Diffusion-weighted imaging of the liver: Comparison of navigator triggered and breathhold acquisitions
Article first published online: 26 AUG 2009
Copyright © 2009 Wiley-Liss, Inc.
Journal of Magnetic Resonance Imaging
Volume 30, Issue 3, pages 561–568, September 2009
How to Cite
Taouli, B., Sandberg, A., Stemmer, A., Parikh, T., Wong, S., Xu, J. and Lee, V. S. (2009), Diffusion-weighted imaging of the liver: Comparison of navigator triggered and breathhold acquisitions. J. Magn. Reson. Imaging, 30: 561–568. doi: 10.1002/jmri.21876
- Issue published online: 26 AUG 2009
- Article first published online: 26 AUG 2009
- Manuscript Accepted: 10 JUN 2009
- Manuscript Received: 17 DEC 2008
- diffusion-weighted imaging;
- single shot EPI
To compare a free breathing navigator triggered single shot echoplanar imaging (SS EPI) diffusion-weighted imaging (DWI) sequence with prospective acquisition correction (PACE) with a breathhold (BH) DWI sequence for liver imaging.
Materials and Methods
Thirty-four patients were evaluated with PACE-DWI and BH DWI of the liver using b-values of 0, 50, and 500 s/mm2. There were 29 focal liver lesions in 18 patients. Qualitative evaluation was performed on a 3-point scale (1–3) by two independent observers (maximum score 9). Quantitative evaluation included estimated SNR (signal to noise ratio), lesion-to-liver contrast ratio, liver and lesion apparent diffusion coefficients (ADCs), and coefficient of variation (CV) of ADC in liver parenchyma and focal liver lesions (estimate of noise contamination in ADC).
PACE-DWI showed significantly better image quality, higher SNR and lesion-to-liver contrast ratio when compared with BH DWI. ADCs of liver and focal lesions with both sequences were significantly correlated (r = 0.838 for liver parenchyma, and 0.904 for lesions, P < 0.0001), but lower with the BH sequence (P < 0.02). There was higher noise contamination in ADC measurement obtained with BH DWI (with a significantly higher SD and CV of ADC).
The use of a navigator echo to trigger SS EPI DWI improves image quality and liver to lesion contrast, and enables a more precise ADC quantification compared with BH DWI acquisition. J. Magn. Reson. Imaging 2009;30:561–568. © 2009 Wiley-Liss, Inc.