Radiology Commons^™

Computed Tomography Findings Of Normal Appendix In Pediatric Population, Thanwarat Koonthong, Teerasak Phewplung*

Chulalongkorn Medical Journal

Background: Appendicitis remains the most common indication for emergency abdominal surgery in children. Computed tomography (CT) plays a vital role in the evaluation of pediatric patients with suspected appendicitis. Yet, there is limited of literature describing the normal appendiceal diameter in the pediatric Asian population.

Objectives: To characterize the normal pediatric appendix and to identify the variables that influence its diameter in pediatric patients aged one day to 18 years who underwent abdominal CT.

Materials and Methods: The study was approved by the IRB. We conducted a retrospective study of 358 children (≤18 years of age) who underwent abdominal CT …

Imaging Of The Centromedian Thalamic Nucleus Using 3d Fast Gray Matter Acquisition T1 Inversion Recovery Sequence In 3t Mri In Epilepsy, Tunchanok Paprad, Thanyachat Yutthakasaemsan, Supada Prakkamakul

Chulalongkorn Medical Journal

Background:

The centromedian thalamic nucleus (CM) is an emerging deep brain stimulation (DBS) target for neurological disorders, including drug-resistant epilepsy. Traditional DBS localization relies on predefined stereotactic coordinates, which may be imprecise. Novel MRI sequences enhance gray-white matter contrast, potentially allowing direct CM visualization, improving accuracy in DBS planning and targeting.

Objective:

This study evaluates the 3D Fast Gray Matter Acquisition T1 Inversion Recovery (FGATIR) MRI sequence for the visualization of the CM in epilepsy patients.

Methods:

This prospective IRB-approved descriptive study included adult epilepsy patients who underwent 3D FGATIR MRI sequence at 3 Tesla. Two neuroradiologists independently assessed CM …

Artificial Intelligence Decision Support In Automated Breast Ultrasound: Improving Diagnostic Accuracy And Reducing Unnecessary Biopsies, Chayaporn Hasdiseve, Jenjeera Prueksadee

Chulalongkorn Medical Journal

Background: Emerging roles of artificial intelligence support in breast imaging leads to improved radiologists’ performance

Objective: To assess the diagnostic performance of the artificial intelligence decision support in the evaluation of breast masses using automated breast ultrasound (ABUS).

Methods: 182 patients (415 breast masses) who received ABUS were included. Two readers, including the experienced breast radiologist (reader1) and the breast imaging fellow (reader2), separately reviewed the ABUS images and the artificial intelligence decision support according to the ACR BI-RADS 5^th edition.

Results: All of the 415 masses; 395 masses (95.2%) were benign and 20 masses …

Superior Mediastinal Cut-Off Measurements In Chest Radiographs For Screening Of Silent Thoracic Aortic Diseases, Kantheera Leesmidt, Boonyarit Sintuvikaiwong, Apichaya Sripariwuth

Chulalongkorn Medical Journal

Objective: To determine cut-off values for superior mediastinal width and the mediastinal width-to-thoracic cage ratio from chest radiographs for the early detection of unrecognized thoracic aortic diseases. Additionally, this study aims to enhance diagnostic strategies for identifying aortic abnormalities.

Materials and Methods: This retrospective analysis included 152 subjects who underwent both computed tomography angiography (CTA) of the thoracic aorta and chest radiograph between April 2007 and January 2021. Superior mediastinal width was measured at 3 levels on chest radiographs. Thoracic CTA findings were categorized into normal and abnormal groups, the latter comprising aortic dissection, intramural hematoma, penetrating atherosclerotic …

Diagnostic Accuracy Of Cerebral Amyloid Angiopathy Criteria In The First Pathologically Confirmed Thai Cohort: A Pilot Study, Thanapoom Taweephol, Thachamai Smitasiri, Thanakit Pongpitakmetha, Sekh Thanprasertsuk, Anand Viswanathan

Chulalongkorn Medical Journal

Background: The gold standard for diagnosing cerebral amyloid angiopathy (CAA), full brain post-mortem examination, is rarely performed. Current diagnostic criteria, primarily based on clinico-radiological features, were developed from Western populations and may have limited applicability to Asian populations.

Objective: We aimed to evaluate the accuracy of current diagnostic criteria and examine the clinico-radiological characteristics of Thai CAA patients.

Methods: Brain histopathological specimens from patients with clinical symptoms of CAA who underwent neurosurgical procedures, including intracerebral hemorrhage (ICH) evacuation, between 2011 and 2021 at King Chulalongkorn Memorial Hospital, Thailand, were reviewed. Patient characteristics and clinical events for each individual were retrospectively …

Quality Control Of Clinical Protocols Of Ct Using The Accreditation Phantom, Walaiporn Suksancharoen, Apawadee Chakrapong, Sakultala Ruenjit, Anchali Krisanachinda

Chulalongkorn Medical Journal

Background: The daily quality control of the Computed Tomography system consists of the measurement of the accuracy of CT Number and the artifact evaluation. The annual quality control includes the clinical protocol review. The CT radiologist is responsible for ensuring that all Quality Assurance (QA) requirements are met. The clinical team reviews and manages the CT protocol to deliver the appropriate radiation dose to the patient for each examination.

Objectives: To verify CT Number Accuracy, to review clinical protocols and to verify that the low-contrast performance of clinical protocols is adequate for diagnosis.

Methods: American College of Radiology (ACR) CT …

A Case Report : Rosai-Dorfman Disease Of The Breast, Jenjeera Prueksadee

Chulalongkorn Medical Journal

Abstract

A case report of Rosai-Dorfman disease (sinus histiocytosis with massive lymphadenopathy) of the breast is one of the rare diseases, characterized by benign proliferative disorder of histiocyte. Most occur within lymph nodes whereas the rest involve extranodal sites. Breast involvement is considered extremely rare but considerable because of radiological findings simulating breast cancer. We report the case of a 59-year-old Thai woman who underwent screening mammography. Her biopsy resulted in abnormal histiocytes with S-100 protein expression, some of them with emperipolesis (lymphophagocytosis). Recognition of Rosai-Dorfman disease leads to correct diagnosis and further appropriate proper treatment strategy.

Primary Lung And Pleural Malignancies In Children: Imaging Of A Case Series, Teerasak Phewplung, Tanitha Phruksahirun

Chulalongkorn Medical Journal

Early diagnosis of primary lung and pleural malignancies is a challenge because it is extremely rare in children. The patient often presents with metastatic disease and non-neoplastic lesions. Clinical detection and imaging studies are nonspecific findings and may be indistinguishable from other lung malformations, resulting in a delay in diagnosis and treatment and an increase in tumor morbidity and mortality.

We present four cases of children whose clinical presentation and initial imaging had suspicious abnormalities and were eventually revealed to be primary lung and pleural malignancies. The literature on primary lung and pleural malignancies is also reviewed.

Analysis Of Breast Mri Performed On Patients With Axillary Nodal Metastasis And Negative Mammogram And Ultrasound, Pakpawee Pichayakul, Palita Hansakul

Chulalongkorn Medical Journal

Background: Occult breast cancer is a rare type of breast cancer which magnetic resonance imaging (MRI) has an immense role to confirm diagnosis and disclose non-demonstrable finding on initial modality.

Objective: To analysis breast MRI findings in patients with axillary nodal metastasis and negative mammogram and ultrasound, and retrospective review of the initial mammography and second-look ultrasound.

Methods: From January 2010 to January 2023, women who diagnosed occult breast cancer by presenting metastatic axillary lymph node on pathological report with negative mammography and ultrasonography, underwent breast MRI to identify occult breast carcinoma. Their breast MRI were retrospectively reviewed …

Mri-Based Radiomics Model From Mesorectal Fat To Predict Perirectal Lymph Node Status And Extramural Venous Invasion In Colorectal Cancer Patients, Yaniga Swaengdee

Chulalongkorn University Theses and Dissertations (Chula ETD)

Colorectal cancer (CRC) is the third most common cancer worldwide and the incidence rate is rising in Asia. Perirectal lymph node metastasis (PLN) and extramural venous invasion (EMVI) are common and associated with poor prognosis in CRC patients. While total mesorectal excision is the gold standard for confirming PLN and EMVI, MRI is keys modality for staging. Radiomics, a technique that extracts quantitative features from medical images, allows for the development of predictive models for PLN and EMVI. This study aimed to build and evaluate a predictive model based on mesorectal fat radiomics from MRI images to improve PLN and …

Varian Halcyon Cone Beam Computed Tomography Dose Measurement By Radiophotoluminescent Glass Dosimeter, Kantida Jittrakool

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cone beam computed tomography (CBCT) is widely used as the primary imaging method in image-guided radiation therapy. The Varian Halcyon system (Varian Medical Systems, Palo Alto, CA, USA) requires daily imaging prior to each patient’s treatment. This study focuses on comparing the radiation doses to normal organs across all available kV-CBCT protocols on the Varian Halcyon system. Radiophotoluminescent glass dosimeters (RPLGD) were used to measure doses, placed inside an Alderson Rando phantom positioned at specific anatomical sites including the head, thorax, breast, and pelvis. CBCT scans were performed using preset protocols, with no modifications to parameters. The average organ dose …

Dosimetric Comparison Between Volumetric Modulated Arc Therapy On Truebeam And Halcyon Of Boost Plan For Total Body Irradiation, Wanwanut Jaihow

Chulalongkorn University Theses and Dissertations (Chula ETD)

Total Body Irradiation (TBI) is a special treatment technique aimed at immunosuppression. The purpose of this study was to compare the dosimetric results of volumetric modulated arc therapy (VMAT) plans of TBI treatment between TrueBeam and Halcyon treatment machines. Eight TBI patients were planned by 6 MV of two lateral opposing with extended SAD technique to 5 meters to receive the prescribed dose of 1200 cGy in 6 fractions at head and legs. A single fraction boosts up the dose ranging from shoulder to mid-thigh. Plans were optimized and calculated in the Eclipse treatment planning system using VMAT by TrueBeam …

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 …

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 …

Breast Cancer Characterization Using Artificial Intelligence In Screening And Diagnostic Mammogram Of Thai Women, Jaroonroj Wongnil

Chulalongkorn University Theses and Dissertations (Chula ETD)

Breast cancer is a significant health issue in Thailand, necessitating accurate detection and characterization for effective treatment. This thesis focuses on leveraging artificial intelligence techniques to develop breast cancer screening and diagnosis using mammography images of Thai women. Furthermore, detecting and classifying mammography calcifications, crucial indicators of malignant or benign conditions had also been focused using RCNN and YOLOv4 in this study. AlexNet CNN was developed to increase the robustness of the RCNN model. AlexNet was tested with three different datasets, each consisting of 4,000 cropped ROI images. These datasets were divided into an 80% training set and a 20% …

Determination Of Kinetic Parameters For Bone Turnover In Chronic Kidney Disease With Hemodialysis Patients Using Dynamics 18f-Naf Pet/Ct Imaging, Viyada Sanoesan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Bone turnover measurement using 18F-NaF PET/CT serves as a valuable imaging biomarker for studying bone metabolism at various sites of skeleton. This study aimed to determine the kinetic parameters (Ki–Patlak) for bone turnover prediction as a non-invasive biomarker from dynamic 18F-NaF PET/CT in chronic kidney disease (CKD) patients with hemodialysis. Moreover, we aimed to investigate whether Ki–Patlak derived from shortened scan time can provide a prediction equivalent to that obtained from routine dynamic scan. Twenty-seven Thai CKD patients on hemodialysis (48 scans) from December 2021 to December 2023 were recruited. After intravenous injection of 18F-NaF of 133±39.3 MBq, dynamic PET/CT …

Characteristics Of Two-Dimensional Ionization Chamber Array For Patient-Specific Quality Assurance In Pencil Beam Scanning Proton Therapy, Nuttida Rawiwan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Proton therapy is an advanced technique that uses positive particles in external treatment. It can spare normal tissue and increase tumor control probability. In radiotherapy, patient-specific quality assurance is an important part, but according to protons’ characteristics, especially finite range, it is challenging to do verification because when the density has changed the finite range will have drastic changes. Although the two-dimensional ionization chamber array is used for patient-specific quality assurance in pencil beam scanning proton therapy, most studies investigate the IBA MatriXX as the dosimetry device, and few studies explored the PTW OCTAVIUS 1500XDR. This research aims to determine …

Determination Of The Surface Dose Correction Factors For Various Detectors In Proton Scanning Therapy, Pakjira Saruang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Proton therapy delivers tumors doses precisely but concerns about skin toxicity due to energy dispersion beyond the Bragg peak remain. Accurate surface dose measurement is crucial for calculating the radiation dose patients receive. Studying factors that improve measurement accuracy is essential, as current methods are challenging and often inaccurate. This research aims to determine the surface dose correction factors (Scf) for various detectors in spot scanning beam proton therapy and study the effect of surface dose according to various clinical factors. The PTW Advanced Markus, PTW Roos chamber and IBA FC65-G Farmer chamber were utilized to measure the surface dose …

Dosimetric Comparison Of Imrt, Co-Planar Vmat, Non-Coplanar Vmat And Hyperarc For Multiple Brain Metastases Srs, Aksarapak Thawornnittayakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Multiple brain metastases patients are typically treated by stereotactic radiosurgery (SRS) or whole brain radiation therapy (WBRT). In addition, there are advanced techniques for treating multiple brain metastases such as 3-dimensional Conformal Radiation Therapy (3D-CRT), Intensity Modulated Radiation Therapy (IMRT), and Volumetric Modulated Arc Therapy (VMAT). A new isocentric VMAT technique called HyperArc was developed for non-coplanar, it is an automated setting for couch angle and collimator angle. This study aims to compare the dosimetric effect for a single isocenter among Intensity Modulated Radiation Therapy, Volumetric Modulated Arc Therapy, and HyperArc for multiple brain metastases stereotactic radiosurgery. For 25 patients …

Accuracy Of 177lu Quantification For Dosimetry Calculation Using 12-Swiveling Czt Detectors Spect/Ct Camera, Panattha Damthongsen

Chulalongkorn University Theses and Dissertations (Chula ETD)

Recently, the 12-cadmium zinc telluride (CZT) based digital detectors SPECT/CT system has been introduced for advanced technology in nuclear medicine instrument, which outperforms conventional cameras. Moreover, the voxel S value-based dosimetry is important and offers more accurate in personalized dosimetry treatment using targeted radionuclide therapy. This study aimed to determine the accuracy of 177Lu quantification through an IEC/NEMA phantom study and to evaluate total-body dosimetry in patients undergoing 177Lu therapy using 12-swiveling digital CZT detectors SPECT/CT camera. The NEMA/IEC body phantom inserted with six fillable spheres (10-, 13-, 17-, 22-, 28-, and 37-mm inner diameter), filled with 177Lu solution of …

Impact Of Contrast Agent Administration On Water Equivalent Diameter For Ssde Calculation In Chest Ct Angiography Examination, Nuttanit Kaewsan

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to determine the impact of intravenous contrast enhancement on the calculation of water equivalent diameter (Dw) for size-specific dose estimate (SSDE) in chest CT angiography (CTA) using different calculation methods in non-contrast and arterial phase images. A cohort of 231 adult patients who underwent chest CT angiography at King Chulalongkorn Memorial Hospital (KCMH) were included. The 3D Slicer image computing software was used to automatically draw the ROI in each axial CT image to measure area and mean CT number. The Dw values were calculated following the American Association of Physicists in Medicine (AAPM) Report No.220 utilizing …

Dose Evaluation Of A Deep Learning-Based Synthetic Ct Generation In Head And Neck Cancer For Photon And Proton Therapy, Ailada Kuibumrung

Chulalongkorn University Theses and Dissertations (Chula ETD)

MRI has been increasingly implemented for the treatment planning process and the MRI-only workflow in both photon and proton therapy. This study aims to investigate and explore the accuracy of dose calculations in head and neck region based on synthetic CT (sCT) images, using the commercial software methods for both volumetric modulated arc therapy (VMAT) and intensity modulated proton therapy (IMPT) plans. The sCT images were generated from MRI images for five head and neck cancer cases that underwent VMAT and IMPT by MRI Planner commercial software. The mean absolute error (MAE) and mean error (ME) within the body, bone …

Comparison Of Modified Formalism Output And Trs-398 Absorbed Dose To Water In Electron Beams Reference Dosimetry In Multiple Radiotherapy Centers, Yasumon Thinka

Chulalongkorn University Theses and Dissertations (Chula ETD)

The study aimed to investigate the feasibility and efficacy of utilizing modified calibration with cylindrical chambers for reference dosimetry in electron beam radiotherapy, challenging the recommendation of using plane-parallel chambers in low-energy electron beams by IAEA's TRS-398 and AAPM's TG-51 standards. Data collection involved six radiotherapy centers in Bangkok using Varian linear accelerators, with chambers including the IBA FC65-G, PTW 30013 cylindrical chambers, and PPC40, Roos plane-parallel chambers. Results of dose comparison between modified and TRS-398 protocols fell within ±2%. For low-energy electron beams, percent dose discrepancies ranged from -1.57% to 0.91%, and from -0.37% to 0.91% for high-energy. The …

Evaluation Of Patient Radiation Dose And Risk Of Cancer From Ct Examinations, Saowapark Poosiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Computed Tomography (CT) examinations have been increasingly requested and become the major sources of patient exposure. The cancer risk from CT scans is contingent upon the amount of organ absorbed dose. This study aims to evaluate the cumulative effective doses (CED) and risk of cancer incidence and mortality from recurrent CT examinations in a single day. The patient data at aged 15 to 75 years old performed CT examinations during the period of five years from January 2018 to December 2022 were collected from two academic centers. The CED and organ doses were evaluated using Radimetrics™ Enterprise Platform from Monte …

The Study Of Local Diagnostic Reference Levels Of Computed Tomography Procedures At Phramongkutklao Hospital, Sutasinee Mahasub

Chulalongkorn University Theses and Dissertations (Chula ETD)

Computed Tomography (CT) is a medical modality of 3D imaging technique using the X-ray photons rotate, transmit and detect the radiation by the multi-detectors. The CT examination results in the higher patient dose than the general radiography. The objective of this study was to establish the Local DRLs of patient radiation dose in CT procedures at Phramongkutklao Hospital. This study is a retrospective analysis at a single center from January-August 2021. Two CT scanners: 160 slices MDCT manufactured by Canon, model AquilionTM Prime and 640 slices MDCT manufactured by Canon, model AquilionTM One Prism have been used to collect the …

Comparative Dosimetry Between 2d Planar-Based And Hybrid-Based Method For Personalized 177 Lu-Psma I&T And 177lu-Dotatate Therapy, Wuri Handayani

Chulalongkorn University Theses and Dissertations (Chula ETD)

Targeted radionuclide therapy (TRT) uses unsealed radiation sources that are accumulated in the target tissues to deliver a damaging radiation dose to the cancerous cells, and a part of the radiopharmaceutical will end up in non-targeted tissues. To avoid treatment-related side effects, dosimetry is mandatory for TRT for each treatment cycle. This study aimed to evaluate and compare the feasibility of 2D planar-based dosimetry and hybrid-based dosimetry for 177Lu-PSMA I&T and 177Lu-DOTATATE therapy. Whole-body planar images and SPECT/CT images were acquired from 27 treatment cycles, 18 patients (13 patients for 177Lu-PSMA I&T and 5 patients for 177Lu-DOTATATE treatment) at immediately, …

Development Of End-To-End Test Phantom For Stereotactic Radiosurgery Using Alanine Dosimeter, Aungsumalin Intang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Alanine dosimeters are generally used in high-dose dosimetry, while accurate and precise dose delivery verification procedures are important in stereotactic radiosurgery (SRS). Hence, an end-to-end test is required. In addition, no end-to-end SRS test employing an alanine dosimeter has been established in Thailand. The objective of this study was to determine the dose accuracy of SRS VMAT plans in end-to-end test phantom using alanine dosimeter. The electron paramagnetic resonance (EPR) parameters were optimized in the 1-2000 cGy dose range. Following that, suitable parameters were used to investigate the alanine characteristics and estimate the uncertainty in radiation therapy dose range. The …