comparison of image quality of low voltage 64-slice multidetector ct angiography with the standard condition in patients suspected of pulmonary embolism

Introduction: reduction of peak kilovoltage (kv) setting has been a useful approach to d creating radiation dose; however, it may have varied effects on noise and the accuracy of diagnosis. thus, we compared image quality between low (80 kv) and standard kilovoltage (100 kv) protocols. material and methods: this triple blind non-randomized parallel quasi-experimental study was conducted on 140 cases of questionable pulmonary embolism. results: image quality was twice as high as the standard protocol in the 80-kv group (odds ratio=2.08). main, segmental, and subsegmental arteries showed significantly higher vascular enhancement (p<0.001) in the 80-kv group. similarly, the mean number of measurable segmental arteries was significantly greater in the 80-kv group relative to the standard group. on the other hand, the mean of image noise was significantly higher in the 80-kv group in comparison with the 100-kv group (mean: 68.4 vs. 43.1; p<0.001). finally, the mean of radiation dose received in the 80-kv group was significantly lower than that in the 100-kv group (mean: 0.94 vs. 2.43 msv; p<0.001). conclusion: lower radiation dose received and higher image quality, but worse image noise, in the 80-kv group compared to the 100-kv group present acceptable evidence in support of reduction of voltage in cases with the suspicion of pulmonary embolism. in these patients, therefore, it is recommended as a good strategy to be adopted in computed tomography angiography.