Yet more evidence that non-aqueous myelin lipids can be directly imaged with ultrashort echo time (UTE) MRI on a clinical 3T scanner: a lyophilized red blood cell membrane lipid study
Soo Hyun Shin,
Dina Moazamian,
Arya Suprana,
Chun Zeng,
Jiyo S. Athertya,
Michael Carl,
Yajun Ma,
Hyungseok Jang,
Jiang Du
Affiliations
Soo Hyun Shin
Department of Radiology, University of California, San Diego, La Jolla, CA, USA
Dina Moazamian
Department of Radiology, University of California, San Diego, La Jolla, CA, USA
Arya Suprana
Department of Radiology, University of California, San Diego, La Jolla, CA, USA; Shu Chien-Gene Lay Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
Chun Zeng
Department of Radiology, University of California, San Diego, La Jolla, CA, USA
Jiyo S. Athertya
Department of Radiology, University of California, San Diego, La Jolla, CA, USA
Michael Carl
GE Healthcare, San Diego, CA, USA
Yajun Ma
Department of Radiology, University of California, San Diego, La Jolla, CA, USA
Hyungseok Jang
Department of Radiology, University of California, San Diego, La Jolla, CA, USA
Jiang Du
Department of Radiology, University of California, San Diego, La Jolla, CA, USA; Shu Chien-Gene Lay Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA; Radiology Service, Veterans Affairs San Diego Healthcare System, La Jolla, CA, USA; Correspondence to.
Direct imaging of semi-solid lipids, such as myelin, is of great interest as a noninvasive biomarker of neurodegenerative diseases. Yet, the short T2 relaxation times of semi-solid lipid protons hamper direct detection through conventional magnetic resonance imaging (MRI) pulse sequences. In this study, we examined whether a three-dimensional ultrashort echo time (3D UTE) sequence can directly acquire signals from membrane lipids. Membrane lipids from red blood cells (RBC) were collected from commercially available blood as a general model of the myelin lipid bilayer and subjected to D2O exchange and freeze-drying for complete water removal. Sufficiently high MR signals were detected with the 3D UTE sequence, which showed an ultrashort T2* of ∼77–271 µs and a short T1 of ∼189 ms for semi-solid RBC membrane lipids. These measurements can guide designing UTE-based sequences for direct in vivo imaging of membrane lipids.
