title: Sex-dependent alterations in resting-state cerebral blood flow, amplitude of low-frequency fluctuations and their coupling relationship in schizophrenia.
abstract: OBJECTIVE
  We aimed to investigate sex-dependent alterations in resting-state relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling in patients with schizophrenia.
  
  
  METHODS
  Resting-state functional magnetic resonance imaging and three-dimensional pseudo-continuous arterial spin labeling imaging were performed to obtain resting-state amplitude of low-frequency fluctuations and relative cerebral blood flow in 95 schizophrenia patients and 99 healthy controls. Sex differences in relative cerebral blood flow and amplitude of low-frequency fluctuations were compared in both groups. Diagnostic group differences in relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling were compared in male and female subjects, respectively.
  
  
  RESULTS
  In both healthy controls and schizophrenia patients, the males had higher relative cerebral blood flow in anterior brain regions and lower relative cerebral blood flow in posterior brain regions than did the females. Compared with multiple regions exhibiting sex differences in relative cerebral blood flow, only the left middle frontal gyrus had a significant sex difference in amplitude of low-frequency fluctuations. In the females, schizophrenia patients exhibited increased relative cerebral blood flow and amplitude of low-frequency fluctuations in the basal ganglia, thalamus and hippocampus and reduced relative cerebral blood flow and amplitude of low-frequency fluctuations in the frontal, parietal and occipital regions compared with those of healthy controls. However, there were fewer brain regions with diagnostic group differences in the males than in the females. Brain regions with diagnostic group differences in relative cerebral blood flow and amplitude of low-frequency fluctuations only partially overlapped. Only the female patients exhibited increased relative cerebral blood flow-amplitude of low-frequency fluctuations couplings compared with those of healthy females.
  
  
  CONCLUSIONS
  The alterations in the relative cerebral blood flow and amplitude of low-frequency fluctuations in schizophrenia are sex-specific, which should be considered in future neuroimaging studies. The relative cerebral blood flow and amplitude of low-frequency fluctuations have different sensitivity in detecting changes in neuronal activity in schizophrenia and can provide complementary information.
authors.affiliation: Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China.
authors.forename: Di
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China.
authors.forename: Yujing
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China.
authors.forename: Chuanjun
authors.initials: C
authors.lastname: Zhuo
authors.affiliation: Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Qin
authors.affiliation: Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China.
authors.forename: Jiajia
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China chunshuiyu@tijmu.edu.cn.
authors.forename: Chunshui
authors.initials: C
authors.lastname: Yu
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D059907:Functional Neuroimaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012146:Rest / Q000502:physiology; D012559:Schizophrenia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012737:Sex Factors; D055815:Young Adult
keywords: Cerebral blood flow; amplitude of low-frequency fluctuations; arterial spin labeling; schizophrenia; sex difference