dc.contributor.author | Freedman, JN | |
dc.contributor.author | Collins, DJ | |
dc.contributor.author | Bainbridge, H | |
dc.contributor.author | Rank, CM | |
dc.contributor.author | Nill, S | |
dc.contributor.author | Kachelrieß, M | |
dc.contributor.author | Oelfke, U | |
dc.contributor.author | Leach, MO | |
dc.contributor.author | Wetscherek, A | |
dc.date.accessioned | 2017-05-23T14:50:32Z | |
dc.date.issued | 2017-10-01 | |
dc.identifier.citation | Investigative radiology, 2017, 52 (10), pp. 563 - 573 | |
dc.identifier.issn | 0020-9996 | |
dc.identifier.uri | https://repository.icr.ac.uk/handle/internal/642 | |
dc.identifier.eissn | 1536-0210 | |
dc.identifier.doi | 10.1097/rli.0000000000000381 | |
dc.description.abstract | OBJECTIVES: The aim of this study was to develop and verify a method to obtain good temporal resolution T2-weighted 4-dimensional (4D-T2w) magnetic resonance imaging (MRI) by using motion information from T1-weighted 4D (4D-T1w) MRI, to support treatment planning in MR-guided radiotherapy. MATERIALS AND METHODS: Ten patients with primary non-small cell lung cancer were scanned at 1.5 T axially with a volumetric T2-weighted turbo spin echo sequence gated to exhalation and a volumetric T1-weighted stack-of-stars spoiled gradient echo sequence with golden angle spacing acquired in free breathing. From the latter, 20 respiratory phases were reconstructed using the recently developed 4D joint MoCo-HDTV algorithm based on the self-gating signal obtained from the k-space center. Motion vector fields describing the respiratory cycle were obtained by deformable image registration between the respiratory phases and projected onto the T2-weighted image volume. The resulting 4D-T2w volumes were verified against the 4D-T1w volumes: an edge-detection method was used to measure the diaphragm positions; the locations of anatomical landmarks delineated by a radiation oncologist were compared and normalized mutual information was calculated to evaluate volumetric image similarity. RESULTS: High-resolution 4D-T2w MRI was obtained. Respiratory motion was preserved on calculated 4D-T2w MRI, with median diaphragm positions being consistent with less than 6.6 mm (2 voxels) for all patients and less than 3.3 mm (1 voxel) for 9 of 10 patients. Geometrical positions were coherent between 4D-T1w and 4D-T2w MRI as Euclidean distances between all corresponding anatomical landmarks agreed to within 7.6 mm (Euclidean distance of 2 voxels) and were below 3.8 mm (Euclidean distance of 1 voxel) for 355 of 470 pairs of anatomical landmarks. Volumetric image similarity was commensurate between 4D-T1w and 4D-T2w MRI, as mean percentage differences in normalized mutual information (calculated over all respiratory phases and patients), between corresponding respiratory phases of 4D-T1w and 4D-T2w MRI and the tie-phase of 4D-T1w and 3-dimensional T2w MRI, were consistent to 0.41% ± 0.37%. Four-dimensional T2w MRI displayed tumor extent, structure, and position more clearly than corresponding 4D-T1w MRI, especially when mobile tumor sites were adjacent to organs at risk. CONCLUSIONS: A methodology to obtain 4D-T2w MRI that retrospectively applies the motion information from 4D-T1w MRI to 3-dimensional T2w MRI was developed and verified. Four-dimensional T2w MRI can assist clinicians in delineating mobile lesions that are difficult to define on 4D-T1w MRI, because of poor tumor-tissue contrast. | |
dc.format | Print | |
dc.format.extent | 563 - 573 | |
dc.language | eng | |
dc.language.iso | eng | |
dc.publisher | LIPPINCOTT WILLIAMS & WILKINS | |
dc.rights.uri | https://creativecommons.org/licenses/by/4.0 | |
dc.subject | Humans | |
dc.subject | Carcinoma, Non-Small-Cell Lung | |
dc.subject | Lung Neoplasms | |
dc.subject | Imaging, Three-Dimensional | |
dc.subject | Radiotherapy Planning, Computer-Assisted | |
dc.subject | Aged | |
dc.subject | Aged, 80 and over | |
dc.subject | Middle Aged | |
dc.subject | Female | |
dc.subject | Male | |
dc.subject | Magnetic Resonance Imaging, Interventional | |
dc.title | T2-Weighted 4D Magnetic Resonance Imaging for Application in Magnetic Resonance-Guided Radiotherapy Treatment Planning. | |
dc.type | Journal Article | |
dcterms.dateAccepted | 2017-03-20 | |
rioxxterms.versionofrecord | 10.1097/rli.0000000000000381 | |
rioxxterms.licenseref.uri | https://creativecommons.org/licenses/by/4.0 | |
rioxxterms.licenseref.startdate | 2017-10 | |
rioxxterms.type | Journal Article/Review | |
dc.relation.isPartOf | Investigative radiology | |
pubs.issue | 10 | |
pubs.notes | No embargo | |
pubs.organisational-group | /ICR | |
pubs.organisational-group | /ICR/Primary Group | |
pubs.organisational-group | /ICR/Primary Group/ICR Divisions | |
pubs.organisational-group | /ICR/Primary Group/ICR Divisions/Radiotherapy and Imaging | |
pubs.organisational-group | /ICR/Primary Group/ICR Divisions/Radiotherapy and Imaging/Magnetic Resonance | |
pubs.organisational-group | /ICR/Primary Group/ICR Divisions/Radiotherapy and Imaging/Radiotherapy Physics Modelling | |
pubs.organisational-group | /ICR/Primary Group/Royal Marsden Clinical Units | |
pubs.organisational-group | /ICR | |
pubs.organisational-group | /ICR/Primary Group | |
pubs.organisational-group | /ICR/Primary Group/ICR Divisions | |
pubs.organisational-group | /ICR/Primary Group/ICR Divisions/Radiotherapy and Imaging | |
pubs.organisational-group | /ICR/Primary Group/ICR Divisions/Radiotherapy and Imaging/Magnetic Resonance | |
pubs.organisational-group | /ICR/Primary Group/ICR Divisions/Radiotherapy and Imaging/Radiotherapy Physics Modelling | |
pubs.organisational-group | /ICR/Primary Group/Royal Marsden Clinical Units | |
pubs.publication-status | Published | |
pubs.volume | 52 | |
pubs.embargo.terms | No embargo | |
icr.researchteam | Magnetic Resonance | |
icr.researchteam | Radiotherapy Physics Modelling | |
dc.contributor.icrauthor | Freedman, Joshua | |
dc.contributor.icrauthor | Collins, David | |
dc.contributor.icrauthor | Bainbridge, Hannah | |
dc.contributor.icrauthor | Nill, Simeon | |
dc.contributor.icrauthor | Leach, Martin | |
dc.contributor.icrauthor | Wetscherek, Andreas | |