Dose and Image Quality in Spectral Computed Tomography Compared to Helical Protocols

Abstract

Objectives: Dual-energy computed tomography (DECT) provides additional diagnostic information compared with conventional single-energy CT (SECT), particularly in oncology. This study aimed to calculate the typical dose values for DECT protocols and compare them with those of SECT, as well as to evaluate the image quality of both modalities. Methods: A retrospective analysis of DECT studies was conducted at an oncology institution. Typical radiation dose values (CTDIvol and DLP) were determined according to the ICRP 135 method. Image quality was assessed in a subset of abdominal studies by three radiologists using a predefined ordinal scale to evaluate noise, sharpness, and overall contrast. Results: The typical dose values for DECT were lower than those obtained with equivalent SECT protocols (CTDIvol: 7.69–9.37 mGy; DLP: 242–480 mGy·cm). Qualitative assessment showed that 95 % of the studies had minimal or mild noise, 98 % were rated as acceptable or higher in sharpness, and 96 % were rated as acceptable or higher in overall contrast. Conclusions: In our experience, DECT did not result in an increased radiation dose compared with SECT and provided additional  diagnostic information with adequate image quality. These findings support the use of DECT as a clinically feasible alternative that balances radiation dose and image quality.