Clinical CT protocol comparison: an Italian multicentre study
Author Block: R. Villa1, M. Daniotti1, C. Ingraito1, A. Italian Digital Radiology Working Group2, N. Paruccini1; 1Monza/IT, 2Milan/IT
Purpose: In CT imaging, differences in manufacturers, models, scanning parameters, reconstruction algorithms, clinical tasks, and user’s experience, introduce variability in the trade-off between diagnostic information and patient’s radiation exposure. The extent to which each of these sources of variabilities impacts the overall procedure performance is still unknown. This study aimed to compare image quality and radiation dose in five acquisition protocols to ascertain how different technical features can affect CT performance, to inform protocol optimisation and design.
Methods or Background: Five different acquisition protocols to investigate five different clinical tasks were investigated: intracranial haemorrhage, pulmonary embolism, acute abdomen, paediatric chest and paediatric acute abdomen.
The Catphan 600 (The Phantom Laboratory, USA), was imaged in 34 CT scanners from 20 hospitals across Italy, for a total of 251 datasets, using the locally optimised clinical protocols. The Catphan body external-annulus was used to assess the effects of tube current modulation for the different manufacturers.
Image quality was quantified in terms of the detectability index using an object contrast ranging 25-700 HU and lesion size ranging 5-25 mm, representative of clinical scenarios related to the examined protocols.
Results or Findings: Each investigated protocol showed differences between manufacturers in terms of dose levels and image quality values. The reconstruction algorithm’s generation proved another driving element for image quality. Nevertheless, variability between CTs was found, even from the same vendor and technology.
Conclusion: This study suggested that manufacturer and reconstruction algorithms play a main role in the optimal trade-off between diagnostic information and radiation dose levels. Furthermore, the other examined CT procedure technical features, have a non-negligible impact. All the potential sources of variability should be included when designing optimization actions in clinical CT.
Limitations: Data numerosity should be increased to improve the study strength, especially for paediatric exams.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: No information provided by the submitter.