title: Reduced diffusion in a subset of acute MS lesions: a serial multiparametric MRI study.
abstract: OBJECTIVE
  MRI studies have focused on newly developing MS lesions to characterize the early pathology of the disease. DWI is highly sensitive to acute and chronic tissue changes in MS. We characterized the development of acute MS lesions by using DWI in a multiparametric MRI protocol.
  
  
  METHODS
  Seventy-two consecutive patients presenting with a new symptom with definite MS or a CIS suggestive of central nervous system demyelination were screened with MRI. Patients who showed an acute MRI lesion with a reduction of ADC were studied with serial MRI for up to 4 months after presentation.
  
  
  RESULTS
  Ten of 72 screened patients who showed a lesion with a reduced ADC were each examined 4-7 times, resulting in 52 examinations in total. We identified a characteristic sequence of signal-intensity changes: 1) days 0-7: slight T2 hyperintensity and prominent ADC reduction (maximum, -66%), faint or no enhancement on postcontrast T1-weighted images; 2) days 7-10: prominent T2 hyperintensity and contrast enhancement, ADC normalization/pseudonormalization; 3) up to 4 weeks: elevated ADC values, prominent enhancement on postcontrast images; 4) after 4 weeks: partial reversibility of T2 hyperintensity, ADC elevation, and resolution of contrast enhancement.
  
  
  CONCLUSIONS
  In a subgroup of patients with MS presenting soon after new symptom onset, a transient reduction of the ADC delineated a short and very early phase of MS lesion evolution. Subsequent pseudonormalization of the ADC occurred along with signs of the development of vasogenic edema.
authors.affiliation: Department of Neurology, UniversitätsMedizin Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Eisele
authors.forename: K
authors.initials: K
authors.lastname: Szabo
authors.forename: M
authors.initials: M
authors.lastname: Griebe
authors.forename: C
authors.initials: C
authors.lastname: Rossmanith
authors.forename: A
authors.initials: A
authors.lastname: Förster
authors.forename: M
authors.initials: M
authors.lastname: Hennerici
authors.forename: A
authors.initials: A
authors.lastname: Gass
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult