Introduction: Among the most common procedures that are performed in both outpatient and inpatient hospital setting, are CT procedures of the abdomen and pelvis regions. Given the frequency of recurrence and mass control in the event of accidental findings in such procedures, it would be wise to find ways to reduce radiation dose and the amount of contrast medium. This can be achieved with different acquisition techniques on a CT scanner. Contrary to single energy CT (SECT), Dual-Energy CT (DECT) allows for better contrast resolution and therefore superior evaluation between tissues. Purpose: The main purpose was to determine if a radiation dose reduction, contrast medium reduction and good image quality is achiveable with the use of DECT imaging technique of the abdomen, comparable to SECT. Methods: The research was carried out on a Siemens Dual Source CT system SOMATOM Drive. 100 patients were reffered for CT examination of the abdomen (50 with DECT and 50 with SECT). The abdominal area was scanned twice using the SECT method – native and venous phase. With the DECT method we recorded only the venous phase (the virtual non-contrast images were extracted from this phase – VNC). Consequently, we collected data on patient AP diameters on the transversal planes at the level of the upper pole of the left kidney. For each patient we collected multiple dose value measurements such as CTDIvol, DLP and effective dose. Objective image quality measurements were done with SNR and CNR measures. We measured image quality on the transversal planes of the native and venous phases and in the area of the vena portae and liver parenchyma. Results: Measurements of the AP diameters performed on the Siemens SOMATOM Drive CT scanner amounted to 1,1 cm (4,2 %) and did not show statistically significant differences (p=0,300). The research showed statistically significant differences in CTDIvol measurements between DECT and SECT methods – 3,1 % (p=0,033). The whole DLP value was lower by 46,8 % when performed by the DECT method and showed that the difference was statistically significantly different (p<0,001). Consequently the effective dose using the DECT technique was lowered by 46,8 % from the one using SECT and was found to be statistically significantly different (p<0,001). When comparing image quality between DECT and SECT techniques, we did not find any statistically significant differences. The results of these were: SNR native - 9,9 %, SNR CE - 5,9 %, CNR liver parenchyma - 1,9 % and CNR vena portae - 5,3 %. Discussion: Due to different imaging techniques on the Siemens SOMATOM Drive CT scanner the results differ from each other. With the use of DECT technique in CT procedures of the abdomen, we could achieve statistically significant differences in DLP and effective dose. Conclusion: While maintaining image quality we were able to achieve lower whole DLP and effective dose values of 46,8 % with the use of the DECT technique. We concluded that the DECT method is more dose efficient than the SECT method in CT imaging of the abdomen and pelvis and has very comparable image quality.
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