Objective To compare blood flow velocity measurements obtained using two different color Doppler imaging(CDI)devices with linear probes of varying frequencies.Methods CDI measurements were performed in 99 eyes of 50 participants from Shenyang Aier Excellent Eye Hospital using two different CDI devices,Apogee Type3500 and Esaote MyLab 7 eHD.These measurements included peak systolic velocity(PSV),end-diastolic velocity(EDV),and resistance index(RI)of the ophthalmic artery(OA),central retinal artery(CRA),and short posterior ciliary arteries(SPCA).The differences in measurements between the two devices were analyzed using a paired t-test.The level of agreement between the two CDI devices was calculated using the Bland-Altman method,and the concordance correlation co-efficient(CCC)was calculated.Results There was a statistically significant difference between the two CDI devices in the PSV,EDV of the OA,CRA,and SPCA,and RI of the CRA and SPCA.The PSV and EDV of each vessel were higher in Apogee than in Esaote,and the RI of the CRA and SPCA were lower for Apogee than for Esaote(P＜0.05).The CCC demonstrated poor overall concordance ranging from 0.136 to 0.517.Conclusion The consistency of most measurements obtained from both devices is poor.CDI inter-device reproducibility is unreliable,even when the measurements are conducted consecutively by a single experienced ultrasonographer.

Objective To compare blood flow velocity measurements obtained using two different color Doppler imaging(CDI)devices with linear probes of varying frequencies.Methods CDI measurements were performed in 99 eyes of 50 participants from Shenyang Aier Excellent Eye Hospital using two different CDI devices,Apogee Type3500 and Esaote MyLab 7 eHD.These measurements included peak systolic velocity(PSV),end-diastolic velocity(EDV),and resistance index(RI)of the ophthalmic artery(OA),central retinal artery(CRA),and short posterior ciliary arteries(SPCA).The differences in measurements between the two devices were analyzed using a paired t-test.The level of agreement between the two CDI devices was calculated using the Bland-Altman method,and the concordance correlation co-efficient(CCC)was calculated.Results There was a statistically significant difference between the two CDI devices in the PSV,EDV of the OA,CRA,and SPCA,and RI of the CRA and SPCA.The PSV and EDV of each vessel were higher in Apogee than in Esaote,and the RI of the CRA and SPCA were lower for Apogee than for Esaote(P＜0.05).The CCC demonstrated poor overall concordance ranging from 0.136 to 0.517.Conclusion The consistency of most measurements obtained from both devices is poor.CDI inter-device reproducibility is unreliable,even when the measurements are conducted consecutively by a single experienced ultrasonographer.