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Axial loading during supine MRI for improved assessment of lumbar spine: comparison with standing MRI
(2023-01-01)
Charoensuk, Jarruwat
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Laothamatas, Jiraporn
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Sungkarat, Witaya
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Worapruekjaru, Ladawan
;
Hooncharoen, Boonthida
Background: There are no studies comparing the morphologic changes of lumbar spines between supine axial-loaded and 90° standing magnetic resonance imaging (MRI) examinations of patients with spinal stenosis. Purpose: To determine whether axial-loaded MRI using a compression device demonstrated similar morphology of intervertebral disc, dural sac, and spinal curvature as those detected by 90° standing MRI in individuals with suspected spinal stenosis. Material and Methods: A total of 54 individuals suspected of having spinal stenosis underwent both axial-loaded and standing MRI studies. The outcome measures included seven radiologic parameters of the lumbar spine: measures of the intervertebral disc (i.e. cross-sectional area [DA], disc height [DH], and anteroposterior distance [DAP]), dural sac (cross-sectional area [DCSA]), spinal curvature (i.e. lumbar lordosis [LL] and L1-L3-L5 angle [LA]), and total lumbar spine height (LH). Results: For agreement between the two methods, intraclass correlation coefficient (ICC) ≥ 0.8 was found for all seven radiologic parameters. Supine axial-loaded MRI underestimated LL but remained correlated (ICC = 0.83) with standing MRI. Minor differences between the two methods (≤5.0%) were observed in DA, DCSA, DAP, LA, and LH, while a major difference was observed in LL (8.1%). Conclusion: Using a compression device with the conventional supine MRI to simulate weight-bearing on the lumbar spine generated MRI morphology, which was strongly correlated with those from a standing MRI.
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A deep learning model (FociRad) for automated detection of γ-H2AX foci and radiation dose estimation
(2022-12-01)
Wanotayan, Rujira
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Chousangsuntorn, Khaisang
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Petisiwaveth, Phasit
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Anuttra, Thunchanok
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Lertchanyaphan, Waritsara
DNA double-strand breaks (DSBs) are the most lethal form of damage to cells from irradiation. γ-H2AX (phosphorylated form of H2AX histone variant) has become one of the most reliable and sensitive biomarkers of DNA DSBs. However, the γ-H2AX foci assay still has limitations in the time consumed for manual scoring and possible variability between scorers. This study proposed a novel automated foci scoring method using a deep convolutional neural network based on a You-Only-Look-Once (YOLO) algorithm to quantify γ-H2AX foci in peripheral blood samples. FociRad, a two-stage deep learning approach, consisted of mononuclear cell (MNC) and γ-H2AX foci detections. Whole blood samples were irradiated with X-rays from a 6 MV linear accelerator at 1, 2, 4 or 6 Gy. Images were captured using confocal microscopy. Then, dose–response calibration curves were established and implemented with unseen dataset. The results of the FociRad model were comparable with manual scoring. MNC detection yielded 96.6% accuracy, 96.7% sensitivity and 96.5% specificity. γ-H2AX foci detection showed very good F1 scores (> 0.9). Implementation of calibration curve in the range of 0–4 Gy gave mean absolute difference of estimated doses less than 1 Gy compared to actual doses. In addition, the evaluation times of FociRad were very short (< 0.5 min per 100 images), while the time for manual scoring increased with the number of foci. In conclusion, FociRad was the first automated foci scoring method to use a YOLO algorithm with high detection performance and fast evaluation time, which opens the door for large-scale applications in radiation triage.
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Evaluation of Micro- and Nano-Bismuth(III) Oxide Coated Fabric for Environmentally Friendly X-Ray Shielding Materials
(2022-08-16)
Kaewpirom, Supranee
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Chousangsuntorn, Khaisang
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Boonsang, Siridech
This research focuses on the development of environmentally friendly textile-based shielding composites, from micro-sized and nanosized Bi<inf>2</inf>O<inf>3</inf>particles, against ionizing radiation. Polyester fabric dyne-coated with either micro- or nano-Bi<inf>2</inf>O<inf>3</inf>particles shields some X-rays but the effectiveness is poor. With only ∼58% uptake of micro-sized Bi<inf>2</inf>O<inf>3</inf>particles dyeing on polyester fabric, the insufficient amount of Bi<inf>2</inf>O<inf>3</inf>leaded to the low density of particles, resulting in only 30% of X-ray shielding at 80 kVp. Cotton fabric coated with either micro- or nano-Bi<inf>2</inf>O<inf>3</inf>/poly(vinyl alcohol) (PVA) composites, on the other hand, demonstrated the capacity to attenuate X-ray generated by high diagnostic X-ray tube voltages of 70-100 kVp, in compliance with medical protection requirements. The X-ray attenuation performance of cotton fabric coated with either micro-Bi<inf>2</inf>O<inf>3</inf>/PVA or nano-Bi<inf>2</inf>O<inf>3</inf>/PVA nanocomposite decreased progressively with increasing tube acceleration voltages, however their ionizing radiation-shielding performance enhanced with the number of fabric layers. Interestingly, for all X-ray tube voltages evaluated, the micro-Bi<inf>2</inf>O<inf>3</inf>/PVA composite outperformed the nano- Bi<inf>2</inf>O<inf>3</inf>/PVA composite in terms of X-ray shielding. At a weight ratio of 66.7% Bi<inf>2</inf>O<inf>3</inf>, 10 layers of cotton fabric coated with micro- Bi<inf>2</inf>O<inf>3</inf>/PVA composite can attenuate 90, 85, and 80% of X-ray photons at 70, 80, and 100 kVp, respectively. As a result, these less harmful X-ray shielding materials have the potential to replace lead-based composites, which are highly toxic to human health and have negative environmental consequences.
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Preliminary Study of Alternative Environmentally Friendly X-ray Shielding Materials Based on Nano-bismuth (III) Oxide Coated Fabric
(2022-03-01)
Suriwong, Natcha
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Janjaroen, Jaroon
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Chousangsuntorn, Khaisang
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Kaewpirom, Supranee
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Boonsang, Siridech
Chest X-ray is the first imaging procedure that play an important role in identification of COVID-19 as well as medical diagnostic and treatment of COVID-19 patients, in order to increase recovery rates and to lower fatality rates. Regardless of their environmental disadvantages and high toxicity, lead aprons are important materials for personal protection of physicians and patients from X-ray radiation during medical operations. Typically, for standard lead protective aprons, the transmittance values for lite-lead (LL) and regular lead (RL) were approximately 18 % and 17 %, respectively. With an aim to find new materials possibly to replace toxic lead-shielding products, in this study, an environmentally friendly and flexible fabric-based radiation shielding material was manufactured. Polyester fabric was coated by Bi2O3 nano particles using a simple, scalable, and cost-effective method to deposit the nano-particles onto the textile fabric surface. This application method allows the potential production of nano-Bi2O3 coated polyester fabric at the maximum %uptake of 45 and mass per unit area of 0.41 g/cm2 for 1 layer fabric. Radiation attenuation of the fabric increased with the numbers of fabric layers. Five layers of the fabric showed X-ray transmission of approximately 85% when measured at 80 kVp tube voltage, the medical application standard. To increase X-ray protection ability, the nano-Bi2O3 coated polyester fabric surface was recoated with PVA/ Bi2O3 coating composites using K-hand coater. The potential application of the recoated fabric as environmentally friendly and flexible fabric-based radiation shielding material for X-ray attenuation was also demonstrated. The 5-layer PLA/nano-Bi2O3 coated fabric showed the lowest X-ray transmission of 65.7%, implying the moderate improvement of shielding ability. This could lead to an X-ray protection textile garment that can potentially replace lead aprons.
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Lumbosacral spinal compression device with the use of a cushion back support in supine MRI
(2021-08-01)
Sungkarat, Witaya
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Laothamatas, Jiraporn
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Worapruekjaru, Ladawan
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Hooncharoen, Boonthida
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Charoensuk, Jarruwat
Background: We hypothesized that axial-loaded magnetic resonance imaging (MRI), modified with the use of a cushion placed behind the lower back (i.e. BS-MRI method), would simulate the standing position more accurately than an axial-loaded MRI without a cushion back support (BS). Purpose: To determine whether the BS-MRI method demonstrated similar morphologies on intervertebral disc (IVD), dural sac, and spinal curvature as those detected on 90° standing MRIs in individuals with suspected spinal stenosis. Material and Methods: Twenty-five subjects underwent a BS-MRI, as well as axial-loaded and standing MRI studies. Outcome measures were four radiographic parameters of the lumbar spine: IVD height (DH); dural sac cross-sectional area (DCSA); and spinal curvature (i.e. lumbar lordosis [LL] and L1-L3-L5 angle [LA]). Results: Major differences (>5%) between standing MRI and BS-MRI methods were observed in DCSA, DH, and LL. Major differences between standing and axial loaded MRIs were observed only in DCSA and LA. Although BS-MRIs demonstrate an image of the lumbar spine curvature (i.e. LA) which is closer to that when standing than axial-loaded MRIs, it is likely to overestimate both narrowing of dural sac and extent of LL. Conclusion: Using a compression device with a BS to simulate weight-bearing on the lumbar spine is not recommended due to: (i) overestimation of the narrowing of the dural sac and extent of LL; and (ii) underestimation of loss of disc height. Supine axial-loading produced DCSA and DH which were strongly correlated with those detected with standing MRIs. Exceptions were that LL and LA were underestimated.
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Axial-Loaded MRI Using a SpineMAC Device to Show Narrowing of Dural Sac and Disc Height in Lumbar Spinal Stenosis
(2020-12-01)
Sungkarat, Witaya
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Laothamatas, Jiraporn
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Worapruekjaru, Ladawan
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Hooncharoen, Boonthida
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Charoensuk, Jarruwat
Background: A lumbosacral spinal compression device has been developed by the authors (SpineMAC) to simulate normal weight-bearing by axial-loading of the lumbar spine while the patient is in the supine position. Objective: To investigate the effect of axial loading using a SpineMAC device, on lumbar spine, spinal canal, and spine curvature, in subjects with suspected spinal stenosis. Materials and Methods: The present study was prospective cross-sectional study. Forty-five (21 males and 24 females) consecutive Thai adults underwent unloaded and axial-loaded supine magnetic resonance imaging (MRI) examinations of the lumbosacral spine. Radiographic parameters included cross-sectional area of disc (DA), cross-sectional area of dural sac (DCSA), disc height (DH), anterior to posterior distance of disc (DAP), L1-L3-L5 angle (LA), and lumbar lordosis (LL). Results: During the axial-loaded MRIs, the pathologic features of the lumbar spinal stenosis such as the disc bulging, nerve root compression, narrowing of the spinal canal, and the spinal neural foramina, were frequently observed in L4-L5 and L5-S1. Radiographic parameters differences of more than 5% between unloaded and axial-loaded supine MRIs were observed in DCSA and DH. Narrowing of the dural sac due to axial compression was observed at the L4-L5 level (8.1%), while loss of DH was found at both the L5-S1 (-7.9%) and the L4-L5 (-6.8%) levels. Axial compression only slightly affected the DA and DAP of the intervertebral discs with a difference of 5% or less. Furthermore, it rarely changed the spine curvature (LL and LA) of the subjects, with a difference of 2% or less. LL decreased during axial loading and may not correlate with the findings during normal standing position. Although the authors found greater DA and DAP values in male (p<0.001) and obese (p<0.05) subjects, changes of radiographic parameters with axial loading were otherwise not correlated with sex, age, or body mass index. Conclusion: An axial-loaded MRI, using a SpineMAC device, may be superior to conventional MRI when evaluating narrowing of the dural sac and disc height of patients.

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