提高负荷-再分布201Tl心肌显像结果可比性的方法探讨

目的 以负荷显像参数为比较基础,通过理论推算,探讨缩小再分布显像总计数与负荷者差异的方法,从而提高负荷-再分布201Tl心肌显像诊断结果的可比性.方法 应用相同参数分别在6 min内和(200.61±13.64)min,对54例患者行负荷-再分布心肌显像,比较二者的总计数、平均每帧计数、计数率和相同层面心肌图像最大计数的差异及其平均值和平均百分比;计算要达到负荷时的总计数,再分布显像数据采集平均每帧需要增加的时间.采用SPSS13.0统计软件对数据作t检验分析.结果 再分布显像的总计数、平均每帧计数、计数率和相同层面心肌图像最大计数比负荷者平均分别下降了(25.29±0.05)%、(28.44±0.09)%、(25.29±0.05)%和(33.48±0.05)%(t=34.56、23.33、34.56和27.61,P值均为0.000),差异有统计学意义;要达到或接近负荷显像时的总计数,再分布显像数据采集时间平均每帧需增加(13.80±3.68)s,平均增加幅度为(34.49±0.09)%(t=27.56,P=0.000).结论 理论上,适当增加再分布显像数据采集时间,可以增加负荷-再分布201Tl心肌显像结果的可比性.

Methodological study on the comparability enhancement of the results from adenosine stress-redistribution myocardial imaging with 201TI

Objective To enhance the comparability of the results from myocardial imaging (MI) with 201Tl by a methodological study on increasing the total counts of the redistribution imaging(RI) on the base of parameters of the adenosine stress imaging (ASI) in this study. Methods Emission data were acquired within 6 min after adenosine stress and (200.61±13.64) min later for the RI by using the same imaging parameters on 54 suspicious coronary heart disease cases. The same reconstruction parameters were used for both ASI and RI image reconstruction. Then the differences and its average values and the average reduction ratio (ARR) of total counts( TC ), average count per frame(AC), average count rate per frame(ACR) and maximal counts on the same slices (MCSS) of RI myocardial images of each case were compared with that of ASI, respectively. Finally, to achieving the same TC level of the ASI, the data acquisition time per frame should be increased for the RI were calculated. The SPSS 13.0 software and the t test were used for the average values statistical analysis. Results The TC, AC, ACR and MCSS of the RI were obviously lower than that of ASI, and the ARRs were 785829.02±216783.48 ( 25.29±0.05 )%, 24557.16±.6774A8( 28.44±0.09 )%, 613.93±169.36 ( 25.29±0.05 )% and 505373.39±77657.02 (33.48±0.05)%, t values were 34.56,23.33,34.56 and 27.61, respectively, and P = 0.00 for each situation. ( 13.80±3.68 )s, (34.49±0.09)% per frame acquisition time on average should be increased for the RI to achieve the same TC level of the ASI according to this study. Conclusion Diagnostic differences of the adenosine stress-redistribution MI with 201Tl can be theoretically improved by increasing the acquisition time of the RI.