title: Dynamic state of water molecular displacement of the brain during the cardiac cycle in idiopathic normal pressure hydrocephalus.
abstract: The predictive accuracy of iNPH diagnoses could be increased using a combination of supplemental tests for iNPH. To evaluate the dynamic state of water displacement during the cardiac cycle in idiopathic normal pressure hydrocephalus (iNPH), we determined the change in water displacement using q-space analysis of diffusion magnetic resonance image. ECG-triggered single-shot diffusion echo planar imaging was used. Water displacement was obtained from the displacement probability profile calculated by Fourier transform of the signal decay fitted as a function of the reciprocal spatial vector q. Then maximum minus minimum displacement (delta-displacement), of all cardiac phase images was calculated. We assessed the delta-displacement in white matter in patients with iNPH and atrophic ventricular dilation (atrophic VD), and in healthy volunteers (control group). Delta-displacement in iNPH was significantly higher than those in the atrophic VD and control. This shows that water molecules of the white matter in iNPH are easily fluctuated by volume loading of the cranium during the cardiac cycle, due to the decrease in intracranial compliance. There was no significant correlation between delta-displacement and displacement. The delta-displacement and the displacement do not necessarily yield the same kind of information. Delta-displacement demonstrated to obtain biophysical information about fluctuation. This analysis may be helpful in the understanding physiology and pathological condition in iNPH and the assisting in the diagnosis.
authors.affiliation: Department of Radiology, Nagoya City University Hospital, 1-Kawasumi, Mizuho-cho Mizuho-ku, Nagoya 4678602, Aichi, Japan; Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 9200942, Ishikawa, Japan. Electronic address: gpx246@yahoo.co.jp.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Kan
authors.affiliation: Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 9200942, Ishikawa, Japan. Electronic address: ramiyati@mhs.mp.kanazawa-u.ac.jp.
authors.forename: Tosiaki
authors.initials: T
authors.lastname: Miyati
authors.affiliation: Department of Neurosurgery, Nagoya City University Hospital, 1-Kawasumi, Mizuho-cho Mizuho-ku, Nagoya 4678602, Aichi, Japan. Electronic address: mitmase@med.nagoya-cu.ac.jp.
authors.forename: Mitsuhito
authors.initials: M
authors.lastname: Mase
authors.affiliation: Department of Neurosurgery, Nagoya City University Hospital, 1-Kawasumi, Mizuho-cho Mizuho-ku, Nagoya 4678602, Aichi, Japan. Electronic address: car66220@pop02.odn.ne.jp.
authors.forename: Tomoshi
authors.initials: T
authors.lastname: Osawa
authors.affiliation: Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 9200942, Ishikawa, Japan. Electronic address: nohno@med.kanazawa-u.ac.jp.
authors.forename: Naoki
authors.initials: N
authors.lastname: Ohno
authors.affiliation: Department of Radiology, Nagoya City University Hospital, 1-Kawasumi, Mizuho-cho Mizuho-ku, Nagoya 4678602, Aichi, Japan. Electronic address: hhkasai@gmail.com.
authors.forename: Harumasa
authors.initials: H
authors.lastname: Kasai
authors.affiliation: Department of Radiology, Nagoya City University Hospital, 1-Kawasumi, Mizuho-cho Mizuho-ku, Nagoya 4678602, Aichi, Japan. Electronic address: rarai51@med.nagoya-cu.ac.jp.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Arai
authors.affiliation: Department of Radiology, Nagoya City University Hospital, 1-Kawasumi, Mizuho-cho Mizuho-ku, Nagoya 4678602, Aichi, Japan. Electronic address: rakawano@med.nagoya-cu.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kawano
authors.affiliation: Department of Radiology, Nagoya City University Hospital, 1-Kawasumi, Mizuho-cho Mizuho-ku, Nagoya 4678602, Aichi, Japan. Electronic address: yshiba@med.nagoya-cu.ac.jp.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shibamoto
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001834:Body Water / Q000378:metabolism*; D001921:Brain; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000175:diagnosis* / Q000378:metabolism*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066127:White Matter / Q000378:metabolism* / Q000473:pathology
chemical_list: D015415:Biomarkers
keywords: Diffusion weighted imaging; Idiopathic normal pressure hydrocephalus; Magnetic resonance imaging; q-space