Characterization of a first-pass gradient-echo spin-echo method to predict brain tumor grade and angiogenesis.
OBJECTIVE
No widespread clinical method provides specific information about the angiogenic characteristics of gliomas. We characterized blood volume and vascular morphologic parameters from combined gradient-echo (GE) and spin-echo (SE) MR imaging and assessed their relationship to tumor grade, a known correlate of glioma angiogenesis.


METHODS
Simultaneous GE and SE echo-planar imaging was performed with bolus gadolinium administration (0.20-0.25 mmol/kg) in 73 patients with glioma. To diminish possible T1 changes due to contrast agent extravasation, a preload (0.05-0.10 mmol/kg) was administered before the study, and a postprocessing correction algorithm was applied. Image maps of total (GE) and microvascular (SE) relative cerebral blood volume (rCBV) and the mean vessel diameter (mVD) calculated from the ratio of GE and SE relaxation rate changes (DeltaR2*/DeltaR2) were compared with tumor grade. A nonparametric K nearest-neighbor decision rule was applied to determine if the combined data could be used to distinguish low-grade (I-II) from high-grade (III-IV) tumors on a per-patient basis.


RESULTS
For whole tumors, significant correlations were found between GE rCBV and grade (P < .0001) and between mVD and grade (P = .0001) but not between SE rCBV and grade (P = .08). For areas of highest SE rCBV (microvascular hotspots), SE rCBV and tumor grade were significantly correlated (P = .0007). In terms of differentiation, 69% of low-grade tumors and 96% of high-grade tumors were correctly classified.


CONCLUSIONS
Combined GE and SE MR imaging provides information consistent with neoplastic angiogenesis, demonstrating its potential to aid in optimizing treatments, categorizing lesions, and influencing patient care.
Schmainda
Kathleen M
KM
Department of Radiology, Medical College of Wisconsin, Milwaukee, WI, USA.
Rand
Scott D
SD
Joseph
Allen M
AM
Lund
Rebecca
R
Ward
B Doug
BD
Pathak
Arvind P
AP
Ulmer
John L
JL
Badruddoja
Michael A
MA
Baddrudoja
Michael A
MA
Krouwer
Hendrikus G J
HG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001810:Blood Volume / Q000502:physiology; D001921:Brain / Q000098:blood supply / Q000473:pathology; D001932:Brain Neoplasms / Q000098:blood supply* / Q000145:classification / Q000175:diagnosis / Q000473:pathology; D003287:Contrast Media / Q000008:administration & dosage; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D005910:Glioma / Q000098:blood supply* / Q000145:classification / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008833:Microcirculation / Q000473:pathology; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000098:blood supply / Q000145:classification / Q000175:diagnosis; D009389:Neovascularization, Pathologic / Q000145:classification / Q000175:diagnosis*; D011379:Prognosis
D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA