Simultaneous ECG-gated PET imaging of multiple mice

Jurgen Seidel; Marcelino L Bernardo; Karen J Wong; Biying Xu; Mark R Williams; Frank Kuo; Elaine M Jagoda; Falguni Basuli; Changhui Li; Gary L Griffiths; Michael V Green; Peter L Choyke

doi:10.1016/j.nucmedbio.2014.03.015

Simultaneous ECG-gated PET imaging of multiple mice

Nucl Med Biol. 2014 Aug;41(7):582-6. doi: 10.1016/j.nucmedbio.2014.03.015. Epub 2014 Mar 29.

Authors

Affiliations

¹ Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; Contractor to Leidos Biomedical Research, Inc., Frederick, MD, USA. Electronic address: jseidel1@mail.nih.gov.
² Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; Leidos Biomedical Research, Inc., Frederick, MD, USA.
³ Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
⁴ Imaging Probe Development Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA; Kelly Services Inc., Troy, MI, USA.
⁵ Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD, USA.
⁶ Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; Clinical Research Directorate/CMRP, Leidos Biomedical Research, Inc. (formerly SAIC-Frederick, Inc.) Frederick National Laboratory for Cancer Research, Frederick, MD, USA.
⁷ Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; Contractor to Leidos Biomedical Research, Inc., Frederick, MD, USA.

Abstract

Introduction: We describe and illustrate a method for creating ECG-gated PET images of the heart for each of several mice imaged at the same time. The method is intended to increase "throughput" in PET research studies of cardiac dynamics or to obtain information derived from such studies, e.g. tracer concentration in end-diastolic left ventricular blood.

Methods: An imaging bed with provisions for warming, anesthetic delivery, etc., was fabricated by 3D printing to allow simultaneous PET imaging of two side-by-side mice. After electrode attachment, tracer injection and placement of the animals in the scanner field of view, ECG signals from each animal were continuously analyzed and independent trigger markers generated whenever an R-wave was detected in each signal. PET image data were acquired in "list" mode and these trigger markers were inserted into this list along with the image data. Since each mouse is in a different spatial location in the FOV, sorting of these data using trigger markers first from one animal and then the other yields two independent and correctly formed ECG-gated image sequences that reflect the dynamical properties of the heart during an "average" cardiac cycle.

Results: The described method yields two independent ECG-gated image sequences that exhibit the expected properties in each animal, e.g. variation of the ventricular cavity volumes from maximum to minimum and back during the cardiac cycle in the processed animal with little or no variation in these volumes during the cardiac cycle in the unprocessed animal.

Conclusion: ECG-gated image sequences for each of several animals can be created from a single list mode data collection using the described method. In principle, this method can be extended to more than two mice (or other animals) and to other forms of physiological gating, e.g. respiratory gating, when several subjects are imaged at the same time.

Keywords: Blood pool imaging; ECG-gated PET imaging; Pre-clinical cardiac PET imaging; [(18)F] albumin.

MeSH terms

Animals
Cardiac-Gated Imaging Techniques / instrumentation
Cardiac-Gated Imaging Techniques / methods*
Mice
Positron-Emission Tomography / instrumentation
Positron-Emission Tomography / methods*
Time Factors

Abstract

MeSH terms

Grants and funding