Simultaneous multi-slice accelerated diffusion-weighted imaging with higher spatial resolution for patients with liver metastases from neuroendocrine tumours

• Published in: Clinical radiology Vol. 76; no. 1; pp. 81.e11 - 81.e19
• Main Authors: Xu, J., Cheng, Y.J., Wang, S.T., Wang, X., Jin, Z.Y., Qian, T.Y., Zhu, J.X., Nickel, M.D., Xue, H.D.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-01-2021
• ISSN: 0009-9260; 1365-229X
• DOI: 10.1016/j.crad.2020.08.024

To evaluate the imaging characteristics of simultaneous multi-slice (SMS) accelerated diffusion-weighted imaging (DWI) with decreased section thickness, with and without motion correction, in comparison to conventional DWI (cDWI) for the detection of lesions in patients with neuroendocrine tumour (NET) liver metastases.
Fifteen patients with NET liver metastases underwent cDWI (section thickness [SL]=4 mm) and SMS-DWI (SL=2 mm). Non-linear motion-corrected (Moco)-SMS-DWI was generated in addition to the original series. Qualitative imaging characteristics (five-point Likert scale), the number of high signal lesions, and the detectability and delineation of lesions were evaluated and compared using the Friedman and the Dunn–Bonferroni tests. The test–retest variability (TRV) of the cDWI and SMS-DWI techniques was investigated among 11 healthy volunteers who underwent cDWI (SL=4 mm) and SMS-DWI (SL=4 mm) twice. The Friedman and the Dunn–Bonferroni post-hoc tests were used to compare the mean apparent diffusion coefficient (ADC) and the TRV in different liver regions between the three series.
Moco-SMS-DWI demonstrated significantly superior overall image quality (p<0.001) with significantly fewer artefacts (p=0.003) than cDWI. The number of lesions detected by cDWI, SMS-DWI, and Moco-SMS-DWI were 348, 504, and 523, respectively. The detectability and delineation of the lesions and the ADC values were significantly higher on the SMS-DWI and Moco-SMS-DWI images than on the cDWI images (all p<0.001). Moco-SMS-DWI showed significantly higher TRV than cDWI in regions near the liver edge (p=0.018).
SMS-DWI achieves higher spatial resolution than cDWI within the same acquisition time, detects more lesions, and provides better lesion delineation. By applying motion correction, the TRV of DWI could be enhanced in regions near the liver edge.
•SMS-DWI achieve higher spatial resolution than cDWI within the same acquisition time.•SMS-DWI provide better detectability and delineation of high signal liver lesions.•Motion correction techniques can further improve the image quality of SMS-DWI.•SMS-DWI with motion correction provide better test-retest variability of ADC values.