Hayes C E, Axel L
Med Phys. 1985 Sep-Oct;12(5):604-7. doi: 10.1118/1.595682.
In this paper we analyze the signal-to-noise ratio (SNR) for surface coil magnetic resonance imaging at 1.5 T. We have applied the treatment of Hoult and Lauterbur to determine the factors that most affect coil performance. We have imaged lossy phantoms with 8-, 10-, and 14-cm-diam circular surface coils and compared the results to body and head coil images. Surface coils can improve SNR by a factor of 4 or more for regions close to the surface. Surface coils are effective for regions up to 6 cm deep in the head and about 12 cm deep in the body. Nonuniformity of image intensity is a necessary requirement for improved SNR in surface coils. Coil losses make only a small contribution to image noise compared to tissue losses at 1.5 T. Surface coils need not be placed in close contact with the patient at 1.5 T.
在本文中，我们分析了1.5T时表面线圈磁共振成像的信噪比（SNR）。我们采用了霍尔特和劳特布尔的方法来确定对线圈性能影响最大的因素。我们用直径为8厘米、10厘米和14厘米的圆形表面线圈对有损耗的体模进行了成像，并将结果与体部和头部线圈图像进行了比较。对于靠近表面的区域，表面线圈可将信噪比提高4倍或更多。表面线圈对头部6厘米深以内和身体约12厘米深以内的区域有效。图像强度的不均匀性是提高表面线圈信噪比的必要条件。在1.5T时，与组织损耗相比，线圈损耗对图像噪声的贡献很小。在1.5T时，表面线圈无需与患者紧密接触。
