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Allmendinger T, Nowak T, Flohr T, Klotz E, Hagenauer J, Alkadhi H, Schmidt B. Photon-Counting Detector CT-Based Vascular Calcium Removal Algorithm: Assessment Using a Cardiac Motion Phantom. Invest Radiol 2022; 57:399-405. [PMID: 35025834 PMCID: PMC9071027 DOI: 10.1097/rli.0000000000000853] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/11/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The diagnostic performance of coronary computed tomography angiography is known to be negatively affected by the presence of severely calcified plaques in the coronary arteries. In this article, the performance of a novel image reconstruction algorithm (PureLumen) based on spectral CT data of a first-generation dual-source photon-counting detector computed tomography (PCD-CT) system was assessed in a phantom study. PureLumen tries to remove only the calcified contributions from the image while leaving the rest unmodified. MATERIALS AND METHODS The study uses 2 iodine contrast filled vessel phantoms (diameter 4 mm) filled with different concentrations of iodine and equipped with calcified stenosis inserts. Each phantom features 2 separate calcified lesions of 25% and 50% percentage diameter stenosis (PDS) size. The vessel phantoms were mounted inside an anthropomorphic thorax phantom attached to an artificial motion device, simulating realistic cardiac motion at heart rates between 50 beats per minute and 100 beats per minute. Acquisitions were performed using a prospectively electrocardiogram triggered dual-source sequence mode on a PCD-CT system (NAEOTOM Alpha, Siemens Healthineers). Images were reconstructed at 80% of the RR interval with virtual monoenergetic images (Mono) and with additional calcium-removal (PureLumen), both at 65 keV. PureLumen is based on a spectral base material decomposition into iodine and calcium, which aims to reconstruct images without calcium contributions, while leaving all other material contribution unchanged. Stenosis grade was assessed individually for each vessel insert in all reconstructed image series by 2 readers. RESULTS The measured median PDS values for the 50% lesion were 56.0% (52.0%, 57.0%) for the Mono case and 50.0% (48.5%, 51.0%) for PureLumen. The 25% lesion median PDS values were 36.0% (29.5%, 39.5%) for Mono and 31.5% (30.5%, 34.0%) for PureLumen. Both lesion sizes demonstrate a significant difference between Mono and PureLumen in their result (P < 0.05) with PureLumen median values being closer to the actual true stenosis size for the 50% and 25% lesion. A visual assessment of the image quality depending on the heart rate yielded good image quality up to a heart rate of 80 beats per minute in the PureLumen case. CONCLUSIONS This phantom study shows that a novel calcium-removal image reconstruction algorithm (PureLumen) using a first-generation dual-source PCD-CT effectively decreases blooming artifacts caused by heavily calcified plaques and improves image interpretability. It also shows that PureLumen retains its performance in the presence of motion with simulated heart rates up to 80 beats per minute. Future in vivo clinical studies are needed to confirm the benefits of this type of reconstruction in terms of coronary computed tomography angiography quality and accuracy.
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Affiliation(s)
| | | | - Thomas Flohr
- From Siemens Healthcare GmbH, Forchheim
- University Tübingen, Tübingen
| | | | | | - Hatem Alkadhi
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Bernhard Schmidt
- From Siemens Healthcare GmbH, Forchheim
- University Erlangen, Erlangen, Germany
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Yi Y, Xu C, Guo N, Sun J, Lu X, Yu S, Wang Y, Vembar M, Jin Z, Wang Y. Performance of an Artificial Intelligence-based Application for the Detection of Plaque-based Stenosis on Monoenergetic Coronary CT Angiography: Validation by Invasive Coronary Angiography. Acad Radiol 2022; 29 Suppl 4:S49-S58. [PMID: 34895831 DOI: 10.1016/j.acra.2021.10.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/19/2021] [Accepted: 10/28/2021] [Indexed: 01/15/2023]
Abstract
RATIONALE AND OBJECTIVES To explore the value of an artificial intelligence (AI)-based application for identifying plaque-specific stenosis and obstructive coronary artery disease from monoenergetic spectral reconstructions on coronary computed tomography angiography (CTA). MATERIALS AND METHODS This retrospective study enrolled 71 consecutive patients (52 men, 19 women; 63.3 ± 10.7 years) who underwent coronary CTA and invasive coronary angiography for diagnosing coronary artery disease. The conventional 120 kVp images and eight different virtual monoenergetic images (VMIs) (from 40 keV to 140 keV at increment of 10 keV) were reconstructed. An AI system automatically detected plaques from the conventional 120 kVp images and VMIs and calculated the degree of stenosis, which was further compared to invasive coronary angiography. The assessment was performed at a segment, vessel, and patient level. RESULTS Vessel and segment-based analyses showed comparable diagnostic performance between conventional CTA images and VMIs from 50 keV to 90 keV. For vessel-based analysis, the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of conventional CTA were 74.3% (95% CI: 64.9%-82.0%), 85.6% (95% CI: 77.0%-91.4%), 84.3% (95% CI: 75.2%-90.7%), 76.1% (95% CI: 67.1%-83.3%) and 79.8% (95% CI: 73.7%-84.9%), respectively; the average sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy values of the VMIs ranging from 50 keV to 90 keV were 71.6%, 90.7%, 87.5%, 64.1% and 81.6%, respectively. For plaque-based assessment, diagnostic performance of the average VMIs ranging from 50 keV to 100 keV showed no significant statistical difference in diagnostic accuracy compared to those of conventional CTA images in detecting calcified (91.4% vs. 93.8%, p > 0.05), noncalcified (92.6% vs. 85.2%, p > 0.05) or mixed (80.2% vs. 81.2%, p > 0.05) stenosis, although the specificity was slightly higher (53.4% vs. 40.0%, p > 0.05) in detecting stenosis caused by mixed plaques. For VMIs above 100 keV, the diagnostic accuracy dropped significantly. CONCLUSION Our study showed that the performance of an AI-based application employed to detect significant coronary stenosis in virtual monoenergetic reconstructions ranging from 50 keV to 90 keV was comparable to conventional 120 kVp reconstructions.
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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.
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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.
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Estimating dual-energy CT imaging from single-energy CT data with material decomposition convolutional neural network. Med Image Anal 2021; 70:102001. [PMID: 33640721 DOI: 10.1016/j.media.2021.102001] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 02/06/2021] [Accepted: 02/11/2021] [Indexed: 01/12/2023]
Abstract
Dual-energy computed tomography (DECT) is of great significance for clinical practice due to its huge potential to provide material-specific information. However, DECT scanners are usually more expensive than standard single-energy CT (SECT) scanners and thus are less accessible to undeveloped regions. In this paper, we show that the energy-domain correlation and anatomical consistency between standard DECT images can be harnessed by a deep learning model to provide high-performance DECT imaging from fully-sampled low-energy data together with single-view high-energy data. We demonstrate the feasibility of the approach with two independent cohorts (the first cohort including contrast-enhanced DECT scans of 5753 image slices from 22 patients and the second cohort including spectral CT scans without contrast injection of 2463 image slices from other 22 patients) and show its superior performance on DECT applications. The deep-learning-based approach could be useful to further significantly reduce the radiation dose of current premium DECT scanners and has the potential to simplify the hardware of DECT imaging systems and to enable DECT imaging using standard SECT scanners.
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Zorlu Y, Brown C, Keil C, Ayhan MM, Haase H, Thompson RB, Lengyel I, Yücesan G. Fluorescent Arylphosphonic Acids: Synergic Interactions between Bone and the Fluorescent Core. Chemistry 2020; 26:11129-11134. [PMID: 32293767 PMCID: PMC7496659 DOI: 10.1002/chem.202001613] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Indexed: 12/23/2022]
Abstract
Herein, we report the third generation of fluorescent probes (arylphosphonic acids) to target calcifications, particularly hydroxyapatite (HAP). In this study, we use highly conjugated porphyrin-based arylphosphonic acids and their diesters, namely 5,10,15,20-tetrakis[m-(diethoxyphosphoryl)phenyl]porphyrin (m-H8 TPPA-OEt8 ) and 5,10,15,20-tetrakis [m-phenylphosphonic acid]porphyrin (m-H8 TPPA), in comparison with their positional isomers 5,10,15,20-tetrakis[p-(diisopropoxyphosphoryl)phenyl]porphyrin (p-H8 TPPA-iPr8 ) and 5,10,15,20-tetrakis [p-phenylphosphonic acid]porphyrin (p-H8 TPPA), which have phosphonic acid units bonded to sp2 carbon atoms of the fluorescent core. The conjugation of the fluorescent core is thus extended to the (HAP) through sp2 -bonded -PO3 H2 units, which generates increased fluorescence upon HAP binding. The resulting fluorescent probes are highly sensitive towards the HAP in rat bone sections. The designed probes are readily taken up by cells. Due to the lower reported toxicity of (p-H8 TPPA), these probes could find applications in monitoring bone resorption or adsorption, or imaging vascular or soft tissue calcifications for breast cancer diagnosis etc.
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Affiliation(s)
- Yunus Zorlu
- Department of ChemistryFaculty of ScienceGebze Technical University41400Gebze-KocaeliTurkey
| | - Connor Brown
- Wellcome-Wolfson Institute for Experimental MedicineSchool of Medicine, Dentistry and Biomedical ScienceQueen's University BelfastBelfastBT9 7BLUK
| | - Claudia Keil
- Technische Universität BerlinChair of Food Chemistry and ToxicologyStraße des 17. Juni 13510623BerlinGermany
| | - M. Menaf Ayhan
- Department of ChemistryFaculty of ScienceGebze Technical University41400Gebze-KocaeliTurkey
| | - Hajo Haase
- Technische Universität BerlinChair of Food Chemistry and ToxicologyStraße des 17. Juni 13510623BerlinGermany
| | - Richard B. Thompson
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMaryland21201USA
| | - Imre Lengyel
- Wellcome-Wolfson Institute for Experimental MedicineSchool of Medicine, Dentistry and Biomedical ScienceQueen's University BelfastBelfastBT9 7BLUK
| | - Gündoğ Yücesan
- Technische Universität BerlinChair of Food Chemistry and ToxicologyStraße des 17. Juni 13510623BerlinGermany
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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.
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Affiliation(s)
- Fernando Uliana Kay
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Brinkmann S, Chang DH, Kuhr K, Hoelscher AH, Spiro J, Bruns CJ, Schroeder W. Stenosis of the celiac trunk is associated with anastomotic leak after Ivor-Lewis esophagectomy. Dis Esophagus 2019; 32:5367736. [PMID: 30820543 DOI: 10.1093/dote/doy107] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Transthoracic esophagectomy with gastric tube formation is the surgical treatment of choice for esophageal cancer. The surgical reconstruction induces changes of gastric microcirculation, which are recognized as potential risk factors of anastomotic leak. This prospective observational study investigates the association of celiac trunk (TC) stenosis with postoperative anastomotic leak. One hundred fifty-four consecutive patients with esophageal cancer scheduled for Ivor-Lewis esophagectomy were included. Preoperative staging computed tomography (CT) was used to identify TC stenosis. Any narrowing of the lumen due to atherosclerotic changes was classified as stenosis. Percentage of stenotic changes was calculated using the North American Symptomatic Carotid Endarterectomy Trial formula. Multivariable analysis was used to identify possible risk factors for leak. The overall incidence of TC stenosis was 40.9%. Anastomotic leak was identified in 15 patients (9.7%). Incidence of anastomotic leak in patients with stenosis was 19.4% compared to 2.3% in patients without stenosis. Incidence of stenosis in patients with leak was 86.7% (13 of 15 patients) and significantly higher than 38.8% (54 of 139 patients) in patients without leak (P < 0.001). There was a significant difference in median degree of TC stenosis (50.0% vs 39.4%; P = 0.032) in patients with and without leak. In the multivariable model, TC stenosis was an independent risk factor for anastomotic leak (odds ratio: 5.98, 95% CI: 1.58-22.61). TC stenosis is associated with postoperative anastomotic leak after Ivor-Lewis esophagectomy. Routine assessment of TC for possible stenosis is recommended to identify patients at risk.
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Affiliation(s)
- S Brinkmann
- Department of General, Visceral and Cancer Surgery, University of Cologne, Germany
| | - D H Chang
- Department of Radiology, University of Cologne, Germany
| | - K Kuhr
- Institute of Medical Statistics, Informatics and Epidemiology, University of Cologne, Germany
| | - A H Hoelscher
- Department of Surgery, AGAPLESION Markus Krankenhaus, Frankfurt, Germany
| | - J Spiro
- Department of Radiology, University of Cologne, Germany
| | - C J Bruns
- Department of General, Visceral and Cancer Surgery, University of Cologne, Germany
| | - W Schroeder
- Department of General, Visceral and Cancer Surgery, University of Cologne, Germany
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van Hamersvelt RW, Išgum I, de Jong PA, Cramer MJM, Leenders GEH, Willemink MJ, Voskuil M, Leiner T. Application of speCtraL computed tomogrAphy to impRove specIficity of cardiac compuTed tomographY (CLARITY study): rationale and design. BMJ Open 2019; 9:e025793. [PMID: 30826767 PMCID: PMC6429912 DOI: 10.1136/bmjopen-2018-025793] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
INTRODUCTION Anatomic stenosis evaluation on coronary CT angiography (CCTA) lacks specificity in indicating the functional significance of a stenosis. Recent developments in CT techniques (including dual-layer spectral detector CT [SDCT] and static stress CT perfusion [CTP]) and image analyses (including fractional flow reserve [FFR] derived from CCTA images [FFRCT] and deep learning analysis [DL]) are potential strategies to increase the specificity of CCTA by combining both anatomical and functional information in one investigation. The aim of the current study is to assess the diagnostic performance of (combinations of) SDCT, CTP, FFRCT and DL for the identification of functionally significant coronary artery stenosis. METHODS AND ANALYSIS Seventy-five patients aged 18 years and older with stable angina and known coronary artery disease and scheduled to undergo clinically indicated invasive FFR will be enrolled. All subjects will undergo the following SDCT scans: coronary calcium scoring, static stress CTP, rest CCTA and if indicated (history of myocardial infarction) a delayed enhancement acquisition. Invasive FFR of ≤0.80, measured within 30 days after the SDCT scans, will be used as reference to indicate a functionally significant stenosis. The primary study endpoint is the diagnostic performance of SDCT (including CTP) for the identification of functionally significant coronary artery stenosis. Secondary study endpoint is the diagnostic performance of SDCT, CTP, FFRCT and DL separately and combined for the identification of functionally significant coronary artery stenosis. ETHICS AND DISSEMINATION Ethical approval was obtained. All subjects will provide written informed consent. Study findings will be disseminated through peer-reviewed conference presentations and journal publications. TRIAL REGISTRATION NUMBER NCT03139006; Pre-results.
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Affiliation(s)
| | - Ivana Išgum
- Image Sciences Institute, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Pim A de Jong
- Department of Radiology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Maarten Jan Maria Cramer
- Department of Cardiology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Geert E H Leenders
- Department of Cardiology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Martin J Willemink
- Department of Radiology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Michiel Voskuil
- Department of Cardiology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Tim Leiner
- Department of Radiology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
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Shen C, Li B, Lou Y, Yang M, Zhou L, Jia X. Multienergy element-resolved cone beam CT (MEER-CBCT) realized on a conventional CBCT platform. Med Phys 2018; 45:4461-4470. [PMID: 30179261 DOI: 10.1002/mp.13169] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 07/29/2018] [Accepted: 08/20/2018] [Indexed: 01/10/2023] Open
Abstract
PURPOSE Cone beam CT (CBCT) has been widely used in radiation therapy. However, its main application is still to acquire anatomical information for patient positioning. This study proposes a multienergy element-resolved (MEER) CBCT framework that employs energy-resolved data acquisition on a conventional CBCT platform and then simultaneously reconstructs images of x-ray attenuation coefficients, electron density relative to water (rED), and elemental composition (EC) to support advanced applications. METHODS The MEER-CBCT framework is realized on a Varian TrueBeam CBCT platform using a kVp-switching scanning scheme. A simultaneous image reconstruction and elemental decomposition model is formulated as an optimization problem. The objective function uses a least square term to enforce fidelity between x-ray attenuation coefficients and projection measurements. Spatial regularization is introduced via sparsity under a tight wavelet-frame transform. Consistency is imposed among rED, EC, and attenuation coefficients and inherently serves as a regularization term along the energy direction. The EC is further constrained by a sparse combination of ECs in a dictionary containing tissues commonly existing in humans. The optimization problem is solved by a novel alternating-direction minimization scheme. The MEER-CBCT framework was tested in a simulation study using an NCAT phantom and an experimental study using a Gammex phantom. RESULTS MEER-CBCT framework was successfully realized on a clinical Varian TrueBeam onboard CBCT platform with three energy channels of 80, 100, and 120 kVp. In the simulation study, the attenuation coefficient image achieved a structural similarity index of 0.98, compared to 0.61 for the image reconstructed by the conventional conjugate gradient least square (CGLS) algorithm, primarily because of reduction in artifacts. In the experimental study, the attenuation image obtained a contrast-to-noise ratio ≥60, much higher than that of CGLS results (~16) because of noise reduction. The median errors in rED and EC were 0.5% and 1.4% in the simulation study and 1.4% and 2.3% in the experimental study. CONCLUSION We proposed a novel MEER-CBCT framework realized on a clinical CBCT platform. Simulation and experimental studies demonstrated its capability to simultaneously reconstruct x-ray attenuation coefficient, rED, and EC images accurately.
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Affiliation(s)
- Chenyang Shen
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Bin Li
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.,State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Yifei Lou
- Department of Mathematical Science, University of Texas at Dallas, Dallas, TX, 75080, USA
| | - Ming Yang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Linghong Zhou
- Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Xun Jia
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
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Li Q, Berman BP, Hagio T, Gavrielides MA, Zeng R, Sahiner B, Gong Q, Fang Y, Liu S, Petrick N. Coronary artery calcium quantification using contrast-enhanced dual-energy computed tomography scans in comparison with unenhanced single-energy scans. Phys Med Biol 2018; 63:175006. [PMID: 30101756 PMCID: PMC6183065 DOI: 10.1088/1361-6560/aad9be] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Extracting coronary artery calcium (CAC) scores from contrast-enhanced computed tomography (CT) images using dual-energy (DE) based material decomposition has been shown feasible, mainly through patient studies. However, the quantitative performance of such DE-based CAC scores, particularly per stenosis, is underexamined due to lack of reference standard and repeated scans. In this work we conducted a comprehensive quantitative comparative analysis of CAC scores obtained with DE and compare to conventional unenhanced single-energy (SE) CT scans through phantom studies. Synthetic vessels filled with iodinated blood mimicking material and containing calcium stenoses of different sizes and densities were scanned with a third generation dual-source CT scanner in a chest phantom using a DE coronary CT angiography protocol with three exposures/CTDIvol: auto-mAs/8 mGy (automatic exposure), 160 mAs/20 mGy and 260 mAs/34 mGy and 10 repeats. As a control, a set of vessel phantoms without iodine was scanned using a standard SE CAC score protocol (3 mGy). Calcium volume, mass and Agatston scores were estimated for each stenosis. For DE dataset, image-based three-material decomposition was applied to remove iodine before scoring. Performance of DE-based calcium scores were analyzed on a per-stenosis level and compared to SE-based scores. There was excellent correlation between the DE- and SE-based scores (correlation coefficient r: 0.92-0.98). Percent bias for the calcium volume and mass scores varied as a function of stenosis size and density for both modalities. Precision (coefficient of variation) improved with larger and denser stenoses for both DE- and SE-based calcium scores. DE-based scores (20 mGy and 34 mGy) provided comparable per-stenosis precision to SE-based (3 mGy). Our findings suggest that on a per-stenosis level, DE-based CAC scores from contrast-enhanced CT images can achieve comparable quantification performance to conventional SE-based scores. However, DE-based CAC scoring required more dose compared with SE for high per-stenosis precision so some caution is necessary with clinical DE-based CAC scoring.
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Affiliation(s)
- Qin Li
- US Food and Drug Administration, CDRH/OSEL/DIDSR, Silver Spring, MD, United States of America
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Low-Dose Characterization of Kidney Stones Using Spectral Detector Computed Tomography. Invest Radiol 2018; 53:457-462. [DOI: 10.1097/rli.0000000000000468] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Cardiac CT: Technological Advances in Hardware, Software, and Machine Learning Applications. CURRENT CARDIOVASCULAR IMAGING REPORTS 2018; 11. [PMID: 31656551 DOI: 10.1007/s12410-018-9459-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Purpose of Review Multidetector row computed tomography (CT) allows noninvasive imaging of the heart and coronary arteries. The purpose of this review is to briefly summarize recent advances in CT hardware and software technology, and machine learning applications for cardiovascular imaging. Recent Findings In the last decades, there have been significant improvements in CT hardware focusing on faster gantry rotation resulting in improved temporal resolution. Concurrent hardware improvements include improved spatial resolution and higher coverage of the patient, enabling faster acquisition. Advances in cardiac CT software include methods for measurement of noninvasive FFR, coronary plaque characterization, and adipose tissue characteristics around the heart. Machine learning approaches using cardiac CT have been shown to improve both risk of prognosis and lesion-specific ischemia. Summary Recent advances in CT hardware and software have expanded the clinical utility of CT for cardiovascular imaging. In the next decades, continued advances can be anticipated in these areas, and in machine learning applications in cardiac CT, as they are incorporated into clinical routine for image acquisition, image analysis, and prediction of patient outcomes.
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Lee D, Lee J, Kim H, Lee T, Soh J, Park M, Kim C, Lee YJ, Cho S. A Feasibility Study of Low-Dose Single-Scan Dual-Energy Cone-Beam CT in Many-View Under-Sampling Framework. IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:2578-2587. [PMID: 29192887 DOI: 10.1109/tmi.2017.2765760] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A single-scan dual-energy low-dose cone-beam CT (CBCT) imaging technique that exploits a multi-slit filter is proposed in this paper. The multi-slit filter installed between the x-ray source and the scanned object is reciprocated during a scan. The x-ray beams through the slits would generate relatively low-energy x-ray projection data, while the filtered beams would make high-energy projection data. An iterative image reconstruction algorithm that uses an adaptive-steepest-descent method to minimize image total-variation under the constraint of data fidelity was applied to reconstructing the image from the low-energy projection data. Since the high-energy projection data suffer from a substantially high noise level due to the beam filtration, we have developed a new algorithm that exploits the joint sparsity between the low- and high-energy CT images for image reconstruction of the high-energy CT image. The proposed image reconstruction algorithm uses a gradient magnitude image (GMI) of the low-energy CT image by regularizing the difference of GMIs of the low- and high-energy CT images to be minimized. The feasibility of the proposed technique has been demonstrated by the use of various phantoms in the experimental CBCT setup. Furthermore, based on the proposed dual-energy imaging, a material differentiation was performed and its potential utility has been shown. The proposed imaging technique produced promising results for its potential application to a low-dose single-scan dual-energy CBCT.
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Kalisz K, Halliburton S, Abbara S, Leipsic JA, Albrecht MH, Schoepf UJ, Rajiah P. Update on Cardiovascular Applications of Multienergy CT. Radiographics 2017; 37:1955-1974. [DOI: 10.1148/rg.2017170100] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Marino MA, Silipigni S, Barbaro U, Mazziotti S, Sofia C, Mazzei MA, Ascenti G. Dual Energy CT Scanning in Evaluation of the Urinary Tract. CURRENT RADIOLOGY REPORTS 2017. [DOI: 10.1007/s40134-017-0243-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Jin KN, Chung JW, Park EA, Lee W. Dual-energy computed tomography angiography: virtual calcified plaque subtraction in a vascular phantom. Acta Radiol Open 2017; 6:2058460117717765. [PMID: 28811929 PMCID: PMC5528944 DOI: 10.1177/2058460117717765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 06/05/2017] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Material decomposition of dual-energy computed tomography (DECT) enables subtraction of calcified plaque. PURPOSE To evaluate the accuracy of lumen area measurement in calcified plaque by subtraction of DECT and to determine the effect of contrast material concentration, lumen diameter, density, and thickness of calcified plaque for the measurement. MATERIAL AND METHODS Vessel phantoms were made with six lumen diameters (5.7, 4.9, 3.9, 3.0, 1.9, and 1.3 mm) and six types of calcified plaques with three densities and two thicknesses were attached. CT scans were performed with three contrast material concentrations (62, 111, and 170 mg iodine/mL). Lumen area discrepancy (AD) was calculated by subtracting the measured lumen area from a reference value. The lumen area underestimation percentage (AU), defined as (AD/reference value) × 100, was calculated. General linear model analysis was used to test the effect of variables for log-transformed AU (ln_AU). RESULTS The AD and AU was calculated to be 6.1 ± 4.8 mm2 and 69.8 ± 29.4%, respectively. Ln_AU was significantly affected by contrast material concentration (P < 0.001), calcium density (P = 0.001), plaque thickness (P = 0.010), and lumen diameter (P < 0.001). Ln_AU was significantly higher in 62 mg iodine/mL than in 111 or 170 mg iodine/mL (P < 0.001 for both). Ln_AU was significantly lower at a lumen diameter of 5.7 mm than 3.9 mm (P = 0.001) or 3.0 (P < 0.001). CONCLUSION Calcified plaque subtraction in DECT substantially underestimates measurements of lumen area. Higher enhancement in larger vessels ensures more accurate subtraction of calcified plaque.
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Affiliation(s)
- Kwang Nam Jin
- Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Republic of Korea
| | - Jin Wook Chung
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Eun-Ah Park
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Whal Lee
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
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Rajiah P, Abbara S, Halliburton SS. Spectral detector CT for cardiovascular applications. Diagn Interv Radiol 2017; 23:187-193. [PMID: 28302592 PMCID: PMC5410998 DOI: 10.5152/dir.2016.16255] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/26/2016] [Accepted: 09/17/2016] [Indexed: 01/23/2023]
Abstract
Spectral detector computed tomography (SDCT) is a novel technology that uses two layers of detectors to simultaneously collect low and high energy data. Spectral data is used to generate conventional polyenergetic images as well as dedicated spectral images including virtual monoenergetic and material composition (iodine-only, virtual unenhanced, effective atomic number) images. This paper provides an overview of SDCT technology and a description of some spectral image types. The potential utility of SDCT for cardiovascular imaging and the impact of this new technology on radiation and contrast dose are discussed through presentation of initial patient studies performed on a SDCT scanner. The value of SDCT for salvaging suboptimal studies including those with poor contrast-enhancement or beam hardening artifacts through retrospective reconstruction of spectral data is discussed. Additionally, examples of specific benefits for the evaluation of aortic disease, imaging before transcatheter aortic valve implantation, evaluation of pulmonary veins pre- and post-pulmonary radiofrequency ablation, evaluation of coronary artery lumen, assessment of myocardial perfusion, detection of pulmonary embolism, and characterization of incidental findings are presented.
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Affiliation(s)
- Prabhakar Rajiah
- From the Department of Radiology (P.R. , S.A.) Southwestern Medical Center, Dallas, Texas, USA; Philips Healthcare (S.S.H.) Cleveland, Ohio, USA
| | - Suhny Abbara
- From the Department of Radiology (P.R. , S.A.) Southwestern Medical Center, Dallas, Texas, USA; Philips Healthcare (S.S.H.) Cleveland, Ohio, USA
| | - Sandra Simon Halliburton
- From the Department of Radiology (P.R. , S.A.) Southwestern Medical Center, Dallas, Texas, USA; Philips Healthcare (S.S.H.) Cleveland, Ohio, USA
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White Paper of the Society of Computed Body Tomography and Magnetic Resonance on Dual-Energy CT, Part 3. J Comput Assist Tomogr 2017; 41:1-7. [DOI: 10.1097/rct.0000000000000538] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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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.
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Carrascosa P, Leipsic JA, Deviggiano A, Capunay C, Vallejos J, Goldsmit A, De Zan MC, Rodriguez-Granillo GA. Virtual Monochromatic Imaging in Patients with Intermediate to High Likelihood of Coronary Artery Disease: Impact of Coronary Calcification. Acad Radiol 2016; 23:1490-1497. [PMID: 27622565 DOI: 10.1016/j.acra.2016.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 08/02/2016] [Accepted: 08/04/2016] [Indexed: 01/26/2023]
Abstract
RATIONALE AND OBJECTIVES We sought to explore the image quality and diagnostic performance of virtual monochromatic imaging derived from dual-energy computed tomography coronary angiography (DE-CTCA) in patients with intermediate to high likelihood of coronary artery disease (CAD) and the influence of calcification. MATERIALS AND METHODS Consecutive symptomatic patients with suspected CAD referred for invasive coronary angiography who underwent DE-CTCA and a coronary artery calcium scoring before the invasive procedure comprised the study population. RESULTS Sixty-seven patients were included. Image quality was significantly lower at 45 keV reconstructions (mean Likert score 45 keV 3.57 ± 0.6, 65 keV 4.07 ± 0.5, and 85 keV 4.09 ± 0.6; P < .0001). Patients with moderate calcification showed a trend toward a significant improvement in the diagnostic performance with 65 keV vs 45 keV reconstructions (45 keV, area under the curve 0.92 [95% confidence interval 0.89-0.95] vs 65 keV, area under the curve 0.96 [95% confidence interval 0.93-0.98], P = .06). The diagnostic performance of DE-CTCA was significantly lower in segments with higher coronary artery calcium scoring compared to segments with none or mild calcification, independent of the energy level applied. CONCLUSIONS In patients with intermediate to high likelihood of CAD, DE-CTCA had a good diagnostic performance, although significantly lower in segments with severe calcification.
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Affiliation(s)
- Patricia Carrascosa
- Department of Cardiovascular Imaging, Diagnóstico Maipú, Av Maipú 1668, Vicente López (B1602ABQ), Buenos Aires, Argentina.
| | | | - Alejandro Deviggiano
- Department of Cardiovascular Imaging, Diagnóstico Maipú, Av Maipú 1668, Vicente López (B1602ABQ), Buenos Aires, Argentina
| | - Carlos Capunay
- Department of Cardiovascular Imaging, Diagnóstico Maipú, Av Maipú 1668, Vicente López (B1602ABQ), Buenos Aires, Argentina
| | - Javier Vallejos
- Department of Cardiovascular Imaging, Diagnóstico Maipú, Av Maipú 1668, Vicente López (B1602ABQ), Buenos Aires, Argentina
| | - Alejandro Goldsmit
- Department of Interventional Cardiology, Sanatorio Guemes, Buenos Aires, Argentina
| | - Macarena C De Zan
- Department of Cardiovascular Imaging, Diagnóstico Maipú, Av Maipú 1668, Vicente López (B1602ABQ), Buenos Aires, Argentina
| | - Gaston A Rodriguez-Granillo
- Department of Cardiovascular Imaging, Diagnóstico Maipú, Av Maipú 1668, Vicente López (B1602ABQ), Buenos Aires, Argentina
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Rodríguez-Granillo GA, Carrascosa P, Deviggiano A, Capunay C, de Zan MC, Goldsmit A. Extensión y distribución espacial de la carga ateroesclerótica mediante imágenes monocromáticas virtuales derivadas de tomografía computarizada de doble energía. Rev Esp Cardiol 2016. [DOI: 10.1016/j.recesp.2016.02.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Rodríguez-Granillo GA, Carrascosa P, Deviggiano A, Capunay C, de Zan MC, Goldsmit A. Extension and Spatial Distribution of Atherosclerotic Burden Using Virtual Monochromatic Imaging Derived From Dual-energy Computed Tomography. REVISTA ESPANOLA DE CARDIOLOGIA (ENGLISH ED.) 2016; 69:915-922. [PMID: 27324434 DOI: 10.1016/j.rec.2016.02.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 02/25/2016] [Indexed: 06/06/2023]
Abstract
INTRODUCTION AND OBJECTIVES We explored the differences between atherosclerotic burden with invasive coronary angiography and virtual monochromatic imaging derived from dual-energy computed tomography coronary angiography. METHODS Eighty consecutive patients referred for invasive coronary angiography underwent dual-energy computed tomography coronary angiography and were categorized according to the atherosclerotic burden extent using the modified Duke prognostic coronary artery disease index, coronary artery disease extension score, segment involvement score, and the segment stenosis score. RESULTS The mean segment involvement score (8.2 ± 3.9 vs 6.0 ± 3.7; P < .0001), modified Duke index (4.33 ± 1.6 vs 4.0 ± 1.7; P = .003), coronary artery disease extension score (4.84 ± 1.8 vs 4.43 ± 2.1; P = .005), and the median segment stenosis score (13.5 [9.0-18.0] vs 9.5 [5.0-15.0]; P < .0001) were significantly higher on dual-energy computed tomography compared with invasive angiography. Dual-energy computed tomography showed a significantly higher number of patients with any left main coronary artery lesion (46 [58%] vs 18 [23%]; P < .0001) and with severe proximal lesions (0.28 ± 0.03 vs 0.26 ± 0.03; P < .0001) than invasive angiography. Levels of coronary artery calcification below and above the median showed a sensitivity, specificity, positive predictive value, and negative predictive value of 100% and 97%; 86% and 50%; 93% and 95%; 100% and 67% for the identification of ≥ 50% stenosis. CONCLUSIONS Dual-energy computed tomography coronary angiography identified a significantly larger atherosclerotic burden compared with invasive coronary angiography, particularly involving the proximal segments.
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Affiliation(s)
| | - Patricia Carrascosa
- Departamento de Imágenes Cardiovasculares, Diagnóstico Maipú, Buenos Aires, Argentina
| | - Alejandro Deviggiano
- Departamento de Imágenes Cardiovasculares, Diagnóstico Maipú, Buenos Aires, Argentina
| | - Carlos Capunay
- Departamento de Imágenes Cardiovasculares, Diagnóstico Maipú, Buenos Aires, Argentina
| | - Macarena C de Zan
- Departamento de Imágenes Cardiovasculares, Diagnóstico Maipú, Buenos Aires, Argentina
| | - Alejandro Goldsmit
- Departamento de Cardiología Intervencionista, Sanatorio Güemes, Buenos Aires, Argentina
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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.
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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.
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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.
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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
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Halliburton SS, Rajiah P. Cardiac CT Scanner Technology: What Is New and What Is Next? CURRENT CARDIOVASCULAR IMAGING REPORTS 2016. [DOI: 10.1007/s12410-016-9370-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Lee NJ, Litt H. Cardiac CT angiography for evaluation of acute chest pain. Int J Cardiovasc Imaging 2015; 32:101-12. [PMID: 26342713 DOI: 10.1007/s10554-015-0763-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 08/31/2015] [Indexed: 01/23/2023]
Abstract
Chest pain is the second most common emergency department (ED) presentation in the United States. Cardiac computed tomography angiography (CCTA) now plays an important role in the evaluation of patients with suspected acute coronary syndrome in the ED setting. In this article, we review the available techniques focused on the use of CCTA to evaluate patients fosr coronary atherosclerosis for timely triage of acute chest pain.
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Affiliation(s)
- Nam Ju Lee
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, PA, USA
| | - Harold Litt
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, PA, USA.
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Sandfort V, Lima JAC, Bluemke DA. Noninvasive Imaging of Atherosclerotic Plaque Progression: Status of Coronary Computed Tomography Angiography. Circ Cardiovasc Imaging 2015; 8:e003316. [PMID: 26156016 DOI: 10.1161/circimaging.115.003316] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The process of coronary artery disease progression is infrequently visualized. Intravascular ultrasound has been used to gain important insights but is invasive and therefore limited to high-risk patients. For low-to-moderate risk patients, noninvasive methods may be useful to quantitatively monitor plaque progression or regression and to understand and personalize atherosclerosis therapy. This review discusses the potential for coronary computed tomography angiography to evaluate the extent and subtypes of coronary plaque. Computed tomographic technology is evolving and image quality of the method approaches the level required for plaque progression monitoring. Methods to quantify plaque on computed tomography angiography are reviewed as well as a discussion of their use in clinical trials. Limitations of coronary computed tomography angiography compared with competing modalities include limited evaluation of plaque subcomponents and incomplete knowledge of the value of the method especially in patients with low-to-moderate cardiovascular risk.
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Affiliation(s)
- Veit Sandfort
- From the Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD (V.S., D.A.B.); and Department of Radiology (J.A.C.L.) and Cardiology Division, Department of Medicine (J.A.C.L.), Johns Hopkins University, Baltimore, MD
| | - Joao A C Lima
- From the Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD (V.S., D.A.B.); and Department of Radiology (J.A.C.L.) and Cardiology Division, Department of Medicine (J.A.C.L.), Johns Hopkins University, Baltimore, MD
| | - David A Bluemke
- From the Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD (V.S., D.A.B.); and Department of Radiology (J.A.C.L.) and Cardiology Division, Department of Medicine (J.A.C.L.), Johns Hopkins University, Baltimore, MD.
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Liguori C, Frauenfelder G, Massaroni C, Saccomandi P, Giurazza F, Pitocco F, Marano R, Schena E. Emerging clinical applications of computed tomography. MEDICAL DEVICES-EVIDENCE AND RESEARCH 2015; 8:265-78. [PMID: 26089707 PMCID: PMC4467659 DOI: 10.2147/mder.s70630] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
X-ray computed tomography (CT) has recently been experiencing remarkable growth as a result of technological advances and new clinical applications. This paper reviews the essential physics of X-ray CT and its major components. Also reviewed are recent promising applications of CT, ie, CT-guided procedures, CT-based thermometry, photon-counting technology, hybrid PET-CT, use of ultrafast-high pitch scanners, and potential use of dual-energy CT for material differentiations. These promising solutions and a better knowledge of their potentialities should allow CT to be used in a safe and effective manner in several clinical applications.
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Affiliation(s)
| | | | - Carlo Massaroni
- Measurement and Biomedical Instrumentation Unit, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Paola Saccomandi
- Measurement and Biomedical Instrumentation Unit, Università Campus Bio-Medico di Roma, Rome, Italy
| | | | | | - Riccardo Marano
- Department of Radiological Sciences, Institute of Radiology, Catholic University of Rome, A Gemelli University Hospital, Rome, Italy
| | - Emiliano Schena
- Measurement and Biomedical Instrumentation Unit, Università Campus Bio-Medico di Roma, Rome, Italy
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Schernthaner RE, Wolf F, Mistelbauer G, Weber M, Sramek M, Groeller E, Loewe C. New hybrid reformations of peripheral CT angiography: do we still need axial images? Clin Imaging 2015; 39:603-7. [PMID: 25825345 DOI: 10.1016/j.clinimag.2015.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 02/16/2015] [Accepted: 03/10/2015] [Indexed: 01/05/2023]
Abstract
PURPOSE To quantify the detectability of peripheral artery stenosis on hybrid CT angiography (CTA) reformations. METHODS Hybrid reformations were developed by combining multipath curved planar reformations (mpCPR) and maximum intensity projections (MIP). Fifty peripheral CTAs were evaluated twice: either with MIP, mpCPR and axial images or with hybrid reformations only. Digital subtraction angiography served as gold standard. RESULTS Using hybrid reformations, two independent readers detected 88.0% and 81.3% of significant stenosis, respectively. However, CTA including axial images detected statistically significant more lesions (98%). CONCLUSION Peripheral CTA reading including axial images is still recommended. Further improvement of these hybrid reformations is necessary.
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Affiliation(s)
- Ruediger Egbert Schernthaner
- Section of Cardiovascular and Interventional Radiology, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
| | - Florian Wolf
- Section of Cardiovascular and Interventional Radiology, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
| | - Gabriel Mistelbauer
- Institute of Computer Graphics and Algorithms, Technical University of Vienna, Favoritenstraße 9-11, 1040 Vienna, Austria.
| | - Michael Weber
- Section of Cardiovascular and Interventional Radiology, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
| | - Milos Sramek
- Commission for Scientific Visualization, Austrian Academy of Sciences, Donau-City Straße 1, 1220 Vienna, Austria.
| | - Eduard Groeller
- Institute of Computer Graphics and Algorithms, Technical University of Vienna, Favoritenstraße 9-11, 1040 Vienna, Austria.
| | - Christian Loewe
- Section of Cardiovascular and Interventional Radiology, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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Hagspiel KD, Flors L, Hanley M, Norton PT. Computed tomography angiography and magnetic resonance angiography imaging of the mesenteric vasculature. Tech Vasc Interv Radiol 2014; 18:2-13. [PMID: 25814198 DOI: 10.1053/j.tvir.2014.12.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are highly accurate cross-sectional vascular imaging modalities that have almost completely replaced diagnostic catheter angiography for the evaluation of the mesenteric vasculature. CTA is the technique of choice when evaluating patients with suspected mesenteric ischemia; it permits to differentiate between occlusive and nonocclusive etiologies, to evaluate indirect signs of bowel ischemia, and in some instances, to provide alternative diagnoses. MRA has the advantage of not using ionizing radiation and iodinated contrast agents and can be appropriate in the nonacute setting. Both CTA and MRA are suitable for the assessment of patients with suspected chronic mesenteric ischemia, allowing to evaluate the degree of atherosclerotic steno-occlusive disease and the existence of collateral circulation, as well as other nonatherosclerotic vascular pathologies such as fibromuscular dysplasia and median arcuate ligament syndrome. CTA provides excellent depiction of visceral aneurysms and has an important role to plan therapy for both occlusive and aneurysmal diseases and in the follow-up of patients after open or endovascular mesenteric revascularization procedures. This article provides an introduction to the CTA and MRA imaging protocol to study the mesenteric vasculature, the imaging findings in patients presenting with acute and chronic mesenteric ischemia and visceral aneurysms, and the value of these imaging techniques for therapy planning and follow-up.
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Affiliation(s)
- Klaus D Hagspiel
- Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, VA.
| | - Lucia Flors
- Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, VA
| | - Michael Hanley
- Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, VA
| | - Patrick T Norton
- Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, VA
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Rajiah P, Halliburton SS. Dual Energy Imaging in Cardiovascular CT: Current Status and Impact on Radiation, Contrast and Accuracy. CURRENT CARDIOVASCULAR IMAGING REPORTS 2014. [DOI: 10.1007/s12410-014-9289-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
Recent technologic advances in computed tomography (CT)--enabling the nearly simultaneous acquisition of clinical images using two different x-ray energy spectra--have sparked renewed interest in dual-energy CT. By interrogating the unique characteristics of different materials at different x-ray energies, dual-energy CT can be used to provide quantitative information about tissue composition, overcoming the limitations of attenuation-based conventional single-energy CT imaging. In the past few years, intensive research efforts have been devoted to exploiting the unique and powerful opportunities of dual-energy CT for a variety of clinical applications. This has led to CT protocol modifications for radiation dose reduction, improved diagnostic performance for detection and characterization of diseases, as well as image quality optimization. In this review, the authors discuss the basic principles, instrumentation and design, examples of current clinical applications in the abdomen and pelvis, and future opportunities of dual-energy CT.
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Affiliation(s)
- Daniele Marin
- From the Department of Radiology, Duke University Medical Center, Box 3808, Room 1531, Erwin Rd, Durham, NC 27710
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Shmilovich H, Cheng VY, Dey D, Rajani R, Nakazato R, Otaki Y, Nakanishi R, Vashistha V, Min JK, Berman DS. Optimizing image contrast display improves quantitative stenosis measurement in heavily calcified coronary arterial segments on coronary CT angiography: A proof-of-concept and comparison to quantitative invasive coronary angiography. Acad Radiol 2014; 21:797-804. [PMID: 24809320 DOI: 10.1016/j.acra.2014.02.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 02/23/2014] [Accepted: 02/25/2014] [Indexed: 11/18/2022]
Abstract
RATIONALE AND OBJECTIVES Blooming artifact from calcified plaques often renders measurement of stenosis impossible on coronary computed tomographic angiography (CTA). We sought to evaluate the impact of modifying window level on reducing blooming artifact, and its impact on stenosis quantification. MATERIALS AND METHODS We analyzed 125 calcified segments from 53 patients who underwent CTA and invasive coronary angiography (ICA). Segmental stenosis on CTA was measured using three window settings: width of 1000 Hounsfield units (HU) and level of 200 HU ("default"), 1500/200 HU ("widened"), and width and level based on the mean HU of the calcified plaque and pericoronary fat ("calcium-specific"). Segmental stenosis on ICA was quantified by a blinded experienced reader. RESULTS ICA found ≥50% stenosis in 30 segments. Displaying segments with widened and calcium-specific settings improved overall accuracy of detecting ≥50% stenosis (P's < 0.001) by increasing the rate of accurately quantifying <50% stenosis (P's < 0.001), and improved correlation of stenosis quantification to ICA (P's < 0.05). There was no difference in stenosis quantification accuracy between widened and calcium-specific window settings. Limits of agreement between CTA stenosis quantification and ICA narrowed with widened and calcium-specific settings. CONCLUSIONS We showed for the first time that in calcified segments, widening display window width significantly improved CTA quantification of stenosis compared to ICA.
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Affiliation(s)
- Haim Shmilovich
- Department of Medicine and Cardiac Imaging, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Taper Building No. 1258, Los Angeles, CA 90048.
| | - Victor Y Cheng
- Department of Medicine and Cardiac Imaging, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Taper Building No. 1258, Los Angeles, CA 90048
| | - Damini Dey
- Department of Medicine and Cardiac Imaging, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Taper Building No. 1258, Los Angeles, CA 90048
| | - Ronak Rajani
- Department of Medicine and Cardiac Imaging, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Taper Building No. 1258, Los Angeles, CA 90048
| | - Ryo Nakazato
- Department of Medicine and Cardiac Imaging, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Taper Building No. 1258, Los Angeles, CA 90048
| | - Yuka Otaki
- Department of Medicine and Cardiac Imaging, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Taper Building No. 1258, Los Angeles, CA 90048
| | - Rine Nakanishi
- Department of Medicine and Cardiac Imaging, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Taper Building No. 1258, Los Angeles, CA 90048
| | | | - James K Min
- Department of Medicine and Cardiac Imaging, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Taper Building No. 1258, Los Angeles, CA 90048
| | - Daniel S Berman
- Department of Medicine and Cardiac Imaging, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Taper Building No. 1258, Los Angeles, CA 90048
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Weininger M, Renker M, Rowe GW, Abro JA, Costello P, Schoepf UJ. Integrative computed tomographic imaging of coronary artery disease. Expert Rev Cardiovasc Ther 2014; 9:27-43. [DOI: 10.1586/erc.10.166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Dual energy MDCT assessment of renal lesions: an overview. Eur Radiol 2013; 24:353-62. [DOI: 10.1007/s00330-013-3030-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 08/26/2013] [Accepted: 09/11/2013] [Indexed: 02/07/2023]
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40
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Dual-energy lung perfusion and ventilation CT in children. Pediatr Radiol 2013; 43:298-307. [PMID: 23417255 DOI: 10.1007/s00247-012-2465-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 07/09/2012] [Indexed: 12/13/2022]
Abstract
Dual-energy thoracic CT provides two key insights into lung physiology, i.e. regional perfusion and ventilation, and has been actively investigated to find clinically relevant applications since the introduction of dual-source CT. This functional information provided by dual-energy thoracic CT is supplementary because high-resolution thoracic anatomy is entirely preserved on dual-energy thoracic CT. In addition, virtual non-contrast imaging can omit pre-contrast scanning. In this respect, dual-energy CT imaging technique is at least dose-neutral, which is a critical requirement for paediatric imaging. In this review, imaging protocols, analysis methods, clinical applications and diagnostic pitfalls of dual-energy thoracic CT for evaluating lung perfusion and ventilation in children are described.
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Bernsen MR, Ruggiero A, van Straten M, Kotek G, Haeck JC, Wielopolski PA, Krestin GP. Computed tomography and magnetic resonance imaging. Recent Results Cancer Res 2013. [PMID: 23179877 DOI: 10.1007/978-3-642-10853-2_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Imaging in Oncology is rapidly moving from the detection and size measurement of a lesion to the quantitative assessment of metabolic processes and cellular and molecular interactions. Increasing insights into cancer as a complex disease with involvement of the tumor stroma in tumor pathobiological processes have made it clear that for successful control of cancer, treatment strategies should not only be directed at the tumor cells but also targeted at the tumor microenvironment. This requires understanding of the complex molecular and cellular interactions in cancer tissue. Recent developments in imaging technology have increased the possibility to image various pathobiological processes in cancer development and response to treatment. For computed tomography (CT) and magnetic resonance imaging (MRI) various improvements in hardware, software, and imaging probes have lifted these modalities from classical anatomical imaging techniques to techniques suitable to image and quantify various physiological processes and molecular and cellular interactions. Next to a more general overview of possible imaging targets in oncology this chapter provides an overview of the various developments in CT and MRI technology and some specific applications.
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Affiliation(s)
- Monique R Bernsen
- Department of Radiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands.
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CT coronary angiography: coronary CT-flow quantification supplements morphological stenosis analysis. Eur J Radiol 2012; 82:608-16. [PMID: 23265182 DOI: 10.1016/j.ejrad.2012.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 07/29/2012] [Accepted: 08/05/2012] [Indexed: 11/22/2022]
Abstract
BACKGROUND Our rationale was to evaluate whether a 64-slice CT scanner allows accurate measurement of computed tomographic (CT) changes in coronary artery flow profiles and whether CT flow measurements are suitable for classifying the significance and hemodynamic relevance of a stenosis and thereby supplement as a functional parameter for morphological stenosis analysis. METHODS A total of 50 patients prospectively underwent computed tomography coronary angiography (coronary CTA) in a multidetector CT scanner (Brilliance 64, Philips)±1 day before or after invasive coronary angiography (ICA). Immediately thereafter, 2 radiologists reviewed the imaging data to detect any vessel segments with morphology poorly evaluable by coronary CTA. A locally constant cyclical measurement was acquired in these coronary arteries in breath-hold technique during the passage of a 50ml bolus of contrast media. For analysis, time-density curves of the bolus passage were registered in the coronary artery and the aorta (internal reference), the up-slopes were determined and correlated with each other. The results were compared with the ICA findings. RESULTS 47 of 50 CT flow measurements were evaluable. A good correlation was found between the degrees of stenosis and slope ratios in aorta and coronary artery (R(2)=0.92). The threshold corridor was 0.55-0.77 for distinguishing hemodynamically (≥70%) from non-hemodynamically relevant stenoses. CONCLUSIONS CT-based coronary artery flow measurements (CTFM) correlate well with the angiographically determined degree of stenosis and can elevate by non-invasive means the diagnostic accuracy of coronary CTA. From both a clinically diagnostic and scientific standpoint, CTFM proves a suitable method for quantifying coronary blood flow.
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Assessment of vascular contrast and depiction of stenoses in abdominopelvic and lower extremity vasculature: comparison of dual-energy MDCT with digital subtraction angiography. Acad Radiol 2012; 19:1149-57. [PMID: 22743115 DOI: 10.1016/j.acra.2012.04.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/12/2012] [Accepted: 04/13/2012] [Indexed: 12/22/2022]
Abstract
RATIONALE AND OBJECTIVES To assess whether dual-energy computed tomography (DECT) multidetector computed tomography (MDCT) angiography improves vascular contrast beyond MDCT angiography and digital subtraction angiography (DSA) while preserving the ability to precisely characterize stenoses, using DSA as reference standard. MATERIALS AND METHODS This prospective, Health Insurance Portability and Accountability Act-compliant, institutional review board-approved study was performed on 25 patients referred for lower extremity DECT angiography and subsequent DSA. Spectral data were postprocessed to create single-energy 120 kVp (MDCT series) and iodine-only (DECT series) datasets. The arterial tree was subdivided into 11 anatomical levels. Contrast-to-noise ratios (CNR) and corresponding coefficient -of variation (CV) of patent vessel segments were evaluated for DECT, MDCT, and DSA using analysis of variance comparisons. Degree of stenoses was determined for DECT, MDCT, and DSA and correlated with t-test, bivariate Pearson comparisons, and Bland-Altman plots. RESULTS Patent vasculature comprised 230 vessel segments. From infrarenal aorta to distal femoral arteries, DECT showed higher CNR compared to DSA and MDCT (P < .05); distal to the popliteal arteries, DSA achieved higher CNR (P < .05). Analyses of contrast homogeneity showed minimal CV above the knee for MDCT (≤9%) and for DSA below the knee (≤7%). Stenotic vasculature comprised 33 segments. Significant correlations of stenosis severity were found comparing DECT and MDCT with DSA as reference standard showing a 0.04-fold mean underestimation of stenoses on MDCT and no detectable mean variation on DECT compared with DSA. CONCLUSION DECT angiography improved contrast in vascular abdominopelvic and thigh distributions beyond MDCT angiography and DSA while preserving the ability to precisely assess severity of stenoses, using DSA as an accepted reference standard.
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State-of-the-art in CT hardware and scan modes for cardiovascular CT. J Cardiovasc Comput Tomogr 2012; 6:154-63. [PMID: 22551595 DOI: 10.1016/j.jcct.2012.04.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 04/03/2012] [Indexed: 11/22/2022]
Abstract
Multidetector row computed tomography (CT) allows noninvasive anatomic and functional imaging of the heart, great vessels, and coronary arteries. In recent years, there have been several advances in CT hardware, which have expanded the clinical utility of CT for cardiovascular imaging; such advances are ongoing. This review article from the Society of Cardiovascular Computed Tomography Basic and Emerging Sciences and Technology Working Group summarizes the technical aspects of current state-of-the-art CT hardware and describes the scan modes this hardware supports for cardiovascular CT imaging.
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Hartman R, Kawashima A, Takahashi N, Silva A, Vrtiska T, Leng S, Fletcher J, McCollough C. Applications of dual-energy CT in urologic imaging: an update. Radiol Clin North Am 2012; 50:191-205, v. [PMID: 22498438 DOI: 10.1016/j.rcl.2012.02.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This article discusses modern dual-energy computed tomography (DECT) and the unique material-specific information these scanners can provide. A description of the technical aspects of the various DECT techniques is provided. Specific clinical applications in urologic imaging, including chemical composition of urolithiasis, evaluation of renal masses, detection of urothelial neoplasms, and adrenal adenoma imaging, are discussed. The unique postprocessed image sets, including virtual noncontrast, iodine overlay, and stone composition, are described.
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Affiliation(s)
- Robert Hartman
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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Goo HW. CT radiation dose optimization and estimation: an update for radiologists. Korean J Radiol 2011; 13:1-11. [PMID: 22247630 PMCID: PMC3253393 DOI: 10.3348/kjr.2012.13.1.1] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 10/18/2011] [Indexed: 11/29/2022] Open
Abstract
In keeping with the increasing utilization of CT examinations, the greater concern about radiation hazards from examinations has been addressed. In this regard, CT radiation dose optimization has been given a great deal of attention by radiologists, referring physicians, technologists, and physicists. Dose-saving strategies are continuously evolving in terms of imaging techniques as well as dose management. Consequently, regular updates of this issue are necessary especially for radiologists who play a pivotal role in this activity. This review article will provide an update on how we can optimize CT dose in order to maximize the benefit-to-risk ratio of this clinically useful diagnostic imaging method.
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Affiliation(s)
- Hyun Woo Goo
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
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Henzler T, Porubsky S, Kayed H, Harder N, Krissak UR, Meyer M, Sueselbeck T, Marx A, Michaely H, Schoepf UJ, Schoenberg SO, Fink C. Attenuation-based characterization of coronary atherosclerotic plaque: Comparison of dual source and dual energy CT with single-source CT and histopathology. Eur J Radiol 2011; 80:54-9. [DOI: 10.1016/j.ejrad.2010.07.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2010] [Accepted: 07/28/2010] [Indexed: 11/26/2022]
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Schwarz F, Treitl M, Grimm J, Cyran C, Nikolaou K, Reiser M, Saam T. The relationship between plaque imaging characterization and treatment modality selection. Interv Cardiol 2011. [DOI: 10.2217/ica.11.67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Stolzmann P, Subramanian S, Abdelbaky A, Maurovich-Horvat P, Scheffel H, Tawakol A, Hoffmann U. Complementary Value of Cardiac FDG PET and CT for the Characterization of Atherosclerotic Disease. Radiographics 2011; 31:1255-69. [DOI: 10.1148/rg.315115028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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50
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Optimization of energy level for coronary angiography with dual-energy and dual-source computed tomography. Int J Cardiovasc Imaging 2011; 28:901-9. [DOI: 10.1007/s10554-011-9897-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 05/20/2011] [Indexed: 11/26/2022]
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