title: Proton density water fraction as a biomarker of bone marrow cellularity: validation in ex vivo spine specimens.
abstract: The purpose of this study was to evaluate a magnetic resonance imaging (MRI) technique for quantifying the proton density water fraction (PDWF) as a biomarker of bone marrow cellularity. Thirty-six human bone marrow specimens from 18 donors were excised and subjected to different measurements of tissue composition: PDWF quantification using a multiple gradient echo MRI technique, three biochemical assays (triglyceride, total lipid and water content) and a histological assessment of cellularity. Results showed a strong correlation between PDWF and bone marrow cellularity from histology (r=0.72). A strong correlation was also found between PDWF and the biochemical assay of water content (r=0.76). These results suggest the PDWF is a predictor of bone marrow cellularity in tissues and can provide a non-invasive assessment of bone marrow changes in clinical patients undergoing radiotherapy.
authors.affiliation: Center for Advanced Radiotherapy Technologies, Department of Radiation Medicine and Applied Sciences, 3855 Health Sciences Dr. #0843, La Jolla, CA, USA.
authors.forename: Iain J
authors.initials: IJ
authors.lastname: MacEwan
authors.affiliation: Scripps Translational Science Institute, 3344 North Torrey Pines Court Suite 300, La Jolla, CA, USA.
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Glembotski
authors.affiliation: Scripps Translational Science Institute, 3344 North Torrey Pines Court Suite 300, La Jolla, CA, USA.
authors.forename: Darryl
authors.initials: D
authors.lastname: D'Lima
authors.affiliation: Department of Radiology, University of California San Diego, 408 Dickinson Street, San Diego, CA, USA.
authors.forename: Won
authors.initials: W
authors.lastname: Bae
authors.affiliation: Skeletal Translational Research Laboratory, Department of Orthopaedic Surgery, School of Medicine, University of California, San Diego, CA, USA.
authors.forename: Koichi
authors.initials: K
authors.lastname: Masuda
authors.affiliation: Department of Pathology, University of California San Diego, School of Medicine & VA Medical Center, San Diego, CA, USA.
authors.forename: Hooman H
authors.initials: HH
authors.lastname: Rashidi
authors.affiliation: Center for Advanced Radiotherapy Technologies, Department of Radiation Medicine and Applied Sciences, 3855 Health Sciences Dr. #0843, La Jolla, CA, USA.
authors.forename: Loren K
authors.initials: LK
authors.lastname: Mell
authors.affiliation: Department of Radiology, University of California San Diego, 408 Dickinson Street, San Diego, CA, USA. Electronic address: mbydder@ucsd.edu.
authors.forename: Mark
authors.initials: M
authors.lastname: Bydder
mesh_terms: D000328:Adult; D000368:Aged; D001834:Body Water; D001853:Bone Marrow / Q000033:anatomy & histology*; D001854:Bone Marrow Cells; D002102:Cadaver; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011522:Protons; D015203:Reproducibility of Results; D013904:Thoracic Vertebrae
chemical_list: D011522:Protons
keywords: Bone marrow; Cellularity; Fat quantification; MRI