An MRI Study on Volumetric Changes in the Brain of Female Adolescents with Autism

Öz

Bu çalışma bazı görüntü işleme tekniklerini bir arada kullanan bir yaklaşımla bilinen beyin hastalıklarından biri olan Otizm hastalığını beyin hacmindeki bölgesel farklılıklardan tespit etmeyi hedeflemektedir. Görüntüler, 17 yaşında 5 otistik kadın ergen hastadan ve 10 kişiden oluşan kadın sağlıklı kontrol grubundan (17 ± 1 yaşında) oluşmaktadır. Bu görüntüler 1,5 mm3 çift eko, hızlı spin eko kesitlerden oluşup Manyetik Rezonans Görüntü tarayıcılarından elde edilmiştir. Kesitler gri cevher ve beyaz cevher olarak ayrılmıştır. Global eşikleme, adaptif eşikleme gibi bazı görüntü işleme teknikleri ve k-means algoritması beyin dokusuna ait volumetrik veriyi hesaplamak için birlikte kullanılmıştır. Bağımsız iki grup olan otistik ve kontrol grubu arasındaki farkı karşılaştırmak için istatistiksel t-testi metodu ile analizi yapılmıştır. Önceden yapılmış olan yapısal nörolojik görüntüleme çalışmaları gözden geçirilmiş; bu çalışmalar gri cevher, beyaz cevher ve tüm beyin volumlerini ortaya çıkarmada kullanılmıştır. Literatür, otistik insanlar arasında her bir yaş grubu için farklı sonuçlar olduğunu göstermektedir. Sonuçlar kontrol grubu ve otistik kadın ergenler arasında tüm beyin hacminde önemli bir büyüklük farkının var olmadığını, fakat 17 yaşında kadın ergenlerde daha büyük beyaz cevher hacminin saptandığını göstermektedir

Anahtar Kelimeler

• Otizm, Eşikleme algoritmaları, K-means, Volum hesaplamaları, Gri seviye dağılım

Otizmli Kadın Ergenlerin Beyinlerindeki Volumetrik Değişimler Üzerine Yapılmış Bir MR Çalışması

Öz

This study attempts to identify regional differences in brain volume between the known brain disorders to detect autism with an integrated approach that uses several image-processing techniques. Neuroimages from 5 autistic 17 years old female patients and 10 female control (17 ± 1 years old), were used. These images were from dual-echo, fast spin echo slices (1,5 mm thickness) that were acquired through Magnetic Resonance Image (MRI) scanners. The slices were segmented into gray matter and white matter. Several image-processing techniques such as global thresholding, adaptive thresholding and kmeans algorithm were used to calculate the volumetric data of the brain tissue. The results are analyzed with independent sample of t-tests to compare the outcome for the autistic subjects with control group. Previous structural neuroimaging studies were reviewed; these studies were integrated to obtain results that detect gray matter, white matter, and whole brain volumes. The literature suggests that there are different results for each age group of autistic people. The results show that there is no significant volumetric growth in whole brain between control group and autistic female adolescents; but larger white matter volume was determined in 17 years old female autistic adolescents

Anahtar Kelimeler

• Autism, Thresholding algorithms, K-means, Volumetric measurements, Gray level distribution

Kaynakça

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