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Perfusion imaging of the brain using Z-score and dynamic images obtained by subtracting images from before and after contrast injection.

Choi S, Liu H, Shin TB, Lee JH, Yoon SK, Oh JY, Lee YI - Korean J Radiol (2004 Jul-Sep)

Bottom Line: 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.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.However, the quality varied with the Z-score threshold and the studies selected in a group.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Radiology, Dong-A University College of Medicine, Seo-gu, Busan, Korea. sschoi317@yahoo.co.kr

ABSTRACT

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.

Materials and 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.

Conclusion: 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.

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Related in: MedlinePlus

A 26-year-old female with arrhythmia showed a right middle cerebral artery occlusion on the magnetic resonance angiography and high signal intensity at the right basal ganglia on the diffusion weighted image (not shown) 3 hours after developing a left hemiplegia.A. The peak Z-score image shows perfusion defects at the right posterior frontal, temporal area and the basal ganglia.B. The late Z-score image shows delayed perfusion at the perfusion defect areas in A.C. The subtraction dynamic image of a level show initially decreased perfusion with delayed and persisted perfusion at the right frontal, temporal area and the basal ganglia. Images from the top left to the bottom right show the sequential changes in the signal intensity (perfusion) every 1.32 seconds.D. Added images of a peak and a late phase subtraction image show a perfusion defect only at the right basal ganglia (arrow), which is consistent with a diffusion weighted image (not shown).
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Figure 2: A 26-year-old female with arrhythmia showed a right middle cerebral artery occlusion on the magnetic resonance angiography and high signal intensity at the right basal ganglia on the diffusion weighted image (not shown) 3 hours after developing a left hemiplegia.A. The peak Z-score image shows perfusion defects at the right posterior frontal, temporal area and the basal ganglia.B. The late Z-score image shows delayed perfusion at the perfusion defect areas in A.C. The subtraction dynamic image of a level show initially decreased perfusion with delayed and persisted perfusion at the right frontal, temporal area and the basal ganglia. Images from the top left to the bottom right show the sequential changes in the signal intensity (perfusion) every 1.32 seconds.D. Added images of a peak and a late phase subtraction image show a perfusion defect only at the right basal ganglia (arrow), which is consistent with a diffusion weighted image (not shown).

Mentions: A 26-year-old female with an arrhythmia showed a right MCA occlusion on magnetic resonance angiography (MRA) and high signal intensity in the right basal ganglia on the diffusion-weighted images. The peak Z-score image indicated perfusion defects in the right posterior frontal and temporal lobes as well as in the basal ganglia (Fig. 2A). The late Z-score image showed delayed perfusion in these same areas, except for the basal ganglia (Fig. 2B). The subtraction dynamic images revealed an initial decrease in perfusion with delayed and persistent perfusion in the right frontal, temporal, and basal ganglia areas (Fig. 2C). The subtraction images from the peak and late phases were added in order to observe the extent of the perfusion defect, which appeared only in the right basal ganglia (Fig. 2D) and was consistent with the diffusion-weighted image.


Perfusion imaging of the brain using Z-score and dynamic images obtained by subtracting images from before and after contrast injection.

Choi S, Liu H, Shin TB, Lee JH, Yoon SK, Oh JY, Lee YI - Korean J Radiol (2004 Jul-Sep)

A 26-year-old female with arrhythmia showed a right middle cerebral artery occlusion on the magnetic resonance angiography and high signal intensity at the right basal ganglia on the diffusion weighted image (not shown) 3 hours after developing a left hemiplegia.A. The peak Z-score image shows perfusion defects at the right posterior frontal, temporal area and the basal ganglia.B. The late Z-score image shows delayed perfusion at the perfusion defect areas in A.C. The subtraction dynamic image of a level show initially decreased perfusion with delayed and persisted perfusion at the right frontal, temporal area and the basal ganglia. Images from the top left to the bottom right show the sequential changes in the signal intensity (perfusion) every 1.32 seconds.D. Added images of a peak and a late phase subtraction image show a perfusion defect only at the right basal ganglia (arrow), which is consistent with a diffusion weighted image (not shown).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2698155&req=5

Figure 2: A 26-year-old female with arrhythmia showed a right middle cerebral artery occlusion on the magnetic resonance angiography and high signal intensity at the right basal ganglia on the diffusion weighted image (not shown) 3 hours after developing a left hemiplegia.A. The peak Z-score image shows perfusion defects at the right posterior frontal, temporal area and the basal ganglia.B. The late Z-score image shows delayed perfusion at the perfusion defect areas in A.C. The subtraction dynamic image of a level show initially decreased perfusion with delayed and persisted perfusion at the right frontal, temporal area and the basal ganglia. Images from the top left to the bottom right show the sequential changes in the signal intensity (perfusion) every 1.32 seconds.D. Added images of a peak and a late phase subtraction image show a perfusion defect only at the right basal ganglia (arrow), which is consistent with a diffusion weighted image (not shown).
Mentions: A 26-year-old female with an arrhythmia showed a right MCA occlusion on magnetic resonance angiography (MRA) and high signal intensity in the right basal ganglia on the diffusion-weighted images. The peak Z-score image indicated perfusion defects in the right posterior frontal and temporal lobes as well as in the basal ganglia (Fig. 2A). The late Z-score image showed delayed perfusion in these same areas, except for the basal ganglia (Fig. 2B). The subtraction dynamic images revealed an initial decrease in perfusion with delayed and persistent perfusion in the right frontal, temporal, and basal ganglia areas (Fig. 2C). The subtraction images from the peak and late phases were added in order to observe the extent of the perfusion defect, which appeared only in the right basal ganglia (Fig. 2D) and was consistent with the diffusion-weighted image.

Bottom Line: 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.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.However, the quality varied with the Z-score threshold and the studies selected in a group.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Radiology, Dong-A University College of Medicine, Seo-gu, Busan, Korea. sschoi317@yahoo.co.kr

ABSTRACT

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.

Materials and 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.

Conclusion: 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.

Show MeSH
Related in: MedlinePlus