolution detectors allow the system to discriminate against scatter, thus negating the need for energy sensitive detectors, which are known to have poor resolution. Therefore the use of polycapillary optics presents …

Retro-Aortic Left Renal Vein, Joann Aichroth, Rdms, Traci B. Fox, Ms, Rt(R), Rdms, Rvt

Department of Radiologic Sciences Faculty Papers

The term retro-aortic left renal vein (RLRV) is defined as the left renal vein coursing posterior to the abdominal aorta. RLRV is an uncommon condition in which the left renal vein passes posterior to the abdominal aorta and anterior to the vertebrae. RLRV may lead to left renal vein hypertension (LRVH) syndrome, which is also known as Nutcracker syndrome. Nutcracker syndrome (NCS) is a condition in which the left renal vein is compressed causing hypertension of the vessel. RLRV and Nutcracker syndrome are vascular anomalies considered to be of clinical importance especially during surgical procedures of the renal vasculature.

A Feasibility Study Using Tomodirect For Craniospinal Irradiation, Ulrich W. Langner, Janelle A. Molloy, John F. Gleason Jr., Jonathan M. Feddock

Radiation Medicine Faculty Publications

The feasibility of delivering craniospinal irradiation (CSI) with TomoDirect is investigated. A method is proposed to generate TomoDirect plans using standard three-dimensional (3D) beam arrangements on Tomotherapy with junctioning of these fields to minimize hot or cold spots at the cranial/spinal junction. These plans are evaluated and compared to a helical Tomotherapy and a three-dimensional conformal therapy (3D CRT) plan delivered on a conventional linear accelerator (linac) for CSI. The comparison shows that a TomoDirect plan with an overlap between the cranial and spinal fields might be preferable over Tomotherapy plans because of decreased low dose to large volumes of …

Mri Features Of Spinal Fluorosis: Results Of An Endemic Community Screening, Iftekhar Ahmed, Saba Sohail, Munawwar Hussain, Nazeer Khan, Masood Hameed Khan

Department of Radiology

Objectives: Fluorosis is endemic in many parts of the world. However community studies on MRI features of fluorosis are lacking. The aim of this study was to determine MRI features of spinal changes in a community with endemic fluorosis in the Thar Desert Pakistan.
Methodology: Randomly selected adults from the Village Samorindh, district Tharparker, Sindh, Pakistan, with spinal fluorosis diagnosed on plain x-rays and raised serum fluoride levels were studied from June 2008 to January 2009. MRI was carried out on 0.5 T open magnet MRI system. Features of vertebral body, spinal ligaments, intervertebral disc, facet joints, iliac wings and …

Treatment Of Nonvariceal Gastrointestinal Hemorrhage By Transcatheter Embolization, Muhammad Ali, Tanveer Ul Haq, Basit Salam, Madiha Beg, Raza Sayani, Muhammad Azeemuddin

Department of Radiology

Purpose. To investigate the sensitivity of mesenteric angiography, technical success of hemostasis, clinical success rate, and complications of transcatheter embolization for the treatment of acute nonvariceal gastrointestinal hemorrhage. Material and Methods. A retrospective review of 200 consecutive patients who underwent mesenteric arteriography for acute nonvariceal gastrointestinal hemorrhage between February 2004 and February 2011 was done. Results. Of 200 angiographic studies, 114 correctly revealed the bleeding site with mesenteric angiography. 47 (41%) patients had upper gastrointestinal hemorrhage and 67 (59%) patients had lower gastrointestinal hemorrhage. Out of these 114, in 112 patients (98%) technical success was achieved with immediate cessation of …

Role Of Ultrasound In Characterization Of Ovarian Masses, Saima Hafeez, Saira Sufian, Quratulain Merchant, Yasir Jamil, Imrana Masroor

Department of Radiology

Background: Ovarian cancer is the second most common malignancy in Pakistani women, accounting for 4% of all cancers in the female population. The aim of this study was to determine sensitivity, specificity, positive and negative predictive values and 95% confidence intervals for ultrasound in characterization of ovarian masses in patients presenting at public and private tertiary care hospitals in Karachi, Pakistan.MATERIALS AND Methods: We adopted a cross-sectional analytical study design to retrospectively collect data from January 2009-11 from medical records of two tertiary care hospitals. Using a non-probability purposive sampling technique, we recruited a sample of 86 women aged between …

Controversies About Radioactive Iodine-131 Remnant Ablation In Low Risk Thyroid Cancers: Are We Near A Consensus?, Maseeh Uz Zaman, Nosheen Fatima, Ajit Kumar Padhy, Unaiza Zaman

Department of Radiology

Well differentiated thyroid cancers (WDTC), including papillary (80%) and follicular (10%) types, are the most common endocrine cancers globally. Over the last few decades most the diagnosed cases have fallen into low risk categories. Radioactive iodine-131 (RAI) has an established role in reducing recurrence and improving the survival in high risk patients. In patients with primary tumor size <1 >cm, RAI is not recommended by many thyroid societies. However, low risk WDTC has been an arena of major controversies, most importantly the role and dose of adjuvant RAI for remnant ablation to minimize chances of recurrence and improving survival. This review …

The Role Of Inflammation In Contrast Induced Nephropathy, Elijah A. Kwasa

Theses & Dissertations

Background: Intravenously administered iodinated contrast media are widely and liberally used in daily diagnostic radiological investigations. Contrast-induced nephropathy (CIN) is notable as the third commonest cause of hospital-acquired renal injury.

Justification: The global prevalence of CIN from various studies ranges from 2-5% but an incidence of CIN of 12-14% in Kenya was highlighted by a recent study without an explanation for the markedly increased incidence. Intravascular contrast has been demonstrated to commonly cause renal vasoconstriction. However, the low incidence of CIN in the general population infers that contrast alone cannot be a causative insult. This study proposes that inflammatory …

Brain Trauma, Pet Scans And Forensic Complexity, Jane Moriarty, Daniel Langleben, James Provenzale

Jane Campbell Moriarty

Positron Emission Tomography (PET) is a medical imaging technique that can be used to show brain function. Courts have admitted PET scan evidence in cases involving brain damage, injury, toxic exposure, or illness ("brain trauma") and to support claims of diminished cognitive abilities and impulse control. Despite the limited data on the relationships between PET, brain trauma and behavior, many courts admit PET scan evidence without much critical analysis. This article examines the use of PET as proof of functional impairment and justification of abnormal behavior by explaining its diagnostic use and limitations, the limited support for claims of its …