title: [Perfusion magnetic resonance imaging for high grade astrocytomas: Can cerebral blood volume, peak height, and percentage of signal intensity recovery distinguish between progression and pseudoprogression?].
abstract: OBJECTIVE
  To study the usefulness of common MRI perfusion parameters for identifying pseudoprogression in high grade astrocytomas.
  
  
  METHODS
  This retrospective case-control study compared the relative cerebral blood volume (rCBV), the relative percentage of signal intensity recovery (rPSR), and the relative peak height (rPH) recorded in a sample of 17 cases of anaplastic astrocytomas and gliomas considered to be undergoing pseudoprogression by biopsy or follow-up with those recorded in a sample of histologically similar tumors that were treated and considered to be undergoing progression by histologic study or follow-up. We evaluated the accuracy of these parameters and the correlations among them. Statistical significance was set at P<.05.
  
  
  RESULTS
  The rCBV, rPSR, and rPH were significantly different between the two groups (P=.001). The cutoff values rPH=1.37, rCBV=0.9, and rPSR=99% yielded sensitivity (S)=88% and specificity (Sp)=82.2% for rPH, S=100% and Sp=100% for rCBV, and S=100% and Sp=70.6% for rPSR, respectively. We found negative correlations between rPRS and rPH (-0.76) and between rPRS and rCBV (-0.81) and a high positive correlation between rPH and rCBV (0.87).
  
  
  CONCLUSIONS
  The variables rPH and rCBV were useful for differentiating between pseudoprogression and true progression in our sample. The variable rPRS was also very sensitive, although the overlap in the values between samples make it less useful a priori.
authors.affiliation: Sección de Neurorradiología, Unidad de Gestión Clínica de Radiodiagnóstico, Hospital Universitario Virgen de las Nieves, Granada, España. Electronic address: almarez83@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Martínez-Martínez
authors.affiliation: Sección de Neurorradiología, Unidad de Gestión Clínica de Radiodiagnóstico, Hospital Universitario Virgen de las Nieves, Granada, España.
authors.forename: J
authors.initials: J
authors.lastname: Martínez-Bosch
mesh_terms: D000328:Adult; D001254:Astrocytoma / Q000175:diagnosis* / Q000503:physiopathology*; D001810:Blood Volume; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000503:physiopathology*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D018450:Disease Progression; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
keywords: Astrocitoma; Astrocytoma; Brain perfusion; Brain tumors; Glioblastoma; Imagen de perfusión por resonancia magnética; Perfusion-weighted magnetic resonance imaging; Perfusión cerebral; Pseudoprogression; Seudoprogresión; Tumores cerebrales