title: Diffusion tensor images in children with early-treated, chronic, malignant phenylketonuric: correlation with intelligence assessment.
abstract: OBJECTIVE
  Diffusion tensor (DT) images can provide information about the nature of white matter changes, including axonal loss and demyelination. We applied DT imaging to verify white matter changes in patients with malignant phenylketonuria (PKU) and to correlate the findings with clinical intelligence quotients (IQs).
  
  
  METHODS
  We compared DT images with T2-weighted images in 12 patients with early-treated, chronic, stable malignant PKU and 12 age-matched control subjects. DT parameters included first, second, and third eigenvalues (EV1-3), apparent diffusion coefficients (ADCs), and fractional anisotropy (FA). Regions of interest were placed the frontoparietal, parieto-occipital, frontal and central white matter and in the anterior and posterior corpus callosum. Eight patients older than 3 years underwent IQ assessment including verbal, performance, and full-scale IQ tests.
  
  
  RESULTS
  In the eight patients older than 3 years, no definite abnormal signal intensity changes were found on T2-weighted images. EV2, EV3, and FA of the parieto-occipital white matter were significantly different in patients and control subjects older than 3 years. EV3 and ADC of the parieto-occipital white matter were significantly and negatively correlated with verbal IQ (r = -0.79, P = .04) and performance IQ (r = -0.93, P = .03). FA of the parieto-occipital central white matter was positively correlated with verbal IQ (r = 0.75, P = .05).
  
  
  CONCLUSIONS
  Though treated early, patients with chronic, stable malignant PKU had abnormal DT findings in the parieto-occipital central white matter. EV2, EV3, and FA maps are potential tools for demonstrating brain changes due to malignant PKU.
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Steven Shinn-Forng
authors.initials: SS
authors.lastname: Peng
authors.forename: Wen-Yih Isaac
authors.initials: WY
authors.lastname: Tseng
authors.forename: Yin-Hsiu
authors.initials: YH
authors.lastname: Chien
authors.forename: Wuh-Liang
authors.initials: WL
authors.lastname: Hwu
authors.forename: Hon-Man
authors.initials: HM
authors.lastname: Liu
mesh_terms: D006916:5-Hydroxytryptophan / Q000008:administration & dosage; D001369:Axons / Q000473:pathology; D001708:Biopterins / Q000008:administration & dosage / Q000031:analogs & derivatives*; D001925:Brain Damage, Chronic / Q000151:congenital* / Q000175:diagnosis / Q000628:therapy; D002540:Cerebral Cortex / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D003337:Corpus Callosum / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007360:Intelligence / Q000502:physiology*; D007980:Levodopa / Q000008:administration & dosage; D008297:Male; D015997:Neonatal Screening; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D010649:Phenylalanine / Q000008:administration & dosage; D010661:Phenylketonurias / Q000175:diagnosis / Q000628:therapy*; D011247:Pregnancy
chemical_list: D001708:Biopterins; D007980:Levodopa; D010649:Phenylalanine; D006916:5-Hydroxytryptophan; C003402:sapropterin