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Purpose: Image inaccuracies and distortions are amplified in cone-beam computed tomography (CBCT), with beam hardening and metal artifacts being particularly pronounced, thereby complicating diagnostic interpretation. An approach, combining dual-energy CBCT based projection-domain material decomposition with virtual monochromatic imaging (VMI) technique, was leveraged to mitigate beam hardening artifacts originating from dental restorative and prosthetic materials on a diagnostic CBCT scanner in a phantom setting.
Methods: Severe artifact-causing dental restorative and prosthetic materials were identified from the literature and six of them were selected for the study. Six different phantoms were developed using selected materials, and 3D-printed cylindrical molds filled with gelatine. Three different tube voltages, such as 80 kilovoltage (kV), 100 kV, 120 kV were selected for scanning and the phantoms were scanned using a commercial CBCT scanner (Viso G7, Planmeca Oy., Helsinki, Finland). A custom-developed material decomposition algorithm, based on polychromatic projection domain modeling, was employed to separate the dual-energy data into water and iron basis materials. VMIs were then synthesized at 200 keV using the decomposed data. For comparison, the 100 kV acquisition (routine protocol) with and without the vendor's inpainting-based MAR algorithm was used to assess VMI techniques' performance for artifact reduction.
Results: Both subjectively and quantitatively, the VMI technique offered better image quality than the routine 100 kV protocol. Further, combining the VMI technique with an inpainting-based MAR algorithm offered superior artifact reduction (p < 0.01) for all tested materials compared to using the routine protocol and the MAR algorithm.
Conclusions: The proposed VMI + MAR technique offered superior artifact reduction compared to a commercial MAR algorithm.
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http://dx.doi.org/10.1007/s10439-025-03811-1 | DOI Listing |
Jpn J Radiol
September 2025
Department of Radiology, the Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221002, Jiangsu, China.
Background: Stroke, frequently associated with carotid artery disease, is evaluated using carotid computed tomography angiography (CTA). Dual-energy CTA (DE-CTA) enhances imaging quality but presents challenges in maintaining high image clarity with low-dose scans.
Objectives: To compare the image quality of 50 keV virtual monoenergetic images (VMI) generated using Deep Learning Image Reconstruction (DLIR) and Adaptive Statistical Iterative Reconstruction-V (ASIR-V) algorithms under a triple-low scanning protocol in carotid CTA.
Radiography (Lond)
September 2025
Department of Radiology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, 221002, China; School of Medical Imaging, Xuzhou Medical University, Xuzhou, Jiangsu, 221002, China; Jiangsu Provincial Engineering Research Center for Medical Imaging and Digital Medicine, Xuzhou, Jiangs
Introduction: Carotid artery disease is a major cause of stroke and is frequently evaluated using Carotid CT Angiography (CTA). However, the associated radiation exposure and contrast agent use raise concerns, particularly for high-risk patients. Recent advances in Deep Learning Image Reconstruction (DLIR) offer new potential to enhance image quality under low-dose conditions.
View Article and Find Full Text PDFActa Oncol
September 2025
Department of Oncology, Copenhagen University Hospital - Herlev and Gentofte, Herlev, Denmark.
Background And Purpose: Photon-counting computed tomography (PCCT) offers enhanced image quality, including improvements in contrast, spatial resolution, and noise reduction. In radiotherapy (RT), optimal image quality is critical for accurate tumor and organ-at-risk delineation. However, reconstruction parameter selection often relies on subjective assessment.
View Article and Find Full Text PDFActa Oncol
September 2025
Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.
Background And Purpose: Accurate stopping-power ratio (SPR) estimation is crucial for proton therapy planning. In brain cancer patients with metal clips, SPR accuracy may be affected by high-density materials and imaging artefacts. Dual-energy CT (DECT)-based methods have been shown to improve SPR accuracy.
View Article and Find Full Text PDFMed Phys
September 2025
Department of Imaging, Cedars-Sinai Medical Center, Los Angeles, California, USA.
Background: Fat volume fraction (FVF) is an important biomarker for non-alcoholic fatty liver disease. However, current CT-based FVF quantification methods lack sufficient accuracy, particularly at lower FVF values.
Purpose: We aimed to analyze the relationship between FVF and Hounsfield units (HU) in unenhanced fatty lesions and identify optimal settings to minimize FVF quantification errors by comparing virtual monochromatic imaging (VMI) from dual-energy CT (DECT) with single-energy CT (SECT) across different patient sizes.