3T MRI-Based Regional Mapping of Magnetization Transfer Ratio in Normal Brain Tissue: A Study of White and Grey Matter Differences

Öz

Background: This study aimed to establish normal regional Magnetization Transfer Ratio (MTR) values in white and grey matter using 3-Tesla MRI in healthy adult subjects, with a particular focus on cortical and deep brain structures. It also aims to assess the variability of these values and provide a baseline for further pathological studies. Materials and Methods: Seventy healthy volunteers (28 females, 42 males, mean age 28 years) were included. MRI scans were performed using a 3.0 Tesla MRI scanner. Conventional cranial MRI sequences were acquired, followed by Magnetization Transfer Imaging (MTI) with off-resonance pulses. MTR maps were generated from proton density-weighted images obtained with and without magnetization transfer pre-pulses. Measurements were performed in 31 white matter and 9 grey matter regions, with additional assessments of CSF for noise control. Statistical analysis was carried out to compare MTR values across different brain regions. Results: The mean MTR value was significantly higher in white matter (23.9 ± 0.21) compared to grey matter (17.3 ± 0.77). The corpus callosum had the highest MTR values within the white matter, particularly in the splenium, while the thalamus exhibited the highest MTR values in the grey matter. Regional variations were observed, with higher MTR values in the occipital and temporal lobes and lower values in the frontal and parietal lobes. MTR measurements showed excellent intra-observer (ICC > 0.9) and good inter-observer reliability (ICC 0.80–0.90). Conclusions: This study provides detailed MTR mapping of normal brain tissue, highlighting significant regional dif-ferences between white and grey matter. The findings offer valuable baseline data for assessing structural changes in CNS diseases and for evaluating the efficacy of therapeutic interventions. MTR measurements demonstrate high reproducibility, making this technique a reliable tool in clinical and research applications for monitoring pathological alterations in the central nervous system.

Anahtar Kelimeler

• Magnetization Transfer Ratio
• MTR
• 3.0 Tesla
• Magnetization Transfer Imaging
• brain.

3 Tesla MRI Kullanılarak Normal Beyin Dokusunda Bölgesel Manyetizasyon Transfer Oranı Haritalaması: Beyaz ve Gri Madde Farklılıklarının İncelenmesi

Öz

Amaç: Bu çalışmanın amacı, sağlıklı yetişkin deneklerde 3 Tesla manyetik rezonans görüntüleme (MRG) kullanarak beyaz ve gri cevherde normal bölgesel Manyetizasyon Transfer Oranı (MTO) değerlerini, özellikle kortikal ve derin beyin yapılarına odaklanarak belirlemek, bu değerlerin değişkenliğini değerlendirmek ve daha ileri patolojik çalışma-lar için bir temel oluşturmaktır. Materyal ve metod: Çalışmaya dahil edilen 70 sağlıklı gönüllünün (28 kadın, 42 erkek, ortalama yaş 28) MRG tarama-ları 3.0 Tesla MRG tarayıcısı kullanılarak gerçekleştirildi. Konvansiyonel kranial MRG sekanslar elde edilmiş, ardından rezonans dışı darbelerle Manyetizasyon Transfer Görüntüleme yapıldı. MTR haritaları, manyetizasyon transferi ön darbeleriyle ve bunlar olmadan elde edilen proton yoğunluk ağırlıklı görüntülerden oluşturuldu. Ölçümler, gürültü kontrolü için ek BOS değerlendirmeleriyle birlikte 31 beyaz cevher ve 9 gri cevher bölgesinde gerçekleştirildi. Farklı beyin bölgelerindeki MTO değerlerini karşılaştırmak için istatistiksel analiz yapıldı. Bulgular: Ortalama MTO değeri beyaz cevherde (23,9 ± 0,21) gri cevhere (17,3 ± 0,77) kıyasla önemli ölçüde daha yüksekti. Korpus kallozum, beyaz cevher içinde, özellikle spleniumda en yüksek MTO değerlerine sahipken, talamus gri cevherde en yüksek MTO değerleri saptandı. Oksipital ve temporal loblarda daha yüksek MTO değerleri ve frontal ve parietal loblarda daha düşük değerlerle bölgesel farklılıklar gözlendi. MTO ölçümleri mükemmel gözlemci içi (ICC > 0,9) ve gözlemciler arası iyi güvenilirlik (ICC 0,80–0,90) gösterdi. Sonuç: Bu çalışma, normal beyin dokusunun ayrıntılı MTO haritalamasını sunarak beyaz ve gri cevher arasındaki önemli bölgesel farklılıkları vurgulamaktadır. Bulgular, MSS hastalıklarındaki yapısal değişiklikleri değerlendirmek ve terapötik müdahalelerin etkinliğini değerlendirmek için değerli temel veriler sunmaktadır. MTO ölçümleri yüksek tek-rarlanabilirlik gösterir ve bu tekniği merkezi sinir sistemindeki patolojik değişiklikleri izlemek için klinik ve araştırma uygulamalarında güvenilir bir araç haline getirir.

Anahtar Kelimeler

• Manyetizasyon Transfer Oranı
• MTR
• 3.0 Tesla
• Manyetizasyon Transfer Görüntüleme
• beyin.

Kaynakça

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