Regional relative blood volume MR maps of meningiomas before and after partial embolization.
OBJECTIVE
Our goal was to evaluate the role of relative blood volume (rBV) measurements in monitoring the embolization effect in meningiomas by using maps of susceptibility-weighted first pass MR data.


METHODS
Eighteen examinations of nine patients before and following partial embolization were performed on a 1.5 T scanner. Embolization was achieved by injection of particles (45-150 microns). During dynamic imaging a bolus (0.2 mmol/kg) of gadopentetate dimeglumine was injected.


RESULTS
The tumor rBV/gray matter rBV ratio was 3.11 +/- 1.40 for untreated tumors and 0.12 +/- 0.09 for successfully embolized tumors. The regional rBV in embolized meningiomas was significantly lower than that in untreated meningiomas (t test, p < 0.001). Vital tumor tissue showed positive enhancement in T1 and high rBV; nonvital tissue lacked T1 enhancement and bolus effect in the first pass, thus leading to low or missing rBV values. However, we also observed lack of bolus formation despite T1 enhancement (6/9 postembolization regions), possibly due to slow collateral flow. One of the patients treated with embolization bled during surgery.


CONCLUSIONS
Maps of relative regional cerebral BV provide hemodynamic information in meningiomas and monitor the treatment effect of embolization in meningiomas more precisely than T1-weighted contrast-enhanced imaging.
Bruening
R
R
Institute of Diagnostic Radiology, Klinikum Grosshadern, Ludwig Maximilian University of Munich, Germany.
Wu
R H
RH
Yousry
T A
TA
Berchtenbreiter
C
C
Weber
J
J
Peller
M
M
Steiger
H J
HJ
Reiser
M
M
D016063:Blood Loss, Surgical / Q000517:prevention & control; D001810:Blood Volume; D001931:Brain Mapping; D002114:Calcinosis / Q000175:diagnosis; D003287:Contrast Media; D004621:Embolization, Therapeutic; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016018:Least-Squares Analysis; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis* / Q000503:physiopathology* / Q000628:therapy*; D008579:Meningioma / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D008875:Middle Aged
D003287:Contrast Media; D019786:Gadolinium DTPA