[Is perfusion MRI feasible in lesions with disrupted blood-brain barrier? Pitfalls and possible solutions].
OBJECTIVE
When using perfusion-weighted magnetic resonance imaging (MRI) in lesions with blood-brain barrier (BBB) disruption two methods are normally applied to eliminate the influence of contrast material uptake on T2* dynamics: injection of contrast agent before starting perfusion imaging (pre-injection) and simultaneous acquisition of T1- and T2*-dynamics using a dual echo (DE)-FLASH sequence. The purpose of this study was to examine both methods with regard to their reliability.


METHODS
We performed four perfusion measurements in a patient with a primary cerebral lymphoma located in the corpus callosum: two measurements with a DE-FLASH sequence and two measurements with a gradient-echo echo-planar-imaging (GE-EPI) sequence, respectively. In both cases there was one measurement with and one without pre-injection of contrast material.


RESULTS
Pre-injection of contrast material reduced the influence of T1 and allowed us to monitor the transient signal drop when using the GE-EPI sequence. Analysis of the time-course of DE-FLASH, however, showed that there was still a T1 decrease even after pre-injection. After the first pass the T2*-dynamics showed a distinct long-term T2*-decrease.


CONCLUSIONS
Neither pre-injection nor DE-FLASH allow us to eliminate the effects of contrast agent uptake completely. Both methods, however, increase the reliability of perfusion MRI. Their efficacy depends on the extent of the BBB disruption.
Heiland
S
S
Abteilung Neuroradiologie, Universitätsklinikum Heidelberg. Sabine_Heiland@med.uni-heidelberg.de
Hartmann
M
M
Sartor
K
K
D000368:Aged; D001812:Blood-Brain Barrier; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000503:physiopathology; D003287:Contrast Media; D003337:Corpus Callosum; D006801:Humans; D008223:Lymphoma / Q000175:diagnosis* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results
D003287:Contrast Media