정상 성인의 활꼴다발에서 나타나는 연령 관련 변화: 확산텐서영상 분석 연구 = The Characteristics of Age-Related Changes of the Arcuate Fasciculus in Healthy Adults: A Diffusion Tensor Imaging Study

다국어 초록 (Multilingual Abstract)

Background: The arcuate fasciculus (AF) is a major white matter tract connecting language comprehension and production regions. Although left–right asymmetry of the AF has been consistently reported, quantitative evidence describing age-related changes and hemispheric differences in healthy Korean adults remains limited.
Purpose: This study aimed to quantitatively investigate the structural properties of the arcuate fasciculus in healthy adults using diffusion tensor imaging (DTI), focusing on fractional anisotropy (FA) and fiber number (FN), and to examine age-related changes and hemispheric differences according to age group.
Methods: DTI data were obtained from 51 healthy adults and classified into three age groups: Group 1 (20–39 years), Group 2 (40–59 years), and Group 3 (60–75 years). FA and FN values of the left and right AF were measured using DTI Studio. Normality was assessed using the Kolmogorov–Smirnov and Shapiro–Wilk tests.
Group differences were analyzed using one-way ANOVA for FN and the Kruskal–Wallis test for FA, with Scheffe post-hoc tests applied when appropriate. Correlation analyses were conducted using Pearson or Spearman coefficients depending on data distribution.
Hemispheric differences between the left and right AF were examined using paired t-tests for FN and Wilcoxon signed-rank tests for FA. Statistical significance was set at p <0.05.
Results: For FN, the left AF showed a significant age-related decline across groups (G1: 611.88 ±124.56; G2: 608.74 ±110.56; G3: 497.07 ±108.59; p = 0.009), with post-hoc analyses indicating significantly lower FN in Group 3 compared to Groups 1 and 2. A similar decline was observed in the right AF (G1: 564.29 ±123.04; G2: 548.68 ±83.52; G3: 465.87 ±87.79; p = 0.017), although post-hoc significance was limited to the comparison between Groups 1 and 3.
FA values exhibited a gradual decreasing trend with age in both hemispheres, but nosignificant group differences were observed(left: p = 0.069; right: p = 0.388).
Correlation analysis showed a significant negative correlation between age and left AF FN (r = −0.300, p = 0.033), suggesting age-related reduction in structural connectivity of the left language pathway. A trend-level negative correlation was also observed for left FA (r = −0.268, p = 0.057).
Conclusion: These findings demonstrate age-related structural changes in the arcuate fasciculus, characterized by a prominent decline in fiber number, particularly in the left hemisphere. While FA showed relative stability across age and hemispheres, FN appeared to be a more sensitive marker of age-related white matter changes. This study provides normative quantitative reference data for the arcuate fasciculus in healthy Korean adults and highlights differential hemispheric aging patterns in language-related white matter pathways.

목차 (Table of Contents)

• Ⅰ. 서론 1
• 1. 연구 배경 1
• 2. 활꼴다발(Arcuate Fasciculus)의 해부학적기능적 특성 1
• 3. 확산텐서영상과 백질 분석 지표(FA, FN) 2
• 4. 활꼴다발의 연령 관련 변화에 대한 선행연구 2
• 5. 연구의 목적 2
• Ⅱ. 연구방법 3
• 1. 연구대상 3
• 1.1 대상자 선정 및 제외 기준 3
• 1.2 연령군 분류 기준 3
• 2. 연구방법 4
• 2.1 영상자료 수집 및 분석 도구 4
• 2.2 활꼴다발 섬유 추적 방법 5
• 2.3 통계분석 6
• Ⅲ. 결과 7
• 3.1 연령군 간 활꼴다발 섬유 수(FN) 비교 8
• 3.2 연령군 간 활꼴다발 분획이방성(FA) 비교 12
• 3.3 연령과 활꼴다발 지표(FN, FA) 간 상관관계 14
• Ⅳ. 고찰 16
• 1. 연령 증가에 따른 활꼴다발 섬유 수(FN)의 변화 16
• 2. 연령 증가에 따른 분획이방성(FA)의 변화 18
• 3. 언어 네트워크 노화에 대한 신경해부학적 의미 19
• 4. 연구의 한계 및 후속 연구 제언 19
• Ⅴ. 결론 20
• References 21