Valette H, Bourguignon M H, Gregoire M C, Merlet P, Pascal O, Briandet P, Le Guludec D, Syrota A
Laboratoire d'Explorations Cardiovasculaires, Hopital de Bicêtre, France.
Phys Med Biol. 1990 Jan;35(1):1-9. doi: 10.1088/0031-9155/35/1/001.
Fourier analysis of gated blood pool studies is performed after filtering the raw data by a spatial median 3 x 3, 9 x 9 or temporo-spatial 9 x 9 x 9 filter. 20 patients and a dynamic cardiac phantom were studied to determine the quantitative effects of these filters and of multiharmonic Fourier filtering (MHFF). The filtered MHFF data, with or without preprocessing, were compared with a 3 D or 2 D filter to the raw data using a chi 2 distribution. The MHFF (two or three harmonics) procedure applied to the raw data of patients without any preprocessing produced the smallest chi 2 value, thus demonstrating the very close relationship between filtered images and raw data. Preprocessing the raw data by the median filter also preserved the signal when two or three harmonics were applied, whereas the 3 D and 2 D (9 x 9) filters did not. The phantom study also demonstrated that MHFF preserved the signal better than any other preprocessing. The median filter introduced a smaller distortion than the 2 D (9 x 9) and 3 D filters. It is concluded that MHFF applied with two or three harmonics on the raw data or after preprocessing by a median (3 x 3) filter is the most successful way of preserving the real signal. It is believed that the other filters should be avoided. The clinical advantage of MHFF processing is to provide both very accurate filtering and parametric images.
在通过空间中值3×3、9×9或时空9×9×9滤波器对原始数据进行滤波后，对门控血池研究进行傅里叶分析。对20名患者和一个动态心脏模型进行了研究，以确定这些滤波器以及多谐波傅里叶滤波（MHFF）的定量效果。使用卡方分布，将经过滤波的MHFF数据（有无预处理）与三维或二维滤波器处理后的原始数据进行比较。将应用于未经任何预处理的患者原始数据的MHFF（两个或三个谐波）程序产生的卡方值最小，从而证明了滤波图像与原始数据之间的密切关系。当中值滤波器对原始数据进行预处理，并且应用两个或三个谐波时，信号也能得以保留，而三维和二维（9×9）滤波器则不能。模型研究还表明，MHFF比任何其他预处理方法能更好地保留信号。中值滤波器引入的失真比二维（9×9）和三维滤波器小。研究得出结论，对原始数据或经过中值（3×3）滤波器预处理后应用两个或三个谐波的MHFF是保留真实信号的最成功方法。人们认为应避免使用其他滤波器。MHFF处理的临床优势在于既能提供非常精确的滤波，又能提供参数图像。
