Journal of Associated Medical Sciences

Radiation dose and image quality optimization in lumbar spine digital radiography for overweight and obese patients: Phantom study

Ausanai Prapan — 2024-05-16

Background: Lumbar spine radiography plays an important role in routine use for clinical practice in overweight and obese patients. The radiographer is responsible for setting suitable exposure factors for the tradeoffs between radiation dose and image quality (IQ).

Objective: To investigate the effect of different kVp values combined with AEC used on radiation dose and IQ for routine lumbar spine radiography in overweight and obese patients.

Materials and methods: A 1.5 and 3 cm thickness of frozen pork lard was placed on a pelvis phantom to simulate an overweight and obese patient, respectively. The phantom was imaged at 10 kVp intervals in combination with AEC used. For IQ evaluation, CNR and SNR were calculated, and the observer study was determined using visual grading scores (VGS) with a 5-point Likert scale. The radiation dose was measured using a DAP meter, and then the figure of merit (FOM) was calculated.

Results: SNR and CNR for both AP and lateral projection showed a slightly decreasing trend when kVp increased in all groups. The DAP values decreased when the higher kVp was selected with AEC used in each group. The VGS by five radiographers showed good image quality in all groups, while the FOM at 100 and 109 kVp was the highest score for both AP and lateral projections.

Conclusion: The optimal kVp setting in this study ranged from 100 to 109 kVp in combination with AEC used, indicating minimal radiation dose, while maintaining diagnostic IQ.

Breast cancer characterization using region-based convolutional neural network with screening and diagnostic mammogram

Jaroonroj Wongnil — 2024-05-23

Background: Detection and classification of microcalcifications in breast tissues is crucial for early breast cancer diagnosis and long-term treatment.

Objective: This paper aims to propose a robust model capable of detection and classification of breast cancer calcifications in digital mammogram images using Deep Convolutional Neural Networks (DCNN).

Materials and methods: An expert breast radiologist annotated the 3,265 clinical mammogram images to create a comprehensive ground truth dataset comprising 2,500 annotations for malignant and benign calcifications. This dataset was utilized to train our model, a two-stage detection system incorporating a Region-based Convolutional Neural Network (RCNN) with AlexNet and support vector machines to enhance the system’s robustness. The proposed model was compared to the one-stage detection, utilizing YOLOv4 combined with the Cross-Stage Partial Darknet53 (CSPDarknet53) architecture. A separate dataset of 504 mammogram images was explicitly set aside for model testing. The efficacy of the proposed model was evaluated based on key performance metrics, including precision, recall, F1 score, and mean average precision (mAP).

Results: The results showed that the proposed RCNN-2 model could automatically identify and categorize calcifications as malignant or benign, outperforming the YOLOv4 models. The RCNN-2’s overall effectiveness, as evaluated by precision, recall, F1 score, and mean average precision (mAP), achieved scores of 0.82, 0.85, 0.83, and 0.74, respectively.

Conclusion: The proposed RCNN-2 model demonstrates very effective detection and classification of calcification in mammogram images, especially in high-dense breast images. The performance of the proposed model was compared to that of YOLOv4, and it can be concluded that the proposed RCNN model yields outstanding performance. The model can be a helpful tool for radiologists.

School performance readiness of elementary students with disabilities before starting the occupational therapy program in special education schools

Suchitporn Lersilp — 2024-06-07

Background: School-based occupational therapists (SBOTs) work as health professionals in educational settings. School performance readiness is within the scope of SBOTs in providing a service for students who might have experienced decreasing performance during their school life.

Objective: This study aimed to explore the school performance readiness of elementary students with disabilities before starting the occupational therapy program in special education schools.

Materials and methods: The school performance readiness checklist for students with disabilities in special education schools was the research instrument. It comprised four areas: physical, social and emotional, pre-academic, and self-care readiness. Seventy-five elementary students with disabilities participated in this study. They consisted of 41 students with intellectual disability, 21 students with physical disability, and 13 students with sensory disability.

Results: Results from the initial semester in special education schools showed that most of the students with disabilities (85.33%) needed support in promoting their school performance readiness, particularly in pre-academic readiness. This included most of those with intellectual disability (33.33%) and all of those with sensory disabilities, while all of the students with physical disabilities needed support in promoting physical readiness.

Conclusion: Most students with disabilities needed support in promoting their school performance readiness according to their type of disability. Although the special education schools had enrolment criteria, SBOTs and school professionals should be concerned with providing related intervention programs to promote school readiness, particularly pre-academic readiness.

Interpretability and appropriate cut-off score of occiput-bed distance to indicate risk of hyperkyphosis in older adults

Roongnapa Intaruk — 2024-06-14

Background: Age-related hyperkyphosis has been described as a new geriatric syndrome. Therefore, early screening is critical. The occiput-bed distance (OBD) was developed as a new tool; however, there needed to be clear evidence supporting its clinical utility compared to the data from standard measurement.

Objective: To investigate the test-retest reliability and minimal detectable change (MDC) with standard measurement error (SEM). Moreover, the practical cut-off scores to determine the risk of hyperkyphosis are crucial compared to a standard Cobb’s method.

Materials and methods: This study was designed as a cross-sectional study conducted in ninety-six hyperkyphosis older adults aged at least 60 years. All participants were assessed for their hyperkyphosis using the OBD. Within seven days, they were at a hospital to complete a radiographic examination to determine the appropriate cut-off score of hyperkyphosis. Additionally, the first 30 participants were assessed for their hyperkyphosis again using the OBD to determine the interpretability.

Results: The outcomes of the OBD had excellent test-retest reliability (ICC 3,3 =0.887, p<0.001). The SEM and MDC95 values were 0.75 and 2.08 cm, respectively. In addition, the cut-off score of OBD was reported to be at least 7.40 cm (sensitivity 71.80%, specificity 73.70%, and AUC =0.734) to indicate the risk of hyperkyphosis.

Conclusion: The OBD is consistent, reliable, and has good diagnostic properties for hyperkyphosis. The findings confirm the use of OBD as a practical alternative method for early detection of hyperkyphosis in older individuals, particularly those who cannot stand for long and cannot access radiology.

Executive function performance in persons with non-syndromic cleft lip and palate

Supaporn Chinchai — 2024-06-17

Background: Executive functions (EFs) are crucial cognitive functions that mature from birth to adolescence. They are vital for daily task execution and overall success and also influence language and communication development. Children with EFs deficits often experience delays in language and speech abilities. These impairments are particularly prevalent among individuals with cleft lip and palate. Consequently, speech and language pathologists must address these impairments through assessments and interventions. Despite this urgent need for action, there is a scarcity of research on executive function performance in this population in Thailand, prompting an investigation to address this issue. This study explores executive function performance in this population to enhance the quality of life for individuals with cleft lip and palate.

Materials and methods: Using a survey-based approach, executive function performance was assessed in 5- to 15-year-old volunteer with non-syndromic cleft lip and palate attending the speech therapy camp provided by the Princess Sirindhorn IT Foundation Craniofacial Center at Chiang Mai University in April 2024. Parents completed the Behavior Rating Inventory of Executive Function (Parent form), with scores ≥65 indicating executive function difficulties.

Results: The study involved 29 participants, 14 males (48.28%) and 15 females (51.72%), with a mean age of 8 years and 9 months. Average scores for executive function abilities in BRI, MI, and GEC were 52.21, 56.48, and 58.90, respectively. There are several participants with abnormal executive function in each age group, along with their average T-scores across different domains. Children aged 5, 6-8, and 9-11 have T-scores for executive function performances falling into problematic levels for 1, 2, and 5 individuals, respectively.

Conclusion: Most of the sample group demonstrated executive function skills within the normal range. However, a certain number of individuals experienced issues with executive function. These findings offer guidance for speech and language pathologists and emphasize the importance of executive function in individuals with cleft palates.

Development of tongue strength and endurance measurement device: A pilot study in healthy adults

Palita Yaemsuan — 2024-06-19

Background: Safe and efficient swallowing relies on adequate tongue strength and endurance. Thus, tongue strength and endurance assessments are essential for swallowing rehabilitation for individuals with swallowing difficulties due to tongue structure and function abnormalities. These tongue functions can be objectively measured using a standard device. However, in Thailand, assessing tongue strength and endurance using standard devices is not widespread in clinical practice due to the high cost of importing these devices.

Objective: This study aimed to develop a precise, accurate, and reliable tongue function measurement device for the clinical assessment of tongue strength and endurance.

Materials and methods: This study was divided into three phases: 1) Development of a tongue strength and endurance measurement device in a laboratory setting and administration of a satisfaction questionnaire, 2) Trial of the prototype device with six participants, and 3) Assessment of the test-retest reliability of the developed device and investigation of tongue strength and endurance values with twenty participants.

Results: As a result of this development, a novel device for measuring tongue strength and endurance was obtained, which provides measurements in units of newtons (N) and kilopascals (kPa) for strength and seconds (s) for endurance. The device’s development cost was significantly lower compared to imported commercially available devices while maintaining the performance standards for medical measurement devices. This was demonstrated by its accuracy ranging from 96.40% to 100%, high precision with a Coefficient of Variation (% CV) of 0.90% to 4.21%, and moderate to excellent reliability with an Intraclass Correlation Coefficient (ICC) of 0.56 to 0.93. Furthermore, statistically significant differences (p<0.01) were observed between genders, especially in anterior tongue strength.

Conclusion: The tongue strength and endurance measurement device developed through this study can be utilized for clinical tongue function assessment, giving patients more access to objective evaluations of tongue strength and endurance at a lower examination cost.

A genetically engineered mouse/human chimeric antibody targeting CD99 enhances antibody-dependent cellular phagocytosis against human mantle cell lymphoma Z138 cells

Kamonporn Kotemul — 2024-06-21

Background: Mantle cell lymphoma (MCL) is an aggressive form of B-cell nonHodgkin lymphoma. The elimination of MCL cells via phagocytosis is essential for cancer eradication. Therefore, discovering novel targeted antibodies that can induce phagocytosis is needed. We have demonstrated that our in-houseproduced mouse anti-CD99 mAb clone MT99/3 could induce potent anticancer activities against MCL cell lines in both in vitro and in vivo mouse xenograft models. Nevertheless, for use in humans, the mouse mAb needs to be transformed into a mouse/human chimeric mAb that contains a human Fc region to activate human immune effector functions, especially macrophage-mediated phagocytosis. Antibody-dependent cellular phagocytosis (ADCP) mediated by mouse/human chimeric mAb MT99/3 against MCL has not been previously reported.

Objective: This study aimed to genetically engineer a mouse/human chimeric antibody against human CD99 derived from mouse mAb MT99/3 and to evaluate its effect in mediating the ADCP mechanism for eradicating MCL cells in vitro using monocyte-derived macrophages.

Materials and methods: The expression plasmid to produce chimeric anti-CD99 antibody, ChAbMT99/3, was constructed by fusing the variable domains of mouse mAb MT99/3 with the constant domains of human IgG1 and the constant domains of kappa light chain. ChAbMT99/3 was expressed in the stable human expression system based on HEK293T cells. ChAbMT99/3 was purified from the culture supernatant of ChAbMT99/3-expressing HEK293T cells using Protein G chromatography. The purity and structure of ChAbMT99/3 were verified by SDS-PAGE and western blotting. The binding specificity and activity were determined by staining with cells expressing recombinant and native human CD99. The anticancer activity of ChAbMT99/3 in mediating the ADCP mechanism against MCL cell line Z138 using human monocytederived macrophages was evaluated.

Results: We successfully constructed the plasmid to produce ChAbMT99/3. Human HEK293T cells stably expressing ChAbMT99/3 were established. The ChAbMT99/3- expressing HEK293T cells could secrete ChAbMT99/3 into the culture supernatant. The high purity and complete IgG structure of ChAbMT99/3 were obtained from the purification process. Crucially, this chimeric antibody retained its binding reactivity to recombinant and native human CD99. In addition, the produced ChAbMT99/3, upon binding to MCL cells, significantly enhanced ADCP against MCL cell line Z138 in a dose-dependent manner.

Conclusion: The production of a mouse/human chimeric antibody against human CD99 derived from mouse mAb MT99/3 was successful. The engineered antibody could mediate ADCP activity against MCL cells. The produced ChAbMT99/3 might be a promising therapeutic candidate for MCL treatment.

Development of a simple HPLC method for the determination of urinary O-aminohippuric acid (OAH) and an establishment of OAH reference interval

Shoon Lae Maw — 2024-06-29

Background: O-aminohippuric acid (OAH) is considered a low-abundance urinary fluorescent metabolite with the potential to be an innovative lung cancer biomarker. There is a lack of simple methods for measuring urinary OAH metabolite, and the measurement needs to be normalized by urinary creatinine, which is produced at a constant rate. Thus, the newly developed method must be able to determine urinary creatinine and OAH simultaneously in the same run.

Objective: This work aimed to develop and validate a simple high-performance liquid chromatography (HPLC) method for measuring urinary OAH and to establish the reference intervals of OAH in healthy individuals.

Materials and methods: We synthesized OAH standard in a simple route and optimized simple HPLC method for simultaneous measurement of creatinine and OAH in a single run. Analysis was performed on a RP-C18 column with a gradient elution system of acetonitrile - ammonium acetate buffer (pH 6.5, 100 mM). After implementing optimal conditions, the procedure was compiled according to the International Council for Harmonisation (ICH) validation parameters. The developed method was used for the establishment of reference intervals of a total of 120 random urine samples of healthy individuals.

Results: The linear range of the calibration curve for creatinine and OAH were 1-1000 µg/mL and 0.1-100 µg/mL, respectively. The recoveries ranged for both metabolites were between 91.35 % and 109.12%. The relative standard deviations (RSDs) for the intra-day and inter-day results ranged from 0.11-0.66 % to 0.16-1.73 %, respectively. The limits of detection (LOD) and quantification (LOQ) were 0.258 µg/mL and 0.783 µg/mL for creatinine, while OAH was 0.045 µg/mL and 0.137 µg/mL, respectively. The method was successfully applied to establish reference intervals of OAH in healthy individuals and was defined as 0.420-2.287 mmol/mol creatinine.

Conclusion: According to various validated parameters, the proposed method was proven to quantify urinary OAH and creatinine in a single run. It can also be analyzed noninvasively without additional sample processing. Reported herein is the first establishment of OAH reference intervals in healthy individuals, which may benefit the utilization of OAH as a noninvasive biomarker for lung cancer detection in the future.