English
Related papers

Related papers: Reconstructing Accurate Synthetic Hounsfield Units…

200 papers

Positron Emission Tomography (PET) imaging requires accurate attenuation correction (AC) to account for photon loss due to tissue density variations. In PET/MR systems, computed tomography (CT), which offers a straightforward estimation of…

Image and Video Processing · Electrical Eng. & Systems 2025-04-11 Weijie Chen , James Wang , Alan McMillan

The ability to synthesise Computed Tomography images - commonly known as pseudo CT, or pCT - from MRI input data is commonly assessed using an intensity-wise similarity, such as an L2-norm between the ground truth CT and the pCT. However,…

Image and Video Processing · Electrical Eng. & Systems 2020-04-15 Kerstin Kläser , Thomas Varsavsky , Pawel Markiewicz , Tom Vercauteren , David Atkinson , Kris Thielemans , Brian Hutton , M Jorge Cardoso , Sebastien Ourselin

Accurate quantification in positron emission tomography (PET) is essential for accurate diagnostic results and effective treatment tracking. A major issue encountered in PET imaging is attenuation. Attenuation refers to the diminution of…

While drastic improvements in CT technology have occurred in the past 25 years, spatial resolution is one area where progress has been limited until recently. New photon counting CT systems, are capable of much better spatial resolution…

Cone-beam computed tomography (CBCT) is widely used for image-guided radiotherapy (IGRT). It provides real time visualization at low cost and dose. However, photon scattering and beam hindrance cause artifacts in CBCT. These include…

Medical Physics · Physics 2025-09-29 Alzahra Altalib , Chunhui Li , Alessandro Perelli

Background: Cone-beam computed tomography (CBCT) scans, performed fractionally (e.g., daily or weekly), are widely utilized for patient alignment in the image-guided radiotherapy (IGRT) process, thereby making it a potential imaging…

Spectral Computed Tomography (CT) is an emerging technology that enables to estimate the concentration of basis materials within a scanned object by exploiting different photon energy spectra. In this work, we aim at efficiently solving a…

Optimization and Control · Mathematics 2021-03-26 Alessandro Perelli , Martin S. Andersen

Photon counting detectors (PCDs) offer promising advancements in computed tomography (CT) imaging by enabling the quantification and 3D imaging of contrast agents and tissue types through multi-energy projections. However, the accuracy of…

Medical Physics · Physics 2023-10-18 Juan C. R. Luna , Mini Das

Spectral CT offers enhanced material discrimination over single-energy systems and enables quantitative estimation of basis material density images. Water/iodine decomposition in contrast-enhanced CT is one of the most widespread…

Medical Physics · Physics 2021-03-30 Matthew Tivnan , Grace Gang , Wenchao Cao , Nadav Shapira , Peter B. Noel , J. Webster Stayman

With the development of computed tomography (CT) imaging technology, it is possible to acquire multi-energy data by spectral CT. Being different from conventional CT, the X-ray energy spectrum of spectral CT is cutting into several narrow…

Medical Physics · Physics 2023-01-25 Yuanwei He , Li Zeng , Qiong Xu , Zhe Wang , Haijun Yu , Zhaoqiang Shen , Zhaojun Yang , Rifeng Zhou

Purpose: Spectral imaging is a method in medical x-ray imaging to extract information about the object constituents by the material-specific energy dependence of x-ray attenuation. The authors have investigated a photon-counting spectral…

Medical Physics · Physics 2021-01-21 Erik Fredenberg , Magnus Hemmendorff , Bjorn Cederstrom , Magnus Aslund , Mats Danielsson

We provide a fast and accurate scatter artifacts correction algorithm for cone beam CT (CBCT) imaging. The method starts with an estimation of coarse scatter profile for a set of CBCT images. A total-variation denoising algorithm designed…

Medical Physics · Physics 2015-01-20 Wei Zhao , Jun Zhu , Luyao Wang

Model-based treatment planning for transcranial ultrasound therapy typically involves mapping the acoustic properties of the skull from an x-ray computed tomography (CT) image of the head. Here, three methods for generating pseudo-CT images…

Radiation therapy (RT) requires precise dose delivery over multiple fractions, with CT fundamental for treatment planning due to its electron density information. Repeated CT acquisitions impose radiation exposure and logistical burdens,…

Hyperspectral neutron computed tomography enables 3D non-destructive imaging of the spectral characteristics of materials. In traditional hyperspectral reconstruction, the data for each neutron wavelength bin is reconstructed separately.…

Quantifying material mass and electron density from computed tomography (CT) reconstructions can be highly valuable in certain medical practices, such as radiation therapy planning. However, uniquely parameterising the X-ray attenuation in…

Medical Physics · Physics 2019-04-30 Jonathan H. Mason , Alessandro Perelli , William H. Nailon , Mike E. Davies

Purpose: To apply a convolutional neural network (CNN) to develop a system that segments intensity calibration phantom regions in computed tomography (CT) images, and to test the system in a large cohort to evaluate its robustness. Methods:…

Computer Vision and Pattern Recognition · Computer Science 2020-12-22 Keisuke Uemura , Yoshito Otake , Masaki Takao , Mazen Soufi , Akihiro Kawasaki , Nobuhiko Sugano , Yoshinobu Sato

With the growing technology of photon-counting detectors (PCD), spectral CT is a widely concerned topic which has the potential of material differentiation. However, due to some non-ideal factors such as cross talk and pulse pile-up of the…

Medical Physics · Physics 2020-07-21 Ao Zheng , Hongkai Yang , Li Zhang , Yuxiang Xing

This paper provides a fast and patient-specific scatter artifact correction method for cone-beam computed tomography (CBCT) used in image-guided interventional procedures. Due to increased irradiated volume of interest in CBCT imaging,…

Medical Physics · Physics 2015-01-20 Wei Zhao , Stephen Brunner , Kai Niu , Sebastian Schafer , Kevin Royalty , Guang-Hong Chen

Photon-counting computed tomography (PCCT) with energy discrimination capabilities hold great potentials to improve the limitations of the conventional CT, including better signal-to-noise ratio (SNR), improved contrast-to-noise ratio…

Medical Physics · Physics 2019-02-12 Xu Dong , Olga V. Pen , Zhicheng Zhang , Guohua Cao