Mohammad Davoodi - MD, Department of Radiology, Ahvaz Jondishapur University of Medical Sciences, Khuzestan, Iran
Soudabeh Belash-Abadi - MD, Ahvaz Jondishapur University of Medical Sciences, Khuzestan, Iran
Seyed Hossein Aalaei-Andabili - MD, Nikan Health Researchers Institute, Tehran, Iran
Ali Kabir - MD, PhD, Minimally Invasive Surgery Research Center, Iran University of Medical Sciences, Tehran, Iran.

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.

Image Enhancement, Image Quality, Computed Tomography Angiography, Pulmonary Embolism, Radiation Dosage