Value of diffusion-weighted imaging and apparent diffusion coefficient in recent cerebral infarctions: a correlative study with contrast-enhanced T1-weighted imaging.
OBJECTIVE
The clinical usefulness and the time course of diffusion-weighted imaging and apparent diffusion coefficient (ADC) in acute and subacute cerebral infarction have not yet been established, although it is known that contrast-enhanced T1-weighted spin-echo imaging can detect a subacute infarct. Our aim was to study which imaging technique is useful in detecting recent infarcts, and whether an increase in ADC or a decrease in signal intensity on diffusion-weighted images is correlated with enhancement on T1-weighted spin-echo images.


METHODS
Forty-one infarctions with a duration of 9 hours to 27 days were studied in 29 patients. The ADC and signal intensity on diffusion-weighted images were compared with the contrast-enhancement ratio (CER) on T1-weighted spin-echo images (CER = signal intensity after contrast injection/signal intensity before contrast injection).


RESULTS
ADC was linearly correlated with CER, and signal intensity on diffusion-weighted images was inversely correlated with CER. The correlation between ADC and age of the infarct in the subacute phase was weak.


CONCLUSIONS
Diffusion-weighted and contrast-enhanced T1-weighted spin-echo images complement each other in detecting subacute infarcts. Neovascularization and disruption of the blood-brain barrier in infarcts can be important in increasing ADC in subacute infarcts.
Yamada
N
N
Department of Radiology, National Cardiovascular Center, Suita, Osaka, Japan.
Imakita
S
S
Sakuma
T
T
D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D002544:Cerebral Infarction / Q000175:diagnosis*; D003287:Contrast Media; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000175:diagnosis; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D013997:Time Factors
D003287:Contrast Media