双探头SPECT符合线路衰减校正对图像分辨率及计数影响的模型研究

目的研究衰减校正对双探头符合成像系统分辨率及图像计数的影响.方法采用GE Hawkeye 双探头符合成像设备,对分辨率模型成像,用X线透射扫描进行衰减校正.计算有、无衰减校正时线源扩展函数的半高宽(FWHM)及线源峰值计数.结果有衰减校正时FWHM显著高于无衰减校正时FWHM,其差值在中心处最大,且线源计数大于无衰减校正时计数,越靠中心其差值越大.结论衰减校正在补偿计数衰减的同时,会使分辨率降低.

Influence of attenuation correction on imaging resolution and counts for dual-head SPECT coincidence imaging: a phantom study

Objective To investigate the influence of attenuation correction (AC) on dual head coincidence imaging resolution and counts. Methods The resolution phantom was imaged using GE Hawkeye dual head coincidence detection equipment. AC was performed with X ray transmission scan. The full width at half maximum (FWHM) of the line resource spread function and the peek pixel counts of the line resource were calculated with and without AC. Results The FWHM with AC was significant larger than that without AC, and the smaller the distance from the center, the larger the difference. The peek pixel counts with AC were more than those without AC, and the counts difference was maximal at center and minimal at the edge of the field of the view. Conclusion AC can compensate the count attenuation but also impair the imaging resolution.