In CT-imaging, an optimal compromise between the radiation burden and the required image quality for the imaging task is needed. In this research, we aim to develop a tool to simulate lower-dose scans from a standard-dose scan. The motivation is to determine the lowest possible radiation dose that still produces sufficient information for proton therapy treatment planning. The tube current reduction is modeled by estimating the noise equivalent number of photons in the high exposure scan and applying a thinning technique to reduce that number. The proposed method accounts for the bowtie filter, for the noise correlation between neighboring detector elements, for the beam hardening effect, and for the non-linear smoothing filter in very low dose scans. Phantom studies show a close agreement between the noise level of the acquired and the simulated lower-dose scans. Simulations of low-dose scans of anthropomorphic thorax and head phantom in a range from 300 to 20 mAs show that the noise standard deviation in the simulated images matches the reconstructions from the real scans with less than 1% and 3% error for sequential and helical scans, respectively.

Hounsfield scale

Image noise

10.1109/nss/mic42101.2019.9059917

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Citations (1)

Author response for "Exploration of Chick Embryo and Chorioallantoic Membrane on Imaging Navigated Platforms for Anticancer Pharmaceutical Evaluations"

Lei Chen Mingyuan Yuan Xinqi Zhang Yongsheng Li Yuanbo Feng

Chorioallantoic membrane

10.1177/15330338231206985/v2/response1

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Evaluation of safety and performance of a new prototype self-expandable nitinol venous stent in an ovine model

JVS Vascular Science (2023)

Mohammad E. Barbati Beate Bechter-Hugl Sarah Thomis Benita Hermanns‐Sachweh Walter Coudyzer

Our study was a prospective in vivo study performed on an animal model to evaluate the safety and performance of a novel venous stent designed specifically for venous applications.The novel stents were implanted in the inferior vena cava of nine sheep. The stents were deployed with different distances between the closed cell rings to test for if the segments might migrate after being deployed at maximal distance. Three different total lengths were 9, 11, and 13 cm. After 1, 3, and 6 months, vascular injury, thrombus, neointima coverage, and stent migration were evaluated through computed tomography venography and histopathology. Imaging, histology, and integration data were analyzed for each group.All stents were deployed successfully, and all sheep survived until the time of harvesting. In all cases, the native blood vessel sections were intact. The segmented stent parts showed a differently pronounced tissue coverage, depending on the duration of the implantation.The new nitinol stent is safe and feasible to implant in the venous system with a rapid surface coverage. Alteration of stent length did not affect the development of neointimal formation and did not cause migration.

Neointima

Venography

Histopathology

10.1016/j.jvssci.2023.100113

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Radiological Analysis of Unused Donor Lungs: A Tool to Improve Donor Acceptance for Transplantation?

American Journal of Transplantation (2017)

Stijn E. Verleden A. Martens Sofie Ordies Tobias Heigl Hannelore Bellon

Despite donor organ shortage, a large proportion of possible donor lungs are declined for transplantation. Criteria for accepting/declining lungs remain controversial because of the lack of adequate tools to aid in decision-making. We collected, air-inflated, and froze a large series of declined/unused donor lungs and subjected these lung specimens to CT examination. Affected target regions were scanned by using micro-CT. Lungs from 28 donors were collected. Two lungs were unused, six were declined for non-allograft-related reasons (collectively denominated nonallograft declines, n = 8), and 20 were declined because of allograft-related reasons. CT scanning demonstrated normal lung parenchyma in only four of eight nonallograft declines, while relatively normal parenchyma was found in 12 of 20 allograft-related declines. CT and micro-CT examinations confirmed the reason for decline in most lungs and revealed unexpected (unknown from clinical files or physical inspection) CT abnormalities in other lungs. CT-based measurements showed a higher mass and density in the lungs with CT alterations compared with lungs without CT abnormalities. CT could aid in the decision-making to accept or decline donor lungs which could lead to an increase in the quantity and quality of lung allografts.

Economic shortage

Parenchyma

10.1111/ajt.14255

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Citations (18)

Strength training at high versus low external resistance in older adults: long-term muscular and functional adaptations

Evelien Van Roie Ivan Bautmans Walter Coudyzer Christophe Delecluse

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Association between vascular FDG uptake during follow-up and the development of thoracic aortic aneurysms in giant cell arteritis

Frontiers in Medicine (2024)

Daniël Blockmans Lien Moreel Albrecht Betrains Steven Vanderschueren Walter Coudyzer

Background A positive PET scan at diagnosis was associated with a greater yearly increase in ascending and descending aortic diameter and thoracic aortic volume in patients with giant cell arteritis (GCA). Radiologic and histopathologic vascular abnormalities persist in a subset of treated patients despite clinical remission. The aim of this study was to evaluate the association between vascular FDG uptake during follow-up and the development of thoracic aortic aneurysms. Methods We recently performed a prospective cohort study of 106 GCA patients, who underwent FDG PET and CT imaging at diagnosis and CT imaging yearly for a maximum of 10 years. In this post hoc analysis, GCA patients who also have had FDG PET imaging during follow-up were included. PET scans were visually scored (0–3) at 7 vascular areas. PET scans were considered positive in case of FDG uptake ≥grade 2 in any large vessel. Results Eighty-eight repeat PET scans were performed in 52 out of 106 GCA patients, who were included in the original prospective cohort. Fifty-five (63%) PET scans were done at the time of a relapse and 33 (38%) were done while in remission. Nine out of ten patients with an incident thoracic aortic aneurysm had both a positive PET scan at diagnosis and during follow-up. Conclusion In addition to the intensity and extent of the initial vascular inflammation, ongoing aortic inflammation may contribute to the development of thoracic aortic aneurysms in GCA. However, this hypothesis should be confirmed in a large prospective trial with repeat PET scans at predefined time points during follow-up.

Thoracic aortic aneurysm

Arteritis

Thoracic aorta

10.3389/fmed.2024.1384533

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Citations (4)

Sarcopenia in patients with symptomatic polycystic liver disease: a more objective parameter for liver allocation?

Hepatology (2012)

Frederik Temmerman Jacques Pirenne Ragna Vanslembrouck Walter Coudyzer Diethard Monbaliu

Polycystic liver disease

Liver disease

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