Synopsis
Dynamic
contrast-enhanced imaging is a critical component of body MR exams. This
lecture will review hardware requirements, and in particular considerations for
optimization at 3T. Further, differences
in contrast agents and the approach to contrast-enhanced dynamic imaging will
be covered, along with bolus injection and timing considerations. Additionally, pulse sequence parameter
selection, sampling techniques, fat suppression methods, and view-sharing
approaches will be reviewed.
ynamic
contrast-enhanced imaging is a critical component of body MR exams. This
lecture will review hardware requirements, and in particular considerations for
optimization at 3T. Further, differences
in contrast agents and the approach to contrast-enhanced dynamic imaging will
be covered, along with bolus injection and timing considerations [1]. Additionally, pulse sequence parameter
selection, sampling techniques, fat suppression methods, and view-sharing
approaches will be reviewed.
In general, 3T enables
higher spatiotemporal resolution imaging, in part because of higher SNR, but
also due to the wider availability of high density coil arrays. T1 relaxation tends to be slower and the
relaxivity of some contrast agents is not quite as pronounced compared to 3T,
but on balance superior quality exams can be obtained. The benefits of 3T are even apparent for MRA.
Fat suppression
choices include no suppression, intermittent spectrally-selective saturation,
and dual echo acquisitions with fat-water separation (Fig. 1 & 2). Each method has its advantages, and trade
offs are different for angiography and for tumor assessment.
Though parallel
imaging is the mainstay of obtaining adequate spatio-temporal resolution, other
approaches are complementary and include view-sharing, non-cartesian
undersampling, and sparsity based image reconstruction [2-6]
Acknowledgements
No acknowledgement found.References
1. Huh J, Kim SY, Yeh BM, Lee SS, Kim KW, Wu EH, Wang ZJ, Zhao LQ, Chang WC. Troubleshooting Arterial-Phase MR Images of Gadoxetate Disodium-Enhanced Liver. Korean J
Radiol. 2015 Nov-Dec;16(6):1207-15.
doi: 10.348/kjr.2015.16.6.1207. Epub 2015 Oct 26.
2. Kazmierczak PM, Theisen D, Thierfelder KM, Sommer WH, Reiser MF, Notohamiprodjo M, Nikolaou K. Improved detection of hypervascular liver lesions with CAIPIRINHA-Dixon-TWIST-volume-interpolated breath-hold examination. Invest
Radiol. 2015
Mar;50(3):153-60. doi: 10.1097/RLI.0000000000000118.
3. Yasunari Fujinaga, Yoshihiro Kitou, Ayumi Ohya,
Yasuo Adachi, Naomichi Tamaru, Aya Shiobara, Hitoshi Ueda, Marcel D. Nickel, Katsuya
Maruyama, Masumi Kadoya. Advantages of
radial volumetric breath-hold examination (VIBE) with k-space weighted image
contrast reconstruction (KWIC) over Cartesian VIBE in liver imaging of
volunteers simulating inadequate or no breath-holding ability. Eur Radiol. 2015 Nov
24.
4. Riederer SJ, Haider CR, Borisch EA, Weavers PT, Young PM. Recent advances in 3D time-resolved contrast-enhnced MR angiography. J Magn Reson Imaging. 2015 Jul;42(1):3-22. doi:
10.1002/jmri.24880. Epub 2015 Jun 1.
5. Chen Y, Lee GR, Wright KL, Badve C, Nakamoto D, Yu A, Schluchter MD, Griswold MA, Seiberlich N, Gulani V. Free-breathing liver perfusion imaging using 3-dimensional through-time spiral generalized autocalibratingpartially parallel acquisition acceleration. Invest
Radiol. 2015
Jun;50(6):367-75. doi: 10.1097/RLI.0000000000000135.
6.
Tsao J, Kozerke S.
MRI temporal acceleration techniques. J
Magn Reson Imaging. 2012
Sep;36(3):543-60. doi: 10.1002/jmri.23640. Review. PMID: 22903655