Medical Specialties Commons^™

Amoebic Liver Abscess: Outcomes Of Percutaneous Needle Aspiration Vs Drain Placement In Paediatric Population, Areej Saleem, Saqib Hamid Qazi, Waseem Mirza, Sarah Masroor Jeelani

Section of Paediatric Surgery

Objective: To compare the effectiveness of percutaneous catheter drain placement with percutaneous needle aspiration in terms of hospital stay, time to resolution of symptoms and cost of intervention performed.
Methods: The retrospective cohort study was conducted at Aga Khan University Hospital, Karachi, and comprised data of patients with amoebic liver abscess from, January 2006 to December 2016 which was collected using non-probability purposeful sampling. Primary outcome included length of hospital stay, time to resolution of symptoms and cost of intervention. Secondary outcomes included development of complications, need for re-intervention and abscess resolution. SPSS 22 was used for data analysis. . …

Is Excision Of Radial Scars Identified On Cnb Necessary?, K. Nimtz, K. Hookim, Md, A. Sevrukov, Md, T. Tsangaris, Md, A. Willis, Md, A. Berger, Md, M. Lazar, Md

Phase 1

Introduction: Quantifying the risk of upgrade to malignancy with radial scars has been an ongoing challenge, as the published upgrade rate varies widely from 0-40%, making management strategy controversial. The lack of consensus on optimal management highlights the need for further analysis. We sought to identify our institutional upgrade rate of radial scar identified on core needle biopsy (CNB).

Methods: A retrospective review of pathology and radiology databases was performed to identify radial scars found on CNB. We excluded patients with malignancy associated with radial scar and those who did not undergo surgical excision. The upgrade rates to …

Deep Learning Based Medical Image Analysis With Limited Data, Jiaxing Tan

Dissertations, Theses, and Capstone Projects

Deep Learning Methods have shown its great effort in the area of Computer Vision. However, when solving the problems of medical imaging, deep learning’s power is confined by limited data available. We present a series of novel methodologies for solving medical imaging analysis problems with limited Computed tomography (CT) scans available. Our method, based on deep learning, with different strategies, including using Generative Adversar- ial Networks, two-stage training, infusing the expert knowledge, voting based or converting to other space, solves the data set limitation issue for the cur- rent medical imaging problems, specifically cancer detection and diagnosis, and shows very …

Adaptive Statistical Iterative Reconstruction-V For Lung Nodule Analysis, Cherry Au, Zhenteng Li, Md, Eric Gingold, Md, Ethan Halpern, Md, Baskaran Sundaram, Md

Phase 1

Introduction: Low-dose CT in lung cancer screening has demonstrated benefits in select patients. As the traditional filtered back projection (FBP) technique is limited by poor image quality, adaptive statistical iterative reconstruction-V (ASIR-V) algorithm has been developed to achieve higher image quality with processing efficiency.

Objective: To investigate the impact of various CT scan parameters on the semi-automated measurement of lung nodules using a Computer Aided Detection (CAD) program.

Methods: This IRB-exempt phantom experiment was conducted with a CT scanner capable of ASIR-V algorithm. Eight lung nodules sized 5-12 mm, of solid or ground glass type, were placed inside a multipurpose …

Network Influence Of The Cerebellum For Predicting Dbs Response In Patients With Advanced Parkinson’S Disease, Lucy Li, Jennifer Muller, Sara Thalheimer, Mackenzie D. Silverman, Mahdi Alizadeh, Tsao-Wei Liang, Kelly Layton, Daniel Kremens, Victor Romo, Feroze Mohamed, Chengyuan Wu

Phase 1

Introduction: Deep brain stimulation (DBS) is a treatment option for reducing motor symptoms in patients with Parkinson’s Disease (PD) when first-line medication becomes ineffective. Existing literature has hypothesized that the clinical outcome of DBS may depend on brain connectivity profiles of the stimulation site to distant brain regions. However, the potential of brain connectivity profiles to predict response to DBS in PD remains unclear.

Objective: This study aimed to investigate how changes in structural and functional connectivity may relate to patient response to DBS, through the examination of brain network changes using graph theory.

Methods: Ten patients with advanced PD …

Effect Of Tort Reform On Diagnostic Imaging Rates, Israel Ojalva, Ba, Arthur Hong, Md, Mph

Phase 1

Introduction: Defensive medicine, is defined as “order[ing] tests, procedures, or visits, or avoid certain high-risk patients or procedures, primarily (but not solely) because of concern about malpractice liability.” Nearly all physician who fear malpractice litigation have admitted to practicing some degree of defensive medicine. In response, many states have enacted policy reforms to lighten the threat of malpractice on physicians.

Objective: The most common defensive medicine behavior is ordering diagnostic imaging tests when it is potentially unwarranted. Many states have enacted non-economic damage caps from 2000-2010. We explored if these laws had an impact on the rates of diagnostic imaging …

Labrad : Vol 45, Issue 1 - February 2019, Aga Khan University Hospital, Karachi

LABRAD - Departments of Pathology & Laboratory Medicine and Radiology Archives

• Cardiac Manifestation of Inherited Metabolic Disorders
• Utility of Plasma Homocysteine in Identifying Inherited Metabolic Disorders (IMDs)
• Chediak-Higashi Syndrome, an Inherited Disorder in Phagocytic Function
• Radiology-Pathology Correlation Rare Diseases of Bone
• Dried Blood Spot (DBS) Sampling: A Method for Blood Collection without Venipuncture
• Newborn Screening Program for Congenital Hypothyroidism
• Rare Disease in Dermatopathology
• Screening for Carbohydrate Metabolism Disorders by Sugar Chromatography in Urine
• Hypophosphatasia a Rare Skeletal Disorder

Primary Malignant Melanoma Of Brainstem Medulla Mimicking As Cavernoma, Adnan Naeem, Fatima Mubarak

Department of Radiology

Aim of this case report is to present a rare case of primary malignant melanoma of brain stem at the region of medulla oblongata mimicking as cavernoma. 40-year-old male presented with vertigo, headache, dizziness for 1 month. MRI showed pear shaped T1 hyperintense lesion at medulla oblongata and predominantly hypointense on T2 with focal area of hemorrhage. Lesion showed diffuse enhancement on postcontrast images. On plain CT lesion was Hyperdense. It was initially reported as Cavernoma. Surgical excision of lesion was done with per-op findings of solid, dark maroon colored lesion with hemorrhage. Histopathology showed neoplastic lesion with abundant melanin …

Diffusion-Weighted Magnetic Resonance Imaging May Be Useful In Differentiating Fungal Abscess From Malignant Intracranial Lesion: Case Report, Syeda Maheen Batool, Fatima Mubarak, Ather Enam

Section of Neurosurgery

Background: Diffusion-weighted magnetic resonance has a well-defined role in differentiating between important intracranial lesions. Sometimes, the surgeon is faced with a dilemma of how to diagnose an infectious versus malignant lesion.
Case Description: A 28-year-old male presented to the neurosurgery clinic with complaints of headache and left-sided weakness for 2 weeks. Neurological examination was intact. Magnetic resonance imaging (MRI) scan showed a large infiltrating heterogeneous mass involving the right parietal lobe. On further reviewing, there was homogenous diffusion restriction in the center of lesion. In addition, its aggressive behavior confirmed it to be a fungal abscess.
Conclusions: Correctly identifying an …

Excluding Ptv From Lung Volume May Better Predict Radiation Pneumonitis For Intensity Modulated Radiation Therapy In Lung Cancer Patients, Yinnan Meng, Haihua Yang, Wei Wang, Xingni Tang, Caiping Jiang, Yichao Shen, Wei Luo

Radiation Medicine Faculty Publications

Background: Lung dose-volume histogram (DVH) in radiotherapy could be calculated from multiple normal lung definitions. The lung dosimetric parameters generated from various approaches are significantly different. However, limited evidence shows which definition should be used to more accurately predict radiation pneumonitis (RP). We aimed to compare the RP prediction accuracy of dosimetric parameters from three lung volume methods in lung cancer patients treated with Intensity-Modulated Radiation Therapy (IMRT).

Methods: We retrospectively reviewed 183 consecutive lung cancer patients treated with IMRT from January 2014 to October 2017. The normal lungs were defined by total bilateral lung volume (Total Lung), excluding PTV …

Target® Intracranial Aneurysm Coiling Prospective Multicenter Registry: Final Analysis Of Peri-Procedural And Long-Term Safety And Efficacy Results, Osama O. Zaidat, Alicia C. Castonguay, Ansaar T. Rai, Aamir Badruddin, William J. Mack, Amer K. Alshekhlee, Qaisar A. Shah, Syed I. Hussain, Mouhammed R. Kabbani, Ketan R. Bulsara, Asif M. Taqi, Vallabh Janardhan, Mary S. Patterson, Britany L. Nordhaus, Lucas Elijovich, Ajit S. Puri

Faculty & Staff Scholarship

Background and Purpose: To describe the final results of the TARGET Registry, a multicenter, real-world study of patients with intracranial aneurysms treated with new generation TARGET Coils.

Methods: The TARGET Registry is a prospective, single-arm study with independent medical event monitoring and core-lab adjudication. Patients with de novo intracranial aneurysms were embolized with either TARGET-360° or helical coils in 12 US centers. The primary outcome was aneurysm packing density (PD), which was assessed immediately post-procedure. The secondary outcomes were immediate and long-term aneurysm occlusion rate using the Raymond Scale, and independent functional outcome using the modified Rankin Scale (mRS). A …

Evaluation Of Plan Quality And Treatment Efficiency For Single-Isocenter/Two-Lesion Lung Stereotactic Body Radiation Therapy, Lana Sanford, Janelle A. Molloy, Sameera S. Kumar, Marcus Randall, Ronald C. Mcgarry, Damodar Pokhrel

Radiation Medicine Faculty Publications

Purpose/objectives: To evaluate the plan quality and treatment delivery efficiency of single‐isocenter/two‐lesions volumetric modulated arc therapy (VMAT) lung stereotactic body radiation therapy (SBRT).

Materials/methods: Eight consecutive patients with two peripherally located early stage nonsmall‐cell‐lung cancer (NSCLC) lung lesions underwent single‐isocenter highly conformal noncoplanar VMAT SBRT treatment in our institution. A single‐isocenter was placed between the two lesions. Doses were 54 or 50 Gy in 3 and 5 fractions respectively. Patients were treated every other day. Plans were calculated in Eclipse with AcurosXB algorithm and normalized to at least 95% of the planning target volume (PTV) receiving 100% of the prescribed …

Radiation Safety Practices Of Dental Hygienists In The United States, Kimberly Lintag, Ann M. Bruhn, Susan Lynn Tolle, Norou Diawara

Dental Hygiene Faculty Publications

Purpose: The As Low As Reasonably Achievable (ALARA) principle was developed to promote awareness and minimization of radiation exposure and is supported by radiation control and professional organizations. The purpose of this study was to determine licensed dental hygienists' current radiation safety practices.

Methods: Data were collected with a 22 item, online survey administered to a convenience sample of 1,500 dental hygienists in the United States. Questions focused on respondents' use of the American Dental Association (ADA) radiographic examination selection guidelines, their individual dental practice policies, and hand-held portable x-ray device use and training. Cross tabulations were obtained using logistic …

Comparison Of Quantitative Analysis To Qualitative Analysis For Interpretation Of Lower‑Limb Lymphoscintigraphy, Edward Nganga, Khalid Makhdomi

Imaging & Diagnostic Radiology, East Africa

Qualitative analysis of lymphoscintigrams is subject to wide variability and may miss subtle differences in ilioinguinal uptake between normal and abnormal limbs. This study compared quantitative analysis to qualitative analysis of lower‑limb lymphoscintigraphy in diagnosing lymphedema. Fifty‑two lymphoscintigrams performed using standardized protocol, 99‑metastable technetium nanocolloid intradermal injection at the first interdigital space, were analyzed quantitatively. Fifty‑three normal and 51 abnormal limbs were analyzed. For each limb, a region of interest (ROI) was drawn around the injection site, and ilioinguinal nodes on the 1.5 h static images and the counts in these ROIs were recorded. Percentage ilioinguinal nodes uptake was then …

Calibrated Short Tr Recovery Mri For Rapid Measurement Of Brain-Blood Partition Coefficient And Correction Of Quantitative Cerebral Blood Flow, Scott William Thalman

Theses and Dissertations--Biomedical Engineering

The high prevalence and mortality of cerebrovascular disease has led to the development of several methods to measure cerebral blood flow (CBF) in vivo. One of these, arterial spin labeling (ASL), is a quantitative magnetic resonance imaging (MRI) technique with the advantage that it is completely non-invasive. The quantification of CBF using ASL requires correction for a tissue specific parameter called the brain-blood partition coefficient (BBPC). Despite regional and inter-subject variability in BBPC, the current recommended implementation of ASL uses a constant assumed value of 0.9 mL/g for all regions of the brain, all subjects, and even all species.

The …

Sparsity Promoting Regularization For Effective Noise Suppression In Spect Image Reconstruction, Wei Zheng, Si Li, Andrzej Krol, C. Ross Schmidtlein, Xueying Zeng, Yuesheng Xu

Mathematics & Statistics Faculty Publications

The purpose of this research is to develop an advanced reconstruction method for low-count, hence high-noise, Single-Photon Emission Computed Tomography (SPECT) image reconstruction. It consists of a novel reconstruction model to suppress noise while conducting reconstruction and an efficient algorithm to solve the model. A novel regularizer is introduced as the nonconvex denoising term based on the approximate sparsity of the image under a geometric tight frame transform domain. The deblurring term is based on the negative log-likelihood of the SPECT data model. To solve the resulting nonconvex optimization problem a Preconditioned Fixed-point Proximity Algorithm (PFPA) is introduced. We prove …

Metastatic Vertebral Lesion Mimicking An Atypical Hemangioma With Negative 18f-Fdg Positron Emission Tomography-Computed Tomography, Ana Cecilia Belzarena Genovese

All Publications

Atypical hemangiomas of the spine can mimic metastatic lesions on magnetic resonance imaging, therefore making this distinction is a diagnostic challenge. In most cases, this conundrum can usually be solved with positron emission tomography/computed tomography images, because hemangiomas do not usually present with increased uptake while metastatic lesions do. Here we present a case of a patient with a unique diagnosis, myxoid liposarcoma, in which the vertebral metastatic lesion did not present with increased uptake in positron emission tomography/computed tomography scans. While keeping the imaging particularity of this rare sarcoma in mind, proceeding with a biopsy when the suspicion of …

A Custom Radiopaque Thermoresponsive Chemotherapy-Loaded Hydrogel For Intratumoural Injection: An In Vitro And Ex Vivo Assessment Of Imaging Characteristics And Material Properties, Seóna M. Rossi, Timothy E. Murray, John Cassidy, Michael J. Lee, Helena M. Kelly

Articles

Purpose Thermoresponsive hydrogels are gels which have different properties at varying temperatures. The objective of this study was to assess the material characteristics, imaging properties and chemotherapeutic drug release profile of a novel radiopaque thermoresponsive hydrogel in vitro, which is liquid at room temperature but solidifies at body temperature, to determine potential suitability for intratumoural delivery. Materials and Methods An iodinated radiopaque thermoresponsive hydrogel was formulated using iodixanol at a range of concentrations and assessed for sol–gel transition, radiopacity and imaging using CT and US. A lead formulation containing iodixanol at a concentration of 9.22% weight by weight (w/w, g …

Measurement Of The Whole Body, Eye Lens And Extremity Occupational Exposures In Nuclear Medicine Staff At King Chulalongkorn Memorial Hospital, Siriwan Sisai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Due to the epidemiology evidence of cataract and eye lens opacity, ICRP Publication 118 in 2012, recommended the new eye lens dose limit of occupational exposure at 20 mSv/year, averaged over 5-year periods, no single year exceeding 50 mSv. For the public eye lens dose limit is 15 mSv/year. After ICRP changed the eye lens dose limit, many reports on eye lens dose measurement using thermoluminescent dosimeter (TLD) from interventional radiologists and interventional cardiologists were published. Few reports on eye lens dose measurement in nuclear medicine (NM) personnel were found. The primary objective of this study is to measure whole …

A Feasibility Study Of Diffusion Weighted Imaging And Parametric Response Map Analysis For Treatment Response Prediction In Nasopharyngeal Cancer, Titiya Jirawatwanith

Chulalongkorn University Theses and Dissertations (Chula ETD)

Diffusion-weighted imaging (DWI) is an MRI technique which provides functional information of tissue by detecting microscopic motion of water molecules. The change of apparent diffusion coefficient (ADC) derived from DWI was used as an imaging biomarker for treatment response prediction in cancers. However, it was based on whole-tumor analysis which did not reflect heterogeneity within the tumor. To overcome this limitation, a new method called parametric response map (PRM) analysis was proposed to evaluate response by quantifying voxel-wise changes in ADC. Here we investigated the use of PRM analysis on ADC from DWI as an imaging biomarker for treatment response …

Dosimetric Comparison Between Single And Double Isocenters Volumetric Arc Therapy For Stereotactic Radiotherapy With Multiple Targets, Wai Lwin Lwin Kyaw

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this study was to evaluate the dosimetric effects between single isocenter (SI) and double isocenters (DI) VMAT SRT of multiple brain metastases. There are two parts of study, which were experimental for energy selection, technique comparison and clinical part to use appropriate technique. As the first part, three lesions with 3 cm distance apart and 1 cm size for all lesions were created as standard plan by varying energy. Twelve VMAT SRT plans by varying energy with 6 MV, 10 MV, 6 FFF and 10 FFF were planned on simulated three lesions of CT image. 18 VMAT …

Reviewers' Responses To Medical Research Articles, Saba Sohail, Jamshed Akhtar

Department of Radiology

Objective: To document the reviewers' responses in terms of reviewers' demographic and professional characteristics, promptness of reply, and duration of reply to the request to review medical research articles for a general biomedical research journal.
Study design: Cross-sectional, observational study.
Place and duration of study: Department of Publications, College of Physicians and Surgeons Pakistan (CPSP), from October to December 2015.
Methodology: Peer reviewed articles edited by a single staff editor were included. Editorials and correspondence were excluded. Manuscript category, discipline, and the total number of reviewers per manuscript were noted. Responses were divided into no response, regrets, and responded, i.e. …

Changes In The Transverse Dimension Of The Nasomaxillary Complex Following Rapid Palatal Expansion – A Post-Retention, Cbct Evaluation, Allison Schubert

Theses & Dissertations

Purpose: The purpose of this investigation was to evaluate the immediate and long-term effects of palatal expansion on the transverse dimension of the nasomaxillary complex.

Materials and Methods: Twenty-eight patients’ CBCTs were obtained at four time points: pre-expansion (T₁), post-expansion (T₂), pre-treatment (T₃), and middle or end of orthodontic treatment (T₄). The patients’ age, sex, cervical vertebral maturation stage, and the number of instructed expander turns were recorded. Measurements of the nasal floor, nasal passage, maxillary sinus, maxillary first molar mesiolingual cusp, maxillary first molar palatal cusp, maxillary first molar buccal cortical …

Utility And Accuracy Of Primary And Secondary Ultrasonographic Signs For Diagnosing Acute Appendicitis In Pediatric Patients, W. Akhtar, Mujtaba Z. Naveed, Kumail Khandwala

Department of Radiology

Introduction Making an accurate diagnosis of acute appendicitis (AA) is vital to prevent the morbid complications associated with untreated AA. This is challenging in up to 30% of pediatric patients which is a significantly high number. Ultrasound (US) has been generally used as the initial mode of imaging in pediatric patients due to the lack of ionizing radiation. Given its variable accuracy, adjuvants such as secondary signs can be used to aid the radiologist in making an accurate diagnosis. Materials and methods Patients between the ages of two and sixteen years with acute abdominal pain suspicious for AA, who underwent …

Labrad : Vol 44, Issue 3 - December 2018, Aga Khan University Hospital, Karachi

LABRAD - Departments of Pathology & Laboratory Medicine and Radiology Archives

• CD20 Negative B-Cell Lymphomas
• Quantification of Monoclonal Protein
• A Quick Guide to Immunofixation Electrophoresis
• Autologous Bone Marrow Transplantation at AKU
• Judicious Use of Immunohistochemistry & Ancillary Techniques in Precise Categorization of Lymphoproliferative Disorders

Medial Temporal Lobe Functional Connectivity Predicts Stimulation-Induced Theta Power., E. A. Solomon, J. E. Kragel, R. Gross, B. Lega, M. R. Sperling, G. Worrell, S. A. Sheth, K. A. Zaghloul, B. C. Jobst, J. M. Stein, S. Das, R. Gorniak, C. S. Inman, S. Seger, D. S. Rizzuto, M. J. Kahana

Department of Neurology Faculty Papers

Focal electrical stimulation of the brain incites a cascade of neural activity that propagates from the stimulated region to both nearby and remote areas, offering the potential to control the activity of brain networks. Understanding how exogenous electrical signals perturb such networks in humans is key to its clinical translation. To investigate this, we applied electrical stimulation to subregions of the medial temporal lobe in 26 neurosurgical patients fitted with indwelling electrodes. Networks of low-frequency (5-13 Hz) spectral coherence predicted stimulation-evoked increases in theta (5-8 Hz) power, particularly when stimulation was applied in or adjacent to white matter. Stimulation tended …

Effect Of Differences In Metabolic Activity Of Melanoma Models On Response To Lonidamine Plus Doxorubicin., Kavindra Nath, Jeffrey Roman, David S. Nelson, Lili Guo, Seung-Cheol Lee, Stepan Orlovskiy, Kevin Muriuki, Daniel F. Heitjan, Stephen Pickup, Dennis B. Leeper, Ian A. Blair, Mary E. Putt, Jerry D. Glickson

Department of Radiation Oncology Faculty Papers

Lonidamine (LND), a metabolic modulator, sensitizes DB-1 human melanoma to doxorubicin (DOX) chemotherapy by acidifying and de-energizing the tumor. This report compares the effects of LND on two human melanoma lines, DB-1 and WM983B, which exhibit different metabolic properties. Using liquid chromatography mass spectrometry and Seahorse analysis, we show that DB-1 was more glycolytic than WM983B in vitro. ³¹P magnetic resonance spectroscopy (MRS) indicates that LND (100 mg/kg, i.p.) induces similar selective acidification and de-energization of WM983B xenografts in immunosuppressed mice. Over three hours, intracellular pH (pHi) of WM983B decreased from 6.91 ± 0.03 to 6.59 ± 0.10 (p …

Radiation In Its Origin: Health Risks Resulting From Prolonged Exposure To Radon, Tetiana Soloviova, Evans Lespinasse

Publications and Research

Among non-smokers, radon is the number one cause of lung cancer, and the second cause of lung cancer overall, according to the Environmental Protection Agency. Radon cannot be detected through one's sense of sight, smell, hearing, taste or touch. The only way to detect it is by testing certain spaces or environments with specialized instruments. This radioactive gas is present in trace quantities in the earth and produced by decaying uranium. It enters buildings through cracks in walls, floors, construction joints or gaps around service pipes, electrical wires and sump pits. It emits heavy nuclear fragments of alpha particles (two …

Waardenburg Syndrome And Left Persistent Superior Vena Cava, Driss Raissi, Alexander Christie, Kimberly Applegate

Radiology Faculty Publications

Waardenburg syndrome (WS) is a rare genetic disorder secondary to neural crest cell developmental abnormalities. It is predominantly described as an auditory-pigmentary syndrome with diverse patient presentation, typically involving congenital sensorineural hearing loss and pigmentation abnormalities of the skin, hair, and iris. Other developmental abnormalities that may be associated with this syndrome are Hirschsprung's disease and a myriad of cardiovascular congenital defects. We present a case of a young girl with WS who found to have a persistent left superior vena cava (PLSVC) draining into the coronary sinus. The prevalence of PLSVC is increased in patients with chromosomal and genetic …

Upper Gastrointestinal Bleed Embolization With Onyx®: The "Tattoo Effect", Driss Raissi, Qian Yu, S. Houssam Mardini

Radiology Faculty Publications

Endoscopic intervention is well validated for the control of upper gastrointestinal bleeding (UGIB). In cases of refractory bleeding, transarterial embolization is a safe and effective alternative. Ethylene vinyl alcohol (EVOH) commonly known as Onyx^® is an inherently black liquid embolic approved for use in cerebrovascular arteriovenous malformations and is increasingly used as an embolic agent in multiple peripheral and visceral territories. Onyx^® has a uniquely undesirable property of causing black color discoloration when used in peripheral applications adjacent to the skin akin to a "tattoo effect." Knowledge of the agents used by the interventional radiologist, clinical correlation, and …