School of Medicine, Swansea University, Swansea, SA2 8PP, UK.
Physiol Meas. 2010 Aug;31(8):S111-25. doi: 10.1088/0967-3334/31/8/S09. Epub 2010 Jul 21.
The feasibility of detecting a cerebral haemorrhage with a hemispherical MIT coil array consisting of 56 exciter/sensor coils of 10 mm radius and operating at 1 and 10 MHz was investigated. A finite difference method combined with an anatomically realistic head model comprising 12 tissue types was used to simulate the strokes. Frequency-difference images were reconstructed from the modelled data with different levels of the added phase noise and two types of a priori boundary errors: a displacement of the head and a size scaling error. The results revealed that a noise level of 3 m degrees (standard deviation) was adequate for obtaining good visualization of a peripheral stroke (volume approximately 49 ml). The simulations further showed that the displacement error had to be within 3-4 mm and the scaling error within 3-4% so as not to cause unacceptably large artefacts on the images.
研究了由 56 个半径为 10 毫米的激发/传感器线圈组成的半球形 MIT 线圈阵列在检测脑出血方面的可行性，该阵列工作频率为 1MHz 和 10MHz。使用有限差分法结合包含 12 种组织类型的解剖逼真的头部模型来模拟中风。从具有不同附加相位噪声水平的模型数据中重建频率差图像，并使用两种类型的先验边界误差：头部位移和大小缩放误差。结果表明，噪声水平为 3mdeg（标准差）足以很好地可视化外周中风（体积约为 49ml）。模拟进一步表明，位移误差必须在 3-4mm 以内，缩放误差必须在 3-4%以内，否则图像上会出现无法接受的大伪影。
