Volume 86, Issue 5 pp. 2402-2411
TECHNICAL NOTE

Specialized computational methods for denoising, B1 correction, and kinetic modeling in hyperpolarized 13C MR EPSI studies of liver tumors

Philip M. Lee

Corresponding Author

Philip M. Lee

UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

Correspondence

Philip M. Lee, Department of Radiology and Biomedical Imaging, University of California, San Francisco, 1700 Fourth Street, Byers Hall Suite 102, San Francisco, CA 94158, USA.

Email: [email protected]

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Hsin-Yu Chen

Hsin-Yu Chen

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Jeremy W. Gordon

Jeremy W. Gordon

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Zihan Zhu

Zihan Zhu

UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Peder E.Z. Larson

Peder E.Z. Larson

UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Nicholas Dwork

Nicholas Dwork

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Mark Van Criekinge

Mark Van Criekinge

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Lucas Carvajal

Lucas Carvajal

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Michael A. Ohliger

Michael A. Ohliger

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Zhen J. Wang

Zhen J. Wang

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Duan Xu

Duan Xu

UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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John Kurhanewicz

John Kurhanewicz

UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Robert A. Bok

Robert A. Bok

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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Rahul Aggarwal

Rahul Aggarwal

Department of Medicine, University of California, San Francisco, San Francisco, California, USA

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Pamela N. Munster

Pamela N. Munster

Department of Medicine, University of California, San Francisco, San Francisco, California, USA

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Daniel B. Vigneron

Daniel B. Vigneron

UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA

Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA

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First published: 03 July 2021
Citations: 6

Funding information

National Institutes of Health, Grant/Award Numbers: R01CA183071, U01EB026412, R01DK115987, and P41EB013598

Abstract

Purpose

To develop a novel post-processing pipeline for hyperpolarized (HP) 13C MRSI that integrates tensor denoising and urn:x-wiley:07403194:media:mrm28901:mrm28901-math-0004 correction to measure pyruvate-to-lactate conversion rates (kPL) in patients with liver tumors.

Methods

Seven HP 13C MR scans of progressing liver tumors were acquired using a custom 13C surface transmit/receive coil and the echo-planar spectroscopic imaging (EPSI) data analysis included B0 correction, tensor rank truncation, and zero- and first-order phase corrections to recover metabolite signals that would otherwise be obscured by spectral noise as well as a correction for inhomogeneous transmit (urn:x-wiley:07403194:media:mrm28901:mrm28901-math-0005) using a urn:x-wiley:07403194:media:mrm28901:mrm28901-math-0006 map aligned to the coil position for each patient scan. Processed HP data and corrected flip angles were analyzed with an inputless two-site exchange model to calculate kPL.

Results

Denoising averages SNR increases of pyruvate, lactate, and alanine were 37.4-, 34.0-, and 20.1-fold, respectively, with lactate and alanine dynamics most noticeably recovered and better defined. In agreement with Monte Carlo simulations, over-flipped regions underestimated kPL and under-flipped regions overestimated kPL. urn:x-wiley:07403194:media:mrm28901:mrm28901-math-0007 correction addressed this issue.

Conclusion

The new HP 13C EPSI post-processing pipeline integrated tensor denoising and urn:x-wiley:07403194:media:mrm28901:mrm28901-math-0008 correction to measure kPL in patients with liver tumors. These technical developments not only recovered metabolite signals in voxels that did not receive the prescribed flip angle, but also increased the extent and accuracy of kPL estimations throughout the tumor and adjacent regions including normal-appearing tissue and additional lesions.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.