Radiological Physics and Technology This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Evaluation of attenuation correction method for head holder in brain perfusion single-photon emission computed tomography
AbstractHead holder attenuation affects brain perfusion single-photon emission computed tomography (SPECT) image quality. Here, we proposed a head holder-attenuation correction (AC) method using attenuation coefficient maps calculated by Chang ’s method from CT images. Then, we evaluated the effectiveness of the head holder-AC method by numerical phantom and clinical cerebral perfusion SPECT studies. In the numerical phantom, the posterior counts were 10.7% lower than the anterior counts without head holder-AC method. However, by perfor ming head holder-AC, the posterior count recovered by approximately 6.8%, approaching...
Source: Radiological Physics and Technology - March 1, 2024 Category: Physics Source Type: research

Development of an open project rectangular collimator for use with intraoral dental X-ray unit
AbstractIn this work, an open beam-limiting device, consisting of a rectangular collimator to be coupled to an intraoral dental X-ray device, was made using recycled lead sheets as a radiation-absorbing element. The collimator was designed for 3D printing, and using Spektr 3.0 software, the number of lead sheets needed to absorb excess radiation was calculated. The rectangular collimator reduced the radiation dose to patients by 65% when using four layers of recycled lead sheets (saturating with a 70% reduction in radiation dose at the limit of eight or more sheets of lead). The rectangular collimator does not negatively i...
Source: Radiological Physics and Technology - March 1, 2024 Category: Physics Source Type: research

Evaluation of deep learning reconstruction on diffusion-weighted imaging quality and apparent diffusion coefficient using an ice-water phantom
This study assessed the influence of deep learning reconstruction (DLR) on the quality of diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) using an ice-water phantom. An ice-water phantom with known diffusion properties (true ADC  = 1.1 × 10–3 mm2/s at 0  °C) was imaged at various b-values (0, 1000, 2000, and 4000 s/mm2) using a 3  T magnetic resonance imaging scanner with slice thicknesses of 1.5 and 3.0 mm. All DWIs were reconstructed with or without DLR. ADC maps were generated using combinations of b-values 0 and 1000, 0 and 2000, and 0 and 4000 s/mm2. Based on the quantitative ...
Source: Radiological Physics and Technology - March 1, 2024 Category: Physics Source Type: research

Assessment of dosimetric approaches in evaluating radiation exposure for interventional cardiologists in Sri Lanka
AbstractInterventional cardiologists face significant radiation exposure during interventional cardiology procedures. Therefore, this study focuses on assessing radiation exposure among interventional cardiologists during their procedures. Specifically, it aims to determine the effectiveness of both single and double dosimeter methods in estimating annual occupational radiation doses. This research holds pioneering significance as it represents the very first study undertaken in Sri Lanka. Thirteen interventional cardiologists performed 486 interventional cardiology procedures over three months in three different healthcar...
Source: Radiological Physics and Technology - March 1, 2024 Category: Physics Source Type: research

Half-value layer measurements using solid-state detectors and single-rotation technique with lead apertures in spiral computed tomography with and without a tin filter
AbstractSolid-state detectors (SSDs) may be used along with a lead collimator for half-value layer (HVL) measurement using computed tomography (CT) with or without a tin filter. We aimed to compare HVL measurements obtained using three SSDs (AGMS-DM+  , X2 R/F sensor, and Black Piranha) with those obtained using the single-rotation technique with lead apertures (SRTLA). HVL measurements were performed using spiral CT at tube voltages of 70–140 kV without a tin filter and 100–140 kV (Sn 100–140 kV) with a tin filter in increments of 10  kV. For SRTLA, a 0.6-cc ionization chamber was suspended at the isocenter to...
Source: Radiological Physics and Technology - March 1, 2024 Category: Physics Source Type: research

Investigation of ionization chamber perturbation factors using proton beam and Fano cavity test for the Monte Carlo simulation code PHITS
AbstractThe reference dose for clinical proton beam therapy is based on ionization chamber dosimetry. However, data on uncertainties in proton dosimetry are lacking, and multifaceted studies are required. Monte Carlo simulations are useful tools for calculating ionization chamber dosimetry in radiation fields and are sensitive to the transport algorithm parameters when particles are transported in a heterogeneous region. We aimed to evaluate the proton transport algorithm of the Particle and Heavy Ion Transport Code System (PHITS) using the Fano test. The response of the ionization chamber\({f}_{{\text{Q}}}\) and beam qual...
Source: Radiological Physics and Technology - March 1, 2024 Category: Physics Source Type: research

Verification of image quality improvement of low-count bone scintigraphy using deep learning
AbstractTo improve image quality for low-count bone scintigraphy using deep learning and evaluate their clinical applicability. Six hundred patients (training, 500; validation, 50; evaluation, 50) were included in this study. Low-count original images (75%, 50%, 25%, 10%, and 5% counts) were generated from reference images (100% counts) using Poisson resampling. Output (DL-filtered) images were obtained after training with U-Net using reference images as teacher data. Gaussian-filtered images were generated for comparison. Peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) to the reference image were calcul...
Source: Radiological Physics and Technology - March 1, 2024 Category: Physics Source Type: research

Selection of Radiological Physics and Technology Awards 2023
(Source: Radiological Physics and Technology)
Source: Radiological Physics and Technology - March 1, 2024 Category: Physics Source Type: research

Subjective and objective image quality of low-dose CT images processed using a self-supervised denoising algorithm
This study aimed to assess the subjective and objective image quality of low-dose computed tomography (CT) images processed using a self-supervised denoising algorithm with deep learning. We trained the self-supervised denoising model using low-dose CT images of 40 patients and applied this model to CT images of another 30 patients. Image quality, in terms of noise and edge sharpness, was rated on a 5-point scale by two radiologists. The coefficient of variation, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were calculated. The values for the self-supervised denoising model were compared with those for th...
Source: Radiological Physics and Technology - February 27, 2024 Category: Physics Source Type: research

Improved detection of cholesterol gallstones using quasi-material decomposition images generated from single-energy computed tomography images via deep learning
This study demonstrated that the lesion detection capability of images obtained from SECT can be improved using a DCNN trained with DECT images obta ined using high-end computed tomography systems. (Source: Radiological Physics and Technology)
Source: Radiological Physics and Technology - February 23, 2024 Category: Physics Source Type: research

Improving image quality using the pause function combination to PROPELLER sequence in brain MRI: a phantom study
This study investigated whether repositioning the head after pausing during PROPELLER imaging enhances image quality. All brain phantom images in this study were obtained using a 3.0 T MRI and acquired using the fast spin-echo T2WI-based PROPELLER with motion correction. By combining the angle of rotational motion of the head phantom and the number of repositioning after a pause, two studies including seven trials were performed. Increasing the rotation angle decreased the image q uality; however, pausing the image and repositioning the head phantom to the original angle improved the image quality. A similar result was ob...
Source: Radiological Physics and Technology - February 17, 2024 Category: Physics Source Type: research

Preclinical magnetic resonance imaging and spectroscopy in the fields of radiological technology, medical physics, and radiology
AbstractMagnetic resonance imaging (MRI) is an indispensable diagnostic imaging technique used in the clinical setting. MRI is advantageous over X-ray and computed tomography (CT), because the contrast provided depends on differences in the density of various organ tissues. In addition to MRI systems in hospitals, more than 100 systems are used for research purposes in Japan in various fields, including basic scientific research, molecular and clinical investigations, and life science research, such as drug discovery, veterinary medicine, and food testing. For many years, additional preclinical imaging studies have been co...
Source: Radiological Physics and Technology - February 14, 2024 Category: Physics Source Type: research

3D-printed boluses for radiotherapy: influence of geometrical and printing parameters on dosimetric characterization and air gap evaluation
AbstractThe work investigates the implementation of personalized radiotherapy boluses by means of additive manufacturing technologies. Boluses materials that are currently used need an excessive amount of human intervention which leads to reduced repeatability in terms of dosimetry. Additive manufacturing can solve this problem by eliminating the human factor in the process of fabrication. Planar boluses with fixed geometry and personalized boluses printed starting from a computed tomography scan of a radiotherapy phantom were produced. First, a dosimetric characterization study on planar bolus designs to quantify the effe...
Source: Radiological Physics and Technology - February 13, 2024 Category: Physics Source Type: research

John Roderick Cameron (1922 –2005): Scientist, teacher, mentor, inventor, and philanthropist extraordinaire
(Source: Radiological Physics and Technology)
Source: Radiological Physics and Technology - February 12, 2024 Category: Physics Source Type: research

Verification of image quality improvement of low-count bone scintigraphy using deep learning
AbstractTo improve image quality for low-count bone scintigraphy using deep learning and evaluate their clinical applicability. Six hundred patients (training, 500; validation, 50; evaluation, 50) were included in this study. Low-count original images (75%, 50%, 25%, 10%, and 5% counts) were generated from reference images (100% counts) using Poisson resampling. Output (DL-filtered) images were obtained after training with U-Net using reference images as teacher data. Gaussian-filtered images were generated for comparison. Peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) to the reference image were calcul...
Source: Radiological Physics and Technology - February 10, 2024 Category: Physics Source Type: research