title: Intraindividual comparison between gadopentetate dimeglumine and gadobutrol for magnetic resonance perfusion in normal brain and intracranial tumors at 3 Tesla.
abstract: BACKGROUND
  In vitro studies have shown that the 3-Tesla (T) magnetic resonance (MR) characteristics of high- and standard-molar gadolinium-based contrast agents differ. Such differences may indicate that high-molar (1.0 M) agents offer advantages for perfusion-weighted imaging (PWI) at 3T, as has been previously reported at 1.5 T.
  
  
  OBJECTIVE
  To investigate possible intraindividual differences of high- versus low-molar contrast agents on PWI at 3T in patients with intracranial space-occupying lesions.
  
  
  METHODS
  Six patients with intraaxial and five patients with extraaxial tumors underwent two MR examinations at 3T, separated by at least 48 hours. On each occasion, an exogenous contrast-based, T2*-weighted, gradient-recalled echo-planar imaging (EPI) technique was used to determine the intracranial perfusion characteristics using one of two intravenous contrast agents: either 5 ml of 1.0 M gadobutrol or 10 ml of 0.5 M gadopentetate dimeglumine. The primary PWI outcome measure was region-of-interest maximal signal change (C(max)).
  
  
  RESULTS
  The difference in C(max) for gray and white matter (Delta C(max)) was significantly higher for gadobutrol compared to gadopentetate dimeglumine (P<0.01). The ratio of C(max) between gray and white matter (rC(max) = C(maxGray)/C(maxWhite)) was also significantly higher (median 24.6%, range 13.7-36.5%) for gadobutrol (P<0.01). The ratio of C(max) between the whole tumor and whole normal side hemisphere was higher in five out of the six intraaxial tumor cases. A significantly higher ratio (Delta C(max)/C(max)) in the difference between C(max) of gray and white matter (from hemisphere without brain lesion) compared to C(max) for the hemisphere containing the neoplasm (hemisphere with brain lesion) was demonstrated for gadobutrol in intraaxial tumors (P<0.05).
  
  
  CONCLUSIONS
  Higher-concentration 1.0 M gadobutrol can offer advantages over standard 0.5 M gadopentetate dimeglumine, particularly with respect to delineation between gray and white matter and for the demarcation of highly vascularized tumor tissue on brain PWI performed at 3T.
authors.affiliation: Department of Radiology, German Cancer Research Center, Heidelberg, Germany. f.giesel@dkfz.de
authors.forename: Frederik L
authors.initials: FL
authors.lastname: Giesel
authors.forename: Amit
authors.initials: A
authors.lastname: Mehndiratta
authors.forename: Frank
authors.initials: F
authors.lastname: Risse
authors.forename: Maria
authors.initials: M
authors.lastname: Rius
authors.forename: Christian M
authors.initials: CM
authors.lastname: Zechmann
authors.forename: Hendrik
authors.initials: H
authors.lastname: von Tengg-Kobligk
authors.forename: Lars
authors.initials: L
authors.lastname: Gerigk
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.forename: Maria
authors.initials: M
authors.lastname: Politi
authors.forename: Marco
authors.initials: M
authors.lastname: Essig
authors.forename: Paul D
authors.initials: PD
authors.lastname: Griffiths
authors.forename: Iain D
authors.initials: ID
authors.lastname: Wilkinson