title: Technical Note: Clinical translation of the Rapid-Steady-State-T1 MRI method for direct cerebral blood volume quantification.
abstract: OBJECTIVE
  In preclinical studies, the Rapid-Steady-State-T1 (RSST1) MRI method has advantages over conventional MRI methods for blood volume fraction (BVf) mapping, since after contrast agent administration, the BVf is directly quantifiable from the signal amplitude corresponding to the vascular equilibrium magnetization. This study focuses on its clinical implementation and feasibility.
  
  
  METHODS
  Following sequence implementation on clinical Philips Achieva scanners, the RSST1-method is assessed at 1.5 and 3 T in the follow-up examination of neurooncological patients receiving 0.1-0.2 mmol/kg Gd-DOTA to determine the threshold dose needed for cerebral BVf quantification. Confounding effects on BVf quantification such as transendothelial water exchange, transverse relaxation, and contrast agent extravasation are evaluated.
  
  
  RESULTS
  For a dose≥0.13 mmol/kg at 1.5 T and ≥0.16 mmol/kg at 3 T, the RSST1-signal time course in macrovessels and brain tissue with Gd-DOTA impermeable vasculature reaches a steady state at maximum amplitude for about 8 s. In macrovessels, a BVf of 100% was obtained validating cerebral microvascular BVf quantification (3.5%-4.5% in gray matter and 1.5%-2.0% in white matter). In tumor tissue, a continuously increasing signal is detected, necessitating signal modeling for tumor BVf calculation.
  
  
  CONCLUSIONS
  Using approved doses of Gd-DOTA, the steady state RSST1-signal in brain tissue is reached during the first pass and corresponds to the BVf. The first-pass duration is sufficient to allow accurate BVf quantification. The RSST1-method is appropriate for serial clinical studies since it allows fast and straightforward BVf quantification without arterial input function determination. This quantitative MRI method is particularly useful to assess the efficacy of antiangiogenic agents.
authors.affiliation: Clinatec INSERM UA01, Centre de Recherche Edmond J. Safra, CEA Grenoble, Grenoble 38054, France.
authors.forename: Teodora-Adriana
authors.initials: TA
authors.lastname: Perles-Barbacaru
authors.affiliation: IRMaGe, Université Grenoble Alpes, Grenoble 38054, France; US 017 INSERM, Grenoble 38054, France; and UMS 3552, CNRS, Grenoble 38054, France.
authors.forename: Irene
authors.initials: I
authors.lastname: Tropres
authors.affiliation: Clinatec INSERM UA01, Centre de Recherche Edmond J. Safra, CEA Grenoble, Grenoble 38054, France.
authors.forename: Michel G
authors.initials: MG
authors.lastname: Sarraf
authors.affiliation: Philips Healthcare, Suresnes 92150, France.
authors.forename: David
authors.initials: D
authors.lastname: Chechin
authors.affiliation: Clinatec INSERM UA01, Centre de Recherche Edmond J. Safra, CEA Grenoble, Grenoble 38054, France.
authors.forename: Affif
authors.initials: A
authors.lastname: Zaccaria
authors.affiliation: Department of Neuroradiology and MRI, Grenoble University Hospital, Grenoble 38054, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Grand
authors.affiliation: Department of Neuroradiology and MRI, Grenoble University Hospital, Grenoble 38054, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Le Bas
authors.affiliation: Clinatec INSERM UA01, Centre de Recherche Edmond J. Safra, CEA Grenoble, Grenoble 38054, France.
authors.forename: François
authors.initials: F
authors.lastname: Berger
authors.affiliation: Clinatec INSERM UA01, Centre de Recherche Edmond J. Safra, CEA Grenoble, Grenoble 38054, France.
authors.forename: Hana
authors.initials: H
authors.lastname: Lahrech
mesh_terms: D000465:Algorithms; D001783:Blood Flow Velocity / Q000502:physiology; D001810:Blood Volume; D001811:Blood Volume Determination / Q000379:methods*; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001927:Brain Diseases / Q000473:pathology / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D003198:Computer Simulation; D003287:Contrast Media / Q000493:pharmacokinetics; D005240:Feasibility Studies; D006571:Heterocyclic Compounds / Q000493:pharmacokinetics; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008954:Models, Biological; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate