title: Whole brain magnetization transfer histogram analysis of pediatric acute lymphoblastic leukemia patients receiving intrathecal methotrexate therapy.
abstract: OBJECTIVE
  The purpose of this prospective study was to evaluate the hypothesis that magnetization transfer ratio (MTR) histogram analysis of the whole brain could detect early and subtle brain changes nonapparent on conventional magnetic resonance imaging (MRI) in children with acute lymphoblastic leukemia (ALL) receiving methotrexate (MTX) therapy.
  
  
  METHODS
  Subjects in this prospective study comprised 10 children with ALL (mean age, 6 years; range, 0-16 years). In addition to conventional MRI, magnetization transfer images were obtained before and after intrathecal and intravenous MTX therapy. MTR values were calculated and plotted as a histogram, and peak height and location were calculated. Differences in peak height and location between pre- and post-MTX therapy scans were statistically analyzed. Conventional MRI was evaluated for abnormal signal area in white matter.
  
  
  RESULTS
  MTR peak height was significantly lower on post-MTX therapy scans than on pre-MTX therapy scans (p = 0.002). No significant differences in peak location were identified between pre- and post-chemotherapy imaging. No abnormal signals were noted in white matter on either pre- or post-MTX therapy conventional MRI.
  
  
  CONCLUSIONS
  This study demonstrates that MTR histogram analysis allows better detection of early and subtle brain changes in ALL patients who receive MTX therapy than conventional MRI.
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto-shi Kyoto 606-8507, Japan. yakira@kuph.kyoto-u.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Yukio
authors.initials: Y
authors.lastname: Miki
authors.forename: Souichi
authors.initials: S
authors.lastname: Adachi
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Kanagaki
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Fushimi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Okada
authors.forename: Michihiro
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Hiramatsu
authors.forename: Katsutsugu
authors.initials: K
authors.lastname: Umeda
authors.forename: Tatsutoshi
authors.initials: T
authors.lastname: Nakahata
authors.forename: Mark A
authors.initials: MA
authors.lastname: van Buchem
authors.forename: Kaori
authors.initials: K
authors.lastname: Togashi
mesh_terms: D000293:Adolescent; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects*; D001921:Brain / Q000187:drug effects* / Q000473:pathology; D001927:Brain Diseases / Q000139:chemically induced / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D005240:Feasibility Studies; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008727:Methotrexate / Q000009:adverse effects*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000473:pathology; D011446:Prospective Studies
chemical_list: D000964:Antimetabolites, Antineoplastic; D008727:Methotrexate