Image correlation of MRI and CT in treatment planning for radiosurgery of intracranial vascular malformations.
Magnetic resonance imaging (MRI) has been incorporated with stereotactic cerebral angiography and computed tomography (CT) in the treatment planning process of heavy ion radiosurgery of intracranial arteriovenous malformations (AVM's). Correlation of the images of the AVM and normal tissue on each of these neuroradiological imaging modalities is achieved by means of fiducial markers. The computerized transfer of angiographic information to the CT images regarding the size, shape, and location of the abnormal vasculature has been described in an earlier report. A separate computer program calculates a fit between individual fiducial markers on the CT and MR images that enables the transfer of contours between the two imaging modalities. The MR images aid in the determination of the 3-dimensional shape of the AVM, adding to the information derived from the two angiographic projections. Currently, MRI cannot replace cerebral angiography in delineating the entire arterial phase of the AVM. Magnetic resonance imaging is invaluable in the treatment planning of angiographically-occult AVM's, determining the location, size, and shape of the volume to be treated. Correlation of the CT and MRI images allows for the transfer of CT-calculated isodose contours to the MRI images to aid in the determination of optimal treatment plans.
Phillips
M H
MH
Research Medicine and Radiation Biophysics, Lawrence Berkeley Laboratory, Berkeley, CA 94720.
Kessler
M
M
Chuang
F Y
FY
Frankel
K A
KA
Lyman
J T
JT
Fabrikant
J I
JI
Levy
R P
RP
D000293:Adolescent; D000328:Adult; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis / Q000532:radiotherapy* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D013238:Stereotaxic Techniques; D014057:Tomography, X-Ray Computed / Q000379:methods*