Radiology Commons^™

Local Diagnostic Reference Level At Nuclear Medicine Centers In Thailand And Myanmar, Yin Moe Aye

Chulalongkorn University Theses and Dissertations (Chula ETD)

Diagnostic reference level (DRL) has been an effective and practical tool in the optimization of radiation protection in medical exposure to patients. Local DRL represents the median value, or 50th percentile, of the quantity distribution of common nuclear medicine examinations. This study aims to establish LDRL at NM centers in Thailand and Myanmar. Methods: The demographic data of adult patients with body weight 45-75kg, radiation metric parameters including radiopharmaceutical administered activity (MBq), Volumetric CT dose index (CTDIvol, mGy), dose length product (DLP, mGy. cm), and scan length (cm), of SPECT, SPECT/CT, and PET/CT imaging were retrospectively collected from January 2023 …

Evaluating Dosimetric Accuracy Of Aaa And Axb Algorithms In Lung Stereotactic Body Radiation Therapy, May Thu Htet

Chulalongkorn University Theses and Dissertations (Chula ETD)

The accuracy of dose calculation in heterogeneous media is heavily influenced by the choice of dose calculation algorithm. This study aimed to compare the dosimetric performance of the Anisotropic Analytical Algorithm (AAA) and Acuros XB (AXB) in stereotactic body radiotherapy (SBRT) for lung cancer. Twenty-four lung cancer patients were divided into two groups: free breathing (FB) and deep inspiration breath hold (DIBH). For each patient, three half-arc volumetric modulated arc therapy (VMAT) plans were generated using 6 MV flattening filter-free (FFF) beams, prescribing 50 Gy in five fractions to the planning target volume (PTV), using the Eclipse Treatment Planning System. …

Tumor Prognosis In Nasopharyngeal Carcinoma Using Deep Transfer Learning With Radimagenet From Ct Images, Parida Petiraksakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nasopharyngeal carcinoma (NPC) is a common malignant tumor in Southeast Asia. It is characterized by complex anatomical features and aggressive behavior. Accurate prognosis prediction plays a crucial role in the optimization of treatment strategies and improvement of patient outcomes. Although recent advances in deep learning, particularly convolutional neural networks (CNNs), have demonstrated promising results in medical image analysis, the limited availability of annotated medical imaging datasets remains a significant challenge. Transfer learning (TL), particularly using domain-specific pretrained datasets, such as RadImageNet, offers a practical solution to this limitation. This study aimed to evaluate the effectiveness of deep transfer learning models …

Enlarged Perivascular Spaces Are A Clinically Relevant Neuroimaging Biomarker Of Cerebral Small Vessel Disease, Timothy Justin Libecap

Theses and Dissertations--Neuroscience

Vascular contributions to cognitive impairment and dementia (VCID) represents the intersection between cerebrovascular disease and cognitive decline. Cerebral small vessel disease (cSVD) is an important risk factor that may precede the onset of VCID by years. cSVD is characterized by in-vivo neuroimaging biomarkers including enlarged perivascular spaces (ePVS). PVS are the site of interchange between interstitial fluid (ISF) and cerebrospinal fluid (CSF) which is believed to play a role in the removal of brain waste. Reduced clearance may lead to enlargement of the PVS and subsequent accumulation of toxic solutes characteristic of neurodegeneration. Given the presence of ePVS in brain …

In Vivo Measurement Of Nadh Fluorescence Lifetime In Skeletal Muscle Via Fiber-Coupled Time-Correlated Single Photon Counting, Kathryn M. Priest, Jacob V. Schluns, Nathania Nischal, Colton L. Gattis, Jeffery C. Wolchok, Timothy J. Muldoon

Biomedical Engineering Faculty Publications and Presentations

Nicotinamide adenine dinucleotide (NADH) is a cofactor that serves to shuttle electrons during metabolic processes such as glycolysis, the tricarboxylic acid cycle, and oxidative phosphorylation (OXPHOS). NADH is autofluorescent, and its fluorescence lifetime can be used to infer metabolic dynamics in living cells. Fiber-coupled time-correlated single photon counting (TCSPC) equipped with an implantable needle probe can be used to measure NADH lifetime in vivo, enabling investigation of changing metabolic demand during muscle contraction or tissue regeneration. This study illustrates a proof of concept for point-based, minimally-invasive NADH fluorescence lifetime measurement in vivo. Volumetric muscle loss (VML) injuries were …

Utility Of Diagnostic Radiology Imaging Techniques In The Diagnosis And Characterization Of Saccular Aneurysm Involving The Right Internal Jugular Vein: A Case Report And Brief Review Of Literature, Javier Hernandez, Poyan Rafiei

Gulf Coast Division GME Research Symposium 2024

No abstract provided.

Novel Engineering Approaches For Orthopedic Injury Treatment And Infection Diagnosis, Cynthia Co

Bioengineering Dissertations - Archive

Bioengineering has made significant contributions to the treatment of orthopedic injury through interdisciplinary approaches. Central to these advancements are many orthopedic implants, including anchors and joint replacements, which have been designed to restore mobility. Despite their functional efficacy, these products have limited lifespan and are associated with many complications, such as implant-associated infection. The success of implant design and function, both in the short and long term, is paramount for enhancing patient outcomes and overall well-being. Therefore, my thesis work is dedicated to addressing these critical challenges, aiming to maximize their treatment effect while minimizing the implant-associated complications.

Long-term patient …

Diagnostic Utility Of Chest Radiographs In Children With Clinically Diagnosed Pneumonia As Per The Kenya Basic Paediatric Protocol, Ivy Waruguru Wakahora

Master of Medicine in Imaging and Diagnostic Radiology

Introduction; Pneumonia causes significant morbidity and mortality in children globally, emphasizing the need for accurate diagnosis. While chest radiographs have traditionally been the gold standard for diagnosis, recent international guidelines discourage their routine use in paediatric community acquired pneumonia (pCAP). Despite this, chest radiographs are still regularly acquired for pneumonia diagnosis, resulting in practice variations and imaging overutilization. This study aims to evaluate the diagnostic utility of chest radiographs in children with clinically diagnosed pneumonia as per the Kenya Basic Paediatric Protocol (KBPP).

Materials and methods: Data was retrospectively reviewed of 159 paediatric patients at Aga Khan University Hospital, Nairobi …

Predicting Radiation-Induced Immune Suppression In Lung Cancer Patients Treated With Stereotactic Body Radiation Therapy, Jonathan Colen, Cam Nguyen, Seth W. Liyanage, Eric Aliotta, Joe Chen, Clayton Alonso, Kara Romano, Sean Peach, Timothy Showalter, Paul Read, James Larner, Krishni Wijesooriya

Data Science Faculty Publications

BACKGROUND: Stereotactic body radiation therapy (SBRT) is known to modulate the immune system and contribute to the generation of anti-tumor T cells and stimulate T cell infiltration into tumors. Radiation-induced immune suppression (RIIS) is a side effect of radiation therapy that can decrease immunological function by killing naive T cells as well as SBRT-induced newly created effector T cells, suppressing the immune response to tumors and increasing susceptibility to infections.

PURPOSE: RIIS varies substantially among patients and it is currently unclear what drives this variability. Models that can accurately predict RIIS in near real time based on treatment plan characteristics …

Radiation Induced Skin Fibrosis (Risf): Opportunity For Angiotensin Ii-Dependent Intervention, Patricia F. Boothe, Vidya P. Kumar, Yali Kong, Kan Wang, Howard Levinson, David Mu, Milton L. Brown

Department of Biomedical and Translational Sciences Faculty Publications

Medical procedures, such as radiation therapy, are a vital element in treating many cancers, significantly contributing to improved survival rates. However, a common long-term complication of such exposure is radiation-induced skin fibrosis (RISF), a complex condition that poses substantial physical and psychological challenges. Notably, about 50% of patients undergoing radiation therapy may achieve long-term remission, resulting in a significant number of survivors managing the aftereffects of their treatment. This article delves into the intricate relationship between RISF, reactive oxygen species (ROS), and angiotensin II (Ang II) signaling. It proposes the underlying mechanisms and examines potential treatments for mitigating skin fibrosis. …

Machine-Learning-Enabled Diagnostics With Improved Visualization Of Disease Lesions In Chest X-Ray Images, Md. Fashiar Rahman, Tzu-Liang (Bill) Tseng, Michael Pokojovy, Peter Mccaffrey, Eric Walser, Scott Moen, Alex Vo, Johnny C. Ho

Mathematics & Statistics Faculty Publications

The class activation map (CAM) represents the neural-network-derived region of interest, which can help clarify the mechanism of the convolutional neural network’s determination of any class of interest. In medical imaging, it can help medical practitioners diagnose diseases like COVID-19 or pneumonia by highlighting the suspicious regions in Computational Tomography (CT) or chest X-ray (CXR) film. Many contemporary deep learning techniques only focus on COVID-19 classification tasks using CXRs, while few attempt to make it explainable with a saliency map. To fill this research gap, we first propose a VGG-16-architecture-based deep learning approach in combination with image enhancement, segmentation-based region …

Assessment Of Forensic And Clinical Criteria Of Orbital Blowout Fractures For Use In Bioarchaeological Analysis, Dylan E. Ornot

Honors Undergraduate Theses

Orbital blowout fractures are a particular facial fracture occurring within the inner eye orbits of the face caused by blunt force trauma to the eyeball or the lower orbital rim. This fracture is common in modern clinical contexts due to physical assaults, but examining this fracture in skeletal material can also provide insights into the patterns of interpersonal violence within the fields of bioarchaeology and forensic anthropology. Issues with analyzing this fracture in skeletal material arise due to the clinical assessment practices of blowout fractures, where medical practitioners are highly focused on the soft tissue presentations of the fracture in …

Lifestyle Management Of Hypertension: International Society Of Hypertension Position Paper Endorsed By The World Hypertension League And European Society Of Hypertension, Fadi J Charchar, Priscilla R Prestes, Charlotte Mills, Siew Mooi Ching, Dinesh Neupane, Francine Z Marques, James E Sharman, Liffert Vogt, Louise M Burrell, Lyudmila Korostovtseva, Manja Zec, Mansi Patil, Martin G Schultz, Matthew P Wallen, Nicolás F Renna, Sheikh Mohammed Shariful Islam, Swapnil Hiremath, Tshewang Gyeltshen, Yook-Chin Chia, Abhinav Gupta, Aletta E Schutte, Britt Klein, Claudio Borghi, Colette J Browning, Marta Czesnikiewicz-Guzik, Hae-Young Lee, Hiroshi Itoh, Katsuyuki Miura, Mattias Brunström, Norm R C Campbell, Olutope Arinola Akinnibossun, Praveen Veerabhadrappa, Richard D Wainford, Ruan Kruger, Shane A Thomas, Takahiro Komori, Udaya Ralapanawa, Véronique A Cornelissen, Vikas Kapil, Yan Li, Yuqing Zhang, Tazeen H Jafar, Nadia Khan, Bryan Williams, George Stergiou, Maciej Tomaszewski

Faculty, Staff and Student Publications

Hypertension, defined as persistently elevated systolic blood pressure (SBP) >140 mmHg and/or diastolic blood pressure (DBP) at least 90 mmHg (International Society of Hypertension guidelines), affects over 1.5 billion people worldwide. Hypertension is associated with increased risk of cardiovascular disease (CVD) events (e.g. coronary heart disease, heart failure and stroke) and death. An international panel of experts convened by the International Society of Hypertension College of Experts compiled lifestyle management recommendations as first-line strategy to prevent and control hypertension in adulthood. We also recommend that lifestyle changes be continued even when blood pressure-lowering medications are prescribed. Specific recommendations based on …

Survivorship, Outcomes, And Risk Factors For Conversion To Total Hip Arthroplasty After Revision Hip Arthroscopic Surgery In Obese Patients: Results At A Minimum 5-Year Follow-Up, Peng Li, Jie Luo, Zilong Zheng, Lu Meng, Anqi Zhang, Wei Cao, Xiaomei Gong

Faculty, Staff and Student Publications

OBJECTIVE: A high number of Non-Small Cell Lung Cancer (NSCLC) patients with brain metastasis who have not had surgery often have a negative outlook. Radiotherapy remains a most common and effective method. Nomograms were developed to forecast the cancer-specific survival (CSS) and overall survival (OS) in NSCLC individuals with nonoperative brain metastases who underwent radiotherapy.

METHODS: Information was gathered from the Surveillance, Epidemiology, and End Results (SEER) database about patients diagnosed with NSCLC who had brain metastases not suitable for surgery. Nomograms were created and tested using multivariate Cox regression models to forecast CSS and OS at intervals of 1, …

Racial Disparities In Thoracic Aortic Surgery: Myth Or Reality?, Ourania Preventza, Elizabeth Akpan-Smart, Khan Lubna, Katherine Simpson, Lorraine Cornwell, Sydney Schmitt, Hiruni S Amarasekara, Scott A Lemaire, Joseph S Coselli

Faculty, Staff and Students Publications

Objective: We examined the relationship between Black or White race and adverse outcomes in patients who underwent surgery of the ascending aorta, aortic root, or aortic arch at our center.

Methods: We analyzed 2335 consecutive patients who identified as Black (n = 217, 9.3%) or White (n = 2118, 90.7%) and underwent proximal aortic surgery. Patient zip codes were used to determine community socioeconomic (CSE) characteristics. The composite adverse outcome comprised mortality, persistent neurologic injury, and renal failure necessitating dialysis at discharge. We performed multivariable analysis, Kaplan-Meier analysis, and propensity score matching adjusted for CSE factors.

Results: Median follow-up time …

Impact Of The Covid-19 Pandemic And Vaccine Availability On Utilization Of Breast Imaging In A Multistate Radiology Practice, Andrew K Hillman, Phil Ramis, Patrick Nielsen, Eric M Rohren

Faculty, Staff and Students Publications

METHOD: Data were obtained from medical health records across 77 Radiology Partners practices in the US. The data provided us with the total monthly mammography, breast ultrasound, and breast MRI procedures from January 2019 to September 2022. An interrupted time-series (ITS) analysis was conducted to evaluate the effect of the COVID-19 pandemic and the COVID-19 vaccination. We chose March 2020 and December 2020 as critical time points in the pandemic and analyzed trends before and after these dates.

RESULTS: The starting level (at baseline in January 2019) of the total breast imaging procedure volume was estimated at 114,901.5, and this …

Myasthenia Gravis And Numb Chin Syndrome With Lung Carcinoma, Rajesh Kumar Gupta, Ashutosh Gupta, Daniel S Um, Zarrin Khameh Neda

Faculty, Staff and Students Publications

No abstract provided.

Prediction The Dose Distributions Of Prostate Cancer Patients Using Deep Learning, Pumipat Chaikamthorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Volumetric Modulated Arc Therapy (VMAT) is one of the advanced modalities in recent radiotherapy. It uses the inverse treatment planning system for optimization and dose calculation. However, this approach is a trial-and-error process, which takes a long time. An accurate deep-learning model that can predict the dose would solve this issue. This approach can save more treatment planning time, by guiding the planners to the optimum dose while maintaining the plan quality. The 40 previously treated prostate cancer plans were collected the volumetric information of PTV and OARs, overlapping volume, and the dosimetric information. The regression deep learning model, which …

Optimal Dual-Time-Point Dynamic 68ga-Psma-11 Pet/Ct Protocols For Parametric Imaging Generation In Prostate Cancer Patients, Paphawarin Burasothikul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Globally, prostate cancer is the second most common cancer for men. Prostate cancer patients presenting metastasis exhibit a poor prognosis, consequently leading to diminished survival rates. Thus, 68Ga-PSMA-11 PET/CT examination plays a critical role in prostate cancer diagnosis. Parametric imaging techniques offer the potential to improve the accuracy of quantification analysis in PET/CT diagnosis, but their effectiveness is constrained by lengthy acquisition protocols. This study developed optimal dual-time-point (DTP) parametric imaging using shortened dynamic 68Ga-PSMA-11 PET/CT scans in prostate cancer patients and investigated the feasibility of parametric images in terms of image quality by comparing them with a routine standardized …

Ai And Radiologist Assessments On The Prevalence Of Tmj Osteoarthritis Using Radiographic Images: A Comparative Study, Louloua Mourad, Nayer Abo El Saad, Yehia El Mahallawy

International Arab Journal of Dentistry

Objectives: This study aims to address the significant discomfort and functional impairment associated with temporomandibular joint osteoarthritis (TMJ OA), which negatively impacts the quality of life. It emphasizes the importance of prompt diagnosis and explores the potential of an Artificial Intelligence (AI) system to enhance TMJ OA diagnosis.

Methods: The prevalence of TMJ OA was evaluated using 3 diagnostic tools: the gold standard, the AI model, and an examiner. In total, 132 patients who performed 190 cone-beam computed tomography (CBCT) images were included.

Results: The prevalence of TMJ OA was 62.11% using the gold standard, 63.68% using …