The Thai Journal of Radiological Technology

Development of specialized radiological examination appointment program in the Radiology Department at Phichit Hospital

2024-12-12T19:19:25+07:00

Background: Specialized radiological examinations are crucial tools for diagnosing and monitoring various diseases. However, the traditional appointment scheduling system faces issues such as delays, illegible handwriting, the duplicate appointments, and inefficiencies, causing inconvenience to patients and reducing the overall service efficiency of hospital. To address these problems, the researchers proposed the development of a specialized radiology appointment scheduling program. Methods: The study began with an analysis of the issues in the traditional appointment system, followed by the design and development of the program. The research evaluated user satisfaction with the new system and compared it with the traditional appointment system. Results: After implementing the program, user satisfaction improved significantly: appointment procedures increased by 70%, data security by 62.50%, convenience by 67.50%, accuracy of data entry by 65%, appointment data retrieval by 72.50%, and reduction of duplicate appointments by 65%. Additionally, the waiting time for appointment slips decreased from 10-15 minutes per case to 2-3 minutes, and no duplicate appointment incidents were reported. Conclusion: The developed specialized radiology appointment program can effectively replace the traditional system, improving service efficiency, reducing appointment steps, decreasing waiting times, enhancing user satisfaction, and supporting better management and delivery of high-quality medical services.

Evaluation of CT calibration curve impact on proton range accuracy in treatment planning

2025-09-10T11:49:47+07:00

Introduction: In proton therapy, the accuracy of dose calculation and proton range determination is critically dependent on the conversion of CT number to proton stopping power ratio (SPR). Any inaccuracy in the CT calibration curve can lead to proton range uncertainties and potential deviations in dose distribution within the target and surrounding organs at risk. Therefore, verification of the accuracy of the CT calibration curve used in treatment planning is essential to ensure precise dose delivery. Objective: To evaluate the accuracy and reliability of the CT calibration curve currently implemented in the proton therapy treatment planning system at the Department of Radiology, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society. Methods: A calibration curve was generated by correlating CT numbers with the proton stopping powers of Gammex tissue-equivalent materials. The resulting curve was applied in the treatment planning system to calculate proton ranges, which were then compared with measurements obtained using a Giraffe dosimeter on a Varian ProBeam system. Both phantom and real tissue samples were evaluated for comparison. Results: No statistically significant difference was found between calculated and measured proton ranges (P = 0.21). The mean differences of R80 and R90 in the phantom and real tissue were 1.53 ± 3.85 mm and 0.51 ± 3.08 mm, and 1.54 ± 3.82 mm and 0.83 ± 2.43 mm, respectively. Six of the Gammex materials met the AAPM TG-185 criteria, while the remaining materials showed consistent results with previous studies using the same CT and proton systems. Conclusion: The current CT calibration curve used in the proton therapy planning system at King Chulalongkorn Memorial Hospital demonstrates acceptable accuracy and reliability for clinical dose calculation and treatment planning applications.

Comparison of F-18 FDG standardized uptake value in PET images attenuation-corrected using CT data with and without contrast media in head and neck cancer

2025-08-19T17:42:32+07:00

Background: PET and CT scanners are now integrated into a single system, enabling the combination of PET images, which display the functional activity of organs, with CT images, which provide detailed anatomical information. Moreover, CT images can be used for attenuation correction of PET data, as they reflect the tissue's radiation absorption properties in regions where photons are present. However, when CT data acquired with contrast media is used for PET image reconstruction, attenuation correction values may be overestimated. This can result in inaccuracies in the evaluation of the Standardized Uptake Value (SUV). Objective: To compare the SUV from PET images corrected for attenuation using CT data with and without contrast media in head and neck cancer patients. Methods: The study was conducted using a phantom containing F-18 FDG at 157 MBq, with three different volumes of contrast media: 0, 100, and 200 milliliters. Regions of interest (ROIs) were drawn in five locations with uniform radioactivity distribution. Subsequently, a clinical study was performed on 32 patients, with a mean age of 48.33 ± 13.27 years, all of whom had no liver abnormalities. ROIs were drawn in five areas: the liver, spleen, heart, subclavian vein, and tumor mass. Results: The percentage differences in SUV values obtained from PET images with attenuation correction using CT data with contrast media, compared to those without contrast media, in the liver, spleen, heart, subclavian vein, and tumor mass were as follows: SUV_max of 7.64 ± 4.19%, 8.05 ± 5.17%, 12.32 ± 5.73%, 9.55 ± 4.85%, and 7.09 ± 5.51%, respectively. The percentage differences in SUV_mean values were 8.19 ± 5.34%, 8.68 ± 5.70%, 12.54 ± 5.86%, 10.04 ± 4.97%, and 6.01 ± 5.04%, respectively. These differences were statistically significant (P value < 0.05) and showed a strong linear correlation between the two correction methods (R^² > 0.95). Conclusion: The SUV_max and SUV_mean values from PET images corrected for attenuation using CT data with contrast agent differed significantly from those without contrast.

Evaluation of set up error in Exactrac Dynamic (EXTD) system for treating thoracic, abdominal and pelvic cancer patients

2025-08-03T14:23:07+07:00

Background: ExacTrac Dynamic (EXTD) is a non-ionizing technology used for patient position verification and has been implemented as an alternative to radiation-based positioning systems. However, a limitation of EXTD is that it cannot directly assess internal organ motion. Objective: This study aims to evaluate the setup deviation in patient positioning using the ExacTrac Dynamic (EXTD) system for patients undergoing radiotherapy for thoracic, abdominal, and pelvic cancers. Methods: A total of 60 patients diagnosed with cancer in the thoracic, abdominal, or pelvic regions were positioned using the Surface-Guided Radiation Therapy (SGRT) function of the EXTD system. All patients received treatment with Volumetric Modulated Arc Therapy (VMAT) using the Varian TrueBeam linear accelerator at the Cancer Hospital’s Radiation Oncology Department. Cone-Beam Computed Tomography (CBCT) was used to verify setup deviations in six directions: vertical, longitudinal, lateral, pitch, roll, and yaw. CBCT images were compared against reference images from the treatment planning system. The mean difference between the EXTD setup and CBCT verification were analyzed to determine whether they remained within the limits set by the International Atomic Energy Agency (IAEA). Results: The mean difference recorded by SGRT using EXTD in the six directions were as follows: Vertical: -0.20 ± 1.87 mm (thoracic), -1.99 ± 1.99 mm (abdominal), -1.36 ± 2.47 mm (pelvic), Longitudinal: -1.76 ± 1.84 mm (thoracic), -1.50 ± 3.00 mm (abdominal), -0.93 ± 4.49 mm (pelvic), Lateral: -0.58 ± 1.40 mm (thoracic), -2.29 ± 2.58 mm (abdominal), -1.12 ± 2.14 mm (pelvic), Yaw: -0.63 ± 0.96° (thoracic), -0.47 ± 1.23° (abdominal), -0.28 ± 0.81° (pelvic), Pitch: -0.32 ± 0.70° (thoracic), 0.09 ± 1.27° (abdominal), -0.08 ± 0.93° (pelvic), Roll: 0.07 ± 0.80° (thoracic), 0.09 ± 0.58° (abdominal), 0.23 ± 0.93° (pelvic)All reported values were within the standard tolerances specified by the IAEA. Conclusion: The study found that patient setup errors using the ExacTrac Dynamic (EXTD) system were within acceptable limits based on international standards. EXTD can replace CBCT in some cases, especially for patients with tumors in the upper chest, upper abdomen, or pelvis, where internal organ motion is minimal. Using EXTD instead of CBCT in patients with low organ movement can reduce the number of repeated scans and the total imaging dose, while keeping treatment accuracy within IAEA standards.

Texture analysis using the grey-level co-occurrence matrix for image quality evaluation between two scanner models in computed tomography of brain

2025-10-12T22:49:49+07:00

Background: The grey-level co-occurrence matrix (GLCM) technique is a widely used texture analysis method for quantitatively assessing CT image quality. Objective: This study aimed to evaluate the image quality of brain computed tomography (CT) scans obtained from two different Multi-Detector CT scanner models from different manufacturers using quantitative texture analysis to determine the optimal tube current (mA) for the experimental scanner achieving image quality equivalent to the standard scanner. Methods: This retrospective analytical study involved 146 patients. Images from the standard scanner (120 kV, 300 mA) were compared with images from the experimental scanner (120 kV, mA adjusted to 280, 300, 310, and 315, IR-B reconstruction). Grey-level co-occurrence matrix (GLCM) texture analysis was performed on regions of interest (ROI) in the skull base, brainstem, and parietal lobe. Mean, Contrast, Homogeneity, and Entropy were calculated for quantitative comparison. Results: The calculated texture feature values ranged from Mean Gray Level (66.24–183.25), Contrast (53.17–93.25), Homogeneity (0.14–0.24), and Entropy (4.24–6.48). Images from the experimental scanner set at 120 kV and 310 mA provided texture analysis values most similar to the standard images. Conclusion: The image quality of the CT scans from the experimental scanner optimized at 310 mA (using IR-B) is comparable to that of the standard scanner (300 mA). These findings establish the optimal tube current setting to maintain equivalent image quality, which is beneficial for routine image Quality Assurance (QA) across the hospital network.

Evaluation of exposure index and deviation index in general digital radiography

2025-11-27T22:27:37+07:00

Background: The Exposure index (EI) and Deviation index (DI) are key indicators for evaluating the appropriateness of radiation dose and the quality of radiographic images in digital radiography systems. Objective: to assess the distribution of EI and DI values in general radiographic examinations of the chest, abdomen, pelvis, and lumbar spine using a digital radiography system. Methods: Patient data, technical exposure parameters, index values, and radiation dose information were retrospectively collected according to inclusion criteria from individuals who underwent general radiographic examinations with a Samsung digital radiography unit between October 2024 and February 2025. A total of 602 cases were analyzed using descriptive statistics. Results: The patients ranged in age from 16 to 93 years, with a higher proportion of females than males and body mass index (BMI) values ranging from 12.45 to 46.06. The majority of EI values across all examination sites were lower than the manufacturer’s target exposure index (EI_T). Most DI values were between –3 and -1, particularly in chest examinations, while a wider distribution of DI values was observed in abdominal, pelvis, and lumbar spine examinations. Conclusion: The EI and DI values in this study indicate radiation exposure outside the optimal range while still providing sufficient quality for clinical interpretation. Using the EI and DI values to assess deviations helps reflect the image quality, appropriateness of the imaging technique, and patient radiation safety

Efficacy of tuberculosis screening using the AI chest 4All (DMS–TU) for Thai people innovation at Udonthani Cancer Hospital

2024-12-12T02:24:39+07:00

Background: The chest X–ray images could be interpreted utilizing "AI Chest 4All (DMS–TU) For Thai People". This study aimed to evaluate the performance of this artificial intelligence system in tuberculosis screening. Methods: A total of 7,175 chest X–ray images from the check–up group at Udonthani Cancer Hospital were employed as the subjects. Data were collected retrospectively between July 2^nd, 2020, and September 30^th, 2023. The interpretation results of the AI Chest 4All (DMS–TU) For Thai People were compared with those of the radiologist, focusing on sensitivity, specificity, and accuracy. Results: The findings revealed that the values for sensitivity, specificity, and accuracy were 87.50, 98.60, and 98.53 respectively. Conclusion: These results demonstrate the potential of AI Chest 4 All (DMS–TU) For Thai People in efficiently screening for tuberculosis, rapidly identifying patients, enabling immediate treatment, achieving more effective tuberculosis control, and reducing the number of tuberculosis cases.