Gadolinium Enhances Dual-energy Computed Tomography Scan of Pulmonary Artery

Objective: To evaluate the feasibility of using gadopentetate dimeglumine (Gd-DTPA) for dual-energy computed tomography pulmonary angiography (CTPA). Methods: Sixty-six patients were randomly divided into three groups and underwent CTPA. Group A had a turbo flash scan using an iohexol injection, Group B had a turbo flash scan using Gd-DTPA, and Group C had a dual-energy scan using Gd-DTPA. The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40, 50, 60, 70, 80, 90, 100, and 110 keV, respectively. The groups were compared in terms of pulmonary artery CT value, image quality, and radiation dose. Results: The pulmonary artery CT values were significantly higher in Group C-40 keV than in Groups B and C, but lower than in Group A. There was no significant difference in the image noise of Groups C-40 keV, B, and C. Moreover, Group A had the largest beam hardening artifacts of the superior vena cava (SVC), followed by Groups B and C. Group C-40 keV showed better vascular branching than the other three groups, among which Group B was superior to Group A. The subjective score of the image quality of Groups A, B, and C showed no significant difference, but the score was significantly higher in Group C-40 keV than in Groups A and B. The radiation dose was significantly lower in Group B than in Groups A and C. Conclusion: Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA. Furthermore, a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.