Objective To enhance the comparability of the results from myocardial imaging(MI)with 2 0 1 Tl 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 SPSS13.0 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±6774.48(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.