In-vivo quantitative T2 mapping of carotid arteries in atherosclerotic patients: segmentation and T2 measurement of plaque components.
BACKGROUND: Atherosclerotic plaques in carotid arteries can be characterized in-vivo by multicontrast cardiovascular magnetic resonance (CMR), which has been thoroughly validated with histology. However, the non-quantitative nature of multicontrast CMR and the need for extensive post-acquisition int...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
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BioMed Central
2013
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| _version_ | 1797056564588183552 |
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| author | Biasiolli, L Lindsay, A Chai, J Choudhury, R Robson, M |
| author_facet | Biasiolli, L Lindsay, A Chai, J Choudhury, R Robson, M |
| author_sort | Biasiolli, L |
| collection | OXFORD |
| description | BACKGROUND: Atherosclerotic plaques in carotid arteries can be characterized in-vivo by multicontrast cardiovascular magnetic resonance (CMR), which has been thoroughly validated with histology. However, the non-quantitative nature of multicontrast CMR and the need for extensive post-acquisition interpretation limit the widespread clinical application of in-vivo CMR plaque characterization. Quantitative T2 mapping is a promising alternative since it can provide absolute physical measurements of plaque components that can be standardized among different CMR systems and widely adopted in multi-centre studies. The purpose of this study was to investigate the use of in-vivo T2 mapping for atherosclerotic plaque characterization by performing American Heart Association (AHA) plaque type classification, segmenting carotid T2 maps and measuring in-vivo T2 values of plaque components. METHODS: The carotid arteries of 15 atherosclerotic patients (11 males, 71 ± 10 years) were imaged at 3 T using the conventional multicontrast protocol and Multiple-Spin-Echo (Multi-SE). T2 maps of carotid arteries were generated by mono-exponential fitting to the series of images acquired by Multi-SE using nonlinear least-squares regression. Two reviewers independently classified carotid plaque types following the CMR-modified AHA scheme, one using multicontrast CMR and the other using T2 maps and time-of-flight (TOF) angiography. A semi-automated method based on Bayes classifiers segmented the T2 maps of carotid arteries into 4 classes: calcification, lipid-rich necrotic core (LRNC), fibrous tissue and recent IPH. Mean ± SD of the T2 values of voxels classified as LRNC, fibrous tissue and recent IPH were calculated. RESULTS: In 37 images of carotid arteries from 15 patients, AHA plaque type classified by multicontrast CMR and by T2 maps (+ TOF) showed good agreement (76% of matching classifications and Cohen's κ = 0.68). The T2 maps of 14 normal arteries were used to measure T2 of tunica intima and media (T2 = 54 ± 13 ms). From 11865 voxels in the T2 maps of 15 arteries with advanced atherosclerosis, 2394 voxels were classified by the segmentation algorithm as LRNC (T2 = 37 ± 5 ms) and 7511 voxels as fibrous tissue (T2 = 56 ± 9 ms); 192 voxels were identified as calcification and one recent IPH (236 voxels, T2 = 107 ± 25 ms) was detected on T2 maps and confirmed by multicontrast CMR. CONCLUSIONS: This carotid CMR study shows the potential of in-vivo T2 mapping for atherosclerotic plaque characterization. Agreement between AHA plaque types classified by T2 maps (+TOF) and by conventional multicontrast CMR was good, and T2 measured in-vivo in LRNC, fibrous tissue and recent IPH demonstrated the ability to discriminate plaque components on T2 maps. |
| first_indexed | 2024-03-06T19:24:27Z |
| format | Journal article |
| id | oxford-uuid:1b3a1ff6-e148-4e27-80e5-59383c22fae7 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:24:27Z |
| publishDate | 2013 |
| publisher | BioMed Central |
| record_format | dspace |
| spelling | oxford-uuid:1b3a1ff6-e148-4e27-80e5-59383c22fae72022-03-26T10:59:15ZIn-vivo quantitative T2 mapping of carotid arteries in atherosclerotic patients: segmentation and T2 measurement of plaque components.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:1b3a1ff6-e148-4e27-80e5-59383c22fae7EnglishSymplectic Elements at OxfordBioMed Central2013Biasiolli, LLindsay, AChai, JChoudhury, RRobson, MBACKGROUND: Atherosclerotic plaques in carotid arteries can be characterized in-vivo by multicontrast cardiovascular magnetic resonance (CMR), which has been thoroughly validated with histology. However, the non-quantitative nature of multicontrast CMR and the need for extensive post-acquisition interpretation limit the widespread clinical application of in-vivo CMR plaque characterization. Quantitative T2 mapping is a promising alternative since it can provide absolute physical measurements of plaque components that can be standardized among different CMR systems and widely adopted in multi-centre studies. The purpose of this study was to investigate the use of in-vivo T2 mapping for atherosclerotic plaque characterization by performing American Heart Association (AHA) plaque type classification, segmenting carotid T2 maps and measuring in-vivo T2 values of plaque components. METHODS: The carotid arteries of 15 atherosclerotic patients (11 males, 71 ± 10 years) were imaged at 3 T using the conventional multicontrast protocol and Multiple-Spin-Echo (Multi-SE). T2 maps of carotid arteries were generated by mono-exponential fitting to the series of images acquired by Multi-SE using nonlinear least-squares regression. Two reviewers independently classified carotid plaque types following the CMR-modified AHA scheme, one using multicontrast CMR and the other using T2 maps and time-of-flight (TOF) angiography. A semi-automated method based on Bayes classifiers segmented the T2 maps of carotid arteries into 4 classes: calcification, lipid-rich necrotic core (LRNC), fibrous tissue and recent IPH. Mean ± SD of the T2 values of voxels classified as LRNC, fibrous tissue and recent IPH were calculated. RESULTS: In 37 images of carotid arteries from 15 patients, AHA plaque type classified by multicontrast CMR and by T2 maps (+ TOF) showed good agreement (76% of matching classifications and Cohen's κ = 0.68). The T2 maps of 14 normal arteries were used to measure T2 of tunica intima and media (T2 = 54 ± 13 ms). From 11865 voxels in the T2 maps of 15 arteries with advanced atherosclerosis, 2394 voxels were classified by the segmentation algorithm as LRNC (T2 = 37 ± 5 ms) and 7511 voxels as fibrous tissue (T2 = 56 ± 9 ms); 192 voxels were identified as calcification and one recent IPH (236 voxels, T2 = 107 ± 25 ms) was detected on T2 maps and confirmed by multicontrast CMR. CONCLUSIONS: This carotid CMR study shows the potential of in-vivo T2 mapping for atherosclerotic plaque characterization. Agreement between AHA plaque types classified by T2 maps (+TOF) and by conventional multicontrast CMR was good, and T2 measured in-vivo in LRNC, fibrous tissue and recent IPH demonstrated the ability to discriminate plaque components on T2 maps. |
| spellingShingle | Biasiolli, L Lindsay, A Chai, J Choudhury, R Robson, M In-vivo quantitative T2 mapping of carotid arteries in atherosclerotic patients: segmentation and T2 measurement of plaque components. |
| title | In-vivo quantitative T2 mapping of carotid arteries in atherosclerotic patients: segmentation and T2 measurement of plaque components. |
| title_full | In-vivo quantitative T2 mapping of carotid arteries in atherosclerotic patients: segmentation and T2 measurement of plaque components. |
| title_fullStr | In-vivo quantitative T2 mapping of carotid arteries in atherosclerotic patients: segmentation and T2 measurement of plaque components. |
| title_full_unstemmed | In-vivo quantitative T2 mapping of carotid arteries in atherosclerotic patients: segmentation and T2 measurement of plaque components. |
| title_short | In-vivo quantitative T2 mapping of carotid arteries in atherosclerotic patients: segmentation and T2 measurement of plaque components. |
| title_sort | in vivo quantitative t2 mapping of carotid arteries in atherosclerotic patients segmentation and t2 measurement of plaque components |
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