Perfusion imaging of the brain using Z-score and dynamic images obtained by subtracting images from before and after contrast injection.
OBJECTIVE
The aim of this study was to examine the feasibility of perfusion imaging of the brain using the Z-score and subtraction dynamic images obtained from susceptibility contrast MR images.


METHODS
Five patients, each with a normal MRI, Moya-moya, a middle cerebral artery occlusion, post-trauma syndrome, and a metastatic brain tumor, were selected for a presentation. A susceptibility-contrast echo-planar image after a routine MRI was taken as the source image with a rapid manual injection of 0.1 mmol/kg of Gd-DTPA. The inflow and washout patterns were observed from the time-signal intensity curve of the serial scans using the standard program of an MRI machine. The repeated Z-score images of the peak and late phases were made using the threshold Z-score values between 1.4 and 2.0 in four to five studies of the pre-contrast, peak, and late phases. Dynamic subtraction images were produced by subtracting sequential post-contrast images from a pre-contrast image and coloring these images using a pseudocolor mapping method.


RESULTS
In the diseases with perfusion abnormalities, the Z-score images revealed information about the degree of perfusion during the peak and late phases. However, the quality varied with the Z-score threshold and the studies selected in a group. The dynamic subtraction images were of sufficient quality with no background noise and more clearly illustrated the temporal changes in perfusion and delayed perfusion.


CONCLUSIONS
The Z-scores and dynamic subtraction images illustrated the degree of perfusion and sequential changes in the pattern of perfusion, respectively. These images can be used as a new complimentary method for observing the perfusion patterns in brain diseases.
Choi
Sunseob
S
Department of Diagnostic Radiology, Dong-A University College of Medicine, Seo-gu, Busan, Korea. sschoi317@yahoo.co.kr
Liu
Haiying
H
Shin
Tae Beom
TB
Lee
Jin Hwa
JH
Yoon
Seong Kuk
SK
Oh
Jong Young
JY
Lee
Young-Il
YI
D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging; D002648:Child; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013382:Subtraction Technique
D003287:Contrast Media; D019786:Gadolinium DTPA