Publications by authors named "Greffier J"
An image-quality CT phantom was scanned with three different 3D X-ray imaging guidance devices in the operating theatre: O-Arm, Loop-X, and Airo TruCT. Default acquisition and reconstruction parameters for lumbar spine procedures were used on each device. The tube current was set to a dose level of around 27 mGy.
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- The study aims to evaluate the effectiveness of Photon-Counting CT (PCCT) compared to Dual-Source CT (DSCT) in reducing radiation dosage while improving the quality of chest CT images.
- Tests were conducted on phantoms using both CT technologies at various dose levels, with parameters like noise magnitude and detectability of specific lung lesions assessed to measure performance.
- Results showed that PCCT had significantly lower noise levels and better detectability of lung lesions, with a potential dose reduction of nearly 59% compared to DSCT, indicating PCCT's promise for safer chest imaging in patients.
Radiology in France has made major advances in recent years through innovations in research and clinical practice. French institutions have developed innovative imaging techniques and artificial intelligence applications in the field of diagnostic imaging and interventional radiology. These include, but are not limited to, a more precise diagnosis of cancer and other diseases, research in dual-energy and photon-counting computed tomography, new applications of artificial intelligence, and advanced treatments in the field of interventional radiology.
View Article and Find Full Text PDFPurpose: The purpose of this study was to compare lung image quality obtained with ultra-high resolution (UHR) spectral photon-counting CT (SPCCT) with that of dual-layer CT (DLCT), at standard and low dose levels using an image quality phantom and an anthropomorphic lung phantom.
Methods: An image quality phantom was scanned using a clinical SPCCT prototype and an 8 cm collimation DLCT from the same manufacturer at 10 mGy. Additional acquisitions at 6 mGy were performed with SPCCT only.
Photon-counting CT systems: A technical review of current clinical possibilities.
Diagn Interv Imaging
September 2024
In recent years, computed tomography (CT) has undergone a number of developments to improve radiological care. The most recent major innovation has been the development of photon-counting detectors. By comparison with the energy-integrating detectors traditionally used in CT, these detectors offer better dose efficiency, eliminate electronic noise, improve spatial resolution and have intrinsic spectral sensitivity.
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- The study aimed to evaluate how well an AI system can detect bone fractures compared to radiologists, using CT scans as the ultimate benchmark.
- It involved 94 adult patients and found that the AI had a sensitivity of 82% and specificity of 69%, meaning it missed some fractures and misidentified some normal cases.
- The radiologists performed better overall, with a sensitivity of 92% and specificity of 88%, indicating they were more accurate in diagnosing the fractures.
Background: Image-guided percutaneous lung biopsy (PLB) may lead to major complications requiring hospitalization. This study aims to evaluate the rate of major PLB complications and determine a predictive computed tomography (CT) score to define patients requiring hospitalization due to these complications.
Methods: This single-center retrospective study included all PLBs performed from July 2019 to December 2020 in Nimes University Hospital, France.
Purpose: To compare the spectral performance of two different DSCT (DSCT-Pulse and DSCT-Force) on virtual monoenergetic images (VMIs) at low energy levels.
Methods: An image quality phantom was scanned on the two DSCTs at three dose levels: 11/6/1.8 mGy.
Purpose: The purpose of this study was to assess image-quality and dose reduction potential using a photon-counting computed tomography (PCCT) system by comparison with two different dual-source CT (DSCT) systems using two phantoms.
Materials And Methods: Acquisitions on phantoms were performed using two DSCT systems (DSCT1 [Somatom Force] and DSCT2 [Somatom Pro.Pulse]) and one PCCT system (Naeotom Alpha) at four dose levels (13/6/3.
Purpose: The purpose of this study was to compare ultra-low dose (ULD) and standard low-dose (SLD) chest computed tomography (CT) in terms of radiation exposure, image quality and diagnostic value for diagnosing pulmonary arteriovenous malformation (AVM) in patients with hereditary hemorrhagic telangiectasia (HHT).
Materials And Methods: In this prospective board-approved study consecutive patients with HHT referred to a reference center for screening and/or follow-up chest CT examination were prospectively included from December 2020 to January 2022. Patients underwent two consecutive non-contrast chest CTs without dose modulation (i.
Article Synopsis
- The study aimed to evaluate the image quality and radiation dose of a photon-counting CT (PCCT) scanner versus a dual-source CT (DSCT) scanner using low energy virtual monoenergetic images (VMIs).
- The researchers conducted scans on a phantom with varying dose levels (11 mGy, 6 mGy, and 1.8 mGy), analyzing noise characteristics, spatial resolution, and lesion detectability across different energy levels.
- Results showed that PCCT generally outperformed DSCT in reducing noise and improving image quality, achieving better noise texture and spatial resolution, and providing higher detectability index scores for simulated lesions at lower radiation doses.
Images from 64 patients undergoing an enhanced abdominal-pelvis scan at portal phase in dual-energy CT mode for the diagnosis of colitis or bowel obstruction were retrospectively analyzed. Acquisitions were performed on a third-generation dual-source CT (DSCT) 100/Sn150 kVp. Mixed images were generated, as well as virtual monoenergetic images (VMIs) at 40/50/60/70 keV.
View Article and Find Full Text PDFPurpose: The purpose of this study was to compare the performance of Precise IQ Engine (PIQE) and Advanced intelligent Clear-IQ Engine (AiCE) algorithms on image-quality according to the dose level in a cardiac computed tomography (CT) protocol.
Materials And Methods: Acquisitions were performed using the CT ACR 464 phantom at three dose levels (volume CT dose indexes: 7.1/5.
A wide variety of coils are available for vascular embolization. This study aimed to evaluate the safety and efficacy of a new Prestige coil. We carried out retrospective analysis of a multicenter's registry data collected between February 2022 and November 2022.
View Article and Find Full Text PDFThe purpose of this study was to compare the quality of low-energy virtual monoenergetic images (VMIs) obtained with three Dual-Energy CT (DECT) platforms according to the phantom diameter. Three sections of the Mercury Phantom 4.0 were scanned on two generations of split-filter CTs (SFCT-1st and SFCT-2nd) and on one Dual-source CT (DSCT).
View Article and Find Full Text PDFBackground: Recently, a second generation of split filter dual-energy CT (SFCT) platform has been developed. The thicknesses of the gold and tin filters used to obtain both low- and high-energy spectra have been changed. These differences in filter thickness may affect the spectral separation between the two spectra and thus the quality of spectral images.
View Article and Find Full Text PDFPurpose: The purpose of this study was to assess the impact of a tin filter on the image quality of ultra-low dose (ULD) chest computed tomography (CT) on three different CT systems.
Materials And Methods: An image quality phantom was scanned on three CT systems including two split-filter dual-energy CT (SFCT-1 and SFCT-2) scanners and one dual-source CT scanner (DSCT). Acquisitions were performed with a volume CT dose index (CTDI) of 0.
Purpose: To assess the impact of the automatic tube current modulation (ATCM) on virtual monoenergetic images (VMIs) quality in dual-source CT(DSCT).
Materials And Methods: Acquisitions were performed on DSCT using the Mercury phantom. The acquisition parameters for an abdomen-pelvic examination with single-energy CT(SECT) and dual-energy CT(DECT) imaging were used.
Article Synopsis
- The study evaluated a deep learning image reconstruction algorithm (DLR) against an iterative reconstruction algorithm (IR) to see which provides better image quality and clarity of liver metastases.
- It involved 30 patients with liver metastasis, measuring various metrics like image noise and quality through established scales by radiologists.
- Results showed that the DLR algorithm significantly reduced image noise compared to IR, especially at the Smooth and Smoother levels, which also scored highest in overall image quality and lesion visibility.
Objectives: To evaluate the quality of virtual monochromatic images (VMIs) from spectral photon-counting CT (SPCCT) and two energy-integrating detector dual-energy CT (EID-DECT) scanners from the same manufacturer, for the coronary lumen.
Methods: A 21-cm section of the Mercury v4.0 phantom was scanned using a cardiac CT protocol.
Purpose: To compare quantitatively and qualitatively brain image quality acquired in helical and axial modes on two wide collimation CT systems according to the dose level and algorithm used.
Methods: Acquisitions were performed on an image quality and an anthropomorphic phantoms at three dose levels (CTDI: 45/35/25 mGy) on two wide collimation CT systems (GE Healthcare and Canon Medical Systems) in axial and helical modes. Raw data were reconstructed using iterative reconstruction (IR) and deep-learning image reconstruction (DLR) algorithms.
Background: A nation-wide study recently published the dose reference levels for the main CT-guided interventional procedures in 5001 patients. We assessed the impact of patient's age, sex and targeted organ on the patient dose during thoracic and abdominopelvic biopsies and punctures/drainages.
Patients And Methods: Data were extracted from the previous nationwide study.