Radiology Commons^™

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.

Focused Abdominal Sonography For Trauma (Fast) In Blunt Paediatric Abdominal Trauma, Ahmad Vaqas Faruque, Saqib Hamid Qazi, Muhammad Arif Mateen Khan, Wassem Akhtar, Amina Majeed

Section of Paediatric Surgery

Objective: To evaluate the role of focussed abdominal sonography for trauma in blunt paediatric abdominal trauma patients, and to see if the role of computed tomography scan could be limited to only those cases in which sonography was positive.
Methods: The retrospective study covered 10 years, from January 1,2000 to December 31,2009, and was conducted at the Department of Radiology and Department of Emergency Medicine, Aga Khan University Hospital, Karachi. It comprised cases of 174 children from birth to 14 years who had presented with blunt abdominal trauma and had focussed abdominal sonography for trauma done at the hospital. The …

Naeglaeria Infection Of The Central Nervous System, Ct Scan Findings: A Case Series, Rohana Naqi, Muhammad Azeemuddin

Department of Radiology

The imaging findings in four cases of a rare infection of the central nervous system caused by amoebae, Naeglaeria fowleri are presented. Naeglaeria fowleri are pathogenic free-living amoebae. They cause primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system. The computed tomography brain findings in 3 (75%) of our cases of pan amoebic meningoencephalitis showed non-specific brain oedema; 2 (66%) of these cases also had moderate hydrocephalus and among that 1 (50%) case showed an old lacunar infarction in peri-ventricular region. In the remaining 1 (25%) case the scan was normal with no evidence of oedema …

Anatomical Variations Of Nose And Para-Nasal Sinuses; Ct Scan Review, Mohammad Adeel, Muhammad Shaheryar Ahmed Rajput, Shabbir Akhter, Mubasher Ikram, Asif Arain, Yasir Jameel Khattak

Section of Otolaryngology, Head & Neck Surgery

Objective: To determine the frequency of anatomic variations on computed tomography scan of para-nasal sinuses.
Methods: The retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised computed tomography scans of 77 patients who had presented between October 2007 and March 2011. All the scans were reviewed using Picture Archiving Communication System computer software. The scans were reviewed for the presence of deviated nasal septum, paradoxical middle turbinate, Haller cell, Onodi cell, and pneumatisation of the middle turbinate and uncinate process.
Results: The mean age of the patients was 31±13.15 years. One or more types of anatomical …

Assessment Of Early Tumor Response To Cytotoxic Chemotherapy With Dynamic Contrast-Enhanced Ultrasound In Human Breast Cancer Xenografts., Jian-Wei Wang, Wei Zheng, Ji-Bin Liu, Yao Chen, Long-Hui Cao, Rong-Zhen Luo, An-Hua Li, Jian-Hua Zhou

Department of Radiology Faculty Papers

There is a strong need to assess early tumor response to chemotherapy in order to avoid adverse effects from unnecessary chemotherapy and allow early transition to second-line therapy. This study was to quantify tumor perfusion changes with dynamic contrast-enhanced ultrasound (CEUS) in the evaluation of early tumor response to cytotoxic chemotherapy. Sixty nude mice bearing with MCF-7 breast cancer were administrated with either adriamycin or sterile saline. CEUS was performed on days 0, 2, 4 and 6 of the treatment, in which time-signal intensity (SI) curves were obtained from the intratumoral and depth-matched liver parenchyma. Four perfusion parameters including peak …

Early Results Of Prostate Cancer Radiation Therapy: An Analysis With Emphasis On Research Strategies To Improve Treatment Delivery And Outcomes., Kosj Yamoah, Kwamena Beecham, Sarah E Hegarty, Terry Hyslop, Timothy Showalter, Joel Yarney

Department of Radiation Oncology Faculty Papers

ABSTRACT: BACKGROUND: There is scant data regarding disease presentation and treatment response among black men living in Africa. In this study we evaluate disease presentation and early clinical outcomes among Ghanaian men with prostate cancer treated with external beam radiotherapy (EBRT). METHODS: A total of 379 men with prostate cancer were referred to the National Center for Radiotherapy, Ghana from 2003 to 2009. Data were collected regarding patient-and tumor-related factors such as age, prostate specific antigen (PSA), Gleason score (GS), clinical stage (T), and use of androgen deprivation therapy (ADT). For patients who received EBRT, freedom from biochemical failure (FFbF) …

Neuroimaging Of A Pilocytic Astrocytoma With Anaplastic Features And Diffusion Tensor Imaging Characteristics, Lara Walkoff, Andrew J. Degnan, Mark Ghassibi, Robert V. Jones, Jonathan H. Sherman, Lucien M. Levy

Radiology Faculty Publications

We report the magnetic resonance imaging findings of an adult patient with a biopsy-proven pilocytic astrocytoma with anaplastic features. Pilocytic astrocytomas rarely occur in adults, and presentation with anaplastic features such as rapid mitotic activity, hypercellularity, and atypia is particularly uncommon. Accurate neuroimaging diagnosis is essential, but differentiation from more malignant neoplastic lesions may be challenging. Diffusion tensor imaging may potentially provide information on cell proliferation, vascularity, and fiber destruction, which can have implications for treatment and prognosis. In this case, tractography and fractional anisotropy maps demonstrated displacement of adjacent parenchyma and relatively intact fractional anisotropy, which is more suggestive …

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 …

Prostate Cancer: Can Multiparametric Mr Imaging Help Identify Patients Who Are Candidates For Active Surveillance?, B. Turkbey, H. Mani, O. Aras, J. Ho, A. Hoang, A. R. Rastinehad, H. Agarwal, V. Shah, M. Bernardo, P. L. Choyke, +8 Additional Authors

Journal Articles

PURPOSE: To determine whether multiparametric magnetic resonance (MR) imaging can help identify patients with prostate cancer who would most appropriately be candidates for active surveillance (AS) according to current guidelines and to compare the results with those of conventional clinical assessment scoring systems, including the D'Amico, Epstein, and Cancer of the Prostate Risk Assessment (CAPRA) systems, on the basis of findings at prostatectomy. MATERIALS AND METHODS: This institutional review board-approved HIPAA-compliant retrospectively designed study included 133 patients (mean age, 59.3 years) with a mean prostate-specific antigen level of 6.73 ng/mL (median, 4.39 ng/mL) who underwent multiparametric MR imaging at 3.0 …

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.

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 …

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.

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.

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.

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 …

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.

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 …

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 …

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 …

An Edge-Directed Interpolation Method For Fetal Spine Mr Images, Shaode Yu, Rui Zhang, Shibin Wu, Jiani Hu, Yaoqin Xie

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Fetal spinal magnetic resonance imaging (MRI) is a prenatal routine for proper assessment of fetus development, especially when suspected spinal malformations occur while ultrasound fails to provide details. Limited by hardware, fetal spine MR images suffer from its low resolution.

High-resolution MR images can directly enhance readability and improve diagnosis accuracy. Image interpolation for higher resolution is required in clinical situations, while many methods fail to preserve edge structures. Edge carries heavy structural messages of objects in visual scenes for doctors to detect suspicions, classify malformations and make correct diagnosis. Effective interpolation with well-preserved edge structures is still …

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 …

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

Master of Medicine in Imaging and Diagnostic Radiology

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 …

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

Master of Medicine in Imaging and Diagnostic Radiology

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 states, …

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 …

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 …

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)).

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 …

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 …