1
|
Guo W, Zhao S, Xu H, He W, Yin L, Yao Z, Xu Z, Jin H, Wu D, Li C, Yang S, Zeng M. Comparison of machine learning-based CT fractional flow reserve with cardiac MR perfusion mapping for ischemia diagnosis in stable coronary artery disease. Eur Radiol 2024:10.1007/s00330-024-10650-6. [PMID: 38409549 DOI: 10.1007/s00330-024-10650-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 11/16/2023] [Accepted: 01/08/2024] [Indexed: 02/28/2024]
Abstract
OBJECTIVES To compare the diagnostic performance of machine learning (ML)-based computed tomography-derived fractional flow reserve (CT-FFR) and cardiac magnetic resonance (MR) perfusion mapping for functional assessment of coronary stenosis. METHODS Between October 2020 and March 2022, consecutive participants with stable coronary artery disease (CAD) were prospectively enrolled and underwent coronary CTA, cardiac MR, and invasive fractional flow reserve (FFR) within 2 weeks. Cardiac MR perfusion analysis was quantified by stress myocardial blood flow (MBF) and myocardial perfusion reserve (MPR). Hemodynamically significant stenosis was defined as FFR ≤ 0.8 or > 90% stenosis on invasive coronary angiography (ICA). The diagnostic performance of CT-FFR, MBF, and MPR was compared, using invasive FFR as a reference. RESULTS The study protocol was completed in 110 participants (mean age, 62 years ± 8; 73 men), and hemodynamically significant stenosis was detected in 36 (33%). Among the quantitative perfusion indices, MPR had the largest area under receiver operating characteristic curve (AUC) (0.90) for identifying hemodynamically significant stenosis, which is in comparison with ML-based CT-FFR on the vessel level (AUC 0.89, p = 0.71), with comparable sensitivity (89% vs 79%, p = 0.20), specificity (87% vs 84%, p = 0.48), and accuracy (88% vs 83%, p = 0.24). However, MPR outperformed ML-based CT-FFR on the patient level (AUC 0.96 vs 0.86, p = 0.03), with improved specificity (95% vs 82%, p = 0.01) and accuracy (95% vs 81%, p < 0.01). CONCLUSION ML-based CT-FFR and quantitative cardiac MR showed comparable diagnostic performance in detecting vessel-specific hemodynamically significant stenosis, whereas quantitative perfusion mapping had a favorable performance in per-patient analysis. CLINICAL RELEVANCE STATEMENT ML-based CT-FFR and MPR derived from cardiac MR performed well in diagnosing vessel-specific hemodynamically significant stenosis, both of which showed no statistical discrepancy with each other. KEY POINTS • Both machine learning (ML)-based computed tomography-derived fractional flow reserve (CT-FFR) and quantitative perfusion cardiac MR performed well in the detection of hemodynamically significant stenosis. • Compared with stress myocardial blood flow (MBF) from quantitative perfusion cardiac MR, myocardial perfusion reserve (MPR) provided higher diagnostic performance for detecting hemodynamically significant coronary artery stenosis. • ML-based CT-FFR and MPR from quantitative cardiac MR perfusion yielded similar diagnostic performance in assessing vessel-specific hemodynamically significant stenosis, whereas MPR had a favorable performance in per-patient analysis.
Collapse
Affiliation(s)
- Weifeng Guo
- Department of Radiology, Zhongshan Hospital, Fudan University, No. 180 Fenglin Road, Shanghai, 200032, China
- Department of Radiology, Shanghai Geriatric Medical Center, 2560 Chunshen Road, Minhang District, Shanghai, 201104, China
| | - Shihai Zhao
- Department of Radiology, Zhongshan Hospital, Fudan University, No. 180 Fenglin Road, Shanghai, 200032, China
- Department of Radiology, Shanghai Geriatric Medical Center, 2560 Chunshen Road, Minhang District, Shanghai, 201104, China
| | - Haijia Xu
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
- School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Wei He
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Lekang Yin
- Department of Radiology, Zhongshan Hospital, Fudan University, No. 180 Fenglin Road, Shanghai, 200032, China
- Department of Radiology, Shanghai Geriatric Medical Center, 2560 Chunshen Road, Minhang District, Shanghai, 201104, China
| | - Zhifeng Yao
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Zhihan Xu
- Siemens Healthineers China, Shanghai, China
| | - Hang Jin
- Department of Radiology, Zhongshan Hospital, Fudan University, No. 180 Fenglin Road, Shanghai, 200032, China
- Department of Radiology, Shanghai Geriatric Medical Center, 2560 Chunshen Road, Minhang District, Shanghai, 201104, China
| | - Dong Wu
- Department of Radiology, Zhongshan Hospital, Fudan University, No. 180 Fenglin Road, Shanghai, 200032, China
- Department of Radiology, Shanghai Geriatric Medical Center, 2560 Chunshen Road, Minhang District, Shanghai, 201104, China
| | - Chenguang Li
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Shan Yang
- Department of Radiology, Zhongshan Hospital, Fudan University, No. 180 Fenglin Road, Shanghai, 200032, China
| | - Mengsu Zeng
- Department of Radiology, Zhongshan Hospital, Fudan University, No. 180 Fenglin Road, Shanghai, 200032, China.
- Department of Radiology, Shanghai Geriatric Medical Center, 2560 Chunshen Road, Minhang District, Shanghai, 201104, China.
| |
Collapse
|
2
|
Chang A, Kang N, Chung J, Gupta AR, Parwani P. Evaluation of Ischemia with No Obstructive Coronary Arteries (INOCA) and Contemporary Applications of Cardiac Magnetic Resonance (CMR). MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1570. [PMID: 37763689 PMCID: PMC10537002 DOI: 10.3390/medicina59091570] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 09/29/2023]
Abstract
Ischemia with no obstructive coronary arteries (INOCA) is a relatively newly discovered ischemic phenotype that affects patients similarly to obstructive coronary artery disease (CAD) but has a unique pathophysiology and epidemiology. Patients with INOCA present with ischemic signs and symptoms but no obstructive CAD seen on coronary CTA or invasive coronary angiography, which can assess epicardial vessels. The mechanisms of INOCA can be grouped into three endotypes: coronary microvascular dysfunction, epicardial coronary vasospasm, or a combination of both. Accurate and comprehensive assessment of both epicardial and microvascular disease in suspected cases of INOCA is crucial for providing targeted therapy and improving outcomes in this underrepresented population. This review aims to clarify the complex pathophysiology of INOCA, present an overview of invasive and non-invasive diagnostic methods, and examine contemporary approaches for coronary perfusion assessment using cardiac magnetic resonance (CMR). We also explore how recent advancements in quantitative CMR can potentially revolutionize the evaluation of suspected INOCA by offering a rapid, accurate, and non-invasive diagnostic approach, thereby reducing the alarming number of cases that go undetected.
Collapse
Affiliation(s)
- Andrew Chang
- Division of Cardiology, Department of Medicine, Loma Linda University Health, Loma Linda, CA 92374, USA; (A.C.); (J.C.)
| | - Nicolas Kang
- Department of Medicine, Loma Linda University Health, Loma Linda, CA 92374, USA; (N.K.); (A.R.G.)
| | - Joseph Chung
- Division of Cardiology, Department of Medicine, Loma Linda University Health, Loma Linda, CA 92374, USA; (A.C.); (J.C.)
| | - Aakash Rai Gupta
- Department of Medicine, Loma Linda University Health, Loma Linda, CA 92374, USA; (N.K.); (A.R.G.)
| | - Purvi Parwani
- Division of Cardiology, Department of Medicine, Loma Linda University Health, Loma Linda, CA 92374, USA; (A.C.); (J.C.)
| |
Collapse
|
3
|
Franks R, Plein S, Chiribiri A. Clinical Application of Dynamic Contrast Enhanced Perfusion Imaging by Cardiovascular Magnetic Resonance. Front Cardiovasc Med 2021; 8:768563. [PMID: 34778420 PMCID: PMC8585782 DOI: 10.3389/fcvm.2021.768563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 09/27/2021] [Indexed: 12/12/2022] Open
Abstract
Functionally significant coronary artery disease impairs myocardial blood flow and can be detected non-invasively by myocardial perfusion imaging. While multiple myocardial perfusion imaging modalities exist, the high spatial and temporal resolution of cardiovascular magnetic resonance (CMR), combined with its freedom from ionising radiation make it an attractive option. Dynamic contrast enhanced CMR perfusion imaging has become a well-validated non-invasive tool for the assessment and risk stratification of patients with coronary artery disease and is recommended by international guidelines. This article presents an overview of CMR perfusion imaging and its clinical application, with a focus on chronic coronary syndromes, highlighting its strengths and challenges, and discusses recent advances, including the emerging role of quantitative perfusion analysis.
Collapse
Affiliation(s)
- Russell Franks
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Sven Plein
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, United Kingdom
| | - Amedeo Chiribiri
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| |
Collapse
|
4
|
The Use of Subclinical Atherosclerosis Imaging to Guide Preventive Cardiology Management. Curr Cardiol Rep 2021; 23:61. [PMID: 33961134 DOI: 10.1007/s11886-021-01490-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/09/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE OF THE REVIEW Clinical atherosclerotic cardiovascular disease (ASCVD) requires years to manifest, providing a window of opportunity for preventive cardiovascular management. Subclinical atherosclerosis imaging leverages this long latency period to estimate and improve future ASCVD risk. RECENT FINDINGS Coronary artery calcium (CAC) scoring has the most robust data in the detection of subclinical atherosclerosis. CAC scan significantly enhances cardiovascular risk stratification in addition to traditional risk models. Coronary computed tomography angiography data show similar strengths in subclinical atherosclerosis detection in addition to plaque morphology characterization with inherent limitations. Carotid intima-media thickness and ankle-brachial index are other modalities whose predictive value becomes incremental when added to the aforementioned modalities. When added to traditional risk models, subclinical atherosclerosis imaging modalities personalize future ASCVD risk stratification and assist in the initiation and rate of intensification of preventive therapies. Emerging imaging techniques exist but further research is required for primetime clinical use.
Collapse
|
5
|
Kotecha T, Chacko L, Chehab O, O’Reilly N, Martinez-Naharro A, Lazari J, Knott KD, Brown J, Knight D, Muthurangu V, Hawkins P, Plein S, Moon JC, Xue H, Kellman P, Rakhit R, Patel N, Fontana M. Assessment of Multivessel Coronary Artery Disease Using Cardiovascular Magnetic Resonance Pixelwise Quantitative Perfusion Mapping. JACC Cardiovasc Imaging 2020; 13:2546-2557. [DOI: 10.1016/j.jcmg.2020.06.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 06/04/2020] [Accepted: 06/24/2020] [Indexed: 01/06/2023]
|
6
|
Mendes JK, Adluru G, Likhite D, Fair MJ, Gatehouse PD, Tian Y, Pedgaonkar A, Wilson B, DiBella EVR. Quantitative 3D myocardial perfusion with an efficient arterial input function. Magn Reson Med 2020; 83:1949-1963. [PMID: 31670858 PMCID: PMC7047561 DOI: 10.1002/mrm.28050] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 10/02/2019] [Accepted: 10/03/2019] [Indexed: 12/21/2022]
Abstract
PURPOSE The purpose of this study was to further develop and combine several innovative sequence designs to achieve quantitative 3D myocardial perfusion. These developments include an optimized 3D stack-of-stars readout (150 ms per beat), efficient acquisition of a 2D arterial input function, tailored saturation pulse design, and potential whole heart coverage during quantitative stress perfusion. THEORY AND METHODS All studies were performed free-breathing on a Prisma 3T MRI scanner. Phantom validation was used to verify sequence accuracy. A total of 21 subjects (3 patients with known disease) were scanned, 12 with a rest only protocol and 9 with both stress (regadenoson) and rest protocols. First pass quantitative perfusion was performed with gadoteridol (0.075 mmol/kg). RESULTS Implementation and quantitative perfusion results are shown for healthy subjects and subjects with known coronary disease. Average rest perfusion for the 15 included healthy subjects was 0.79 ± 0.19 mL/g/min, the average stress perfusion for 6 healthy subject studies was 2.44 ± 0.61 mL/g/min, and the average global myocardial perfusion reserve ratio for 6 healthy subjects was 3.10 ± 0.24. Perfusion deficits for 3 patients with ischemia are shown. Average resting heart rate was 59 ± 7 bpm and the average stress heart rate was 81 ± 10 bpm. CONCLUSION This work demonstrates that a quantitative 3D myocardial perfusion sequence with the acquisition of a 2D arterial input function is feasible at high stress heart rates such as during stress. T1 values and gadolinium concentrations of the sequence match the reference standard well in a phantom, and myocardial rest and stress perfusion and myocardial perfusion reserve values are consistent with those published in literature.
Collapse
Affiliation(s)
- Jason Kraig Mendes
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City UT, USA
| | - Ganesh Adluru
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City UT, USA
| | - Devavrat Likhite
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City UT, USA
| | - Merlin J Fair
- Cardiovascular Research Centre, Royal Brompton Hospital, London, UK
- National Heart & Lung Institute, Imperial College London, London, UK
| | - Peter D Gatehouse
- Cardiovascular Research Centre, Royal Brompton Hospital, London, UK
- National Heart & Lung Institute, Imperial College London, London, UK
| | - Ye Tian
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City UT, USA
| | - Apoorva Pedgaonkar
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City UT, USA
| | - Brent Wilson
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City UT, USA
| | - Edward VR DiBella
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City UT, USA
| |
Collapse
|
7
|
Kotecha T, Martinez-Naharro A, Boldrini M, Knight D, Hawkins P, Kalra S, Patel D, Coghlan G, Moon J, Plein S, Lockie T, Rakhit R, Patel N, Xue H, Kellman P, Fontana M. Automated Pixel-Wise Quantitative Myocardial Perfusion Mapping by CMR to Detect Obstructive Coronary Artery Disease and Coronary Microvascular Dysfunction: Validation Against Invasive Coronary Physiology. JACC Cardiovasc Imaging 2019; 12:1958-1969. [PMID: 30772231 DOI: 10.1016/j.jcmg.2018.12.022] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 12/03/2018] [Accepted: 12/06/2018] [Indexed: 02/08/2023]
Abstract
OBJECTIVES This study sought to assess the performance of cardiovascular magnetic resonance (CMR) myocardial perfusion mapping against invasive coronary physiology reference standards for detecting coronary artery disease (CAD, defined by fractional flow reserve [FFR] ≤0.80), microvascular dysfunction (MVD) (defined by index of microcirculatory resistance [IMR] ≥25) and the ability to differentiate between the two. BACKGROUND Differentiation of epicardial (CAD) and MVD in patients with stable angina remains challenging. Automated in-line CMR perfusion mapping enables quantification of myocardial blood flow (MBF) to be performed rapidly within a clinical workflow. METHODS Fifty patients with stable angina and 15 healthy volunteers underwent adenosine stress CMR at 1.5T with quantification of MBF and myocardial perfusion reserve (MPR). FFR and IMR were measured in 101 coronary arteries during subsequent angiography. RESULTS Twenty-seven patients had obstructive CAD and 23 had nonobstructed arteries (7 normal IMR, 16 abnormal IMR). FFR positive (epicardial stenosis) areas had significantly lower stress MBF (1.47 ± 0.48 ml/g/min) and MPR (1.75 ± 0.60) than FFR-negative IMR-positive (MVD) areas (stress MBF: 2.10 ± 0.35 ml/g/min; MPR: 2.41 ± 0.79) and normal areas (stress MBF: 2.47 ± 0.50 ml/g/min; MPR: 2.94 ± 0.81). Stress MBF ≤1.94 ml/g/min accurately detected obstructive CAD on a regional basis (area under the curve: 0.90; p < 0.001). In patients without regional perfusion defects, global stress MBF <1.82 ml/g/min accurately discriminated between obstructive 3-vessel disease and MVD (area under the curve: 0.94; p < 0.001). CONCLUSIONS This novel automated pixel-wise perfusion mapping technique can be used to detect physiologically significant CAD defined by FFR, MVD defined by IMR, and to differentiate MVD from multivessel coronary disease. A CMR-based diagnostic algorithm using perfusion mapping for detection of epicardial disease and MVD warrants further clinical validation.
Collapse
Affiliation(s)
- Tushar Kotecha
- Institute of Cardiovascular Science, University College London, United Kingdom; Royal Free Hospital, London, United Kingdom
| | - Ana Martinez-Naharro
- Royal Free Hospital, London, United Kingdom; Division of Medicine, University College London, United Kingdom
| | | | - Daniel Knight
- Institute of Cardiovascular Science, University College London, United Kingdom; Royal Free Hospital, London, United Kingdom
| | - Philip Hawkins
- Royal Free Hospital, London, United Kingdom; Division of Medicine, University College London, United Kingdom
| | | | | | | | - James Moon
- Institute of Cardiovascular Science, University College London, United Kingdom; Barts Heart Centre, London, United Kingdom
| | - Sven Plein
- Institute of Cardiovascular and Metabolic Medicine, University of Leeds, United Kingdom
| | - Tim Lockie
- Royal Free Hospital, London, United Kingdom
| | - Roby Rakhit
- Institute of Cardiovascular Science, University College London, United Kingdom; Royal Free Hospital, London, United Kingdom
| | - Niket Patel
- Institute of Cardiovascular Science, University College London, United Kingdom; Royal Free Hospital, London, United Kingdom
| | - Hui Xue
- National Heart, Lung, and Blood Institute, National Institute of Health, Bethesda, Maryland
| | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institute of Health, Bethesda, Maryland
| | - Marianna Fontana
- Royal Free Hospital, London, United Kingdom; Division of Medicine, University College London, United Kingdom.
| |
Collapse
|
8
|
Gómez-Revelles S, Rossello X, Díaz-Villanueva J, López-Lima I, Sciarresi E, Estofán M, Carreras F, Pujadas S, Pons-Lladó G. Prognostic value of a new semiquantitative score system for adenosine stress myocardial perfusion by CMR. Eur Radiol 2018; 29:2263-2271. [PMID: 30406310 DOI: 10.1007/s00330-018-5774-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/24/2018] [Accepted: 09/19/2018] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Cardiovascular magnetic resonance (CMR) provides information on myocardial ischemia through stress perfusion studies. In clinical practice, the grading of induced perfusion defects is performed by visual estimation of their extension. The aim of our study is to devise a score of the degree of ischemia and to test its prognostic value. METHODS Between 2009 and 2011, patients with diagnosed or suspected coronary artery disease underwent stress perfusion CMR. A score of ischemic burden was calculated on the basis of (1) stress-induced perfusion defect, (2) persistence, (3) transmurality, and (4) stress-induced contractile defect. Follow-up was censored after 4 years and primary end-point was defined by a composite of death, heart failure episode, acute coronary syndrome, and ventricular arrhythmias. Univariate and multivariate logistic regressions were used to assess the strength of the association between the CMR ischemic variables, and the composite outcome. RESULTS Forty-four of the 128 patients (34%) presented with adverse events, while 84 (66%) did not. Sixty-one patients (48%) had negative perfusion studies while 67 (52%) showed perfusion defect. Patients with positive perfusion studies and adverse events (n = 39) had higher number of segments with persistent defect (3.3 vs 1.3, p = 0.001) and highest score (19.6 vs 13.3 p = 0.012) than patients with positive perfusion studies and absence of events (n = 28). The number of segments with persistent defect showed the strongest predictive value of adverse events (OR 1.54; CI 1.19-2.00; p < 0.001). CONCLUSIONS The score of ischemic burden proposed herein has prognostic value. Persistence of a perfusion defect has the strongest impact on prognosis. KEY POINTS • Cardiovascular magnetic resonance provides information on myocardial ischemia by visual estimation of the presence of perfusion defects induced by stress. • There is not a standardized method for grading perfusion defects which, in practice, is performed by visual estimation of their extension. • As proven in this study, the integration of several parameters of perfusion defects (in addition to extension) into a semiquantitative score has prognostic value.
Collapse
Affiliation(s)
- Sonia Gómez-Revelles
- Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, C/ Mas Casanovas 90, 08041, Barcelona, Spain.
- Clínica Creu Blanca, Barcelona, Spain.
- Universitat Autònoma de Barcelona, Barcelona, Spain.
| | - Xavier Rossello
- Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, C/ Mas Casanovas 90, 08041, Barcelona, Spain
| | | | | | | | | | - Francesc Carreras
- Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, C/ Mas Casanovas 90, 08041, Barcelona, Spain
- Clínica Creu Blanca, Barcelona, Spain
- Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Sandra Pujadas
- Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, C/ Mas Casanovas 90, 08041, Barcelona, Spain
- Clínica Creu Blanca, Barcelona, Spain
| | - Guillem Pons-Lladó
- Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, C/ Mas Casanovas 90, 08041, Barcelona, Spain
- Clínica Creu Blanca, Barcelona, Spain
- Universitat Autònoma de Barcelona, Barcelona, Spain
| |
Collapse
|
9
|
Min JY, Ko SM, Song IY, Yi JG, Hwang HK, Shin JK. Comparison of the Diagnostic Accuracies of 1.5T and 3T Stress Myocardial Perfusion Cardiovascular Magnetic Resonance for Detecting Significant Coronary Artery Disease. Korean J Radiol 2018; 19:1007-1020. [PMID: 30386133 PMCID: PMC6201977 DOI: 10.3348/kjr.2018.19.6.1007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/11/2018] [Indexed: 11/15/2022] Open
Abstract
Objective To compare the diagnostic performance of cardiovascular magnetic resonance (CMR) myocardial perfusion at 1.5- and 3-tesla (T) for detecting significant coronary artery disease (CAD), with invasive coronary angiography (ICA) as the reference method. Materials and Methods We prospectively enrolled 281 patients (age 62.4 ± 8.3 years, 193 men) with suspected or known CAD who had undergone 1.5T or 3T CMR and ICA. Two independent radiologists interpreted perfusion defects. With ICA as the reference standard, the diagnostic performance of 1.5T and 3T CMR for identifying significant CAD (≥ 50% diameter reduction of the left main and ≥ 70% diameter reduction of other epicardial arteries) was determined. Results No differences were observed in baseline characteristics or prevalence of CAD and old myocardial infarction (MI) using 1.5T (n = 135) or 3T (n = 146) systems. Sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curve (AUC) for detecting significant CAD were similar between the 1.5T (84%, 64%, 74%, 76%, and 0.75 per patient and 68%, 83%, 66%, 84%, and 0.76 per vessel) and 3T (80%, 71%, 71%, 80%, and 0.76 per patient and 75%, 86%, 64%, 91%, and 0.81 per vessel) systems. In patients with multi-vessel CAD without old MI, the sensitivity, specificity, and AUC with 3T were greater than those with 1.5T on a per-vessel basis (71% vs. 36%, 92% vs. 69%, and 0.82 vs. 0.53, respectively). Conclusion 3T CMR has similar diagnostic performance to 1.5T CMR in detecting significant CAD, except for higher diagnostic performance in patients with multi-vessel CAD without old MI.
Collapse
Affiliation(s)
- Jee Young Min
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 05030, Korea
| | - Sung Min Ko
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 05030, Korea
| | - In Young Song
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 05030, Korea
| | - Jung Geun Yi
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 05030, Korea
| | - Hweung Kon Hwang
- Department of Cardiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 05030, Korea
| | - Je Kyoun Shin
- Department of Thoracic Surgery, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 05030, Korea
| |
Collapse
|
10
|
Motwani M, Motlagh M, Gupta A, Berman DS, Slomka PJ. Reasons and implications of agreements and disagreements between coronary flow reserve, fractional flow reserve, and myocardial perfusion imaging. J Nucl Cardiol 2018; 25:104-119. [PMID: 26715599 DOI: 10.1007/s12350-015-0375-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 12/02/2015] [Indexed: 01/10/2023]
Abstract
Information on coronary physiology and myocardial blood flow (MBF) in patients with suspected angina is increasingly important to inform treatment decisions. A number of different techniques including myocardial perfusion imaging (MPI), noninvasive estimation of MBF, and coronary flow reserve (CFR), as well as invasive methods for CFR and fractional flow reserve (FFR) are now readily available. However, despite their incorporation into contemporary guidelines, these techniques are still poorly understood and their interpretation to guide revascularization decisions is often inconsistent. In particular, these inconsistencies arise when there are discrepancies between the various techniques. The purpose of this article is therefore to review the basic principles, techniques, and clinical value of MPI, FFR, and CFR-with particular focus on interpreting their agreements and disagreements.
Collapse
Affiliation(s)
- Manish Motwani
- Departments of Imaging and Medicine and the Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Mahsaw Motlagh
- Departments of Imaging and Medicine and the Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Anuj Gupta
- Division of Cardiovascular Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Daniel S Berman
- Departments of Imaging and Medicine and the Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Piotr J Slomka
- Departments of Imaging and Medicine and the Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
| |
Collapse
|
11
|
Detecting Triple-Vessel Disease with Cadmium Zinc Telluride-Based Single-Photon Emission Computed Tomography Using the Intensity Signal-to-Noise Ratio between Rest and Stress Studies. CONTRAST MEDIA & MOLECULAR IMAGING 2017; 2017:4945680. [PMID: 29114176 PMCID: PMC5661073 DOI: 10.1155/2017/4945680] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 08/10/2017] [Accepted: 08/27/2017] [Indexed: 12/23/2022]
Abstract
The purpose of this study was to investigate if a novel parameter, the stress-to-rest ratio of the signal-to-noise ratio (RSNR) obtained with a cadmium zinc telluride (CZT) SPECT scanner, could be used to distinguish triple-vessel disease (TVD) patients. Methods. One hundred and two patients with suspected coronary artery disease were retrospectively involved. Each subject underwent a Tl-201 SPECT scan and subsequent coronary angiography. Subjects were separated into TVD (n = 41) and control (n = 61) groups based on coronary angiography results using 50% as the stenosis cutoff. The RSNR was calculated by dividing the stress signal-to-noise ratio (SNR) by the rest SNR. Summed scores were calculated using quantitative perfusion SPECT (QPS) for all subjects. Results. The RSNR in the TVD group was found to be significantly lower than that in the control group (0.83 ± 0.15 and 1.06 ± 0.17, resp.; P < 0.01). Receiver-operating characteristic (ROC) analysis showed that RSNR can detect TVD more accurately than the summed difference score with higher sensitivity (85% versus 68%), higher specificity (90% versus 72%), and higher accuracy (88% versus 71%). Conclusion. The RSNR may serve as a useful index to assist the diagnosis of TVD when a fully automatic quantification method is used in CZT-based SPECT studies.
Collapse
|
12
|
Shirani J, Singh A, Agrawal S, Dilsizian V. Cardiac molecular imaging to track left ventricular remodeling in heart failure. J Nucl Cardiol 2017; 24:574-590. [PMID: 27480973 DOI: 10.1007/s12350-016-0620-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 07/13/2016] [Indexed: 12/11/2022]
Abstract
Cardiac left ventricular (LV) remodeling is the final common pathway of most primary cardiovascular diseases that manifest clinically as heart failure (HF). The more advanced the systolic HF and LV dysfunction, the worse the prognosis. The knowledge of the molecular, cellular, and neurohormonal mechanisms that lead to myocardial dysfunction and symptomatic HF has expanded rapidly and has allowed sophisticated approaches to understanding and management of the disease. New therapeutic targets for pharmacologic intervention in HF have also been identified through discovery of novel cellular and molecular components of membrane-bound receptor-mediated intracellular signal transduction cascades. Despite all advances, however, the prognosis of systolic HF has remained poor in general. This is, at least in part, related to the (1) relatively late institution of treatment due to reliance on gross functional and structural abnormalities that define the "heart failure phenotype" clinically; (2) remarkable genetic-based interindividual variations in the contribution of each of the many molecular components of cardiac remodeling; and (3) inability to monitor the activity of individual pathways to cardiac remodeling in order to estimate the potential benefits of pharmacologic agents, monitor the need for dose titration, and minimize side effects. Imaging of the recognized ultrastructural components of cardiac remodeling can allow redefinition of heart failure based on its "molecular phenotype," and provide a guide to implementation of "personalized" and "evidence-based" evaluation, treatment, and longitudinal monitoring of the disease beyond what is currently available through randomized controlled clinical trials.
Collapse
Affiliation(s)
- Jamshid Shirani
- Department of Cardiology, St. Luke's University Health Network, 801 Ostrum Street, Bethlehem, PA, USA.
| | - Amitoj Singh
- Department of Cardiology, St. Luke's University Health Network, 801 Ostrum Street, Bethlehem, PA, USA
| | - Sahil Agrawal
- Department of Cardiology, St. Luke's University Health Network, 801 Ostrum Street, Bethlehem, PA, USA
| | - Vasken Dilsizian
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| |
Collapse
|
13
|
Foley JRJ, Plein S, Greenwood JP. Assessment of stable coronary artery disease by cardiovascular magnetic resonance imaging: Current and emerging techniques. World J Cardiol 2017; 9:92-108. [PMID: 28289524 PMCID: PMC5329750 DOI: 10.4330/wjc.v9.i2.92] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 09/15/2016] [Accepted: 12/02/2016] [Indexed: 02/07/2023] Open
Abstract
Coronary artery disease (CAD) is a leading cause of death and disability worldwide. Cardiovascular magnetic resonance (CMR) is established in clinical practice guidelines with a growing evidence base supporting its use to aid the diagnosis and management of patients with suspected or established CAD. CMR is a multi-parametric imaging modality that yields high spatial resolution images that can be acquired in any plane for the assessment of global and regional cardiac function, myocardial perfusion and viability, tissue characterisation and coronary artery anatomy, all within a single study protocol and without exposure to ionising radiation. Advances in technology and acquisition techniques continue to progress the utility of CMR across a wide spectrum of cardiovascular disease, and the publication of large scale clinical trials continues to strengthen the role of CMR in daily cardiology practice. This article aims to review current practice and explore the future directions of multi-parametric CMR imaging in the investigation of stable CAD.
Collapse
|
14
|
Hussain ST, Chiribiri A, Morton G, Bettencourt N, Schuster A, Paul M, Perera D, Nagel E. Perfusion cardiovascular magnetic resonance and fractional flow reserve in patients with angiographic multi-vessel coronary artery disease. J Cardiovasc Magn Reson 2016; 18:44. [PMID: 27430288 PMCID: PMC4949877 DOI: 10.1186/s12968-016-0263-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/29/2016] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Perfusion cardiovascular magnetic resonance (CMR) and fractional flow reserve (FFR) are emerging as the most accurate tools for the assessment of myocardial ischemia noninvasively or in the catheter laboratory. However, there is limited data comparing CMR and FFR in patients with multi-vessel disease. This study aims to evaluate the correlation between myocardial ischemia detected by CMR with FFR in patients with multivessel coronary disease at angiography. METHODS AND RESULTS Forty-one patients (123 vascular territories) with angiographic 2- or 3-vessel coronary artery disease (visual stenosis >50 %) underwent high-resolution adenosine stress perfusion CMR at 1.5 T and FFR measurement. An FFR value of <0.75 was considered significant. On a per patient basis, CMR and FFR detected identical ischemic territories in 19 patients (46 %) (mean number of territories 0.7+/-0.7 in both (p = 1.0)). On a per vessel basis, 89 out of 123 territories demonstrated concordance between the CMR and FFR results (72 %). In 34 % of the study population, CMR resulted in fewer ischemic territories than FFR; in 12 % CMR resulted in more ischemic territories than FFR. There was good concordance between the two methods to detect myocardial ischemia on a per-patient (k =0.658 95 % CI 0.383-0.933) level and moderate concordance on a per-vessel (k = 0.453 95 % CI 0.294-0.612) basis. CONCLUSIONS There is good concordance between perfusion CMR and FFR for the identification of myocardial ischemia in patients with multi-vessel disease. However, some discrepancy remains and at this stage it is unclear whether CMR underestimates or FFR overestimates the number of ischemic segments in multi-vessel disease.
Collapse
Affiliation(s)
- Shazia T. Hussain
- />Papworth Hospital NHS trust, Papworth Everard, Papworth Everard, Cambridgeshire UK
- />Cardiology Department, Papworth Hospital, Papworth Everard, CB23 3RE UK
| | - Amedeo Chiribiri
- />King’s College London BHF Centre of Excellence, NIHR Biomedical Research Centre and Welcome Trust and EPSRC Medical Engineering Centre at Guy’s and St. Thomas’ NHS Foundation Trust, Division of Imaging Sciences, The Rayne Institute, London, UK
| | | | - Nuno Bettencourt
- />Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Vila Nova de Gaia, Portugal
| | - Andreas Schuster
- />Department of Cardiology and Pulmonology and German Centre for Cardiovascular Research, Göttingen, Germany
| | - Matthias Paul
- />Luzerner Kantonsspital, 6000 Luzern 16, Switzerland
| | - Divaka Perera
- />King’s College London BHF Centre of Excellence, NIHR Biomedical Research Centre at Guy’s and St. Thomas’ NHS Foundation Trust, Cardiovascular Division, The Rayne Institute, London, UK
| | - Eike Nagel
- />DZHK Centre for Cardiovascular Imaging, University Hospital Frankfurt/Main, Frankfurt/Main, Germany
| |
Collapse
|
15
|
McDiarmid AK, Ripley DP, Mohee K, Kozerke S, Greenwood JP, Plein S, Motwani M. Three-dimensional whole-heart vs. two-dimensional high-resolution perfusion-CMR: a pilot study comparing myocardial ischaemic burden. Eur Heart J Cardiovasc Imaging 2015; 17:900-8. [PMID: 26450417 DOI: 10.1093/ehjci/jev231] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 08/26/2015] [Indexed: 01/20/2023] Open
Abstract
AIMS Typically, myocardial perfusion imaging with two-dimensional (2D) cardiovascular magnetic resonance (CMR) acquires data in three to four myocardial slices at a spatial resolution of 2-3 mm. However, accelerated data acquisition can facilitate higher spatial resolution (<2 mm) or three-dimensional (3D) whole-heart coverage (up to 16 slices). This study aims to compare image quality, diagnostic confidence, and quantitation of myocardial ischaemic burden (MIB) between 2D high-resolution and 3D whole-heart perfusion-CMR. METHODS AND RESULTS Twenty-seven patients with stable angina underwent both high-resolution 2D and whole-heart 3D perfusion-CMR. Total perfusion defect (TPD) and total scar burden (TSB) areas were contoured and expressed as percentage myocardium. MIB was calculated by subtracting TSB from TPD. Image quality, artefact, and diagnostic confidence scores were similar for both techniques (P>0.05). The mean MIB from high-resolution and 3D acquisition was similar (4.3±5.2% vs. 4.1±4.9%; P=0.81), with a strong correlation between techniques (r=0.72; P<0.001). There was no systematic bias for estimates of MIB between techniques [mean bias=-0.17%, 95% confidence interval (CI): -1.7 to -1.3%] and the 95% limits of agreement were -7.5 to 7.2%. When used to categorize MIB as >10% or <10%, there was only fair agreement between the two techniques (κ=0.29, 95% CI: -0.12 to 0.70). CONCLUSION There is strong correlation and broad agreement between estimates of MIB from both techniques. However, the 95% limits of agreement are relatively wide and therefore a larger comparative study is needed before they can be considered interchangeable-particularly around the clinically relevant 10% threshold.
Collapse
Affiliation(s)
- Adam K McDiarmid
- Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - David P Ripley
- Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Kevin Mohee
- Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - John P Greenwood
- Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Sven Plein
- Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Manish Motwani
- Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| |
Collapse
|
16
|
Edvardsen T, Bucciarelli-Ducci C, Saraste A, Pierard LA, Knuuti J, Maurer G, Habib G, Lancellotti P. The year 2014 in the European Heart Journal - Cardiovascular Imaging. Part I. Eur Heart J Cardiovasc Imaging 2015; 16:712-8. [DOI: 10.1093/ehjci/jev150] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
|
17
|
Wongpraparut N, Piyophirapong S, Maneesai A, Sribhen K, Krittayaphong R, Pongakasira R, White HD. High-sensitivity cardiac troponin T in stable patients undergoing pharmacological stress testing. Clin Cardiol 2015; 38:293-9. [PMID: 25955350 DOI: 10.1002/clc.22392] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 01/03/2015] [Accepted: 01/06/2015] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Acute changes in high-sensitivity troponin T (hs-TnT) are induced by myocardial ischemia during exercise stress testing, but there are no reports of pharmacological stress testing. HYPOTHESIS The pattern of troponin release by myocardial ischemia-induced pharmacological stress testing differs according to the ischemic burden in stable patients. METHODS In total, 250 patients with suspected coronary artery disease underwent pharmacological stress magnetic resonance imaging (MRI). The amount and degree of myocardial ischemia on MRI and ischemic outcomes at 6 months were determined. hs-TnT levels were measured at baseline and 1 and 3 hours after testing. The 6-month clinical outcome was prespecified. RESULTS Fifty-one patients had moderate to severe myocardial ischemia (group A), and 199 patients had no or mild myocardial ischemia (group B). hs-TnT levels were significantly higher in group A than B at baseline (11 vs 8 pg/mL, P = 0.016) and at 1 hour (12 vs 8 pg/mL, P = 0.009) and 3 hours after testing (12 vs 9 pg/mL, P = 0.012). Baseline hs-TnT levels of ≥14 pg/mL showed a 43% sensitivity and 77% specificity in predicting moderate to severe ischemia by MRI (P = 0.03; area under the curve: 0.608, P = 0.017). Patients administered dobutamine had a higher acute change in hs-TnT levels 3 hours after testing than did those administered adenosine (21 vs 0 pg/mL, P < 0.001). There was a trend toward a higher incidence of myocardial infarction in patients with baseline hs-TnT levels of ≥14 pg/mL. CONCLUSIONS hs-TnT levels are significantly higher in patients with moderate to severe than no or mild myocardial ischemia.
Collapse
Affiliation(s)
- Nattawut Wongpraparut
- Division of Cardiology, Department of Medicine, Faculty of Medicine Siriraj hospital, Mahidol University, Bangkok, Thailand
| | - Sudarat Piyophirapong
- Department of Clinical Pathology, Faculty of Medicine Siriraj hospital, Mahidol University, Bangkok, Thailand
| | - Adisak Maneesai
- Division of Cardiology, Department of Medicine, Faculty of Medicine Siriraj hospital, Mahidol University, Bangkok, Thailand
| | - Kosit Sribhen
- Department of Clinical Pathology, Faculty of Medicine Siriraj hospital, Mahidol University, Bangkok, Thailand
| | - Rungroj Krittayaphong
- Division of Cardiology, Department of Medicine, Faculty of Medicine Siriraj hospital, Mahidol University, Bangkok, Thailand
| | - Rungtiwa Pongakasira
- Her Majesty Cardiac Center, Faculty of Medicine Siriraj hospital, Mahidol University, Bangkok, Thailand
| | - Harvey D White
- Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand
| |
Collapse
|
18
|
Ko SM, Hwang HK, Kim SM, Cho IH. Multi-modality imaging for the assessment of myocardial perfusion with emphasis on stress perfusion CT and MR imaging. Int J Cardiovasc Imaging 2015; 31 Suppl 1:1-21. [PMID: 25809387 DOI: 10.1007/s10554-015-0645-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 03/16/2015] [Indexed: 01/29/2023]
Abstract
High-quality and non-invasive diagnostic tools for assessing myocardial ischemia are necessary for therapeutic decisions regarding coronary artery disease. Myocardial perfusion has been studied using myocardial contrast echo perfusion, single-photon emission computed tomography, positron emission tomography, cardiovascular magnetic resonance, and, more recently, computed tomography. The addition of coronary computed tomography angiography to myocardial perfusion imaging improves the specificity and overall diagnostic accuracy of detecting the hemodynamic significance of coronary artery stenosis. This study reviews the benefits, limitations, and imaging findings of various imaging modalities for assessing myocardial perfusion, with particular emphasis on stress perfusion computed tomography and cardiovascular magnetic resonance imaging.
Collapse
Affiliation(s)
- Sung Min Ko
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, 120-1 Neungdong-ro, Hwayang-dong, Gwangjin-gu, Seoul, 143-729, Korea,
| | | | | | | |
Collapse
|
19
|
|