1. Technical Note: Diffusion-weighted MRI with minimal distortion in head-and-neck radiotherapy using a turbo spin echo acquisition method.
- Author
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Schakel, Tim, Hoogduin, Johannes M., Terhaard, Chris H.J., and Philippens, Marielle E.P.
- Subjects
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HEAD & neck cancer , *DIFFUSION magnetic resonance imaging , *RADIOTHERAPY , *ELECTRON spin echoes , *DIFFUSION coefficients - Abstract
Purpose Diffusion-weighted ( DW) MRI, showing high contrast between tumor and background tissue, is a promising technique in radiotherapy for tumor delineation. However, its use for head-and-neck patients is hampered by poor geometric accuracy in conventional echo planar imaging ( EPI) DW- MRI. An alternative turbo spin echo sequence, DW- SPLICE, is implemented and demonstrated in patients. Methods The DW- SPLICE sequence was implemented on a 3.0 T system and evaluated in 10 patients. The patients were scanned in treatment position, using a customized head support and immobilization mask. Image distortions were quantified at the gross tumor volume ( GTV) using field map analysis. The apparent diffusion coefficient ( ADC) was evaluated using an ice water phantom. Results The DW images acquired by DW- SPLICE showed no image distortions. Field map analysis at the gross tumor volumes resulted in a median distortion of 0.2 mm for DW- SPLICE, whereas for the conventional method this was 7.2 mm. ADC values, measured using an ice water phantom were in accordance with literature values. Conclusions The implementation of DW- SPLICE allows for diffusion-weighted imaging of patients in treatment position with excellent geometrical accuracy. The images can be used to facilitate target volume delineation in RT treatment planning. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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