Abstract Background Daily or weekly cone‐beam computed tomography (CBCT) scans are commonly used for accurate patient positioning during the image‐guided radiotherapy (IGRT) process, making it an ideal option adaptive (ART) replanning. However, presence of severe artifacts and inaccurate Hounsfield unit (HU) values prevent its use quantitative applications such as organ segmentation dose calculation. To enable clinical practice online ART, is crucial to obtain CBCT with a quality comparable...

Abstract Background and purpose Magnetic resonance imaging (MRI)‐based synthetic computed tomography (sCT) simplifies radiation therapy treatment planning by eliminating the need for CT simulation error‐prone image registration, ultimately reducing patient dose setup uncertainty. In this work, we propose a MRI‐to‐CT transformer‐based improved denoising diffusion probabilistic model (MC‐IDDPM) to translate MRI into high‐quality sCT facilitate planning. Methods MC‐IDDPM implements processes...

Abstract Objective . High-resolution magnetic resonance imaging (MRI) can enhance lesion diagnosis, prognosis, and delineation. However, gradient power hardware limitations prohibit recording thin slices or sub-1 mm resolution. Furthermore, long scan time is not clinically acceptable. Conventional high-resolution images generated using statistical analytical methods include the limitation of capturing complex, high-dimensional image data with intricate patterns structures. This study aims to...

Abstract The advantage of proton therapy as compared to photon stems from the Bragg peak effect, which allows protons deposit most their energy directly at tumor while sparing healthy tissue. However, even with such benefits, does present certain challenges. biological effectiveness differences between and photons are not fully incorporated into clinical treatment planning processes. In current practice, relative (RBE) is set constant 1.1. Numerous studies have suggested that RBE can exhibit...

Positron Emission Tomography (PET) has been a commonly used imaging modality in broad clinical applications. One of the most important tradeoffs PET is between image quality and radiation dose: high comes with exposure. Improving desirable for all applications while minimizing exposure needed to reduce risk patients.

This study aims to develop a novel Cycle-guided Denoising Diffusion Probability Model (CG-DDPM) for cross-modality MRI synthesis. The CG-DDPM deploys two DDPMs that condition each other generate synthetic images from different pulse sequences. exchange random latent noise in the reverse processes, which helps regularize both and matching modalities. improves image-to-image translation ac-curacy. We evaluated quantitatively using mean absolute error (MAE), multi-scale structural similarity...

In the sphere of Cone Beam Computed Tomography (CBCT), acquiring X-ray projections from sufficient angles is indispensable for traditional image reconstruction methods to accurately reconstruct 3D anatomical intricacies. However, this acquisition procedure linear accelerator-mounted CBCT systems in radiotherapy takes approximately one minute, impeding its use ultra-fast intra-fractional motion monitoring during treatment delivery. To address challenge, we introduce Patient-specific...

The purpose of this study is to reduce radiation exposure in PET imaging while preserving high-quality clinical images. We propose the Consistency Model (PET-CM), an efficient diffusion-model-based approach, estimate full-dose images from low-dose PETs. PET-CM delivers synthetic comparable quality state-of-the-art diffusion-based methods but with significantly higher efficiency. process involves adding Gaussian noise PETs through a forward diffusion and then using U-shaped network (PET-Unet)...

Abstract Background Dual‐energy computed tomography (DECT) and material decomposition play vital roles in quantitative medical imaging. However, the process may suffer from significant noise amplification, leading to severely degraded image signal‐to‐noise ratios (SNRs). While existing iterative algorithms perform suppression using different priors, these heuristic priors cannot accurately represent features of target manifold. Although deep learning‐based methods have been reported, are...

Although cone beam computed tomography (CBCT) has lower resolution compared to planning CTs (pCT), its dose, higher high-contrast resolution, and shorter scanning time support widespread use in clinical applications, especially ensuring accurate patient positioning during the image-guided radiation therapy (IGRT) process.

This study aims to simplify radiation therapy treatment planning by proposing an MRI-to-CT transformer-based denoising diffusion probabilistic model (CT-DDPM) generate high-quality synthetic computed tomography (sCT) from magnetic resonance imaging (MRI). The goal is reduce patient dose and setup uncertainty eliminating the need for CT simulation image registration during planning. CT-DDPM utilizes a process with shifted-window transformer network transform MRI into sCT. comprises two...

Objective: Positron Emission Tomography (PET) has been a commonly used imaging modality in broad clinical applications. One of the most important tradeoffs PET is between image quality and radiation dose: high comes with exposure. Improving desirable for all applications while minimizing exposure needed to reduce risk patients. Approach: We introduce Consistency Model (PET-CM), an efficient diffusion-based method generating high-quality full-dose images from low-dose images. It employs...

Vitamin D signaling not only controls calcium (Ca2+) and phosphorus uptake transport, but also correlates with neurocognitive decline neurodegenerative diseases. Almost all actions of are mediated by the transcription factor, vitamin receptor (VDR), which has been widely identified in central nervous system. Although previous studies have substantially advanced understanding action VDR brain, much remains unknown concerning how relates to stress. Multiple lines evidence indicate that...

This work aims at exploring the irradiation resistance of oxide-dispersion-strengthened reduced-activation ferritic/martensitic (ODS-RAFM) steel prepared by a rapid and cost-efficient method, wire arc additive manufacturing (WAAM). WAAM ODS-RAFM RAFM were using flux cored wires with without addition Y2O3, respectively. Both specimens irradiated 2.5 MeV Fe ions 450 ℃ to fluence 1.84×1016 cm-2, corresponding peak damage dose 20 dpa. The microstructure, hardness defect structure before after...

Cone-beam CT (CBCT) is installed in the treatment room to facilitate online clinical applications, including image guidance radiation and surgery. Half-fan short-can are commonly used modes applications expand imaging volume reduce exposure. Anatomical structures faithfully reconstructed using CBCT while deep information material composition not feasible its current form. Dual-energy computed tomography (DECT) an advanced medical technology with superior capability of differentiation by...

This study aims to enhance the resolution of Magnetic Resonance Imaging (MRI) using a cutting-edge diffusion probabilistic Deep Learning (DL) technique, addressing challenges posed by long image acquisition times and limited scanning dimensions. In this research, we propose novel approach utilizing DL model synthesize High-Resolution MRI (HR-MRI) images from Low-Resolution (LR) inputs. The proposed consists two main steps. forward process, Gaussian noise is systematically introduced LR...

Iodine maps can be obtained from contrast enhanced dual-energy compute tomography (DECT) scans to emphasize iodine agent uptake in cancer patients' tissues, which benefits radiation oncologists the treatment planning process. However, DECT scanners are not widely equipped among therapy centers. Furthermore, certain patients, i.e., either with allergies or renal dysfunction, suitable for scans. The purpose of this work is generate synthetic based on non-contrast single-energy CT (SECT) images...

Computed tomography (CT) imaging is widely used for medical diagnosis and image guidance treatment. Metal artifacts are observed on the reconstructed CT images if metal implants carried by patients due to beam hardening effects. In this condition, acquired projection data cannot be analytical reconstruction as they do not meet Tuy's sufficiency condition. Numerous deep learning-based methods have been developed artifact reduction (MAR), providing superior performance. Nevertheless, all...

Background: Dual-energy imaging on cone-beam CT (CBCT) scanners has great potential in different clinical applications, including image-guided surgery and adaptive proton therapy. However, the practice of dual-energy CBCT (DE-CBCT) been hindered by requirement sophisticated hardware components. Purpose: In this work, we aim to propose a practical solution for single-scan current without modifications, using two complementary limited-angle scans with projection-consistent diffusion model....

Dual-energy cone-beam CT (DECBCT) has great potential for quantitative imaging tasks in CBCT-guided radiation therapy. However, the lack of a practical single-scan solution data acquisition impedes practice CBCT-based adaptive radiotherapy (ART). In this work, we propose an efficient way to achieve DECBCT using primary beam splitting single short scan or half-fan scan. To restore complete dual-energy sinograms sufficient analytical image reconstruction, conditional diffusion model is...