title: Dynamic perfusion MRI characteristics of dural metastases and meningiomas: a pilot study characterizing the first-pass wash-in phase beyond relative cerebral blood volume.
abstract: OBJECTIVE
  Dural metastases and meningiomas are extraaxial lesions that may be difficult to distinguish using conventional imaging methods. This distinction, however, is clinically important. Perfusion MRI may play a role in preoperative assessment. The aim of this study was to evaluate the utility of perfusion parameters in differentiating between these two entities. In particular, we evaluated two new metrics that reflect the first-pass wash-in characteristics of perfusion.
  
  
  METHODS
  Patients with intracranial extraaxial masses who underwent perfusion MRI were included. Region-of-interest analysis was performed and several perfusion metrics were calculated including relative cerebral blood volume (rCBV), mean transit time and time to peak (TTP) enhancement from initial bolus enhancement (T0), calculated as TTP-T(0). Two new metrics characterizing first pass wash-in enhancement were also measured: relative wash-in time and wash-in slope. Lesions were divided into two groups: meningioma and metastasis. Comparisons between the two groups were made using Wilcoxon rank sum and Fisher exact tests.
  
  
  RESULTS
  Twenty lesions were studied (12 meningioma and 8 metastases). Compared with meningiomas, relative wash-in time was statistically lower in metastases (p < 0.05). No other statistically significant differences were observed. Specifically, there was no difference between the two study groups in rCBV.
  
  
  CONCLUSIONS
  First-pass wash-in characteristics of dural lesions may be useful for evaluating and characterizing lesions. In particular, a metric describing the wash-in phase of perfusion-that is, relative wash-in time-was found to be lower in metastases compared with meningiomas. Contrary to a prior report, we found rCBV to be limited in the evaluation of extraaxial lesions.
authors.affiliation: Department of Radiology, Albert Einstein College of Medicine, Montefiore Medical Center, 111 E 210th St, Bronx, NY 10467-2490, USA. ylui@montefiore.org
authors.forename: Yvonne W
authors.initials: YW
authors.lastname: Lui
authors.forename: Amit
authors.initials: A
authors.lastname: Malhotra
authors.forename: Joaquim M
authors.initials: JM
authors.lastname: Farinhas
authors.forename: Swetha B
authors.initials: SB
authors.lastname: Dasari
authors.forename: Karen
authors.initials: K
authors.lastname: Weidenheim
authors.forename: Katherine
authors.initials: K
authors.lastname: Freeman
authors.forename: Patrick A
authors.initials: PA
authors.lastname: LaSala
mesh_terms: D001810:Blood Volume; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D003937:Diagnosis, Differential; D004388:Dura Mater / Q000473:pathology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008577:Meningeal Neoplasms / Q000556:secondary*; D008579:Meningioma / Q000473:pathology*; D008875:Middle Aged; D009367:Neoplasm Staging; D010865:Pilot Projects; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media