Medical Biophysics, Medical Sciences Building, The University of Western Ontario, London, ON, Canada.
J Magn Reson Imaging. 2012 Aug;36(2):476-82. doi: 10.1002/jmri.23612. Epub 2012 Mar 7.
To create a standardized, MRI-compatible, life-sized phantom of the brain ventricles to evaluate ventricle segmentation methods using T(1) -weighted MRI. An objective phantom is needed to test the many different segmentation programs currently used to measure ventricle volumes in patients with Alzheimer's disease.
A ventricle model was constructed from polycarbonate using a digital mesh of the ventricles created from the 3 Tesla (T) MRI of a subject with Alzheimer's disease. The ventricle was placed in a brain mold and surrounded with material composed of 2% agar in water, 0.01% NaCl and 0.0375 mM gadopentetate dimeglumine to match the signal intensity properties of brain tissue in 3T T(1) -weighted MRI. The 3T T(1) -weighted images of the phantom were acquired and ventricle segmentation software was used to measure ventricle volume.
The images acquired of the phantom successfully replicated in vivo signal intensity differences between the ventricle and surrounding tissue in T(1) -weighted images and were robust to segmentation. The ventricle volume was quantified to 99% accuracy at 1-mm voxel size.
The phantom represents a simple, realistic and objective method to test the accuracy of lateral ventricle segmentation methods and we project it can be extended to other anatomical structures.
创建一个标准化的、与磁共振成像兼容的、真人大小的脑室内模型，以评估使用 T1 加权磁共振成像的脑室分割方法。需要一个客观的模型来测试目前用于测量阿尔茨海默病患者脑室容积的许多不同分割程序。
使用从阿尔茨海默病患者 3T MRI 生成的脑室数字网格，从聚碳酸酯构建了一个脑室模型。将脑室置于脑模具中，并被由 2%琼脂、0.01%NaCl 和 0.0375mM 钆喷替酸二葡甲胺组成的材料包围，以匹配 3T T1 加权 MRI 中脑组织的信号强度特性。采集了模型的 3T T1 加权图像，并使用脑室分割软件测量了脑室容积。
成功地复制了体内信号强度差异，在 T1 加权图像中，脑室与周围组织之间的图像采集到的信号强度差异，并具有强大的分割能力。当体素大小为 1mm 时，脑室体积的定量达到 99%的准确性。
该模型代表了一种简单、现实和客观的方法，可以测试侧脑室分割方法的准确性，我们预计它可以扩展到其他解剖结构。
