T2, FLAIR, T1 강조 MR영상에서 나이에 따른 뇌피질의 회질과 백질의 미세구조 변화 The Age-related Microstructural Changes of the Cortical Gray and White Matter Ratios on T2-, FLAIR and T1- weighted MR Images원문보기
목적: 정상인의 나이에 따른 뇌피질의 회질과 백질의 T2 강조, FLAIR, T1 강조 영상에서의 두께와 신호강도의 미세구조 변화 양상을 알고자 한다. 대상 및 방법: 남녀 각각 10 명씩의 10세, 20세, 30세, 40세, 50세, 60세, 70세, 80세, 90세 군의 T2, FLAIR, T1 강조 MR영상을 이용하였다. 뇌의 난형중심 부위의 축상영상에서 일정한 두께를 보이는 후중심뇌회 부위에서 피질의 회질과 백질의 두께와 신호강도를 측정하여, 각 군의 평균값을 구하여 나이 증가에 따른 회질/백질 두께 비와 회질/백질의 신호강도 비의 변화 양상을 비교 관찰하였다. 결과: T2 강조영상에서 회질/백질 두께 비는 남녀 각각 10세에는 0.81과 0.79, 90세에는 0.73과 0.71로써 회질이 백질의 두께보다 더 감소하였으며, 회질/백질 신호 비는 10세에는 1.53과 1.43, 90세에는 1.23과 1.27로써 남녀 각 20%와 11% 감소하였다. FLAIR 영상에서 회질/백질 두께 비는 남녀 각각 10세에는 1.09와 1.00, 70세에는 1.11과 0.95였으며, 회질/백질 신호 비는 10세에는 1.23과 1.25, 90세에는 1.06과 1.05로써 남녀 각각 14%와 16% 감소하였다. T1 강조영상에서 회질/백질 두께 비는 남녀 각각 10세에는 0.66과 0.80이었고, 90세에는 0.90과 0.78로 변화하였으며, 회질/백질 신호 비는 10세에는 0.86과 0.85, 90세에는 0.90과 0.87로써 남녀 각각 5%와 2% 증가하였다. 결론: T2, FLAIR, T1 강조영상에서 뇌파질의 회질과 백질의 나이증가에 따른 두께와 미세신호강도의 변화 양상은 특징적이며, 이 양상을 이해하는 것은 뇌의 정상 노화와 퇴행성 질환을 구별하는데 도움을 줄 것으로 생각된다.
목적: 정상인의 나이에 따른 뇌피질의 회질과 백질의 T2 강조, FLAIR, T1 강조 영상에서의 두께와 신호강도의 미세구조 변화 양상을 알고자 한다. 대상 및 방법: 남녀 각각 10 명씩의 10세, 20세, 30세, 40세, 50세, 60세, 70세, 80세, 90세 군의 T2, FLAIR, T1 강조 MR영상을 이용하였다. 뇌의 난형중심 부위의 축상영상에서 일정한 두께를 보이는 후중심뇌회 부위에서 피질의 회질과 백질의 두께와 신호강도를 측정하여, 각 군의 평균값을 구하여 나이 증가에 따른 회질/백질 두께 비와 회질/백질의 신호강도 비의 변화 양상을 비교 관찰하였다. 결과: T2 강조영상에서 회질/백질 두께 비는 남녀 각각 10세에는 0.81과 0.79, 90세에는 0.73과 0.71로써 회질이 백질의 두께보다 더 감소하였으며, 회질/백질 신호 비는 10세에는 1.53과 1.43, 90세에는 1.23과 1.27로써 남녀 각 20%와 11% 감소하였다. FLAIR 영상에서 회질/백질 두께 비는 남녀 각각 10세에는 1.09와 1.00, 70세에는 1.11과 0.95였으며, 회질/백질 신호 비는 10세에는 1.23과 1.25, 90세에는 1.06과 1.05로써 남녀 각각 14%와 16% 감소하였다. T1 강조영상에서 회질/백질 두께 비는 남녀 각각 10세에는 0.66과 0.80이었고, 90세에는 0.90과 0.78로 변화하였으며, 회질/백질 신호 비는 10세에는 0.86과 0.85, 90세에는 0.90과 0.87로써 남녀 각각 5%와 2% 증가하였다. 결론: T2, FLAIR, T1 강조영상에서 뇌파질의 회질과 백질의 나이증가에 따른 두께와 미세신호강도의 변화 양상은 특징적이며, 이 양상을 이해하는 것은 뇌의 정상 노화와 퇴행성 질환을 구별하는데 도움을 줄 것으로 생각된다.
Purpose : The purpose of this study was to investigate the microstructural changes according to aging on the thickness and signal intensity (SI) of the cortical gray matter (GM) and white matter (WM) on the T2-, fluid-attenuated inversion recovery (FLAIR) and T1-weighted MR images in normal subjects...
Purpose : The purpose of this study was to investigate the microstructural changes according to aging on the thickness and signal intensity (SI) of the cortical gray matter (GM) and white matter (WM) on the T2-, fluid-attenuated inversion recovery (FLAIR) and T1-weighted MR images in normal subjects. Materials and Methods : The 10, 20, 30, 40, 50, 60, 70, 80 and 90 year age groups of men and women (each 10 individuals) who underwent routine brain MRI, including the T2-, FLAIR and T1-weighted images, were selected for this study. We measured the thickness and the SI of the cortical GM and WM at the postcentral gyrus, which has an even thickness at the level of centrum semiovale, on the axial scans and we calculated the mean values of the thickness ratio of the gray/white matter (TRGW) and the signal intensity ratio of the gray/white matter (SRGW), and we compared the ratios of each age group. Results : On the T2-weighted images, the TRGWs were 0.81 and 0.79 at the age of 10 and they were 0.73 and 0.71 at the age of 90 in the men and women, respectively. So, the GM thickness was decreased more than the WM thickness was with aging. On the FLAIR images, the TRGWs were 1.09 and 1.00 at the age of 10 and they were 1.11 and 0.95 at the age of 70 in the men and women, respectively. On the T1-weighted images, the TRGWs were 0.66 and 0.80 at the age of 10, and the ratio was changed to 0.90 and 0.78 at the age of 90 in the men and women, respectively. On the T2-weighted image, the SRGWs were 1.53 and 1.43 at the age of 10, and they were 1.23 and 1.27 at the age of 90 in the men and women, respectively. On the FLAIR images, the SRGWs were 1.23 and 1.25 at the age of 10 and they were 1.06 and 1.05 at the age of 90 in the men and women, respectively. On the T1-weighted images, the SRGWs were 0.86 and 0.85 at the age of 10, and they were 0.90 and 0.87 at the age of 90 in the men and women, respectively. Conclusion : We suggest that the age-related microstructural changes of the thickness and the SI of the cortical GM and WM on the T2-, FLAIR and T1-weighted images are unique, and so this knowledge will be helpful to differentiate neurodegenerative disease from normal aging of the brain.
Purpose : The purpose of this study was to investigate the microstructural changes according to aging on the thickness and signal intensity (SI) of the cortical gray matter (GM) and white matter (WM) on the T2-, fluid-attenuated inversion recovery (FLAIR) and T1-weighted MR images in normal subjects. Materials and Methods : The 10, 20, 30, 40, 50, 60, 70, 80 and 90 year age groups of men and women (each 10 individuals) who underwent routine brain MRI, including the T2-, FLAIR and T1-weighted images, were selected for this study. We measured the thickness and the SI of the cortical GM and WM at the postcentral gyrus, which has an even thickness at the level of centrum semiovale, on the axial scans and we calculated the mean values of the thickness ratio of the gray/white matter (TRGW) and the signal intensity ratio of the gray/white matter (SRGW), and we compared the ratios of each age group. Results : On the T2-weighted images, the TRGWs were 0.81 and 0.79 at the age of 10 and they were 0.73 and 0.71 at the age of 90 in the men and women, respectively. So, the GM thickness was decreased more than the WM thickness was with aging. On the FLAIR images, the TRGWs were 1.09 and 1.00 at the age of 10 and they were 1.11 and 0.95 at the age of 70 in the men and women, respectively. On the T1-weighted images, the TRGWs were 0.66 and 0.80 at the age of 10, and the ratio was changed to 0.90 and 0.78 at the age of 90 in the men and women, respectively. On the T2-weighted image, the SRGWs were 1.53 and 1.43 at the age of 10, and they were 1.23 and 1.27 at the age of 90 in the men and women, respectively. On the FLAIR images, the SRGWs were 1.23 and 1.25 at the age of 10 and they were 1.06 and 1.05 at the age of 90 in the men and women, respectively. On the T1-weighted images, the SRGWs were 0.86 and 0.85 at the age of 10, and they were 0.90 and 0.87 at the age of 90 in the men and women, respectively. Conclusion : We suggest that the age-related microstructural changes of the thickness and the SI of the cortical GM and WM on the T2-, FLAIR and T1-weighted images are unique, and so this knowledge will be helpful to differentiate neurodegenerative disease from normal aging of the brain.
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가설 설정
Knowledge of the microstructual changes of the brain cortex would be helpful for difforaititing degenerative disease from normal aing. There have been reports that the cortical thickness shows linear changes according to aging (lf 2), and the cortical thickness decreased most significantly with age in the superior frontal area, and it showed a minimal difference in the gray matter (GM)/white matter(WM) ratio between men and women (3).
제안 방법
In our study ( any gender differences in the TRGW and SRGW were not evident. In this study, there is basic limitation in the measurement of the thickness of the GM and WM because of lage voxel size compared with the object thickness itself, and it also has possibility of intraobserver variance according to the manual measurements.
Using PACS tool, we measured whole thickness of the gyrus, and measured the thickness and the SI of the cortical GM and WM at the postcentral gyrus, where it has an even thickness at the level of centrum semiovale, on the axial scans (Figs. 1, 2), and we calculated the mean values of the thickness ratio of gray/white matter(TRGW) and the signal intensity ratio of gray/white matter(SRGW) in each age group, and we compared the ratios according to the age of the men and women ( Tables 1( 2). Statistical analysis was performed using Mest.
대상 데이터
One hundred eighty patients (90 men and 90 women) who underwent routine brain MRI because of clinically suspected neurologic diseases, but who were diagnosed as normal on the basis of the MR findings and clinical follow up were selected for this study. The subject were grouped with 10 individuals of the age of 10f 20, 3Q 450; 60, 70, 80 and 90 for the men and women, spectivoly {a total of 18 groups).
up were selected for this study. The subject were grouped with 10 individuals of the age of 10f 20, 3Q 450; 60, 70, 80 and 90 for the men and women, spectivoly {a total of 18 groups).
성능/효과
The GM SI was decreased in the medial frontal area, and the WM SI was decreased in the superior and medial frontal areas, demonstrating decreased overall contrast with aging, and the GM/WM ratio was changed in the superior and inferior frontal areas (3). In our study, on the T2-weighted images, the contrast between the GM and WM was decreased in the aged brain due to decreased GM SI and increased WM SI. FLAIR is an inversion-recovery pulse sequence designed to nullify or greatly reduce the SI from CSF and brain parenchyma, but it can more clearly show parenchyma.
On the FLAIR image, compared with the age of 10f the Sis at e e of 90 wewdecreased 9% and 10% in le GM and they were increased 7% and 8% in the WM in the men and women respectively. The SRGWs were 1.
3). On the FLAIR images, the thickness of the gyrus was 7.3 mm and 7.2 mm at the age of 10, and 5.8 mm and 6.1 mm at the age of 70, and so it was decreased 21% and 15% for the whole thickness, with a 20% and 17% decrease of the GM, and a 22% and 13% decrease of the WM in the men and women, respectively. The TRGWs were 1.
On the T2-weighted image, as compared with the age of 10, the Sis at the age of 90 were decreased 11% and 6% in the GM, and the Sis were increased 9% and 5% in the WM in the men and women, respectively. The SRGWs were 1.
On the T2-weighted images, the thicknesses of the gyrus were 7.1 mm and 7.2 mm at the age of 10, and 5.4 mm and 5.1 mm at the age of 90 in men and women, respectively, and so the whole thickness was decreased 24% and 29%, with a 27% and 32% decrease of the GM and a 19% and 25% decrease of the WM in the men and women, respectively. The TRGWs were 0.
On the Tl- weighted image, the thickness of the gyrus was 7.4 mm and 7.8 mm at the age of 10, and 5.6 mm and 5.9 mm at the age of 90, and so it decreased 24% and 24% for the whole thickness, with a 14% and 25% decrease of the GM and a 38% and 23% decrease of the WM in the men and women, respectively. The whole thickness of the gyrus was measured as 8% thicker on the Tl-weighted images than that on the T2-weighted images.
On the Tl-weighted images, the Sis of the GM are increased 6% in the men and they were decreased 2% in the women, and the WM was increased 1% in the men and they were decreased 4% in the women, respectively. The SRGWs were 0.
We excluded the images of the young children and the elderly subjects who had obvious high WM SI on the FLAIR images. The GM SI was decreased in the medial frontal area, and the WM SI was decreased in the superior and medial frontal areas, demonstrating decreased overall contrast with aging, and the GM/WM ratio was changed in the superior and inferior frontal areas (3). In our study, on the T2-weighted images, the contrast between the GM and WM was decreased in the aged brain due to decreased GM SI and increased WM SI.
There have been reports that the cortical thickness shows linear changes according to aging (lf 2), and the cortical thickness decreased most significantly with age in the superior frontal area, and it showed a minimal difference in the gray matter (GM)/white matter(WM) ratio between men and women (3). The GM signal intensity(SI) was decreased with strong effects in the medial frontal area and the WM SI decreased in the superior and medial frontal areasf which demonstrated decreased overall contrast with aging in T1 weighted images. These findings may be an important biomarker of the pathologic changes with aging and according to disease j3).
In the present study, the border became unclear after the age of 40f and the measurements of the GM and WM SI separately were not possible on the Tl-weighted images in 2 cases of the 80 and 90 year age groups, respectively. The patterns of change of the SI ratio on the T2-weighted and FLAIR images look similar with advancing age, and the ratios showed the highest value on the T2-weighted images and the lowest value on the Tl-weighted images. The causes of the SI change are considered to be decreased water content, an increased iron concentration etc.
후속연구
We suggest that the agsl&ted microstructural changes of the xickness and the SI of the cortical GM and WM on the T2-f FLAIR and TLweiited images are unique, and so this knowledge will be helpful for differentiating between neurodegenerative disease and normal aging of the brain.
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