Abstract
Objectives
To evaluate the feasibility of zoomed diffusion-weighted EPI (z-EPI) in the head and neck in a healthy volunteer population and to compare to conventional single-shot EPI (c-EPI).
Material and Methods
Nine volunteers were included in this prospective, IRB-approved study. Examinations were performed on a 3 T-MR system equipped with a two-channel, fully-dynamic parallel transmit array. The acquired sequences consisted of a T2w-TSE, a c-EPI, and two z-EPI acquisitions. For quantitative assessment of distortion artefacts, DW images were fused with T2-TSE images. Misregistration of DW images with T2-TSE images was assessed in the cervical spine. For qualitative assessment, two readers ranked c-EPI and z-EPI sequences in terms of susceptibility artefacts, image blur, and overall imaging preference. ADC values of several anatomical regions were calculated and compared between sequences.
Results
Mean maximum distortion with the c-EPI was 5.9 mm ± 1.6 mm versus 2.4 mm ± 1 mm (p < 0.05) with z-EPI. Both readers found more blur and susceptibility artefacts in every case with c-EPI. No statistically significant differences in calculated ADC values were observed.
Conclusion
z-EPI of the head and neck leads to substantial image quality improvements relative to c-EPI due to a reduction in susceptibility artefacts and image blur.
Key Points
• Zoomed DWI is feasible in the head and neck.
• Image quality improves substantially with zoomed DWI of the neck.
• Zoomed DWI exhibits markedly reduced susceptibility artefacts.
References
Mansfield P, Maudsley AA (1977) Medical imaging by NMR. Br J Radiol 50(591):188–194
Padhani AR, Liu G, Koh DM, Chenevert TL, Thoeny HC, Takahara T, Dzik-Jurasz A, Ross BD, Van Cauteren M, Collins D, Hammoud DA, Rustin GJ, Taouli B, Choyke PL (2009) Diffusion-weighted magnetic resonance imaging as a cancer biomarker: consensus and recommendations. Neoplasia 11(2):102–125
Wang J, Takashima S, Takayama F, Kawakami S, Saito A, Matsushita T, Momose M, Ishiyama T (2001) Head and neck lesions: characterization with diffusion-weighted echo-planar MR imaging. Radiology 220(3):621–630
Sumi M, Sakihama N, Sumi T, Morikawa M, Uetani M, Kabasawa H, Shigeno K, Hayashi K, Takahashi H, Nakamura T (2003) Discrimination of metastatic cervical lymph nodes with diffusion-weighted MR imaging in patients with head and neck cancer. AJNR Am J Neuroradiol 24(8):1627–1634
Holzapfel K, Duetsch S, Fauser C, Eiber M, Rummeny EJ, Gaa J (2009) Value of diffusion-weighted MR imaging in the differentiation between benign and malignant cervical lymph nodes. Eur J Radiol 72(3):381–387
Rieseberg S, Frahm J, Finsterbusch J (2002) Two-dimensional spatially-selective RF excitation pulses in echo-planar imaging. Magn Reson Med 47(6):1186–1193
Pfeuffer J, van de Moortele PF, Yacoub E, Shmuel A, Adriany G, Andersen P, Merkle H, Garwood M, Ugurbil K, Hu X (2002) Zoomed functional imaging in the human brain at 7 Tesla with simultaneous high spatial and high temporal resolution. Neuroimaging 17(1):272–286
Saritas EU, Cunningham CH, Lee JH, Han ET, Nishimura DG (2008) DWI of the spinal cord with reduced FOV single-shot EPI. Magn Reson Med 60(2):468–473
Schneider R, Haueisen J, Pfeuffer J (2012) Novel 2DRF optimization framework for spatially selective rf pulses incorporating B1, B0 and variable-density trajectory design. Intl Soc Mag Reson Med 20.
Morelli J, Porter D, Ai F, Gerdes C, Saettele M, Feiweier T, Padua A, Dix J, Marra M, Rangaswamy R, Runge V (2013) Clinical evaluation of single-shot and readout-segmented diffusion-weighted imaging in stroke patients at 3 T. Acta Radiol 54(3):299–306
Wei XE, Li WB, Li MH, Li YH, Wang D, Zhang YZ, Jin LX (2011) Detection of brain lesions at the skull base using diffusion-weighted imaging with readout-segmented echo-planar imaging and generalized autocalibrating partially parallel acquisitions. Neurol India 59(6):839–843
Porter DA, Heidemann RM (2009) High resolution diffusion-weighted imaging using readout-segmented echo-planar imaging, parallel imaging and a two-dimensional navigator-based reacquisition. Magn Reson Med 62(2):468–475
Holdsworth SJ, Skare S, Newbould RD, Guzmann R, Blevins NH, Bammer R (2008) Readout-segmented EPI for rapid high resolution diffusion imaging at 3 T. Eur J Radiol 65(1):36–46
Turner R, von Kienlin M, Moonen CT, van Zijl PC (1990) Single-shot localized echo-planar imaging (STEAM-EPI) at 4.7 tesla. Magn Reson Med 14(2):401–408
Acknowledgments
The scientific guarantor of this publication is Dr. Stefan Haneder. The authors of this manuscript declare relationships with the following companies: Dr. Josef Pfeuffer is an employee of Siemens Healthcare. The Institute of Clinical Radiology and Nuclear Medicine has research agreements with Siemens healthcare Sector. The authors state that this work has not received any funding.
No complex statistical methods were necessary for this paper. Institutional Review Board approval was obtained. Written informed consent was obtained from all subjects (patients) in this study. Approval from the institutional animal care committee was not required because the study was not on animals. Methodology: Prospective, intraindividual comparison study, performed at one institution
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Riffel, P., Michaely, H.J., Morelli, J.N. et al. Zoomed EPI-DWI of the head and neck with two-dimensional, spatially-selective radiofrequency excitation pulses. Eur Radiol 24, 2507–2512 (2014). https://doi.org/10.1007/s00330-014-3287-6
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00330-014-3287-6