Comparison of diffusion-weighted MRI using imaging split acquisition of fast spin echo signal (SPLICE) and single-shot echo-planar imaging (SS-EPI) in tumours of the head and neck
Hedda Joanne van der Hulst, Amsterdam / Netherlands
Author Block: H. J. van der Hulst, R. Martens, B. Westerink, L. Braun, L. C. ter Beek, R. Tissier, R. G. H. Beets-Tan, M. van den Brekel, J. A. Castelijns; Amsterdam/NLPurpose: Traditionally, diffusion-weighted imaging (DWI) uses single-shot echo planar imaging (SS-EPI) for its fast read-out but struggles with distortion, predominantly near bone-air interfaces. Turbo Spin Echo (TSE) DWI, like split acquisition of fast spin echo signal for diffusion imaging (SPLICE), may reduce this issue, especially in the head and neck area. This study compares DW-SPLICE with DW-SS-EPI for head and neck lesions (HN-lesions).Methods or Background: Between August 2020 and January 2022, 57 potential MRI HN-lesion exams were conducted using both SS-EPI and SPLICE techniques on a - 0T MRI system. Lesions >0.5cm³ were delineated on both DWI-MRIs. The study assessed differences in whole lesion ADC-values through interclass correlation (ICC), Bland-Altman plots, and mixed-effect model regression. Two blinded radiologists evaluated image quality and distortion levels using a standardised questionnaire.
Results or Findings: Preliminary findings: The eligible 41 MRI exams of 41 patients included 40 benign and 20 malignant HN-lesions, visible on both DWI techniques. Strong interclass correlation coefficients were found for mean ADC values (ICC agreement - 864, 95% CI 0.782-0.917), consistency 0.862 (95% CI 0.780-0.915). The Bland-Altman regression showed discrepancies between SPLICE and EPI for higher average ADC values (ß=0.16, p=0.02), but not when assessing benign and malignant lesions separately. Radiologist evaluations of visual distortion showed a trend towards less distortion and better image quality for SPLICE-DWI.
Conclusion: High agreement and consistency in mean ADC values were seen for HN-lesions measured with both techniques. Qualitative analyses of radiologists resulted in a trend towards better distortion and image quality scores for SPLICE-DWI. While a potential ADC value discrepancy was observed in the Bland-Altman analyses, its clinical impact may be minimal if DWI-SPLICE can effectively replace SS-EPI.Limitations: Identified limitations were: (1) the cohort consists of a mixed group of HN-lesions; (2) data is currently still preliminary.Funding for this study: No funding was received for this study.Has your study been approved by an ethics committee? YesEthics committee - additional information: The study was approved by the IRBd22-270, registered at - 10.2022.