Towards Widening the Use of Dual/Multi-energy CT in Diagnostic Imaging: Barriers and Benchmarking

Abstract

Context: Dual energy CT (DECT) is an increasingly available advanced imaging technique. DECT offers advantages over single energy CT (SECT) but is not in wide spread use. Purpose: To investigate the current use of DECT in adult and paediatric patients and establish perceived barriers to use from key stakeholders. Additionally, to benchmark radiation dose and image quality of adult and paediatric DECT abdominal protocols against existing clinical SECT abdominal protocols. A public and patient engagement (PPIE) session was also carried out to promote and establish level of engagement with early-stage research. Method: The current use, barriers to implementation and suggestions for increasing use of DECT clinically were explored using an online survey tool. Initial survey responses were from Radiographers and Medical Physicists, then supplemented with Radiologists’ views. Inspired by the survey results, scanning factors for available adult and paediatric SECT and DECT abdominal protocols were established using a 32 cm CT dose index phantom for nine CT scanners. Using these parameters to image a multi-energy image quality phantom, CT number, contrast to noise ratio (CNR), root mean square error (RMSE) and mean structural similarity index (MSSIM) for SECT and DECT “single-energy-like” images were evaluated. Spectral separation and dual energy index (DEI)) were additionally evaluated. Lastly, findings of a PPIE session conducted with a youth research group are reported. Results: The survey showed whilst DECT scanners are available, clinical protocols are limited for both adult and paediatric patients. The main barriers to implementation were concerns about radiation dose, lack of DECT experience and clinical protocols. Suggestions to further implement DECT were a better understanding of benefits and establishing clinical protocols. Measurements demonstrated protocols with comparable SECT and DECT doses had matched CNR and CT numbers for “single energy like” images. Protocols with unmatched doses had variable CT number and CNR agreement, indicating optimisation opportunities, reenforcing the survey findings. Low RMSE and high MSSIM values indicted well matched perceived structural information. Spectral separation and DEI values agreed with published literature. The PPIE session showed young people had interest and high engagement with early-stage research. Conclusion: DECT is an available but under-used resource. A common theme shown by the survey and measurements was limited availability of paediatric protocols. Data suggests compared with SECT, DECT can be dose neutral with equivalent “single-energy-like” image quality, though differences between scanners/protocols were observed. Lack of available and correctly set-up protocols (e.g., paediatric specific) represents a barrier to implementation.

Date of Award	31 Dec 2023
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Eliana Vasquez Osorio (Supervisor) & Marianne Aznar (Supervisor)