Enhanced super-resolution reconstruction of T1w time-resolved 4DMRI in low-contrast tissue using 2-step hybrid deformable image registration

© 2020 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine..

PURPOSE: Deformable image registration (DIR) in low-contrast tissues is often suboptimal because of low visibility of landmarks, low driving-force to deform, and low penalty for misalignment. We aim to overcome the shortcomings for improved reconstruction of time-resolved four-dimensional magnetic resonance imaging (TR-4DMRI).

METHODS AND MATERIALS: Super-resolution TR-4DMRI reconstruction utilizes DIR to combine high-resolution (highR:2x2x2mm3 ) breath-hold (BH) and low-resolution (lowR:5x5x5mm3 ) free-breathing (FB) 3D cine (2Hz) images to achieve clinically acceptable spatiotemporal resolution. A 2-step hybrid DIR approach was developed to segment low-dynamic-range (LDR) regions: low-intensity lungs and high-intensity "bodyshell" (=body-lungs) for DIR refinement after conventional DIR. The intensity in LDR regions was renormalized to the full dynamic range (FDR) to enhance local tissue contrast. A T1-mapped 4D XCAT digital phantom was created, and seven volunteers and five lung cancer patients were scanned with two BH and one 3D cine series per subject to compare the 1-step conventional and 2-step hybrid DIR using: (a) the ground truth in the phantom, (b) highR-BH references, which were used to simulate 3D cine images by down-sampling and Rayleigh-noise-adding, and (c) cross-verification between two TR-4DMRI images reconstructed from two BHs. To assess DIR improvement, 8-17 blood vessel bifurcations were used in volunteers, and lung tumor position, size, and shape were used in phantom and patients, together with the voxel intensity correlation (VIC), structural similarity (SSIM), and cross-consistency check (CCC).

RESULTS: The 2-step hybrid DIR improves contrast and DIR accuracy. In volunteers, it improves low-contrast alignment from 6.5 ± 1.8 mm to 3.3 ± 1.0 mm. In phantom, it improves tumor center of mass alignment (COM = 1.3 ± 0.2 mm) and minimizes DIR directional difference. In patients, it produces almost-identical tumor COM, size, and shape (dice> 0.85) as the reference. The VIC and SSIM are significantly increased and the number of CCC outliers are reduced by half.

CONCLUSION: The 2-step hybrid DIR improves low-contrast-tissue alignment and increases lung tumor fidelity. It is recommended to adopt the 2-step hybrid DIR for TR-4DMRI reconstruction.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:21

Enthalten in:

Journal of applied clinical medical physics - 21(2020), 10 vom: 04. Okt., Seite 25-39

Sprache:

Englisch

Beteiligte Personen:

Nie, Xingyu [VerfasserIn]
Huang, Kirk [VerfasserIn]
Deasy, Joseph [VerfasserIn]
Rimner, Andreas [VerfasserIn]
Li, Guang [VerfasserIn]

Links:

Volltext

Themen:

Deformable image registration (DIR)
Journal Article
Radiotherapy
Respiratory-induced tumor motion
Super-resolution image reconstruction
Time-resolved 4DMRI

Anmerkungen:

Date Completed 21.06.2021

Date Revised 21.06.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1002/acm2.12988

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM315321873