Koyun beyninin 3 tesla manyetik rezonans görüntülerinin üç boyutlu rekonstrüksiyonu
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Dosyalar
Tarih
2021
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Selçuk Üniversitesi Sağlık Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışma formaldehit ile tespit edilmiş ex vivo koyun beyninden 3 Tesla MRG ile yüksek çözünürlükte görüntü elde edilmesi ve bu görüntüler kullanılarak koyun beyninin üç boyutlu rekonstrüksiyonunun oluşturulması amacıyla gerçekleştirildi. Bu amaç doğrultusunda erişkin, sağlıklı ve herhangi bir anomalisi bulunmayan 9 adet dişi ve 9 adet erkek olmak üzere toplam 18 adet Akkaraman koyun beyni kullanıldı. Beyinlerin %10 formaldehit ile cavum cranii içerisinde tespiti gerçekleştirildi. Dura mater korunacak şekilde dorsal yaklaşım ile beyinlerin kraniotomisi gerçekleştirildi ve cavum cranii'den çıkarıldı. Beyin zarlarının diseksiyonu sırasında hypophysis'in beynin üzerinde kalması sağlandı. Görüntüleme öncesi beyinlerde morfometrik ölçümler yapıldı. MRG öncesi formaldehitin sinyal yoğunluğu üzerindeki etkisini ortadan kaldırmak için beyinler musluk suyu altında bekletildi. Bu esnada sulcus ve gyrus'lar arasında oluşan ve görüntüde artefakta neden olan hava kabarcılarının beyin dokusundan uzaklaştırılması için beyinler görüntüleme öncesi vakum pompası yağı içerisinde muhafaza edildi. Hypophysis'in zarar görmemesi için beyinlerin 3 Tesla MR görüntülemesi supine pozisyonunda gerçekleştirildi. Gri ve ak madde arasındaki en yüksek kontrast T2 ağırlıklı görüntüde elde edildi. DICOM formatında elde edilen görüntüler NIfTI formatına dönüştürülerek görüntü analizi yapıldı. Görüntü analizinde beyinlerin üç boyutlu rekonstrüksiyonu ve segmentasyonu gerçekleştirildi. Morfometrik ölçüm sonuçlarına göre beynin ve sol hemispherium cerebri'nin erkeklerde daha uzun olduğu, benzer şekilde cerebellum ve medulla oblongata'nın erkeklerde daha uzun ve geniş olduğu belirlendi. Yönler (sağ/sol) açısından erkeklerde sol hemispherium cerebri'nin daha uzun, sağ hemispherium cerebri'nin ise daha yüksek olduğu gözlendi. Dişilerde ise sol hemispherium cerebri'nin daha uzun olduğu tespit edildi. Segmentasyon ve üç boyutlu rekonstrüksiyon sonucu elde edilen hacim sonuçlarına göre cinsiyetler arasında bir fark tespit edilmedi. Prosencephalon, mesencephalon ve rhombencephalon'un erkeklerde toplam beyin hacminin sırasıyla %78.49, %4.06 ve %17.44'ünü oluşturduğu belirlendi. Dişilerde ise bu oranın sırasıyla %78.67, %4.19 ve %17.13 olduğu gözlendi. Sonuç olarak formaldehit ile tespit edilmiş beyin dokusundan 3 Tesla MRG ile yüksek çözünürlükte elde edilen görüntülerin farklı türler için de uyarlanabileceği ve yüksek çöznürlükte görüntü elde etmek için gerekli olan uzun MR görüntüleme süresinde oluşan hareket artefaktı önlenerek, beyine ait küçük yapıların daha detaylı görüntülenebileceği gözlenmiştir. Böylece ruminant, sus veya diğer türlerde oluşturulan nörodejeneratif hastalık modellerinde yapılacak deneysel çalışmalarda, ilgilenilen beyin bölgesindeki hacimsel, morfometrik veya morfolojik değişimlerin daha detaylı incelenebileceği düşünülmektedir. Ayrıca üç boyutlu yazıcı ile elde edilen beyin modelinin anatomi eğitiminde kullanılabileceği tahmin edilmektedir.
This study was carried out to obtain high resolution images with 3 Tesla MRI from ex vivo sheep brain fixed with formaldehyde and to obtain three-dimensional reconstruction of sheep brain using these images. For this purpose, 18 Akkaraman sheep brains (9 males / 9 females) which were adult, healthy and without any anomalies were used in the study. The brains were fixed with %10 formaldehyde in the cavum cranii. Craniotomy of the brains was performed with a dorsal approach while preserving the dura mater and the brains were removed from the cavum cranii. During the dissection of the meninges, the pituitary gland was kept on the brain. Morphometric measurements were obtained from the brains before imaging. Before magnetic resonance imaging, brains were kept under tap water to eliminate the effect of formaldehyde on signal intensity. The brains were immersed in vacuum pump oil before imaging in order to remove the air bubbles formed between the gyri and sulci and causing artifacts from the brain. MR acquisitions were performed in the supine position in the 3T clinical scanner to avoid any deformation of the pituitary gland. Better contrast between gray and white matter was obtained in the T2-weighted image. Before image analysis, images acquired in DICOM file format were first converted into 3D volumes in NIfTI file format. Three-dimensional reconstruction and segmentation of the brains were performed in image analysis. According to the morphometric measurement results, it was determined that the brain and left cerebral hemisphere were longer in males. Similarly, the cerebellum and medulla oblongata were longer and wider in males. In terms of the right and left sides, it was observed that the left cerebral hemisphere has longer and the right cerebral hemisphere was higher in males. It was detected that the left cerebral hemisphere has longer in females. There was no difference between genders in the volume results obtained from segmentation and three-dimensional reconstruction. It was determined that prosencephalon, mesencephalon and rhombencephalon were formed 78.49%, 4.06% and 17.44% of the total brain volume in males, respectively. In females, this rate was determined to be 78.67%, 4.19% and 17.13%, respectively. As a result, it is thought that high-resolution images acquired with 3 Tesla MRI scanner from the brain (formaldehyde-fixed) can be adapted to different species. In the present study, it was observed that the substructures of the brain could be shown in more detail by preventing the motion artifact that occurs during the long MR imaging time required to obtain high-resolution images. Thus, it is thought that the volumetric, morphometric or morphological changes in the brain region of interest can be examined in more detail in experimental studies to be performed in neurodegenerative disease models created in ruminant, sus or other species. In addition, it is estimated that the brain model obtained with 3D print can be used in anatomy education.
This study was carried out to obtain high resolution images with 3 Tesla MRI from ex vivo sheep brain fixed with formaldehyde and to obtain three-dimensional reconstruction of sheep brain using these images. For this purpose, 18 Akkaraman sheep brains (9 males / 9 females) which were adult, healthy and without any anomalies were used in the study. The brains were fixed with %10 formaldehyde in the cavum cranii. Craniotomy of the brains was performed with a dorsal approach while preserving the dura mater and the brains were removed from the cavum cranii. During the dissection of the meninges, the pituitary gland was kept on the brain. Morphometric measurements were obtained from the brains before imaging. Before magnetic resonance imaging, brains were kept under tap water to eliminate the effect of formaldehyde on signal intensity. The brains were immersed in vacuum pump oil before imaging in order to remove the air bubbles formed between the gyri and sulci and causing artifacts from the brain. MR acquisitions were performed in the supine position in the 3T clinical scanner to avoid any deformation of the pituitary gland. Better contrast between gray and white matter was obtained in the T2-weighted image. Before image analysis, images acquired in DICOM file format were first converted into 3D volumes in NIfTI file format. Three-dimensional reconstruction and segmentation of the brains were performed in image analysis. According to the morphometric measurement results, it was determined that the brain and left cerebral hemisphere were longer in males. Similarly, the cerebellum and medulla oblongata were longer and wider in males. In terms of the right and left sides, it was observed that the left cerebral hemisphere has longer and the right cerebral hemisphere was higher in males. It was detected that the left cerebral hemisphere has longer in females. There was no difference between genders in the volume results obtained from segmentation and three-dimensional reconstruction. It was determined that prosencephalon, mesencephalon and rhombencephalon were formed 78.49%, 4.06% and 17.44% of the total brain volume in males, respectively. In females, this rate was determined to be 78.67%, 4.19% and 17.13%, respectively. As a result, it is thought that high-resolution images acquired with 3 Tesla MRI scanner from the brain (formaldehyde-fixed) can be adapted to different species. In the present study, it was observed that the substructures of the brain could be shown in more detail by preventing the motion artifact that occurs during the long MR imaging time required to obtain high-resolution images. Thus, it is thought that the volumetric, morphometric or morphological changes in the brain region of interest can be examined in more detail in experimental studies to be performed in neurodegenerative disease models created in ruminant, sus or other species. In addition, it is estimated that the brain model obtained with 3D print can be used in anatomy education.
Açıklama
Anahtar Kelimeler
Koyun, Beyin, Sheep, Brain, Manyetik rezonans görüntüleme, Üç boyutlu rekonstrüksiyon, Magnetic resonance imaging, Three dimensional reconstruction
Kaynak
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
Künye
Aydoğdu, S. (2021). Koyun beyninin 3 Tesla manyetik rezonans görüntülerinin üç boyutlu rekonstrüksiyonu. (Doktora Tezi). Selçuk Üniversitesi, Sağlık Bilimleri Enstitüsü, Konya.
