| Project/Area Number |
14571309
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Cerebral neurosurgery
|
|---|
| Research Institution | Shiga University of Medical Science |
|---|
Principal Investigator |
SHIINO Akihiko Shiga University of Medical Science, Neurosurgery, Assistant Professor, 医学部, 講師 (50215935)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
INUBUSHI Toshiro Shiga University of Medical Science, molecular Neuroscience Research Center, Professor, MR医学総合研究センター, 教授 (20213142)
|
|---|
| Project Period (FY) |
2002 – 2004
|
| Project Status |
Completed (Fiscal Year 2004)
|
| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2004: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2002: ¥900,000 (Direct Cost: ¥900,000)
|
|---|
| Keywords | perfusion / cerebral blood flow / dynamic susceptibility contrast / infarction / magnetic resonance / brain / ischemia / quantification / 脳循環代謝 / 脳血流 / 定量 / MRI / DSC |
|---|
| Research Abstract |
Quantitative measurement of CBF by dynamic dynamic susceptibility contrast(DSC) technique is an important and challenging examination. For quantification of rCBF value on pixel-by-pixel basis, the arterial input function(AIF) has to be measured. The limited spatial resolution associated with the EPI sequences can potentially lead to inaccuracy and variability in the CBF measurements. In this study, a correction scheme is proposed to correct the errors. Subjects were studied with both MR and PET so that the accuracy of MR measured CBF can be assessed.
Five healthy volunteers were studied. All MR images were acquired on a General Electric 1.5 Signa clinical scanner. Since single shot EPI sequence provide only a very low bandwidth in phase encoding direction leading to prominent signal misregistration, we used multishot EPI technique which minimized the signal loss or distortion. All images were transferred to a SGI Workstation for post-processing. The AIF and venous output function(VOF) w
… More
ere automatically obtained from large basal artery (IC or MCA or PCA) and the superior sagittal sinus, respectively. FT was employed to deconvolve the tissue function by the experimentally measured AIF and thus quantitative estimate of CBF was obtained. The AIF of each subject was corrected by the VOF, which was also obtained by integrating the delta-R_2^* curve obtained from the superior sagittal sinus. For normalization of the position between the MRI and the PET, three-dimensional anatomical fitting was performed.
A total of 100 circular ROIs in each subject were placed in both the PET and MR CBF maps and were used to obtain regional estimate of CBF. As a result, there was good correlation in the CBF values among the two modalities (correlation coefficient=0.8) with the exception of the area including large vessels.
Although several factors can potentially account for the observed variability in this study, the most plausible explanations are the partial volume effects of the AIF caused by the limited spatial resolution of the EPI sequence. The areas of AIF may be underestimated, leading to an overestimation as well as variability in the CBF measurement. We made an assumption that the integral of the delta-R_2^* curve of both the AIF and the VOF should be equal. The VOF corrected the partial volume effect and variables came from the AIF selection. In summary, we have presented an improved partial volume correction method, which reduces the errors in AIF determination. Less
|
