Gd-DTPA MR detection of blood-brain barrier opening in rats after hyperosmotic shock.
OBJECTIVE
Detection of blood-brain barrier (BBB) opening in neonates has required invasive methods not clinically applicable. We set out to develop a noninvasive approach to detect such opening.


METHODS
Wistar rats were studied using MRI with Gd-DTPA contrast before and after injection of hyperosmotic solutions known to produce barrier opening. Arabinose was given via right carotid artery to produce unilateral barrier opening; urea was given via tail vein to produce bilateral opening; controls received normal saline. Next, all animals received Gd-DTPA via tail vein.


RESULTS
Animals receiving carotid hyperosmotic injections showed increased signal in the ipsilateral brain hemisphere; those receiving venous hyperosmotic injections showed increased signal bilaterally. Similar increases were not found prior to administration of hyperosmotic agent or in saline controls. In both cases, barrier opening was detectable using the relative partitioning of Gd-DTPA between intrabarrier and extrabarrier structures, even in the absence of a hemispheric control.


CONCLUSIONS
We conclude that MRI with Gd-DTPA contrast allows noninvasive detection of BBB opening in the rat.
Rhine
W D
WD
Department of Pediatrics, Stanford University School of Medicine, CA 94304.
Benaron
D A
DA
Enzmann
D R
DR
Chung
C
C
Gonzales-Mendez
R
R
Sayre
J R
JR
Stevenson
D K
DK
D000818:Animals; D001089:Arabinose; D001812:Blood-Brain Barrier; D019786:Gadolinium DTPA; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009942:Organometallic Compounds; D009997:Osmotic Pressure; D004369:Pentetic Acid; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride; D014508:Urea
D009942:Organometallic Compounds; D012965:Sodium Chloride; D004369:Pentetic Acid; D014508:Urea; D001089:Arabinose; D019786:Gadolinium DTPA