title: Confirming improved detection of gadolinium in bone using in vivo XRF.
abstract: The safety of using Gd in MRI contrast agents has recently been questioned, due to recent evidence of the retention of Gd in individuals with healthy renal function. Bone has proven to be a storage site for Gd, as unusually high concentrations have been measured in femoral heads of patients undergoing hip replacement surgery, as well as in autopsy samples. All previous measurements of Gd in bone have been invasive and required the bone to be removed from the body. X-ray fluorescence (XRF) offers a non-invasive and non-destructive method for carrying out in vivo measurements of Gd in humans. An updated XRF system provides improved detection limits in a short measurement time of 30-min. A new four-detector system and higher activity Cd-109 excitation source of 5GBq results in minimum detection limits (MDLs) of 1.64-1.72μgGd/g plaster for an average overlaying tissue thickness of the tibia. These levels are well within the range of previous in vitro Gd measurements. Additional validation through comparison with ICP-MS measurements has confirmed the ability of the XRF system for detecting Gd further, proving it is a feasible system to carry out human measurements.
authors.affiliation: Radiation Sciences Graduate Program, McMaster University, Hamilton, Canada L8S 4L8. Electronic address: lordml@mcmaster.ca.
authors.forename: M L
authors.initials: ML
authors.lastname: Lord
authors.affiliation: Department of Physics and Astronomy, McMaster University, Hamilton, Canada L8S 4L8. Electronic address: fmcneill@mcmaster.ca.
authors.forename: F E
authors.initials: FE
authors.lastname: McNeill
authors.affiliation: Department of Physics, Ryerson University, Toronto, Canada M5B 2K3. Electronic address: james.grafe@ryerson.ca.
authors.forename: J L
authors.initials: JL
authors.lastname: Gräfe
authors.affiliation: Department of Environmental Health Sciences, School of Public Health, The University at Albany, State University of New York, Albany, New York 12222 United States; Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, New York 12201 United States. Electronic address: aubrey.galusha@health.ny.gov.
authors.forename: A L
authors.initials: AL
authors.lastname: Galusha
authors.affiliation: Department of Environmental Health Sciences, School of Public Health, The University at Albany, State University of New York, Albany, New York 12222 United States; Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, New York 12201 United States. Electronic address: patrick.parsons@health.ny.gov.
authors.forename: P J
authors.initials: PJ
authors.lastname: Parsons
authors.affiliation: McMaster School of Biomedical Engineering, McMaster University, Hamilton, Canada L8S 4L8; Imaging Research, St. Joseph's Healthcare, Hamilton, Canada L8N 4A6; Department of Radiology, McMaster University, Hamilton, Canada L8S 4L8; Department of Electrical and Computer Engineering, McMaster University, Hamilton, Canada L8S 4L8. Electronic address: nosewor@mcmaster.ca.
authors.forename: M D
authors.initials: MD
authors.lastname: Noseworthy
authors.affiliation: Department of Medicine, Division of Gastroenterology and Nutrition, Albany Medical College, Albany, New York 12208 United States. Electronic address: howardL@mail.amc.edu.
authors.forename: L
authors.initials: L
authors.lastname: Howard
authors.affiliation: Department of Physics and Astronomy, McMaster University, Hamilton, Canada L8S 4L8. Electronic address: chettle@mcmaster.ca.
authors.forename: D R
authors.initials: DR
authors.lastname: Chettle
mesh_terms: D000328:Adult; D001842:Bone and Bones / Q000737:chemistry* / Q000000981:diagnostic imaging* / Q000378:metabolism; D003287:Contrast Media / Q000009:adverse effects / Q000032:analysis* / Q000493:pharmacokinetics; D005682:Gadolinium / Q000009:adverse effects / Q000032:analysis* / Q000493:pharmacokinetics; D006801:Humans; D057230:Limit of Detection; D008279:Magnetic Resonance Imaging; D019047:Phantoms, Imaging; D013052:Spectrometry, X-Ray Emission / Q000295:instrumentation / Q000379:methods*; D053719:Tandem Mass Spectrometry
chemical_list: D003287:Contrast Media; D005682:Gadolinium
keywords: Gadolinium in bone; Gadolinium retention; ICP-MS; MRI; X-ray fluorescence