TY - JOUR
T1 - CAPTURE
T2 - Consistently Acquired Projections for Tuned and Robust Estimation: A Self-Navigated Respiratory Motion Correction Approach
AU - Eldeniz, Cihat
AU - Fraum, Tyler
AU - Salter, Amber
AU - Chen, Yasheng
AU - Gach, H. Michael
AU - Parikh, Parag J.
AU - Fowler, Kathryn J.
AU - An, Hongyu
N1 - Funding Information:
Received for publication September 9, 2017; and accepted for publication, after revi-sion, November 16, 2017. From the *Center for Clinical Imaging Research, Mallinckrodt Institute of Radi-ology, †Radiology, ‡Biostatistics, §Neurology, and ||Radiation Oncology, and Biomedical Engineering, Washington University in St Louis, St Louis, MO. Partially supported by 2 grants from National Institute of Health National Cancer Insti-tute R01 CA159471 (H. Michael Gach) and National Institute of Health P30 NS098577 (Hongyu An). Conflicts of interest and source of funding: none declared. Supplemental digital contents are available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.investigativeradiology.com). Correspondence to: Cihat Eldeniz, PhD, Mallinckrodt Institute of Radiology, Washington University in St Louis, Center for Clinical Imaging and Research, 510 S Kingshighway Blvd, St Louis, MO 63110. E-mail: cihat.eldeniz@wustl. edu; Hongyu An, DSc, Mallinckrodt Institute of Radiology, Washington Univer-sity in St Louis, Center for Clinical Imaging Research, 510 S Kingshighway Blvd, St Louis, MO 63110. E-mail: hongyuan@wustl.edu. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0020-9996/18/5305–0293 DOI: 10.1097/RLI.0000000000000442
Publisher Copyright:
© 2018 Wolters Kluwer Health, Inc. All rights reserved.
PY - 2018/5/1
Y1 - 2018/5/1
N2 - Objectives In this study, we present a fully automated and robust self-navigated approach to obtain 4-dimensional (4-D) motion-resolved images during free breathing. Materials and Methods The proposed method, Consistently Acquired Projections for Tuned and Robust Estimation (CAPTURE), is a variant of the stack-of-stars gradient-echo sequence. A 1-D navigator was consistently acquired at a fixed azimuthal angle for all stacks of spokes to reduce nonphysiological signal contamination due to system imperfections. The resulting projections were then "tuned" using complex phase rotation to adapt to scan-to-scan variations, followed by the detection of the respiratory curve. Four-dimensional motion-corrected and uncorrected images were then reconstructed via respiratory and temporal binning, respectively. This Health Insurance Portability and Accountability Act-compliant study was performed with Institutional Review Board approval. A phantom experiment was performed using a custom-made deformable motion phantom with an adjustable frequency and amplitude. For in vivo experiments, 10 healthy participants and 12 liver tumor patients provided informed consent and were imaged with the CAPTURE sequence. Two radiologists, blinded to which images were motion-corrected and which were not, independently reviewed the images and scored the image quality using a 5-point Likert scale. Results In the respiratory motion phantom experiment, CAPTURE reversed the effects of motion blurring and restored edge sharpness from 36% to 78% of that observed in the images from the static scan. Despite large intra- and intersubject variability in respiration patterns, CAPTURE successfully detected the respiratory motion signal in all participants and significantly improved the image quality according to the subjective radiological assessments of 2 raters (P < 0.05 for both raters) with a 1 to 2-point improvement in the median Likert scores across the whole set of participants. Small lesions (<1 cm in size) which might otherwise be missed on uncorrected images because of motion blurring were more clearly depicted on the CAPTURE images. Conclusions CAPTURE provides a robust and fully automated solution for obtaining 4-D motion-resolved images in a free-breathing setting. With its unique tuning feature, CAPTURE can adapt to large intersubject and interscan variations. CAPTURE also enables better lesion delineation because of improved image sharpness, thereby increasing the visibility of small lesions.
AB - Objectives In this study, we present a fully automated and robust self-navigated approach to obtain 4-dimensional (4-D) motion-resolved images during free breathing. Materials and Methods The proposed method, Consistently Acquired Projections for Tuned and Robust Estimation (CAPTURE), is a variant of the stack-of-stars gradient-echo sequence. A 1-D navigator was consistently acquired at a fixed azimuthal angle for all stacks of spokes to reduce nonphysiological signal contamination due to system imperfections. The resulting projections were then "tuned" using complex phase rotation to adapt to scan-to-scan variations, followed by the detection of the respiratory curve. Four-dimensional motion-corrected and uncorrected images were then reconstructed via respiratory and temporal binning, respectively. This Health Insurance Portability and Accountability Act-compliant study was performed with Institutional Review Board approval. A phantom experiment was performed using a custom-made deformable motion phantom with an adjustable frequency and amplitude. For in vivo experiments, 10 healthy participants and 12 liver tumor patients provided informed consent and were imaged with the CAPTURE sequence. Two radiologists, blinded to which images were motion-corrected and which were not, independently reviewed the images and scored the image quality using a 5-point Likert scale. Results In the respiratory motion phantom experiment, CAPTURE reversed the effects of motion blurring and restored edge sharpness from 36% to 78% of that observed in the images from the static scan. Despite large intra- and intersubject variability in respiration patterns, CAPTURE successfully detected the respiratory motion signal in all participants and significantly improved the image quality according to the subjective radiological assessments of 2 raters (P < 0.05 for both raters) with a 1 to 2-point improvement in the median Likert scores across the whole set of participants. Small lesions (<1 cm in size) which might otherwise be missed on uncorrected images because of motion blurring were more clearly depicted on the CAPTURE images. Conclusions CAPTURE provides a robust and fully automated solution for obtaining 4-D motion-resolved images in a free-breathing setting. With its unique tuning feature, CAPTURE can adapt to large intersubject and interscan variations. CAPTURE also enables better lesion delineation because of improved image sharpness, thereby increasing the visibility of small lesions.
KW - complex phase rotation
KW - gradient delay
KW - motion correction
KW - self-navigated
UR - http://www.scopus.com/inward/record.url?scp=85045471760&partnerID=8YFLogxK
U2 - 10.1097/RLI.0000000000000442
DO - 10.1097/RLI.0000000000000442
M3 - Article
C2 - 29315083
AN - SCOPUS:85045471760
SN - 0020-9996
VL - 53
SP - 293
EP - 305
JO - Investigative Radiology
JF - Investigative Radiology
IS - 5
ER -