1
|
Pallasch FB, Rau A, Reisert M, Rau S, Diallo T, Stein T, Faby S, Bamberg F, Weiss J. Photon-counting detector computed tomography for metal artifact reduction: a comparative study of different artifact reduction techniques in patients with orthopedic implants. LA RADIOLOGIA MEDICA 2024; 129:890-900. [PMID: 38689182 PMCID: PMC11168992 DOI: 10.1007/s11547-024-01822-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 04/16/2024] [Indexed: 05/02/2024]
Abstract
PURPOSE Artifacts caused by metallic implants remain a challenge in computed tomography (CT). We investigated the impact of photon-counting detector computed tomography (PCD-CT) for artifact reduction in patients with orthopedic implants with respect to image quality and diagnostic confidence using different artifact reduction approaches. MATERIAL AND METHODS In this prospective study, consecutive patients with orthopedic implants underwent PCD-CT imaging of the implant area. Four series were reconstructed for each patient (clinical standard reconstruction [PCD-CTStd], monoenergetic images at 140 keV [PCD-CT140keV], iterative metal artifact reduction (iMAR) corrected [PCD-CTiMAR], combination of iMAR and 140 keV monoenergetic [PCD-CT140keV+iMAR]). Subsequently, three radiologists evaluated the reconstructions in a random and blinded manner for image quality, artifact severity, anatomy delineation (adjacent and distant), and diagnostic confidence using a 5-point Likert scale (5 = excellent). In addition, the coefficient of variation [CV] and the relative quantitative artifact reduction potential were obtained as objective measures. RESULTS We enrolled 39 patients with a mean age of 67.3 ± 13.2 years (51%; n = 20 male) and a mean BMI of 26.1 ± 4 kg/m2. All image quality measures and diagnostic confidence were significantly higher for the iMAR vs. non-iMAR reconstructions (all p < 0.001). No significant effect of the different artifact reduction approaches on CV was observed (p = 0.26). The quantitative analysis indicated the most effective artifact reduction for the iMAR reconstructions, which was higher than PCD-CT140keV (p < 0.001). CONCLUSION PCD-CT allows for effective metal artifact reduction in patients with orthopedic implants, resulting in superior image quality and diagnostic confidence with the potential to improve patient management and clinical decision making.
Collapse
Affiliation(s)
- Fabian Bernhard Pallasch
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany.
| | - Alexander Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Marco Reisert
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Stephan Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thierno Diallo
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thomas Stein
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Sebastian Faby
- Siemens Healthcare GmbH, Siemensstr. 3, 91301, Forchheim, Germany
| | - Fabian Bamberg
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Jakob Weiss
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| |
Collapse
|
2
|
Pallasch FB, Rau A, Reisert M, Rau S, Diallo T, Stein T, Faby S, Bamberg F, Weiss J. Impact of different metal artifact reduction techniques in photon-counting computed tomography head and neck scans in patients with dental hardware. Eur Radiol 2024; 34:3742-3749. [PMID: 37968474 PMCID: PMC11166854 DOI: 10.1007/s00330-023-10430-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 09/18/2023] [Accepted: 10/02/2023] [Indexed: 11/17/2023]
Abstract
OBJECTIVES Metal artifacts remain a challenge in computed tomography. We investigated the potential of photon-counting computed tomography (PCD-CT) for metal artifact reduction using an iterative metal artifact reduction (iMAR) algorithm alone and in combination with high keV monoenergetic images (140 keV) in patients with dental hardware. MATERIAL AND METHODS Consecutive patients with dental implants were prospectively included in this study and received PCD-CT imaging of the craniofacial area. Four series were reconstructed (standard [PCD-CTstd], monoenergetic at 140 keV [PCD-CT140keV], iMAR corrected [PCD-CTiMAR], combination of iMAR and 140 keV monoenergetic [PCD-CTiMAR+140keV]). All reconstructions were assessed qualitatively by four radiologists (independent and blinded reading on a 5-point Likert scale [5 = excellent; no artifact]) regarding overall image quality, artifact severity, and delineation of adjacent and distant anatomy. To assess signal homogeneity and evaluate the magnitude of artifact reduction, we performed quantitative measures of coefficient of variation (CV) and a region of interest (ROI)-based relative change in artifact reduction [PCD-CT/PCD-CTstd]. RESULTS We enrolled 48 patients (mean age 66.5 ± 11.2 years, 50% (n = 24) males; mean BMI 25.2 ± 4.7 kg/m2; mean CTDIvol 6.2 ± 6 mGy). We found improved overall image quality, reduced artifacts and superior delineation of both adjacent and distant anatomy for the iMAR vs. non-iMAR reconstructions (all p < 0.001). No significant effect of the different artifact reduction approaches on CV was observed (p = 0.42). The ROI-based analysis indicated the most effective artifact reduction for the iMAR reconstructions, which was significantly higher compared to PCD-CT140keV (p < 0.001). CONCLUSION PCD-CT offers highly effective approaches for metal artifact reduction with the potential to overcome current diagnostic challenges in patients with dental implants. CLINICAL RELEVANCE STATEMENT Metallic artifacts pose a significant challenge in CT imaging, potentially leading to missed findings. Our study shows that PCD-CT with iMAR post-processing reduces artifacts, improves image quality, and can possibly reveal pathologies previously obscured by artifacts, without additional dose application. KEY POINTS • Photon-counting detector CT (PCD-CT) offers highly effective approaches for metal artifact reduction in patients with dental fillings/implants. • Iterative metal artifact reduction (iMAR) is superior to high keV monoenergetic reconstructions at 140 keV for artifact reduction and provides higher image quality. • Signal homogeneity of the reconstructed images is not affected by the different artifact reduction techniques.
Collapse
Affiliation(s)
- Fabian Bernhard Pallasch
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany.
| | - Alexander Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Marco Reisert
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Stephan Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thierno Diallo
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thomas Stein
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Sebastian Faby
- Siemens Healthcare GmbH, Siemensstr. 3, 91301, Forchheim, Germany
| | - Fabian Bamberg
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Jakob Weiss
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| |
Collapse
|
3
|
Cau R, Saba L, Balestrieri A, Meloni A, Mannelli L, La Grutta L, Bossone E, Mantini C, Politi C, Suri JS, Cavaliere C, Punzo B, Maffei E, Cademartiri F. Photon-Counting Computed Tomography in Atherosclerotic Plaque Characterization. Diagnostics (Basel) 2024; 14:1065. [PMID: 38893593 PMCID: PMC11172199 DOI: 10.3390/diagnostics14111065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/02/2024] [Accepted: 05/16/2024] [Indexed: 06/21/2024] Open
Abstract
Atherosclerotic plaque buildup in the coronary and carotid arteries is pivotal in the onset of acute myocardial infarctions or cerebrovascular events, leading to heightened levels of illness and death. Atherosclerosis is a complex and multistep disease, beginning with the deposition of low-density lipoproteins in the arterial intima and culminating in plaque rupture. Modern technology favors non-invasive imaging techniques to assess atherosclerotic plaque and offer insights beyond mere artery stenosis. Among these, computed tomography stands out for its widespread clinical adoption and is prized for its speed and accessibility. Nonetheless, some limitations persist. The introduction of photon-counting computed tomography (PCCT), with its multi-energy capabilities, enhanced spatial resolution, and superior soft tissue contrast with minimal electronic noise, brings significant advantages to carotid and coronary artery imaging, enabling a more comprehensive examination of atherosclerotic plaque composition. This narrative review aims to provide a comprehensive overview of the main concepts related to PCCT. Additionally, we aim to explore the existing literature on the clinical application of PCCT in assessing atherosclerotic plaque. Finally, we will examine the advantages and limitations of this recently introduced technology.
Collapse
Affiliation(s)
- Riccardo Cau
- Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.) di Cagliari-Polo di Monserrato, S.S. 554, 09045 Monserrato, Italy; (R.C.); (A.B.); (C.P.)
| | - Luca Saba
- Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.) di Cagliari-Polo di Monserrato, S.S. 554, 09045 Monserrato, Italy; (R.C.); (A.B.); (C.P.)
| | - Antonella Balestrieri
- Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.) di Cagliari-Polo di Monserrato, S.S. 554, 09045 Monserrato, Italy; (R.C.); (A.B.); (C.P.)
| | - Antonella Meloni
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy; (A.M.); (F.C.)
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Lorenzo Mannelli
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy; (L.M.); (C.C.); (B.P.); (E.M.)
| | - Ludovico La Grutta
- Department of Radiology, University Hospital “P. Giaccone”, 90127 Palermo, Italy;
| | - Eduardo Bossone
- Cardiology Unit, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Cesare Mantini
- Department of Neuroscience, Imaging and Clinical Sciences, “G.d’Annunzio” University, 66100 Chieti, Italy;
| | - Carola Politi
- Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.) di Cagliari-Polo di Monserrato, S.S. 554, 09045 Monserrato, Italy; (R.C.); (A.B.); (C.P.)
| | - Jasjit S. Suri
- Stroke Monitoring and Diagnostic Division, AtheroPoint™, Roseville, CA 95661, USA;
| | - Carlo Cavaliere
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy; (L.M.); (C.C.); (B.P.); (E.M.)
| | - Bruna Punzo
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy; (L.M.); (C.C.); (B.P.); (E.M.)
| | - Erica Maffei
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy; (L.M.); (C.C.); (B.P.); (E.M.)
| | - Filippo Cademartiri
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy; (A.M.); (F.C.)
| |
Collapse
|
4
|
Meloni A, Maffei E, Clemente A, De Gori C, Occhipinti M, Positano V, Berti S, La Grutta L, Saba L, Cau R, Bossone E, Mantini C, Cavaliere C, Punzo B, Celi S, Cademartiri F. Spectral Photon-Counting Computed Tomography: Technical Principles and Applications in the Assessment of Cardiovascular Diseases. J Clin Med 2024; 13:2359. [PMID: 38673632 PMCID: PMC11051476 DOI: 10.3390/jcm13082359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
Spectral Photon-Counting Computed Tomography (SPCCT) represents a groundbreaking advancement in X-ray imaging technology. The core innovation of SPCCT lies in its photon-counting detectors, which can count the exact number of incoming x-ray photons and individually measure their energy. The first part of this review summarizes the key elements of SPCCT technology, such as energy binning, energy weighting, and material decomposition. Its energy-discriminating ability represents the key to the increase in the contrast between different tissues, the elimination of the electronic noise, and the correction of beam-hardening artifacts. Material decomposition provides valuable insights into specific elements' composition, concentration, and distribution. The capability of SPCCT to operate in three or more energy regimes allows for the differentiation of several contrast agents, facilitating quantitative assessments of elements with specific energy thresholds within the diagnostic energy range. The second part of this review provides a brief overview of the applications of SPCCT in the assessment of various cardiovascular disease processes. SPCCT can support the study of myocardial blood perfusion and enable enhanced tissue characterization and the identification of contrast agents, in a manner that was previously unattainable.
Collapse
Affiliation(s)
- Antonella Meloni
- Bioengineering Unit, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.)
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Erica Maffei
- Department of Radiology, Istituto di Ricovero e Cura a Carattere Scientifico SYNLAB SDN, 80131 Naples, Italy; (E.M.); (C.C.); (B.P.)
| | - Alberto Clemente
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Carmelo De Gori
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Mariaelena Occhipinti
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Vicenzo Positano
- Bioengineering Unit, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.)
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Sergio Berti
- Diagnostic and Interventional Cardiology Department, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Ludovico La Grutta
- Department of Radiology, University Hospital “P. Giaccone”, 90127 Palermo, Italy;
| | - Luca Saba
- Department of Radiology, University Hospital of Cagliari, 09042 Monserrato (CA), Italy; (L.S.); (R.C.)
| | - Riccardo Cau
- Department of Radiology, University Hospital of Cagliari, 09042 Monserrato (CA), Italy; (L.S.); (R.C.)
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy;
| | - Cesare Mantini
- Department of Radiology, “G. D’Annunzio” University, 66100 Chieti, Italy;
| | - Carlo Cavaliere
- Department of Radiology, Istituto di Ricovero e Cura a Carattere Scientifico SYNLAB SDN, 80131 Naples, Italy; (E.M.); (C.C.); (B.P.)
| | - Bruna Punzo
- Department of Radiology, Istituto di Ricovero e Cura a Carattere Scientifico SYNLAB SDN, 80131 Naples, Italy; (E.M.); (C.C.); (B.P.)
| | - Simona Celi
- BioCardioLab, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Filippo Cademartiri
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| |
Collapse
|
5
|
Shami A, Sun J, Gialeli C, Markstad H, Edsfeldt A, Aurumskjöld ML, Gonçalves I. Atherosclerotic plaque features relevant to rupture-risk detected by clinical photon-counting CT ex vivo: a proof-of-concept study. Eur Radiol Exp 2024; 8:14. [PMID: 38286959 PMCID: PMC10825079 DOI: 10.1186/s41747-023-00410-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 11/12/2023] [Indexed: 01/31/2024] Open
Abstract
BACKGROUND To identify subjects with rupture-prone atherosclerotic plaques before thrombotic events occur is an unmet clinical need. Thus, this proof-of-concept study aims to determine which rupture-prone plaque features can be detected using clinically available photon-counting computed tomography (PCCT). METHODS In this retrospective study, advanced atherosclerotic plaques (ex vivo, paraffin-embedded) from the Carotid Plaque Imaging Project were scanned by PCCT with reconstructed energy levels (45, 70, 120, 190 keV). Density in HU was measured in 97 regions of interest (ROIs) representing rupture-prone plaque features as demonstrated by histopathology (thrombus, lipid core, necrosis, fibrosis, intraplaque haemorrhage, calcium). The relationship between HU and energy was then assessed using a mixed-effects model for each plaque feature. RESULTS Plaques from five men (age 79 ± 8 [mean ± standard deviation]) were included in the study. Comparing differences in coefficients (b1diff) of matched ROIs on plaque images obtained by PCCT and histology confirmed that calcium was distinguishable from all other analysed features. Of greater novelty, additional rupture-prone plaque features proved discernible from each other, particularly when comparing haemorrhage with fibrous cap (p = 0.017), lipids (p = 0.003) and necrosis (p = 0.004) and thrombus compared to fibrosis (p = 0.048), fibrous cap (p = 0.028), lipids (p = 0.015) and necrosis (p = 0.017). CONCLUSIONS Clinically available PCCT detects not only calcification, but also other rupture-prone features of human carotid plaques ex vivo. RELEVANCE STATEMENT Improved atherosclerotic plaque characterisation by photon-counting CT provides the ability to distinguish not only calcium, but also rupture-prone plaque features such as haemorrhage and thrombus. This may potentially improve monitoring and risk stratification of atherosclerotic patients in order to prevent strokes. KEY POINTS • CT of atherosclerotic plaques mainly detects calcium. • Many components, such as intra-plaque haemorrhage and lipids, determine increased plaque rupture risk. • Ex vivo carotid plaque photon-counting CT distinguishes haemorrhage and thrombus. • Improved plaque photon-counting CT evaluation may refine risk stratification accuracy to prevent strokes.
Collapse
Affiliation(s)
- Annelie Shami
- Department of Clinical Sciences Malmö, Lund University, Clinical Research Center, Jan Waldenströms Gata 35, CRC 91:12, 214 28, Malmö, Sweden.
| | - Jiangming Sun
- Department of Clinical Sciences Malmö, Lund University, Clinical Research Center, Jan Waldenströms Gata 35, CRC 91:12, 214 28, Malmö, Sweden
| | - Chrysostomi Gialeli
- Department of Clinical Sciences Malmö, Lund University, Clinical Research Center, Jan Waldenströms Gata 35, CRC 91:12, 214 28, Malmö, Sweden
| | - Hanna Markstad
- Department of Clinical Sciences Malmö, Lund University, Clinical Research Center, Jan Waldenströms Gata 35, CRC 91:12, 214 28, Malmö, Sweden
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund/Malmö, Sweden
| | - Andreas Edsfeldt
- Department of Clinical Sciences Malmö, Lund University, Clinical Research Center, Jan Waldenströms Gata 35, CRC 91:12, 214 28, Malmö, Sweden
- Department of Cardiology, Malmö, Skåne University Hospital, Lund University, Lund, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Marie-Louise Aurumskjöld
- Department of Clinical Sciences Malmö, Medical Radiation Physics, Skåne University Hospital, Lund University, 205 02, Malmö, Sweden
- Department of Hematology, Oncology and Radiation Physics, Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Isabel Gonçalves
- Department of Clinical Sciences Malmö, Lund University, Clinical Research Center, Jan Waldenströms Gata 35, CRC 91:12, 214 28, Malmö, Sweden
- Department of Cardiology, Malmö, Skåne University Hospital, Lund University, Lund, Sweden
| |
Collapse
|
6
|
Saba L, Scicolone R, Johansson E, Nardi V, Lanzino G, Kakkos SK, Pontone G, Annoni AD, Paraskevas KI, Fox AJ. Quantifying Carotid Stenosis: History, Current Applications, Limitations, and Potential: How Imaging Is Changing the Scenario. Life (Basel) 2024; 14:73. [PMID: 38255688 PMCID: PMC10821425 DOI: 10.3390/life14010073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 12/24/2023] [Accepted: 12/29/2023] [Indexed: 01/24/2024] Open
Abstract
Carotid artery stenosis is a major cause of morbidity and mortality. The journey to understanding carotid disease has developed over time and radiology has a pivotal role in diagnosis, risk stratification and therapeutic management. This paper reviews the history of diagnostic imaging in carotid disease, its evolution towards its current applications in the clinical and research fields, and the potential of new technologies to aid clinicians in identifying the disease and tailoring medical and surgical treatment.
Collapse
Affiliation(s)
- Luca Saba
- Department of Radiology, University of Cagliari, 09042 Cagliari, Italy;
| | - Roberta Scicolone
- Department of Radiology, University of Cagliari, 09042 Cagliari, Italy;
| | - Elias Johansson
- Neuroscience and Physiology, Sahlgrenska Academy, 41390 Gothenburg, Sweden;
| | - Valentina Nardi
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55905, USA;
| | - Giuseppe Lanzino
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA;
| | - Stavros K. Kakkos
- Department of Vascular Surgery, University of Patras, 26504 Patras, Greece;
| | - Gianluca Pontone
- Centro Cardiologico Monzino IRCCS, Via C. Parea 4, 20138 Milan, Italy; (G.P.); (A.D.A.)
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, 20122 Milan, Italy
| | - Andrea D. Annoni
- Centro Cardiologico Monzino IRCCS, Via C. Parea 4, 20138 Milan, Italy; (G.P.); (A.D.A.)
| | | | - Allan J. Fox
- Department of Medical Imaging, Neuroradiology Section, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON M4N 3M5, Canada;
| |
Collapse
|
7
|
Sakai Y, Cao Q, Rubin J, Witsch J, Cohen‐Addad D, de Macedo Rodrigues K, Coco‐Martin MB, Pasyar P, Juega J, Fan Z, Kasner SE, Cucchiara BL, Song JW. Imaging Biomarkers and Prevalence of Complex Aortic Plaque in Cryptogenic Stroke: A Systematic Review. J Am Heart Assoc 2023; 12:e031797. [PMID: 38014682 PMCID: PMC10727354 DOI: 10.1161/jaha.123.031797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/30/2023] [Indexed: 11/29/2023]
Abstract
BACKGROUND Complex aortic plaque (CAP) is a potential embolic source in patients with cryptogenic stroke (CS). We review CAP imaging criteria for transesophageal echocardiogram (TEE), computed tomography angiography (CTA), and magnetic resonance imaging and calculate CAP prevalence in patients with acute CS. METHODS AND RESULTS PubMed and EMBASE databases were searched up to December 2022 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. Two independent reviewers extracted data on study design, imaging techniques, CAP criteria, and prevalence. The Cochrane Collaboration tool and Guideline for Reporting Reliability and Agreement Studies were used to assess risk of bias and reporting completeness, respectively. From 2293 studies, 45 were reviewed for CAP imaging biomarker criteria in patients with acute CS (N=37 TEE; N=9 CTA; N=6 magnetic resonance imaging). Most studies (74%) used ≥4 mm plaque thickness as the imaging criterion for CAP although ≥1 mm (N=1, CTA), ≥5 mm (N=5, TEE), and ≥6 mm (N=2, CTA) were also reported. Additional features included mobility, ulceration, thrombus, protrusions, and assessment of plaque composition. From 23 prospective studies, CAP was detected in 960 of 2778 patients with CS (0.32 [95% CI, 0.24-0.41], I2=94%). By modality, prevalence estimates were 0.29 (95% CI, 0.20-0.40; I2=95%) for TEE; 0.23 (95% CI, 0.15-0.34; I2=87%) for CTA and 0.22 (95% CI, 0.06-0.54; I2=92%) for magnetic resonance imaging. CONCLUSIONS TEE was commonly used to assess CAP in patients with CS. The most common CAP imaging biomarker was ≥4 mm plaque thickness. CAP was observed in one-third of patients with acute CS. However, high study heterogeneity suggests a need for reproducible imaging methods.
Collapse
Affiliation(s)
- Yu Sakai
- Department of RadiologyUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Quy Cao
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Jeremy Rubin
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Jens Witsch
- Department of NeurologyUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Dan Cohen‐Addad
- Department of Radiology and Imaging SciencesEmory UniversityAtlantaGAUSA
| | | | | | - Pouyan Pasyar
- Department of RadiologyUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Jesús Juega
- Department of NeurologyVall d’Hebron University HospitalBarcelonaSpain
| | - Zhaoyang Fan
- Departments of Radiology, Biomedical Engineering, and Radiation OncologyUniversity of Southern CaliforniaLos AngelesCAUSA
| | - Scott E. Kasner
- Department of NeurologyUniversity of PennsylvaniaPhiladelphiaPAUSA
| | | | - Jae W. Song
- Department of RadiologyUniversity of PennsylvaniaPhiladelphiaPAUSA
| |
Collapse
|
8
|
Vattay B, Szilveszter B, Boussoussou M, Vecsey-Nagy M, Lin A, Konkoly G, Kubovje A, Schwarz F, Merkely B, Maurovich-Horvat P, Williams MC, Dey D, Kolossváry M. Impact of virtual monoenergetic levels on coronary plaque volume components using photon-counting computed tomography. Eur Radiol 2023; 33:8528-8539. [PMID: 37488295 PMCID: PMC10667372 DOI: 10.1007/s00330-023-09876-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 03/29/2023] [Accepted: 05/05/2023] [Indexed: 07/26/2023]
Abstract
OBJECTIVES Virtual monoenergetic images (VMIs) from photon-counting CT (PCCT) may change quantitative coronary plaque volumes. We aimed to assess how plaque component volumes change with respect to VMIs. METHODS Coronary CT angiography (CTA) images were acquired using a dual-source PCCT and VMIs were reconstructed between 40 and 180 keV in 10-keV increments. Polychromatic images at 120 kVp (T3D) were used as reference. Quantitative plaque analysis was performed on T3D images and segmentation masks were copied to VMI reconstructions. Calcified plaque (CP; > 350 Hounsfield units, HU), non-calcified plaque (NCP; 30 to 350 HU), and low-attenuation NCP (LAP; - 100 to 30 HU) volumes were calculated using fixed thresholds. RESULTS We analyzed 51 plaques from 51 patients (67% male, mean age 65 ± 12 years). Average attenuation and contrast-to-noise ratio (CNR) decreased significantly with increasing keV levels, with similar values observed between T3D and 70 keV images (299 ± 209 vs. 303 ± 225 HU, p = 0.15 for mean HU; 15.5 ± 3.7 vs. 15.8 ± 3.5, p = 0.32 for CNR). Mean NCP volume was comparable between T3D and 100-180-keV reconstructions. There was a monotonic decrease in mean CP volume, with a significant difference between all VMIs and T3D (p < 0.05). LAP volume increased with increasing keV levels and all VMIs showed a significant difference compared to T3D, except for 50 keV (28.0 ± 30.8 mm3 and 28.6 ± 30.1 mm3, respectively, p = 0.63). CONCLUSIONS Estimated coronary plaque volumes significantly differ between VMIs. Normalization protocols are needed to have comparable results between future studies, especially for LAP volume which is currently defined using a fixed HU threshold. CLINICAL RELEVANCE STATEMENT Different virtual monoenergetic images from photon-counting CT alter attenuation values and therefore corresponding plaque component volumes. New clinical standards and protocols are required to determine the optimal thresholds to derive plaque volumes from photon-counting CT. KEY POINTS • Utilizing different VMI energy levels from photon-counting CT for the analysis of coronary artery plaques leads to substantial changes in attenuation values and corresponding plaque component volumes. • Low-energy images (40-70 keV) improved contrast-to-noise ratio, however also increased image noise. • Normalization protocols are needed to have comparable results between future studies, especially for low-attenuation plaque volume which is currently defined using a fixed HU threshold.
Collapse
Affiliation(s)
- Borbála Vattay
- MTA-SE "Lendület" Cardiovascular Imaging Research Group, Semmelweis University Heart and Vascular Center, Városmajor Street 68., 1122, Budapest, Hungary
| | - Bálint Szilveszter
- MTA-SE "Lendület" Cardiovascular Imaging Research Group, Semmelweis University Heart and Vascular Center, Városmajor Street 68., 1122, Budapest, Hungary.
| | - Melinda Boussoussou
- MTA-SE "Lendület" Cardiovascular Imaging Research Group, Semmelweis University Heart and Vascular Center, Városmajor Street 68., 1122, Budapest, Hungary
| | - Milán Vecsey-Nagy
- MTA-SE "Lendület" Cardiovascular Imaging Research Group, Semmelweis University Heart and Vascular Center, Városmajor Street 68., 1122, Budapest, Hungary
| | - Andrew Lin
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, 116 N Robertson Blvd, Suite 400, CA, 90048, Los Angeles, USA
| | - Gábor Konkoly
- MTA-SE "Lendület" Cardiovascular Imaging Research Group, Semmelweis University Heart and Vascular Center, Városmajor Street 68., 1122, Budapest, Hungary
| | - Anikó Kubovje
- Semmelweis University Medical Imaging Center, Korányi Sándor Street 2., 1082, Budapest, Hungary
| | - Florian Schwarz
- Clinic for Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156, Augsburg, Germany
| | - Béla Merkely
- MTA-SE "Lendület" Cardiovascular Imaging Research Group, Semmelweis University Heart and Vascular Center, Városmajor Street 68., 1122, Budapest, Hungary
| | - Pál Maurovich-Horvat
- Semmelweis University Medical Imaging Center, Korányi Sándor Street 2., 1082, Budapest, Hungary
| | - Michelle C Williams
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
| | - Damini Dey
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, 116 N Robertson Blvd, Suite 400, CA, 90048, Los Angeles, USA
| | - Márton Kolossváry
- Gottsegen National Cardiovascular Center, 29 Haller Utca, 1096, Budapest, Hungary.
- Physiological Controls Research Center, University Research and Innovation Center, Óbuda University, Bécsi Út 96/B, 1034, Budapest, Hungary.
| |
Collapse
|
9
|
Csore J, Drake M, Roy TL. Peripheral arterial disease treatment planning using noninvasive and invasive imaging methods. J Vasc Surg Cases Innov Tech 2023; 9:101263. [PMID: 37767348 PMCID: PMC10520537 DOI: 10.1016/j.jvscit.2023.101263] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 06/06/2023] [Indexed: 09/29/2023] Open
Abstract
With the growing prevalence and mortality of peripheral arterial disease, preoperative assessment, risk stratification, and determining the correct indication for endovascular and open surgical procedures are essential for therapeutic decision-making. The effectiveness of interventional procedures is significantly influenced by the plaque composition and calcification pattern. Therefore, the identification of patients for whom endovascular treatment is the most appropriate therapeutic solution often remains a challenge. The most commonly used imaging techniques have their own limitations and do not provide findings detailed enough for specific, personalized treatment planning. Using state-of-the-art noninvasive and invasive imaging modalities, it is now possible to obtain a view, not only of the complex vascular anatomy and plaque burden of the lower extremity arterial system, but also of complex plaque structures and various pathologic calcium distribution patterns. In the future, as these latest advancements in diagnostic methods become more widespread, we will be able to obtain more accurate views of the plaque structure and anatomic complexity to guide optimal treatment planning and device selection. We reviewed the implications of the most recent invasive and noninvasive lower extremity imaging techniques and future directions.
Collapse
Affiliation(s)
- Judit Csore
- DeBakey Heart and Vascular Center, Houston Methodist Hospital, Houston, TX
| | - Madeline Drake
- DeBakey Heart and Vascular Center, Houston Methodist Hospital, Houston, TX
| | - Trisha L. Roy
- DeBakey Heart and Vascular Center, Houston Methodist Hospital, Houston, TX
| |
Collapse
|
10
|
Douek PC, Boccalini S, Oei EHG, Cormode DP, Pourmorteza A, Boussel L, Si-Mohamed SA, Budde RPJ. Clinical Applications of Photon-counting CT: A Review of Pioneer Studies and a Glimpse into the Future. Radiology 2023; 309:e222432. [PMID: 37787672 PMCID: PMC10623209 DOI: 10.1148/radiol.222432] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 03/24/2023] [Accepted: 04/11/2023] [Indexed: 10/04/2023]
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.
Collapse
Affiliation(s)
| | | | - Edwin H. G. Oei
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - David P. Cormode
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Amir Pourmorteza
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Loic Boussel
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Salim A. Si-Mohamed
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Ricardo P. J. Budde
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| |
Collapse
|
11
|
Meloni A, Cademartiri F, Positano V, Celi S, Berti S, Clemente A, La Grutta L, Saba L, Bossone E, Cavaliere C, Punzo B, Maffei E. Cardiovascular Applications of Photon-Counting CT Technology: A Revolutionary New Diagnostic Step. J Cardiovasc Dev Dis 2023; 10:363. [PMID: 37754792 PMCID: PMC10531582 DOI: 10.3390/jcdd10090363] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 09/28/2023] Open
Abstract
Photon-counting computed tomography (PCCT) is an emerging technology that can potentially transform clinical CT imaging. After a brief description of the PCCT technology, this review summarizes its main advantages over conventional CT: improved spatial resolution, improved signal and contrast behavior, reduced electronic noise and artifacts, decreased radiation dose, and multi-energy capability with improved material discrimination. Moreover, by providing an overview of the existing literature, this review highlights how the PCCT benefits have been harnessed to enhance and broaden the diagnostic capabilities of CT for cardiovascular applications, including the detection of coronary artery calcifications, evaluation of coronary plaque extent and composition, evaluation of coronary stents, and assessment of myocardial tissue characteristics and perfusion.
Collapse
Affiliation(s)
- Antonella Meloni
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
- Unità Operativa Complessa di Bioingegneria, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy
| | - Filippo Cademartiri
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
| | - Vicenzo Positano
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
- Unità Operativa Complessa di Bioingegneria, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy
| | - Simona Celi
- BioCardioLab, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Sergio Berti
- Diagnostic and Interventional Cardiology Department, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Alberto Clemente
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
| | - Ludovico La Grutta
- Department of Radiology, University Hospital “P. Giaccone”, 90127 Palermo, Italy;
| | - Luca Saba
- Department of Radiology, University Hospital of Cagliari, 09042 Monserrato, CA, Italy;
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy;
| | - Carlo Cavaliere
- Department of Radiology, Istituto di Ricerca e Cura a Carattere Scientifico SynLab-SDN, 80131 Naples, Italy; (C.C.); (B.P.)
| | - Bruna Punzo
- Department of Radiology, Istituto di Ricerca e Cura a Carattere Scientifico SynLab-SDN, 80131 Naples, Italy; (C.C.); (B.P.)
| | - Erica Maffei
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
| |
Collapse
|
12
|
Healy J, Searle E, Panta RK, Chernoglazov A, Roake J, Butler P, Butler A, Gieseg SP. Ex-vivo atherosclerotic plaque characterization using spectral photon-counting CT: Comparing material quantification to histology. Atherosclerosis 2023; 378:117160. [PMID: 37495488 DOI: 10.1016/j.atherosclerosis.2023.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 07/28/2023]
Abstract
BACKGROUND AND AIMS Atherosclerotic plaques are characterized as being vulnerable to rupture based on a series of histologically defined features, including a lipid-rich necrotic core, spotty calcification and ulceration. Existing imaging modalities have limitations in their ability to distinguish between different materials and structural features. We examined whether X-ray spectral photon-counting computer tomography (SPCCT) images were able to distinguish key plaque features in a surgically excised specimen from the carotid artery with comparison to histological images. METHODS An excised carotid plaque was imaged in the diagnostic X-ray energy range of 30-120 keV using a small-bore SPCCT scanner equipped with a Medipix3RX photon-counting spectral X-ray detector with a cadmium telluride (CdTe) sensor. Material identification and quantification (MIQ) images of the carotid plaque were generated using proprietary MIQ software at 0.09 mm volumetric pixels (voxels). The plaque was sectioned, stained and photographed at high resolution for comparison. RESULTS A lipid-rich core with spotty calcification was identified in the MIQ images and confirmed by histology. MIQ showed a core region containing lipid, with a mean concentration of 260 mg lipid/ml corresponding to a mean value of -22HU. MIQ showed calcified regions with mean concentration of 41 mg Ca/ml corresponded to a mean value of 123HU. An ulceration of the carotid wall at the bifurcation was identified to be lipid-lined, with a small calcification identified near the breach of the artery wall. CONCLUSIONS SPCCT derived material identification and quantification images showed hallmarks of vulnerable plaque including a lipid-rich necrotic core, spotty calcifications and ulcerations.
Collapse
Affiliation(s)
- Joe Healy
- Free Radical Biochemistry Laboratory, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand; MARS Bioimaging Ltd., Christchurch, New Zealand
| | - Emily Searle
- Free Radical Biochemistry Laboratory, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand; MARS Bioimaging Ltd., Christchurch, New Zealand
| | - Raj Kumar Panta
- Department of Radiology, University of Otago, Christchurch, New Zealand; MARS Bioimaging Ltd., Christchurch, New Zealand; European Organization for Nuclear Research (CERN), Geneva, Switzerland
| | | | - Justin Roake
- Department of Surgery, University of Otago, Christchurch, New Zealand
| | - Phil Butler
- Department of Physics and Astronomy, University of Canterbury, New Zealand; MARS Bioimaging Ltd., Christchurch, New Zealand; European Organization for Nuclear Research (CERN), Geneva, Switzerland
| | - Anthony Butler
- Department of Physics and Astronomy, University of Canterbury, New Zealand; Department of Radiology, University of Otago, Christchurch, New Zealand; MARS Bioimaging Ltd., Christchurch, New Zealand; European Organization for Nuclear Research (CERN), Geneva, Switzerland
| | - Steven P Gieseg
- Free Radical Biochemistry Laboratory, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand; Department of Radiology, University of Otago, Christchurch, New Zealand; European Organization for Nuclear Research (CERN), Geneva, Switzerland.
| |
Collapse
|
13
|
Si-Mohamed SA, Boccalini S, Villien M, Yagil Y, Erhard K, Boussel L, Douek PC. First Experience With a Whole-Body Spectral Photon-Counting CT Clinical Prototype. Invest Radiol 2023; 58:459-471. [PMID: 36822663 PMCID: PMC10259214 DOI: 10.1097/rli.0000000000000965] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 01/20/2023] [Indexed: 02/25/2023]
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.
Collapse
Affiliation(s)
- Salim A. Si-Mohamed
- From the University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France
- Department of Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France
| | - Sara Boccalini
- From the University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France
- Department of Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France
| | | | | | | | - Loic Boussel
- From the University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France
- Department of Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France
| | - Philippe C. Douek
- From the University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France
- Department of Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France
| |
Collapse
|
14
|
Cademartiri F, Meloni A, Pistoia L, Degiorgi G, Clemente A, Gori CD, Positano V, Celi S, Berti S, Emdin M, Panetta D, Menichetti L, Punzo B, Cavaliere C, Bossone E, Saba L, Cau R, Grutta LL, Maffei E. Dual-Source Photon-Counting Computed Tomography-Part I: Clinical Overview of Cardiac CT and Coronary CT Angiography Applications. J Clin Med 2023; 12:jcm12113627. [PMID: 37297822 DOI: 10.3390/jcm12113627] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 06/12/2023] Open
Abstract
The photon-counting detector (PCD) is a new computed tomography detector technology (photon-counting computed tomography, PCCT) that provides substantial benefits for cardiac and coronary artery imaging. Compared with conventional CT, PCCT has multi-energy capability, increased spatial resolution and soft tissue contrast with near-null electronic noise, reduced radiation exposure, and optimization of the use of contrast agents. This new technology promises to overcome several limitations of traditional cardiac and coronary CT angiography (CCT/CCTA) including reduction in blooming artifacts in heavy calcified coronary plaques or beam-hardening artifacts in patients with coronary stents, and a more precise assessment of the degree of stenosis and plaque characteristic thanks to its better spatial resolution. Another potential application of PCCT is the use of a double-contrast agent to characterize myocardial tissue. In this current overview of the existing PCCT literature, we describe the strengths, limitations, recent applications, and promising developments of employing PCCT technology in CCT.
Collapse
Affiliation(s)
| | - Antonella Meloni
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Laura Pistoia
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Giulia Degiorgi
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Alberto Clemente
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Carmelo De Gori
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Vincenzo Positano
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Simona Celi
- BioCardioLab, Department of Bioengineering, Fondazione Monasterio/CNR, 54100 Massa, Italy
| | - Sergio Berti
- Cardiology Unit, Ospedale del Cuore, Fondazione Monasterio/CNR, 54100 Massa, Italy
| | - Michele Emdin
- Department of Cardiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Daniele Panetta
- Institute of Clinical Physiology, National Council of Research, 56124 Pisa, Italy
| | - Luca Menichetti
- Institute of Clinical Physiology, National Council of Research, 56124 Pisa, Italy
| | - Bruna Punzo
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy
| | - Carlo Cavaliere
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy
| | - Luca Saba
- Department of Radiology, University Hospital, 09042 Monserrato, Italy
| | - Riccardo Cau
- Department of Radiology, University Hospital, 09042 Monserrato, Italy
| | - Ludovico La Grutta
- Department of Radiology, University Hospital "P. Giaccone", 90127 Palermo, Italy
| | - Erica Maffei
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| |
Collapse
|
15
|
Cademartiri F, Meloni A, Pistoia L, Degiorgi G, Clemente A, De Gori C, Positano V, Celi S, Berti S, Emdin M, Panetta D, Menichetti L, Punzo B, Cavaliere C, Bossone E, Saba L, Cau R, Grutta LL, Maffei E. Dual Source Photon-Counting Computed Tomography-Part II: Clinical Overview of Neurovascular Applications. J Clin Med 2023; 12:jcm12113626. [PMID: 37297821 DOI: 10.3390/jcm12113626] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 06/12/2023] Open
Abstract
Photon-counting detector (PCD) is a novel computed tomography detector technology (photon-counting computed tomography-PCCT) that presents many advantages in the neurovascular field, such as increased spatial resolution, reduced radiation exposure, and optimization of the use of contrast agents and material decomposition. In this overview of the existing literature on PCCT, we describe the physical principles, the advantages and the disadvantages of conventional energy integrating detectors and PCDs, and finally, we discuss the applications of the PCD, focusing specifically on its implementation in the neurovascular field.
Collapse
Affiliation(s)
| | - Antonella Meloni
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Laura Pistoia
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Giulia Degiorgi
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Alberto Clemente
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Carmelo De Gori
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Vincenzo Positano
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Simona Celi
- BioCardioLab, Department of Bioengineering, Fondazione Monasterio/CNR, 54100 Massa, Italy
| | - Sergio Berti
- Cardiology Unit, Ospedale del Cuore, Fondazione Monasterio/CNR, 54100 Massa, Italy
| | - Michele Emdin
- Department of Cardiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Daniele Panetta
- Institute of Clinical Physiology, National Council of Research, 56124 Pisa, Italy
| | - Luca Menichetti
- Institute of Clinical Physiology, National Council of Research, 56124 Pisa, Italy
| | - Bruna Punzo
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy
| | - Carlo Cavaliere
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy
| | - Luca Saba
- Department of Radiology, University Hospital, 09042 Monserrato, Italy
| | - Riccardo Cau
- Department of Radiology, University Hospital, 09042 Monserrato, Italy
| | - Ludovico La Grutta
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties-ProMISE, Department of Radiology, University Hospital "P. Giaccone", 90127 Palermo, Italy
| | - Erica Maffei
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| |
Collapse
|
16
|
Cau R, Gupta A, Kooi ME, Saba L. Pearls and Pitfalls of Carotid Artery Imaging: Ultrasound, Computed Tomography Angiography, and MR Imaging. Radiol Clin North Am 2023; 61:405-413. [PMID: 36931758 DOI: 10.1016/j.rcl.2023.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Stroke represents a major cause of morbidity and mortality worldwide with carotid atherosclerosis responsible for a large proportion of ischemic strokes. Given the high burden of the disease , early diagnosis and optimal secondary prevention are essential elements in clinical practice. For a long time, the degree of stenosis had been considered the parameter to judge the severity of carotid atherosclerosis. Over the last 30 years, literature has shifted attention from stenosis to structural characteristics of atherosclerotic lesion, eventually leading to the "vulnerable plaque" model. These "vulnerable plaques" frequently demonstrate high-risk imaging features that can be assessed by various non-invasive imaging modalities.
Collapse
Affiliation(s)
- Riccardo Cau
- Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato, s.s. 554, Monserrato, Cagliari 09045, Italy
| | - Ajay Gupta
- Department of Radiology Weill Cornell Medical College, New York, NY, USA
| | - Marianne Eline Kooi
- Department of Radiology and Nuclear Medicine, CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Luca Saba
- Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato, s.s. 554, Monserrato, Cagliari 09045, Italy.
| |
Collapse
|
17
|
Photon-Counting Computed Tomography (PCCT): Technical Background and Cardio-Vascular Applications. Diagnostics (Basel) 2023; 13:diagnostics13040645. [PMID: 36832139 PMCID: PMC9955798 DOI: 10.3390/diagnostics13040645] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 01/28/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023] Open
Abstract
Photon-counting computed tomography (PCCT) is a new advanced imaging technique that is going to transform the standard clinical use of computed tomography (CT) imaging. Photon-counting detectors resolve the number of photons and the incident X-ray energy spectrum into multiple energy bins. Compared with conventional CT technology, PCCT offers the advantages of improved spatial and contrast resolution, reduction of image noise and artifacts, reduced radiation exposure, and multi-energy/multi-parametric imaging based on the atomic properties of tissues, with the consequent possibility to use different contrast agents and improve quantitative imaging. This narrative review first briefly describes the technical principles and the benefits of photon-counting CT and then provides a synthetic outline of the current literature on its use for vascular imaging.
Collapse
|
18
|
Hu GQ, Ge YQ, Hu XK, Wei W. Predicting coronary artery calcified plaques using perivascular fat CT radiomics features and clinical risk factors. BMC Med Imaging 2022; 22:134. [PMID: 35906532 PMCID: PMC9338488 DOI: 10.1186/s12880-022-00858-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 07/14/2022] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE The purpose of this study was to develop a combined radiomics model to predict coronary plaque texture using perivascular fat CT radiomics features combined with clinical risk factors. METHODS The data of 200 patients with coronary plaques were retrospectively analyzed and randomly divided into a training group and a validation group at a ratio of 7:3. In the training group, The best feature set was selected by using the maximum correlation minimum redundancy method and the least absolute shrinkage and selection operator. Radiomics models were built based on different machine learning algorithms. The clinical risk factors were then screened using univariate logistic regression analysis. and finally a combined radiomics model was developed using multivariate logistic regression analysis to combine the best performing radiomics model with clinical risk factors and validated in the validation group. The efficacy of the model was assessed by a receiver operating characteristic curve, the consistency of the nomogram was assessed using calibration curves, and the clinical usefulness of the nomogram was assessed using decision curve analysis. RESULTS Twelve radiomics features were used by different machine learning algorithms to construct the radiomics model. Finally, the random forest algorithm built the best radiomics model in terms of efficacy, and this was combined with age to construct a combined radiomics model. The area under curve for the training and validation group were 0.98 (95% confidence interval, 0.95-1.00) and 0.97 (95% confidence interval, 0.92-1.00) with sensitivities of 0.92 and 0.86 and specificities of 0.99 and 1, respectively. The calibration curve demonstrated that the nomogram had good consistency, and the decision curve analysis demonstrated that the nomogram had high clinical utility. CONCLUSIONS The combined radiomics model established based on CT radiomics features and clinical risk factors has high value in predicting coronary artery calcified plaque and can provide a reference for clinical decision-making.
Collapse
Affiliation(s)
- Guo-Qing Hu
- Department of Radiology, The First Affiliated Hospital of USTC, Wannan Medical College, Wuhu, 241002, Anhui, China
| | - Ya-Qiong Ge
- GE Healthcare China, No. 1 Huatuo Road, Pudong New Town, Shanghai, 210000, China
| | - Xiao-Kun Hu
- Department of Radiology, The First Affiliated Hospital of USTC, Wannan Medical College, Wuhu, 241002, Anhui, China
| | - Wei Wei
- Department of Radiology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230001, Anhui, China.
| |
Collapse
|
19
|
Inkinen SI, Juntunen MAK, Ketola J, Korhonen K, Sepponen P, Kotiaho A, Pohjanen VM, Nieminen M. Virtual monochromatic imaging reduces beam hardening artefacts in cardiac interior photon counting computed tomography: a phantom study with cadaveric specimens. Biomed Phys Eng Express 2021; 8. [PMID: 34911047 DOI: 10.1088/2057-1976/ac4397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 12/15/2021] [Indexed: 11/11/2022]
Abstract
In interior cardiac computed tomography (CT) imaging, the x-ray beam is collimated to a limited field-of-view covering the heart volume, which decreases the radiation exposure to surrounding tissues. Spectral CT enables the creation of virtual monochromatic images (VMIs) through a computational material decomposition process. This study investigates the utility of VMIs for beam hardening (BH) reduction in interior cardiac CT, and further, the suitability of VMIs for coronary artery calcium (CAC) scoring and volume assessment is studied using spectral photon counting detector CT (PCD-CT).Ex vivocoronary artery samples (N = 18) were inserted in an epoxy rod phantom. The rod was scanned in the conventional CT geometry, and subsequently, the rod was positioned in a torso phantom and re-measured in the interior PCD-CT geometry. The total energy (TE) 10-100 keV reconstructions from PCD-CT were used as a reference. The low energy 10-60 keV and high energy 60-100 keV data were used to perform projection domain material decomposition to polymethyl methacrylate and calcium hydroxylapatite basis. The truncated basis-material sinograms were extended using the adaptive detruncation method. VMIs from 30-180 keV range were computed from the detruncated virtual monochromatic sinograms using filtered back projection. Detrending was applied as a post-processing method prior to CAC scoring. The results showed that BH artefacts from the exterior structures can be suppressed with high (≥100 keV) VMIs. With appropriate selection of the monoenergy (46 keV), the underestimation trend of CAC scores and volumes shown in Bland-Altman (BA) plots for TE interior PCD-CT was mitigated, as the BA slope values were -0.02 for the 46 keV VMI compared to -0.21 the conventional TE image. To conclude, spectral PCD-CT imaging using VMIs could be applied to reduce BH artefacts interior CT geometry, and further, optimal selection of VMI may improve the accuracy of CAC scoring assessment in interior PCD-CT.
Collapse
Affiliation(s)
- Satu I Inkinen
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland
| | - Mikael A K Juntunen
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Oulu University Hospital, Department of Diagnostic Radiology, Oulu, Finland
| | - Juuso Ketola
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,The South Savo Social and Health Care Authority, Mikkeli Central Hospital, Mikkeli, Finland
| | - Kristiina Korhonen
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland
| | - Pasi Sepponen
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland
| | - Antti Kotiaho
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Oulu University Hospital, Department of Diagnostic Radiology, Oulu, Finland
| | - Vesa-Matti Pohjanen
- Cancer and Translational Medicine Research Unit, Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Miika Nieminen
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Oulu University Hospital, Department of Diagnostic Radiology, Oulu, Finland
| |
Collapse
|
20
|
Spectral Photon-Counting CT Technology in Chest Imaging. J Clin Med 2021; 10:jcm10245757. [PMID: 34945053 PMCID: PMC8704215 DOI: 10.3390/jcm10245757] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/30/2021] [Accepted: 12/02/2021] [Indexed: 12/17/2022] Open
Abstract
The X-ray imaging field is currently undergoing a period of rapid technological innovation in diagnostic imaging equipment. An important recent development is the advent of new X-ray detectors, i.e., photon-counting detectors (PCD), which have been introduced in recent clinical prototype systems, called PCD computed tomography (PCD-CT) or photon-counting CT (PCCT) or spectral photon-counting CT (SPCCT) systems. PCD allows a pixel up to 200 microns pixels at iso-center, which is much smaller than that can be obtained with conventional energy integrating detectors (EID). PCDs have also a higher dose efficiency than EID mainly because of electronic noise suppression. In addition, the energy-resolving capabilities of these detectors allow generating spectral basis imaging, such as the mono-energetic images or the water/iodine material images as well as the K-edge imaging of a contrast agent based on atoms of high atomic number. In recent years, studies have therefore been conducted to determine the potential of PCD-CT as an alternative to conventional CT for chest imaging.
Collapse
|
21
|
Xu C, Yi Y, Han Y, Xie H, Lu X, Vembar M, Leiner T, Jin Z, Wang Y. Incremental improvement of diagnostic performance of coronary CT angiography for the assessment of coronary stenosis in the presence of calcium using a dual-layer spectral detector CT: validation by invasive coronary angiography. Int J Cardiovasc Imaging 2021; 37:2561-2572. [PMID: 34176031 DOI: 10.1007/s10554-021-02205-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 02/22/2021] [Indexed: 01/10/2023]
Abstract
To investigate value of spectral reconstructions for the quantification of coronary stenosis in the presence of calcified or partially calcified plaques using a dual-layer spectral detector CT (SDCT). Seventy-two consecutive patients were retrospectively enrolled. Conventional 120 kVp images, eight virtual monoenergetic images (VMI) (70 to 140 keV), the effective atomic number (Z effective) and iodine no water images were reconstructed. Invasive coronary angiography was used as the reference standard. Parallel and serial testing were used to assess the incremental diagnostic value of Z effective and iodine no water images to the best VMI series. 122 coronary lesions of 72 patients (49 men and 23 women; 63.7 ± 10.2 years) were enrolled in analysis. Reconstruction at 100 keV yielded optimal diagnostic performance, the sensitivity, specificity, PPV, NPV and diagnostic accuracy to identify stenosis ≥ 50% or ≥ 70% were 84%, 70%, 80%, 76%, 79% and 78%, 98%, 93%, 91%, 92%, respectively. A serial combination (100 keV VMI followed by Z effective images) resulted in an improved specificity (from 70 to 80%) with a moderate loss of sensitivity (81% from 84%) in identifying ≥ 50% stenosis (P = 0.021). For patients with high Agatston score, this combination could further reduce false positive cases and improve diagnostic accuracy. 100 keV VMI provide optimal diagnostic performance for the detection of coronary stenosis in the presence of calcified or partially calcified plaques using a dual-layer SDCT, with further improvements obtained with the combined use of Z effective images.
Collapse
Affiliation(s)
- Cheng Xu
- Department of Radiology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College , No.1, Shuaifuyuan, Dongcheng District, Beijing, 100730, China
| | - Yan Yi
- Department of Radiology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College , No.1, Shuaifuyuan, Dongcheng District, Beijing, 100730, China
| | - Yechen Han
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hongzhi Xie
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiaomei Lu
- Clinical Science, Philips Healthcare, Beijing, China
| | - Mani Vembar
- CT Clinical Science, Philips Healthcare, Cleveland, OH, USA
| | - Tim Leiner
- Department of Radiology, University Medical Center of Utrecht, Utrecht, The Netherlands
| | - Zhengyu Jin
- Department of Radiology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College , No.1, Shuaifuyuan, Dongcheng District, Beijing, 100730, China
| | - Yining Wang
- Department of Radiology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College , No.1, Shuaifuyuan, Dongcheng District, Beijing, 100730, China.
| |
Collapse
|
22
|
Si-Mohamed SA, Sigovan M, Hsu JC, Tatard-Leitman V, Chalabreysse L, Naha PC, Garrivier T, Dessouky R, Carnaru M, Boussel L, Cormode DP, Douek PC. In Vivo Molecular K-Edge Imaging of Atherosclerotic Plaque Using Photon-counting CT. Radiology 2021; 300:98-107. [PMID: 33944628 PMCID: PMC8217298 DOI: 10.1148/radiol.2021203968] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Background Macrophage burden is a major factor in the risk of atherosclerotic plaque rupture, and its evaluation remains challenging with molecular noninvasive imaging approaches. Photon-counting CT (PCCT) with k-edge imaging aims to allow for the specific detection of macrophages using gold nanoparticles. Purpose To perform k-edge imaging in combination with gold nanoparticles to detect and quantify the macrophage burden within the atherosclerotic aortas of rabbits. Materials and Methods Atherosclerotic and control New Zealand white rabbits were imaged before and at several time points up to 2 days after intravenous injection of gold nanoparticles (3.5 mL/kg, 65 mg gold per milliliter). Aortic CT angiography was performed at the end of the follow-up using an intravenous injection of an iodinated contrast material. Gold k-edge and conventional CT images were reconstructed for qualitative and quantitative assessment of the macrophage burden. PCCT imaging results were compared with findings at histologic examination, quantitative histomorphometry, transmission electron microscopy, and quantitative inductively coupled plasma optical emission spectrometry. Pearson correlations between the macrophage area measured in immunostained sections and the concentration of gold and attenuation measured in the corresponding PCCT sections were calculated. Results Seven rabbits with atherosclerosis and four control rabbits without atherosclerosis were analyzed. In atherosclerotic rabbits, calcifications were observed along the aortic wall before injection. At 2 days after injection of gold nanoparticles, only gold k-edge images allowed for the distinction of plaque enhancement within calcifications and for lumen enhancement during angiography. A good correlation was observed between the gold concentration measured within the wall and the macrophage area in 35 plaques (five per rabbit) (r = 0.82; 95% CI: 0.67, 0.91; P < .001), which was higher than that observed on conventional CT images (r = 0.41; 95% CI: 0.09, 0.65; P = .01). Transmission electron microscopy and inductively coupled plasma optical emission spectrometry analyses confirmed the gold k-edge imaging findings. Conclusion Photon-counting CT with gold nanoparticles allowed for the noninvasive evaluation of both molecular and anatomic information in vivo in rabbits with atherosclerotic plaques. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Leiner in this issue.
Collapse
Affiliation(s)
- Salim A Si-Mohamed
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - Monica Sigovan
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - Jessica C Hsu
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - Valérie Tatard-Leitman
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - Lara Chalabreysse
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - Pratap C Naha
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - Thibaut Garrivier
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - Riham Dessouky
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - Miruna Carnaru
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - Loic Boussel
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - David P Cormode
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| | - Philippe C Douek
- From the University of Lyon, National Institute of Applied Sciences of Lyon, University Claude Bernard Lyon 1, Jean Monnet University-Saint Etienne, French National Centre for Scientific Research, Institut national de la santé et de la recherche médicale, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé Unité mixte de recherche 5220, U1206, F-69621, Lyon, France (S.A.S.M., M.S., V.T.L., R.D., L.B., P.C.D.); Departments of Radiology (S.A.S.M., T.G., L.B., P.C.D.) and Pathology (L.C.), Hospices Civils de Lyon, Lyon, France; Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pa (J.C.H., P.C.N., D.P.C.); Department of Radiology, Faculty of Medicine, Zagazig University, Egypt (R.D.); and Department of Rheumatology, Allergy, and Immunology, Yale University, New Haven, Conn (M.C.)
| |
Collapse
|
23
|
Abstract
The introduction of photon-counting detectors is expected to be the next major breakthrough in clinical x-ray computed tomography (CT). During the last decade, there has been considerable research activity in the field of photon-counting CT, in terms of both hardware development and theoretical understanding of the factors affecting image quality. In this article, we review the recent progress in this field with the intent of highlighting the relationship between detector design considerations and the resulting image quality. We discuss detector design choices such as converter material, pixel size, and readout electronics design, and then elucidate their impact on detector performance in terms of dose efficiency, spatial resolution, and energy resolution. Furthermore, we give an overview of data processing, reconstruction methods and metrics of imaging performance; outline clinical applications; and discuss potential future developments.
Collapse
Affiliation(s)
- Mats Danielsson
- Department of Physics, KTH Royal Institute of Technology, AlbaNova University Center, SE-106 91 Stockholm, Sweden. Prismatic Sensors AB, AlbaNova University Center, SE-106 91 Stockholm, Sweden
| | | | | |
Collapse
|
24
|
Jacobsen MC, Thrower SL. Multi-energy computed tomography and material quantification: Current barriers and opportunities for advancement. Med Phys 2020; 47:3752-3771. [PMID: 32453879 PMCID: PMC8495770 DOI: 10.1002/mp.14241] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 04/20/2020] [Accepted: 05/07/2020] [Indexed: 12/21/2022] Open
Abstract
Computed tomography (CT) technology has rapidly evolved since its introduction in the 1970s. It is a highly important diagnostic tool for clinicians as demonstrated by the significant increase in utilization over several decades. However, much of the effort to develop and advance CT applications has been focused on improving visual sensitivity and reducing radiation dose. In comparison to these areas, improvements in quantitative CT have lagged behind. While this could be a consequence of the technological limitations of conventional CT, advanced dual-energy CT (DECT) and photon-counting detector CT (PCD-CT) offer new opportunities for quantitation. Routine use of DECT is becoming more widely available and PCD-CT is rapidly developing. This review covers efforts to address an unmet need for improved quantitative imaging to better characterize disease, identify biomarkers, and evaluate therapeutic response, with an emphasis on multi-energy CT applications. The review will primarily discuss applications that have utilized quantitative metrics using both conventional and DECT, such as bone mineral density measurement, evaluation of renal lesions, and diagnosis of fatty liver disease. Other topics that will be discussed include efforts to improve quantitative CT volumetry and radiomics. Finally, we will address the use of quantitative CT to enhance image-guided techniques for surgery, radiotherapy and interventions and provide unique opportunities for development of new contrast agents.
Collapse
Affiliation(s)
- Megan C. Jacobsen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sara L. Thrower
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| |
Collapse
|
25
|
Kay FU. Dual-energy CT and coronary imaging. Cardiovasc Diagn Ther 2020; 10:1090-1107. [PMID: 32968662 PMCID: PMC7487394 DOI: 10.21037/cdt.2020.04.04] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 04/03/2020] [Indexed: 12/12/2022]
Abstract
Dual-energy computed tomography has been proposed for enhancing the evaluation of coronary artery disease in many fronts. However, the clinical translation of such applications has followed a slower pace of clinical translation. This paper will review the evidence supporting the use of dual-energy computed tomography in coronary artery disease (CAD) and provide some practical illustrations, while underscoring the challenges and gaps in knowledge that have contributed to this phenomenon.
Collapse
Affiliation(s)
- Fernando Uliana Kay
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| |
Collapse
|
26
|
From CT to artificial intelligence for complex assessment of plaque-associated risk. Int J Cardiovasc Imaging 2020; 36:2403-2427. [PMID: 32617720 DOI: 10.1007/s10554-020-01926-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 06/25/2020] [Indexed: 02/07/2023]
Abstract
The recent technological developments in the field of cardiac imaging have established coronary computed tomography angiography (CCTA) as a first-line diagnostic tool in patients with suspected coronary artery disease (CAD). CCTA offers robust information on the overall coronary circulation and luminal stenosis, also providing the ability to assess the composition, morphology, and vulnerability of atherosclerotic plaques. In addition, the perivascular adipose tissue (PVAT) has recently emerged as a marker of increased cardiovascular risk. The addition of PVAT quantification to standard CCTA imaging may provide the ability to extract information on local inflammation, for an individualized approach in coronary risk stratification. The development of image post-processing tools over the past several years allowed CCTA to provide a significant amount of data that can be incorporated into machine learning (ML) applications. ML algorithms that use radiomic features extracted from CCTA are still at an early stage. However, the recent development of artificial intelligence will probably bring major changes in the way we integrate clinical, biological, and imaging information, for a complex risk stratification and individualized therapeutic decision making in patients with CAD. This review aims to present the current evidence on the complex role of CCTA in the detection and quantification of vulnerable plaques and the associated coronary inflammation, also describing the most recent developments in the radiomics-based machine learning approach for complex assessment of plaque-associated risk.
Collapse
|
27
|
Grönberg F, Lundberg J, Sjölin M, Persson M, Bujila R, Bornefalk H, Almqvist H, Holmin S, Danielsson M. Feasibility of unconstrained three-material decomposition: imaging an excised human heart using a prototype silicon photon-counting CT detector. Eur Radiol 2020; 30:5904-5912. [PMID: 32588212 PMCID: PMC7554013 DOI: 10.1007/s00330-020-07017-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 05/11/2020] [Accepted: 06/05/2020] [Indexed: 11/05/2022]
Abstract
Rationale and objectives The purpose of this study was to evaluate the feasibility of unconstrained three-material decomposition in a human tissue specimen containing iodinated contrast agent, using an experimental multi-bin photon-counting silicon detector. It was further to evaluate potential added clinical value compared to a 1st-generation state-of-the-art dual-energy computed tomography system. Materials and methods A prototype photon-counting silicon detector in a bench-top setup for x-ray tomographic imaging was calibrated using a multi-material calibration phantom. A heart with calcified plaque was obtained from a deceased patient, and the coronary arteries were injected with an iodinated contrast agent mixed with gelatin. The heart was imaged in the experimental setup and on a 1st-generation state-of-the-art dual-energy computed tomography system. Projection-based three-material decomposition without any constraints was performed with the photon-counting detector data, and the resulting images were compared with those obtained from the dual-energy system. Results The photon-counting detector images show better separation of iodine and calcium compared to the dual-energy images. Additional experiments confirmed that unbiased estimates of soft tissue, calcium, and iodine could be achieved without any constraints. Conclusion The proposed experimental system could provide added clinical value compared to current dual-energy systems for imaging tasks where mix-up of iodine and calcium is an issue, and the anatomy is sufficiently small to allow iodine to be differentiated from calcium. Considering its previously shown count rate capability, these results show promise for future integration of this detector in a clinical CT scanner. Key Points • Spectral photon-counting detectors can solve some of the fundamental problems with conventional single-energy CT. • Dual-energy methods can be used to differentiate iodine and calcium, but to do so must rely on constraints, since solving for three unknowns with only two measurements is not possible. Photon-counting detectors can improve upon these methods by allowing unconstrained three-material decomposition. • A prototype photon-counting silicon detector with high count rate capability allows performing unconstrained three-material decomposition and qualitatively shows better differentiation of iodine and calcium than dual-energy CT.
Collapse
Affiliation(s)
- Fredrik Grönberg
- Department of Physics, AlbaNova University Center, KTH Royal Institute of Technology, SE-106 91, Stockholm, Sweden.
| | - Johan Lundberg
- Department of Clinical Neuroscience, Karolinska Institutet and the Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Martin Sjölin
- Department of Physics, AlbaNova University Center, KTH Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| | - Mats Persson
- Department of Physics, AlbaNova University Center, KTH Royal Institute of Technology, SE-106 91, Stockholm, Sweden.,Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Robert Bujila
- Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Hans Bornefalk
- Department of Physics, AlbaNova University Center, KTH Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| | - Håkan Almqvist
- Department of Clinical Neuroscience, Karolinska Institutet and the Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Staffan Holmin
- Department of Clinical Neuroscience, Karolinska Institutet and the Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Mats Danielsson
- Department of Physics, AlbaNova University Center, KTH Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| |
Collapse
|
28
|
Abstract
Unstable coronary plaques that are prone to erosion and rupture are the major cause of acute coronary syndromes. Our expanding understanding of the biological mechanisms of coronary atherosclerosis and rapid technological advances in the field of medical imaging has established cardiac computed tomography as a first-line diagnostic test in the assessment of suspected coronary artery disease, and as a powerful method of detecting the vulnerable plaque and patient. Cardiac computed tomography can provide a noninvasive, yet comprehensive, qualitative and quantitative assessment of coronary plaque burden, detect distinct high-risk morphological plaque features, assess the hemodynamic significance of coronary lesions and quantify the coronary inflammatory burden by tracking the effects of arterial inflammation on the composition of the adjacent perivascular fat. Furthermore, advances in machine learning, computational fluid dynamic modeling, and the development of targeted contrast agents continue to expand the capabilities of cardiac computed tomography imaging. In our Review, we discuss the current role of cardiac computed tomography in the assessment of coronary atherosclerosis, highlighting its dual function as a clinical and research tool that provides a wealth of structural and functional information, with far-reaching diagnostic and prognostic implications.
Collapse
Affiliation(s)
- Evangelos K. Oikonomou
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, United Kingdom
| | - Henry W. West
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, United Kingdom
| | - Charalambos Antoniades
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, United Kingdom
| |
Collapse
|
29
|
Scully PR, Bastarrika G, Moon JC, Treibel TA. Myocardial Extracellular Volume Quantification by Cardiovascular Magnetic Resonance and Computed Tomography. Curr Cardiol Rep 2018; 20:15. [PMID: 29511861 PMCID: PMC5840231 DOI: 10.1007/s11886-018-0961-3] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW This review article discusses the evolution of extracellular volume (ECV) quantification using both cardiovascular magnetic resonance (CMR) and computed tomography (CT). RECENT FINDINGS Visualizing diffuse myocardial fibrosis is challenging and until recently, was restricted to the domain of the pathologist. CMR and CT both use extravascular, extracellular contrast agents, permitting ECV measurement. The evidence base around ECV quantification by CMR is growing rapidly and just starting in CT. In conditions with high ECV (amyloid, oedema and fibrosis), this technique is already being used clinically and as a surrogate endpoint. Non-invasive diffuse fibrosis quantification is also generating new biological insights into key cardiac diseases. CMR and CT can estimate ECV and in turn diffuse myocardial fibrosis, obviating the need for invasive endomyocardial biopsy. CT is an attractive alternative to CMR particularly in those individuals with contraindications to the latter. Further studies are needed, particularly in CT.
Collapse
Affiliation(s)
- Paul R. Scully
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew’s Hospital, 2nd Floor, King George V Building, West Smithfield, London, EC1A 7BE UK
- Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
| | - Gorka Bastarrika
- Clínica Universidad de Navarra, University of Navarra, Avda/Pio XII 55, 31008 Pamplona, Spain
| | - James C. Moon
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew’s Hospital, 2nd Floor, King George V Building, West Smithfield, London, EC1A 7BE UK
- Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
| | - Thomas A. Treibel
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew’s Hospital, 2nd Floor, King George V Building, West Smithfield, London, EC1A 7BE UK
- Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
| |
Collapse
|
30
|
Getzin M, Garfield JJ, Rundle DS, Kruger U, Butler APH, Gkikas M, Wang G. Increased separability of K-edge nanoparticles by photon-counting detectors for spectral micro-CT. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2018; 26:707-726. [PMID: 29991154 DOI: 10.3233/xst-18382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
BACKGROUND X-ray CT/micro-CT methods with photon-counting detectors (PCDs) and high Z materials are a hot research topic. One method using PCDs allows for spectral imaging in 5 energy windows while conventional X-ray detectors only collect energy-integrating data. OBJECTIVE To demonstrate the enhanced separation of contrast materials by using PCDs, multivariate analysis, and linear discriminant methods. METHODS Phantoms containing iodine and aqueous nanomaterials were scanned on a MARS spectral micro-CT. Image volumes were segmented into separate material-specific populations. Contrast comparisons were made by calculating T2 test statistics in the univariate, pseudo-conventional and multivariate, spectral CT data sets. Separability after Fisher discriminant analysis (FDA) was also assessed. RESULTS The T2 values calculated for material comparisons increased as a result of the spectral expansion. The majority of the tested contrast agents showed increased T2 values by a factor of ∼2 -3. The total significant T2 statistics in the pure and mixed lanthanide image sets increased in the spectral data set. CONCLUSION This work consolidates the groundwork for photon-counting-based material decomposition with micro-CT, facilitating future development of novel nanomaterials and their preclinical applications.
Collapse
Affiliation(s)
- Matthew Getzin
- Biomedical Engineering Department, Rensselaer Polytechnic Institute, Troy, NY, USA
| | | | | | - Uwe Kruger
- Biomedical Engineering Department, Rensselaer Polytechnic Institute, Troy, NY, USA
| | | | - Manos Gkikas
- Chemistry Department, University of Massachusetts Lowell, Lowell, MA, USA
| | - Ge Wang
- Biomedical Engineering Department, Rensselaer Polytechnic Institute, Troy, NY, USA
| |
Collapse
|
31
|
|
32
|
Kim J, Chhour P, Hsu J, Litt HI, Ferrari VA, Popovtzer R, Cormode DP. Use of Nanoparticle Contrast Agents for Cell Tracking with Computed Tomography. Bioconjug Chem 2017; 28:1581-1597. [PMID: 28485976 PMCID: PMC5481820 DOI: 10.1021/acs.bioconjchem.7b00194] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
![]()
Efforts
to develop novel cell-based therapies originated with the
first bone marrow transplant on a leukemia patient in 1956. Preclinical
and clinical examples of cell-based treatment strategies have shown
promising results across many disciplines in medicine, with recent
advances in immune cell therapies for cancer producing remarkable
response rates, even in patients with multiple treatment failures.
However, cell-based therapies suffer from inconsistent outcomes, motivating
the search for tools that allow monitoring of cell delivery and behavior
in vivo. Noninvasive cell imaging techniques, also known as cell tracking,
have been developed to address this issue. These tools can allow real-time,
quantitative, and long-term monitoring of transplanted cells in the
recipient, providing insight on cell migration, distribution, viability,
differentiation, and fate, all of which play crucial roles in treatment
efficacy. Understanding these parameters allows the optimization of
cell choice, delivery route, and dosage for therapy and advances cell-based
therapy for specific clinical uses. To date, most cell tracking work
has centered on imaging modalities such as MRI, radionuclide imaging,
and optical imaging. However, X-ray computed tomography (CT) is an
emerging method for cell tracking that has several strengths such
as high spatial and temporal resolution, and excellent quantitative
capabilities. The advantages of CT for cell tracking are enhanced
by its wide availability and cost effectiveness, allowing CT to become
one of the most popular clinical imaging modalities and a key asset
in disease diagnosis. In this review, we will discuss recent advances
in cell tracking methods using X-ray CT in various applications, in
addition to predictions on how the field will progress.
Collapse
Affiliation(s)
| | | | | | | | | | - Rachela Popovtzer
- Department of Engineering, Bar-Ilan University , Ramat Gan, 5290002, Israel
| | | |
Collapse
|
33
|
Ghekiere O, Salgado R, Buls N, Leiner T, Mancini I, Vanhoenacker P, Dendale P, Nchimi A. Image quality in coronary CT angiography: challenges and technical solutions. Br J Radiol 2017; 90:20160567. [PMID: 28055253 PMCID: PMC5605061 DOI: 10.1259/bjr.20160567] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 10/13/2016] [Accepted: 01/03/2017] [Indexed: 11/05/2022] Open
Abstract
Multidetector CT angiography (CTA) has become a widely accepted examination for non-invasive evaluation of the heart and coronary arteries. Despite its ongoing success and worldwide clinical implementation, it remains an often-challenging procedure in which image quality, and hence diagnostic value, is determined by both technical and patient-related factors. Thorough knowledge of these factors is important to obtain high-quality examinations. In this review, we discuss several key elements that may adversely affect coronary CTA image quality as well as potential measures that can be taken to mitigate their impact. In addition, several recent vendor-specific advances and future directions to improve image quality are discussed.
Collapse
Affiliation(s)
- Olivier Ghekiere
- Department of Radiology, Centre Hospitalier Chrétien (CHC), Liège, Belgium
- Department of Radiology, Jessa Ziekenhuis, Hasselt, Belgium
- Faculty of Medicine and Life Sciences, Hasselt University, Hasselt, Belgium
| | - Rodrigo Salgado
- Department of Radiology, Antwerp University Hospital (UZA), Edegem, Belgium
| | - Nico Buls
- Department of Radiology, UZ Brussel, Brussels, Belgium
| | - Tim Leiner
- Department of Radiology, Utrecht University Medical Center, Utrecht, Netherlands
| | - Isabelle Mancini
- Department of Radiology, Centre Hospitalier Chrétien (CHC), Liège, Belgium
| | | | - Paul Dendale
- Heart Center Hasselt, Jessa Ziekenhuis, Hasselt, Belgium
| | - Alain Nchimi
- GIGA Cardiovascular Sciences, Liège University (ULg), Domaine Universitaire du Sart Tilman, Rue de l'hôpital, Liège, Belgium
| |
Collapse
|
34
|
Dual-contrast agent photon-counting computed tomography of the heart: initial experience. Int J Cardiovasc Imaging 2017; 33:1253-1261. [DOI: 10.1007/s10554-017-1104-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 02/25/2017] [Indexed: 11/25/2022]
|
35
|
Ehn S, Sellerer T, Mechlem K, Fehringer A, Epple M, Herzen J, Pfeiffer F, Noël PB. Basis material decomposition in spectral CT using a semi-empirical, polychromatic adaption of the Beer–Lambert model. Phys Med Biol 2016; 62:N1-N17. [DOI: 10.1088/1361-6560/aa4e5c] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
36
|
Abstract
Advances in cardiovascular computed tomography (CT) have resulted in an excellent ability to exclude coronary heart disease (CHD). Anatomical information, functional information, and spectral information can already be obtained with current CT technologies. Moreover, novel developments such as targeted nanoparticle contrast agents, photon-counting CT, and phase contrast CT will further enhance the diagnostic value of cardiovascular CT. This review provides an overview of current state of the art and future cardiovascular CT imaging.
Collapse
|
37
|
Lorsakul A, Fakhri GE, Worstell W, Ouyang J, Rakvongthai Y, Laine AF, Li Q. Numerical observer for atherosclerotic plaque classification in spectral computed tomography. J Med Imaging (Bellingham) 2016; 3:035501. [PMID: 27429999 PMCID: PMC4940624 DOI: 10.1117/1.jmi.3.3.035501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/20/2016] [Indexed: 11/14/2022] Open
Abstract
Spectral computed tomography (SCT) generates better image quality than conventional computed tomography (CT). It has overcome several limitations for imaging atherosclerotic plaque. However, the literature evaluating the performance of SCT based on objective image assessment is very limited for the task of discriminating plaques. We developed a numerical-observer method and used it to assess performance on discrimination vulnerable-plaque features and compared the performance among multienergy CT (MECT), dual-energy CT (DECT), and conventional CT methods. Our numerical observer was designed to incorporate all spectral information and comprised two-processing stages. First, each energy-window domain was preprocessed by a set of localized channelized Hotelling observers (CHO). In this step, the spectral image in each energy bin was decorrelated using localized prewhitening and matched filtering with a set of Laguerre-Gaussian channel functions. Second, the series of the intermediate scores computed from all the CHOs were integrated by a Hotelling observer with an additional prewhitening and matched filter. The overall signal-to-noise ratio (SNR) and the area under the receiver operating characteristic curve (AUC) were obtained, yielding an overall discrimination performance metric. The performance of our new observer was evaluated for the particular binary classification task of differentiating between alternative plaque characterizations in carotid arteries. A clinically realistic model of signal variability was also included in our simulation of the discrimination tasks. The inclusion of signal variation is a key to applying the proposed observer method to spectral CT data. Hence, the task-based approaches based on the signal-known-exactly/background-known-exactly (SKE/BKE) framework and the clinical-relevant signal-known-statistically/background-known-exactly (SKS/BKE) framework were applied for analytical computation of figures of merit (FOM). Simulated data of a carotid-atherosclerosis patient were used to validate our methods. We used an extended cardiac-torso anthropomorphic digital phantom and three simulated plaque types (i.e., calcified plaque, fatty-mixed plaque, and iodine-mixed blood). The images were reconstructed using a standard filtered backprojection (FBP) algorithm for all the acquisition methods and were applied to perform two different discrimination tasks of: (1) calcified plaque versus fatty-mixed plaque and (2) calcified plaque versus iodine-mixed blood. MECT outperformed DECT and conventional CT systems for all cases of the SKE/BKE and SKS/BKE tasks (all [Formula: see text]). On average of signal variability, MECT yielded the SNR improvements over other acquisition methods in the range of 46.8% to 65.3% (all [Formula: see text]) for FBP-Ramp images and 53.2% to 67.7% (all [Formula: see text]) for FBP-Hanning images for both identification tasks. This proposed numerical observer combined with our signal variability framework is promising for assessing material characterization obtained through the additional energy-dependent attenuation information of SCT. These methods can be further extended to other clinical tasks such as kidney or urinary stone identification applications.
Collapse
Affiliation(s)
- Auranuch Lorsakul
- Massachusetts General Hospital, Division of Nuclear Medicine and Molecular Imaging, Gordon Center for Medical Imaging, 55 Fruit Street, White 427, Boston, Massachusetts 02114, United States
- Columbia University, Department of Biomedical Engineering, 1210 Amsterdam Avenue, New York, New York 10027, United States
| | - Georges El Fakhri
- Massachusetts General Hospital, Division of Nuclear Medicine and Molecular Imaging, Gordon Center for Medical Imaging, 55 Fruit Street, White 427, Boston, Massachusetts 02114, United States
- Harvard Medical School, Department of Radiology, 25 Shattuck Street, Boston, Massachusetts 02115, United States
| | - William Worstell
- PhotoDiagnostic System Inc., 85 Swanson Road, Boxborough, Massachusetts 01719, United States
| | - Jinsong Ouyang
- Massachusetts General Hospital, Division of Nuclear Medicine and Molecular Imaging, Gordon Center for Medical Imaging, 55 Fruit Street, White 427, Boston, Massachusetts 02114, United States
- Harvard Medical School, Department of Radiology, 25 Shattuck Street, Boston, Massachusetts 02115, United States
| | - Yothin Rakvongthai
- Massachusetts General Hospital, Division of Nuclear Medicine and Molecular Imaging, Gordon Center for Medical Imaging, 55 Fruit Street, White 427, Boston, Massachusetts 02114, United States
- Chulalongkorn University, Department of Radiology, Faculty of Medicine, 1873 Rama 4 Road, Pathumwan, Bangkok 10330, Thailand
| | - Andrew F. Laine
- Columbia University, Department of Biomedical Engineering, 1210 Amsterdam Avenue, New York, New York 10027, United States
| | - Quanzheng Li
- Massachusetts General Hospital, Division of Nuclear Medicine and Molecular Imaging, Gordon Center for Medical Imaging, 55 Fruit Street, White 427, Boston, Massachusetts 02114, United States
- Harvard Medical School, Department of Radiology, 25 Shattuck Street, Boston, Massachusetts 02115, United States
| |
Collapse
|
38
|
Danad I, Fayad ZA, Willemink MJ, Min JK. New Applications of Cardiac Computed Tomography: Dual-Energy, Spectral, and Molecular CT Imaging. JACC Cardiovasc Imaging 2016; 8:710-23. [PMID: 26068288 DOI: 10.1016/j.jcmg.2015.03.005] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/20/2015] [Accepted: 03/02/2015] [Indexed: 01/16/2023]
Abstract
Computed tomography (CT) has evolved into a powerful diagnostic tool, and it is impossible to imagine current clinical practice without CT imaging. Because of its widespread availability, ease of clinical application, superb sensitivity for the detection of coronary artery disease, and noninvasive nature, CT has become a valuable tool within the armamentarium of cardiologists. In the past few years, numerous technological advances in CT have occurred, including dual-energy CT, spectral CT, and CT-based molecular imaging. By harnessing the advances in technology, cardiac CT has advanced beyond the mere evaluation of coronary stenosis to an imaging tool that permits accurate plaque characterization, assessment of myocardial perfusion, and even probing of molecular processes that are involved in coronary atherosclerosis. Novel innovations in CT contrast agents and pre-clinical spectral CT devices have paved the way for CT-based molecular imaging.
Collapse
Affiliation(s)
- Ibrahim Danad
- Department of Radiology, Weill Cornell Medical College, Dalio Institute of Cardiovascular Imaging, New York-Presbyterian Hospital, New York, New York
| | - Zahi A Fayad
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Martin J Willemink
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Radiology, University Medical Center, Utrecht, the Netherlands
| | - James K Min
- Department of Radiology, Weill Cornell Medical College, Dalio Institute of Cardiovascular Imaging, New York-Presbyterian Hospital, New York, New York.
| |
Collapse
|
39
|
den Harder AM, Willemink MJ, de Jong PA, Schilham AMR, Rajiah P, Takx RAP, Leiner T. New horizons in cardiac CT. Clin Radiol 2016; 71:758-67. [PMID: 26932775 DOI: 10.1016/j.crad.2016.01.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 12/23/2015] [Accepted: 01/21/2016] [Indexed: 12/13/2022]
Abstract
Until recently, cardiovascular computed tomography angiography (CCTA) was associated with considerable radiation doses. The introduction of tube current modulation and automatic tube potential selection as well as high-pitch prospective ECG-triggering and iterative reconstruction offer the ability to decrease dose with approximately one order of magnitude, often to sub-millisievert dose levels. In parallel, advancements in computational technology have enabled the measurement of fractional flow reserve (FFR) from CCTA data (FFRCT). This technique shows potential to replace invasively measured FFR to select patients in need of coronary intervention. Furthermore, developments in scanner hardware have led to the introduction of dual-energy and photon-counting CT, which offer the possibility of material decomposition imaging. Dual-energy CT reduces beam hardening, which enables CCTA in patients with a high calcium burden and more robust myocardial CT perfusion imaging. Future-generation CT systems will be capable of counting individual X-ray photons. Photon-counting CT is promising and may result in a substantial further radiation dose reduction, vastly increased spatial resolution, and the introduction of a whole new class of contrast agents.
Collapse
Affiliation(s)
- A M den Harder
- Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508GA Utrecht, The Netherlands.
| | - M J Willemink
- Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508GA Utrecht, The Netherlands
| | - P A de Jong
- Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508GA Utrecht, The Netherlands
| | - A M R Schilham
- Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508GA Utrecht, The Netherlands
| | - P Rajiah
- Cardiothoracic Imaging Division, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, USA
| | - R A P Takx
- Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508GA Utrecht, The Netherlands
| | - T Leiner
- Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508GA Utrecht, The Netherlands
| |
Collapse
|