title: Measurement of liver iron overload: noninvasive calibration of MRI-R2* by magnetic iron detector susceptometer.
abstract: An accurate assessment of body iron accumulation is essential for the diagnosis and therapy of iron overload in diseases such as thalassemia or hemochromatosis. Magnetic iron detector susceptometry and MRI are noninvasive techniques capable of detecting iron overload in the liver. Although the transverse relaxation rate measured by MRI can be correlated with the presence of iron, a calibration step is needed to obtain the liver iron concentration. Magnetic iron detector provides an evaluation of the iron overload in the whole liver. In this article, we describe a retrospective observational study comparing magnetic iron detector and MRI examinations performed on the same group of 97 patients with transfusional or congenital iron overload. A biopsy-free linear calibration to convert the average transverse relaxation rate in iron overload (R(2) = 0.72), or in liver iron concentration evaluated in wet tissue (R(2) = 0.68), is presented. This article also compares liver iron concentrations calculated in dry tissue using MRI and the existing biopsy calibration with liver iron concentrations evaluated in wet tissue by magnetic iron detector to obtain an estimate of the wet-to-dry conversion factor of 6.7 ± 0.8 (95% confidence level).
authors.affiliation: Centro della Microcitemia e delle Anemie Congenite, E. O. Ospedali Galliera, Genova, Italy. gianesin@ge.infn.it
authors.forename: B
authors.initials: B
authors.lastname: Gianesin
authors.forename: D
authors.initials: D
authors.lastname: Zefiro
authors.forename: M
authors.initials: M
authors.lastname: Musso
authors.forename: A
authors.initials: A
authors.lastname: Rosa
authors.forename: C
authors.initials: C
authors.lastname: Bruzzone
authors.forename: M
authors.initials: M
authors.lastname: Balocco
authors.forename: P
authors.initials: P
authors.lastname: Carrara
authors.forename: L
authors.initials: L
authors.lastname: Bacigalupo
authors.forename: S
authors.initials: S
authors.lastname: Banderali
authors.forename: G A
authors.initials: GA
authors.lastname: Rollandi
authors.forename: M
authors.initials: M
authors.lastname: Gambaro
authors.forename: M
authors.initials: M
authors.lastname: Marinelli
authors.forename: G L
authors.initials: GL
authors.lastname: Forni
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002138:Calibration; D002648:Child; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007501:Iron / Q000378:metabolism*; D019190:Iron Overload / Q000175:diagnosis* / Q000378:metabolism*; D007558:Italy; D008107:Liver Diseases / Q000175:diagnosis* / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000592:standards; D060306:Magnetometry / Q000295:instrumentation* / Q000592:standards; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D007501:Iron