• Book : 604()
• Pub. Date : 2025
• Page : pp.155502
• Keyword :

• Book : 860()
• Pub. Date : 2025
• Page : pp.139145
• Keyword :

• Book : 604()
• Pub. Date : 2025
• Page : pp.155504
• Keyword :

Abstract

Micro‐x‐ray fluorescence (μ‐XRF) is a commonly used elemental analysis technique for glass physical evidence in forensic cases, which can detect major and trace elements in samples and potentially identify glass fragments according to the differences in elemental composition. However, when a sample is irradiated with polychromatic x‐rays, bremsstrahlung scattering from the source radiation provides noise in the fluorescence spectrum and affects the detection results. To improve the signal‐to‐noise ratio of the fluorescence spectrum, a Mμ‐XRF spectrometer constructed under the low‐power Mo target x‐ray tube condition was used to analyze ten kinds of common glass fragments. The application of laboratory Mμ‐XRF analysis in single‐point detection of tiny glass materials was studied. Experimental results show that the detection limit of Sr element was 51 μg/L, and the spectrometer can distinguish different types of small glass fragments according to the fluorescence spectrum information.

• Book : 54(1)
• Pub. Date : 2025
• Page : pp.47-53
• Keyword :

• Book : 213()
• Pub. Date : 2025
• Page : pp.111072
• Keyword :

• Book : 35(1)
• Pub. Date : 2025
• Page : pp.4-10
• Keyword :

• Book : 35(1)
• Pub. Date : 2025
• Page : pp.1-3
• Keyword :

Objective

This study aimed to evaluate the diagnostic performance of ^99mTc-hydroxymethylene diphosphonate (^99mTc-HMDP) imaging for cardiac amyloidosis and to demonstrate changes in cardiac uptake of ^99mTc-HMDP after tafamidis treatment.

Methods

Seventy-five patients with suspected cardiac amyloidosis who underwent ^99mTc-HMDP imaging were included. We compared visual Perugini grades and semiquantitative heart-to-contralateral (H/CL) area ratios, myocardial maximum standardized uptake value (SUVmax), and peak of SUV (SUVpeak) between cardiac transthyretin amyloidosis (ATTR) and amyloid light-chain amyloidosis (AL). Comparison of interobserver reproducibility between H/CL ratios and myocardial SUVmax/SUVpeak was performed. H/CL ratio of ^99mTc-HMDP and myocardial SUVmax/SUVpeak were compared before and after tafamidis administration for cardiac wild-type ATTR.

Results

Among 75 patients, 20 patients (26.7%) were visually positive based on Perugini grade. Fifteen and three patients were pathologically identified as cardiac ATTR and AL, respectively. ATTR group (n = 15) had significantly higher H/CL ratios of ^99mTc-HMDP than AL group (n = 3) (P = 0.003). ATTR group (n = 15) had significantly higher myocardial SUVmax/SUVpeak of ^99mTc-HMDP than AL group (n = 2) (P = 0.015). Myocardial SUVmax/SUVpeak had better interobserver reproducibility than H/CL ratios. After tafamidis treatment for cardiac wild-type ATTR, the decrease in myocardial SUVpeak was significant but not in H/CL ratios and myocardial SUVmax.

Conclusion

H/CL ratio and SUVmax/SUVpeak in ^99mTc-HMDP imaging were useful for diagnosing cardiac ATTR. Myocardial SUVpeak may be useful for monitoring changes in cardiac uptake after tafamidis treatment for cardiac ATTR.

• Book : 46(1)
• Pub. Date : 2025
• Page : pp.38-46
• Keyword :

Introduction

Multiplexed PET imaging revolutionized clinical decision-making by simultaneously capturing various radiotracer data in a single scan, enhancing diagnostic accuracy and patient comfort. Through a transformer-based deep learning, this study underscores the potential of advanced imaging techniques to streamline diagnosis and improve patient outcomes.

Patients and Methods

The research cohort consisted of 120 patients spanning from cognitively unimpaired individuals to those with mild cognitive impairment, dementia, and other mental disorders. Patients underwent various imaging assessments, including 3D T1-weighted MRI, amyloid PET scans using either ¹⁸F-florbetapir (FBP) or ¹⁸F-flutemetamol (FMM), and ¹⁸F-FDG PET. Summed images of FMM/FBP and FDG were used as proxy for simultaneous scanning of 2 different tracers. A SwinUNETR model, a convolution-free transformer architecture, was trained for image translation. The model was trained using mean square error loss function and 5-fold cross-validation. Visual evaluation involved assessing image similarity and amyloid status, comparing synthesized images with actual ones. Statistical analysis was conducted to determine the significance of differences.

Results

Visual inspection of synthesized images revealed remarkable similarity to reference images across various clinical statuses. The mean centiloid bias for dementia, mild cognitive impairment, and healthy control subjects and for FBP tracers is 15.70 ± 29.78, 0.35 ± 33.68, and 6.52 ± 25.19, respectively, whereas for FMM, it is −6.85 ± 25.02, 4.23 ± 23.78, and 5.71 ± 21.72, respectively. Clinical evaluation by 2 readers further confirmed the model's efficiency, with 97 FBP/FMM and 63 FDG synthesized images (from 120 subjects) found similar to ground truth diagnoses (rank 3), whereas 3 FBP/FMM and 15 FDG synthesized images were considered nonsimilar (rank 1). Promising sensitivity, specificity, and accuracy were achieved in amyloid status assessment based on synthesized images, with an average sensitivity of 95 ± 2.5, specificity of 72.5 ± 12.5, and accuracy of 87.5 ± 2.5. Error distribution analyses provided valuable insights into error levels across brain regions, with most falling between −0.1 and +0.2 SUV ratio. Correlation analyses demonstrated strong associations between actual and synthesized images, particularly for FMM images (FBP: Y = 0.72X + 20.95, R² = 0.54; FMM: Y = 0.65X + 22.77, R² = 0.77).

Conclusions

This study demonstrated the potential of a novel convolution-free transformer architecture, SwinUNETR, for synthesizing realistic FDG and FBP/FMM images from summation scans mimicking simultaneous dual-tracer imaging.

• Book : 50(1)
• Pub. Date : 2025
• Page : pp.1-10
• Keyword :

• Book : 382()
• Pub. Date : 2025
• Page : pp.137797
• Keyword :