Comparison of MRI and CT for detection of acute intracerebral hemorrhage.
BACKGROUND
Noncontrast computed tomography (CT) is the standard brain imaging study for the initial evaluation of patients with acute stroke symptoms. Multimodal magnetic resonance imaging (MRI) has been proposed as an alternative to CT in the emergency stroke setting. However, the accuracy of MRI relative to CT for the detection of hyperacute intracerebral hemorrhage has not been demonstrated.


OBJECTIVE
To compare the accuracy of MRI and CT for detection of acute intracerebral hemorrhage in patients presenting with acute focal stroke symptoms.


METHODS
A prospective, multicenter study was performed at 2 stroke centers (UCLA Medical Center and Suburban Hospital, Bethesda, Md), between October 2000 and February 2003. Patients presenting with focal stroke symptoms within 6 hours of onset underwent brain MRI followed by noncontrast CT.


METHODS
Acute intracerebral hemorrhage and any intracerebral hemorrhage diagnosed on gradient recalled echo (GRE) MRI and CT scans by a consensus of 4 blinded readers.


RESULTS
The study was stopped early, after 200 patients were enrolled, when it became apparent at the time of an unplanned interim analysis that MRI was detecting cases of hemorrhagic transformation not detected by CT. For the diagnosis of any hemorrhage, MRI was positive in 71 patients with CT positive in 29 (P<.001). For the diagnosis of acute hemorrhage, MRI and CT were equivalent (96% concordance). Acute hemorrhage was diagnosed in 25 patients on both MRI and CT. In 4 other patients, acute hemorrhage was present on MRI but not on the corresponding CT--each of these 4 cases was interpreted as hemorrhagic transformation of an ischemic infarct. In 3 patients, regions interpreted as acute hemorrhage on CT were interpreted as chronic hemorrhage on MRI. In 1 patient, subarachnoid hemorrhage was diagnosed on CT but not on MRI. In 49 patients, chronic hemorrhage, most often microbleeds, was visualized on MRI but not on CT.


CONCLUSIONS
MRI may be as accurate as CT for the detection of acute hemorrhage in patients presenting with acute focal stroke symptoms and is more accurate than CT for the detection of chronic intracerebral hemorrhage.
Kidwell
Chelsea S
CS
UCLA Stroke Center, Los Angeles, Calif, USA. ckidwell@ucla.edu
Chalela
Julio A
JA
Saver
Jeffrey L
JL
Starkman
Sidney
S
Hill
Michael D
MD
Demchuk
Andrew M
AM
Butman
John A
JA
Patronas
Nicholas
N
Alger
Jeffry R
JR
Latour
Lawrence L
LL
Luby
Marie L
ML
Baird
Alison E
AE
Leary
Megan C
MC
Tremwel
Margaret
M
Ovbiagele
Bruce
B
Fredieu
Andre
A
Suzuki
Shuichi
S
Villablanca
J Pablo
JP
Davis
Stephen
S
Dunn
Billy
B
Todd
Jason W
JW
Ezzeddine
Mustapha A
MA
Haymore
Joseph
J
Lynch
John K
JK
Davis
Lisa
L
Warach
Steven
S
D000208:Acute Disease; D000328:Adult; D000368:Aged; D002543:Cerebral Hemorrhage / Q000175:diagnosis*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed