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  1. Article ; Online: Reply to the Letter to the Editor: Quantitative accuracy of virtual monoenergetic images from multi-energy CT.

    Greffier, Joel / Yagil, Yoad / Erhard, Klaus / Douek, Philippe C / Si-Mohamed, Salim A

    European radiology

    2023  

    Language English
    Publishing date 2023-11-07
    Publishing country Germany
    Document type Letter
    ZDB-ID 1085366-2
    ISSN 1432-1084 ; 0938-7994 ; 1613-3749
    ISSN (online) 1432-1084
    ISSN 0938-7994 ; 1613-3749
    DOI 10.1007/s00330-023-10286-y
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Image quality improvement of a one-step spectral CT reconstruction on a prototype photon-counting scanner.

    Rodesch, Pierre-Antoine / Si-Mohamed, Salim A / Lesaint, Jérôme / Douek, Philippe C / Rit, Simon

    Physics in medicine and biology

    2023  Volume 69, Issue 1

    Abstract: ... ...

    Abstract Objective
    MeSH term(s) Humans ; Quality Improvement ; Tomography, X-Ray Computed/methods ; Tomography Scanners, X-Ray Computed ; Algorithms ; Phantoms, Imaging ; Image Processing, Computer-Assisted/methods
    Language English
    Publishing date 2023-12-22
    Publishing country England
    Document type Journal Article
    ZDB-ID 208857-5
    ISSN 1361-6560 ; 0031-9155
    ISSN (online) 1361-6560
    ISSN 0031-9155
    DOI 10.1088/1361-6560/ad11a3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: First Experience With a Whole-Body Spectral Photon-Counting CT Clinical Prototype.

    Si-Mohamed, Salim A / Boccalini, Sara / Villien, Marjorie / Yagil, Yoad / Erhard, Klaus / Boussel, Loic / Douek, Philippe C

    Investigative radiology

    2023  Volume 58, Issue 7, Page(s) 459–471

    Abstract: Abstract: Spectral photon-counting computed tomography (SPCCT) technology holds great promise for becoming the next generation of computed tomography (CT) systems. Its technical characteristics have many advantages over conventional CT imaging. For ... ...

    Abstract Abstract: Spectral photon-counting computed tomography (SPCCT) technology holds great promise for becoming the next generation of computed tomography (CT) systems. Its technical characteristics have many advantages over conventional CT imaging. For example, SPCCT provides better spatial resolution, greater dose efficiency for ultra-low-dose and low-dose protocols, and tissue contrast superior to that of conventional CT. In addition, SPCCT takes advantage of several known approaches in the field of spectral CT imaging, such as virtual monochromatic imaging and material decomposition imaging. In addition, SPCCT takes advantage of a new approach in this field, known as K-edge imaging, which allows specific and quantitative imaging of a heavy atom-based contrast agent. Hence, the high potential of SPCCT systems supports their ongoing investigation in clinical research settings. In this review, we propose an overview of our clinical research experience of a whole-body SPCCT clinical prototype, to give an insight into the potential benefits for clinical human imaging on image quality, diagnostic confidence, and new approaches in spectral CT imaging.
    MeSH term(s) Humans ; Phantoms, Imaging ; Tomography, X-Ray Computed/methods ; Photons ; Tomography Scanners, X-Ray Computed
    Language English
    Publishing date 2023-02-22
    Publishing country United States
    Document type Review ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 80345-5
    ISSN 1536-0210 ; 0020-9996
    ISSN (online) 1536-0210
    ISSN 0020-9996
    DOI 10.1097/RLI.0000000000000965
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Virtual monochromatic images for coronary artery imaging with a spectral photon-counting CT in comparison to dual-layer CT systems: a phantom and a preliminary human study.

    Greffier, Joel / Si-Mohamed, Salim A / Lacombe, Hugo / Labour, Joey / Djabli, Djamel / Boccalini, Sara / Varasteh, Mohammad / Villien, Marjorie / Yagil, Yoad / Erhard, Klaus / Boussel, Loic / Beregi, Jean-Paul / Douek, Philippe C

    European radiology

    2023  Volume 33, Issue 8, Page(s) 5476–5488

    Abstract: 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 ...

    Abstract 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. VMIs from 40 to 90 keV were reconstructed using high-resolution (HR) parameters for EID-DECT and SPCCT (CB and HRB kernels at 0.67 mm slice thickness, respectively). Ultra-high-resolution (UHR) parameters were used in addition to SPCCT (detailed-2 kernel, 0.43 mm slice thickness). Noise-power-spectrum (NPS), task-based transfer function (TTF), and detectability index (d') were computed for 2-mm-diameter lumen detection. In consensus, two radiologists analyzed the quality of the images from 8 patients who underwent coronary CTA on both CT systems.
    Results: For all keV images, f
    Conclusion: HR and UHR-SPCCT images gave greater detectability of the coronary lumen for 40 to 90 keV VMIs compared to two EID-DECT systems, with benefits of higher lumen sharpness and overall quality.
    Key points: • Compared with 2 dual-energy CT systems, spectral photon-counting CT (SPCCT) improved spatial resolution, noise texture, noise magnitude, and detectability of the coronary lumen. • Use of ultra-high-resolution parameters with SPCCT improved spatial resolution and noise texture and provided high detectability of the coronary lumen, despite an increase in noise magnitude. • In eight patients, radiologists found greater overall image quality with SPCCT for all virtual monochromatic images with a greater difference at low keV, compared with dual-energy CT systems.
    MeSH term(s) Humans ; Coronary Vessels/diagnostic imaging ; Tomography, X-Ray Computed/methods ; Phantoms, Imaging ; Heart ; Photons
    Language English
    Publishing date 2023-03-15
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1085366-2
    ISSN 1432-1084 ; 0938-7994 ; 1613-3749
    ISSN (online) 1432-1084
    ISSN 0938-7994 ; 1613-3749
    DOI 10.1007/s00330-023-09529-9
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  5. Article ; Online: Clinical Applications of Photon-counting CT: A Review of Pioneer Studies and a Glimpse into the Future.

    Douek, Philippe C / Boccalini, Sara / Oei, Edwin H G / Cormode, David P / Pourmorteza, Amir / Boussel, Loic / Si-Mohamed, Salim A / Budde, Ricardo P J

    Radiology

    2023  Volume 309, Issue 1, Page(s) e222432

    Abstract: CT systems equipped with photon-counting detectors (PCDs), referred to as photon-counting CT (PCCT), are beginning to change imaging in several subspecialties, such as cardiac, vascular, thoracic, and musculoskeletal radiology. Evidence has been building ...

    Abstract CT systems equipped with photon-counting detectors (PCDs), referred to as photon-counting CT (PCCT), are beginning to change imaging in several subspecialties, such as cardiac, vascular, thoracic, and musculoskeletal radiology. Evidence has been building in the literature underpinning the many advantages of PCCT for different clinical applications. These benefits derive from the distinct features of PCDs, which are made of semiconductor materials capable of converting photons directly into electric signal. PCCT advancements include, among the most important, improved spatial resolution, noise reduction, and spectral properties. PCCT spatial resolution on the order of 0.25 mm allows for the improved visualization of small structures (eg, small vessels, arterial walls, distal bronchi, and bone trabeculations) and their pathologies, as well as the identification of previously undetectable anomalies. In addition, blooming artifacts from calcifications, stents, and other dense structures are reduced. The benefits of the spectral capabilities of PCCT are broad and include reducing radiation and contrast material dose for patients. In addition, multiple types of information can be extracted from a single data set (ie, multiparametric imaging), including quantitative data often regarded as surrogates of functional information (eg, lung perfusion). PCCT also allows for a novel type of CT imaging, K-edge imaging. This technique, combined with new contrast materials specifically designed for this modality, opens the door to new applications for imaging in the future.
    MeSH term(s) Humans ; Tomography, X-Ray Computed ; Arteries ; Artifacts ; Bronchi ; Contrast Media
    Chemical Substances Contrast Media
    Language English
    Publishing date 2023-10-03
    Publishing country United States
    Document type Journal Article ; Review ; Research Support, Non-U.S. Gov't
    ZDB-ID 80324-8
    ISSN 1527-1315 ; 0033-8419
    ISSN (online) 1527-1315
    ISSN 0033-8419
    DOI 10.1148/radiol.222432
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  6. Article: MultiHance in MRA of peripheral vasculature.

    Douek, Philippe C

    European radiology

    2008  Volume 15 Suppl 5, Page(s) E17–23

    Abstract: Magnetic resonance angiography (MRA) is a cost effective technique able to detect and quantify stenoses, provide sub-millimeter resolution with full arterial coverage, and show true vessel delineation without artifacts.The quality of images obtained with ...

    Abstract Magnetic resonance angiography (MRA) is a cost effective technique able to detect and quantify stenoses, provide sub-millimeter resolution with full arterial coverage, and show true vessel delineation without artifacts.The quality of images obtained with gadolinium-enhanced MRA depends on the gradient system, coil, sequence design, and contrast agent (volume, dose and injection rate). MRA protocols are evolving from standard k-space sampling (linear from the periphery or the center) to elliptic centric view ordering and to time-resolved MRA. Finally, the gadolinium-based contrast agent Gd-BOPTA (gadobenate dimeglumine, MultiHance; Bracco Imaging, Milan, Italy) offers considerably greater imaging efficacy compared to conventional gadolinium chelates,because identical results can be obtained at lower doses. In conclusion, MRA of the peripheral vasculature is a simple and fast technique, which permits evaluation of a large field of view without risk of radiation exposure.
    MeSH term(s) Contrast Media ; Humans ; Image Interpretation, Computer-Assisted ; Magnetic Resonance Angiography/methods ; Meglumine/analogs & derivatives ; Organometallic Compounds ; Peripheral Vascular Diseases/diagnosis
    Chemical Substances Contrast Media ; Organometallic Compounds ; gadobenic acid (15G12L5X8K) ; Meglumine (6HG8UB2MUY)
    Language English
    Publishing date 2008-07-11
    Publishing country Germany
    Document type Journal Article ; Review
    ZDB-ID 1085366-2
    ISSN 1432-1084 ; 0938-7994 ; 1613-3749
    ISSN (online) 1432-1084
    ISSN 0938-7994 ; 1613-3749
    DOI 10.1007/s10406-005-0162-1
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  7. Article ; Online: Gadolinium K-edge angiography with a spectral photon counting CT in atherosclerotic rabbits.

    Boccalini, Sara / Dessouky, Riham / Rodesch, Pierre-Antoine / Lacombe, Hugo / Yagil, Yoad / Lahoud, Elias / Erhard, Klaus / Brendel, Bernhard / Coulon, Philippe / Langlois, Jean-Baptiste / Chaput, Frederic / Parola, Stephane / Boussel, Loic / Lerouge, Frederic / Si-Mohamed, Salim / Douek, Philippe C

    Diagnostic and interventional imaging

    2023  Volume 104, Issue 10, Page(s) 490–499

    Abstract: Purpose: The purpose of this study was to investigate the feasibility of gadolinium-K-edge-angiography (angio-Gd-K-edge) with gadolinium-based contrast agents (GBCAs) as obtained with spectral photon counting CT (SPCCT) in atherosclerotic rabbits.: ... ...

    Abstract Purpose: The purpose of this study was to investigate the feasibility of gadolinium-K-edge-angiography (angio-Gd-K-edge) with gadolinium-based contrast agents (GBCAs) as obtained with spectral photon counting CT (SPCCT) in atherosclerotic rabbits.
    Materials and methods: Seven atherosclerotic rabbits underwent angio-SPCCT acquisitions with two GBCAs, with similar intravenous injection protocol. Conventional and angio-Gd-K-edge images were reconstructed with the same parameters. Regions of interest were traced in different locations of the aorta and its branches. Hounsfield unit values, Gd concentrations, signal-to-noise (SNR) and contrast-to-noise (CNR) were calculated and compared. The maximum diameter and the diameter of the aorta in regard to atherosclerotic plaques were measured by two observers. Images were subjectively evaluated regarding vessels' enhancement, artefacts, border sharpness and overall image quality.
    Results: In the analyzable six rabbits, Gd-K-edge allowed visualization of target vessels and no other structures. HU values and Gd concentrations were greatest in the largest artery (descending aorta, 5.6 ± 0.8 [SD] mm), and lowest in the smallest (renal arteries, 2.1 ± 0.3 mm). While greater for conventional images, CNR and SNR were satisfactory for both images (all P < 0.001). For one observer there were no statistically significant differences in either maximum or plaque-diameters (P = 0.45 and all P > 0.05 in post-hoc analysis, respectively). For the second observer, there were no significant differences for images reconstructed with the same parameters (all P < 0.05). All subjective criteria scored higher for conventional images compared to K-edge (all P < 0.01), with the highest scores for enhancement (4.3-4.4 vs. 3.1-3.4).
    Conclusion: With SPCCT, angio-Gd-K-edge after injection of GBCAs in atherosclerotic rabbits is feasible and allows for angiography-like visualization of small arteries and for the reliable measurement of their diameters.
    MeSH term(s) Animals ; Rabbits ; Gadolinium ; Tomography, X-Ray Computed/methods ; Angiography ; Contrast Media ; Abdomen
    Chemical Substances Gadolinium (AU0V1LM3JT) ; Contrast Media
    Language English
    Publishing date 2023-05-27
    Publishing country France
    Document type Journal Article
    ZDB-ID 2648283-6
    ISSN 2211-5684 ; 2211-5684
    ISSN (online) 2211-5684
    ISSN 2211-5684
    DOI 10.1016/j.diii.2023.05.002
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  8. Article: MultiHance in MRA of peripheral vasculature.

    Douek, Philippe C

    European radiology

    2004  Volume 14 Suppl 7, Page(s) O55–60; discussion O61–2

    MeSH term(s) Angiography, Digital Subtraction/methods ; Aorta, Abdominal/pathology ; Contrast Media/administration & dosage ; Foot/blood supply ; Foot/pathology ; Humans ; Image Processing, Computer-Assisted/methods ; Leg/blood supply ; Leg/pathology ; Magnetic Resonance Angiography/methods ; Meglumine/analogs & derivatives ; Organometallic Compounds ; Peripheral Vascular Diseases/diagnosis ; Sensitivity and Specificity ; Signal Processing, Computer-Assisted
    Chemical Substances Contrast Media ; Organometallic Compounds ; gadobenic acid (15G12L5X8K) ; Meglumine (6HG8UB2MUY)
    Language English
    Publishing date 2004-10-21
    Publishing country Germany
    Document type Journal Article ; Review
    ZDB-ID 1085366-2
    ISSN 1432-1084 ; 0938-7994 ; 1613-3749
    ISSN (online) 1432-1084
    ISSN 0938-7994 ; 1613-3749
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  9. Article ; Online: Early Prediction of Cardiac Complications in Acute Myocarditis by Means of Extracellular Volume Quantification With the Use of Dual-Energy Computed Tomography.

    Si-Mohamed, Salim A / Congi, Anaelle / Ziegler, Arthur / Tomasevic, Danka / Tatard-Leitman, Valerie / Broussaud, Thomas / Boccalini, Sara / Bensalah, Mourad / Rouvière, Anne-Sophie / Bonnefoy-Cudraz, Eric / Bochaton, Thomas / Boussel, Loic / Douek, Philippe C

    JACC. Cardiovascular imaging

    2021  Volume 14, Issue 10, Page(s) 2041–2042

    MeSH term(s) Acute Disease ; Heart Diseases ; Humans ; Myocarditis/diagnostic imaging ; Predictive Value of Tests ; Tomography, X-Ray Computed
    Language English
    Publishing date 2021-05-19
    Publishing country United States
    Document type Letter
    ZDB-ID 2491503-8
    ISSN 1876-7591 ; 1936-878X
    ISSN (online) 1876-7591
    ISSN 1936-878X
    DOI 10.1016/j.jcmg.2021.04.008
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  10. Article ; Online: "Dark-blood" dual-energy computed tomography angiography for thoracic aortic wall imaging.

    Rotzinger, David C / Si-Mohamed, Salim A / Shapira, Nadav / Douek, Philippe C / Meuli, Reto A / Boussel, Loïc

    European radiology

    2019  Volume 30, Issue 1, Page(s) 425–431

    Abstract: Objectives: To assess the capability of a newly developed material decomposition method from contrast-enhanced dual-energy CT images, aiming to better visualize the aortic wall and aortic intramural hematoma (IMH), compared with true non-contrast (TNC) ... ...

    Abstract Objectives: To assess the capability of a newly developed material decomposition method from contrast-enhanced dual-energy CT images, aiming to better visualize the aortic wall and aortic intramural hematoma (IMH), compared with true non-contrast (TNC) CT.
    Materials and methods: Twenty-two patients (11 women; mean age, 61 ± 20 years) with acute chest pain underwent 25 dual-layer non-contrast and contrast-enhanced CT. CT-angiography images were retrospectively processed using two-material decomposition analysis, where we defined the first material as the content of a region of interest placed in the ascending aorta for each patient, and the second material as water. Two independent radiologists assessed the images from the second material termed "dark-blood" images and the TNC images regarding contrast-to-noise ratio (CNR) between the wall and the lumen, diagnostic quality regarding the presence of aortic wall thickening, and the inner/outer vessel wall conspicuity.
    Results: Diagnostic quality scores in normal aortic segments were 0.9 ± 0.3 and 2.7 ± 0.6 (p < 0.001) and wall conspicuity scores were 0.7 ± 0.5 and 1.8 ± 0.3 (p < 0.001) on TNC and dark-blood images, respectively. In aortic segments with IMH, diagnostic quality scores were 1.7 ± 0.5 and 2.4 ± 0.6 (p < 0.001) and wall conspicuity scores were 0.7 ± 0.7 and 1.8 ± 0.3 (p < 0.001) on TNC and dark-blood images, respectively. In normal aortic segments, CNRs were 0.3 ± 0.2 and 2.8 ± 0.9 on TNC and dark-blood images, respectively (p < 0.001). In aortic segments with IMH, CNRs were 0.3 ± 0.2 and 4.0 ± 1.0 on TNC and dark-blood images, respectively (p < 0.001).
    Conclusions: Compared with true non-contrast CT, dark-blood material decomposition maps enhance quantitative and qualitative image quality for the assessment of normal aortic wall and IMH.
    Key points: • Current dual-energy CT-angiography provides virtual non-contrast and bright-blood images. • Dark-blood images represent a new way to assess the vascular wall structure with dual-energy CT and can improve the lumen-to-wall contrast compared with true non-contrast CT. • This dual-energy CT material decomposition method is likely to improve contrast resolution in other applications as well, taking advantage of the high spatial resolution of CT.
    MeSH term(s) Adult ; Aged ; Aged, 80 and over ; Aorta, Thoracic/diagnostic imaging ; Aortic Diseases/diagnostic imaging ; Computed Tomography Angiography/methods ; Contrast Media ; Feasibility Studies ; Female ; Hematoma/diagnostic imaging ; Humans ; Male ; Middle Aged ; Radiographic Image Interpretation, Computer-Assisted/methods ; Reproducibility of Results ; Retrospective Studies ; Sensitivity and Specificity ; Tomography, X-Ray Computed/methods
    Chemical Substances Contrast Media
    Language English
    Publishing date 2019-07-22
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1085366-2
    ISSN 1432-1084 ; 0938-7994 ; 1613-3749
    ISSN (online) 1432-1084
    ISSN 0938-7994 ; 1613-3749
    DOI 10.1007/s00330-019-06336-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

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