Dynamic Contrast Enhanced MRI / MRA
Shreyas Vasanawala

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

Figures

Dynamic contrast enhanced imaging with view sharing technique combined with two-point Dixon fat water separation shows rapidly enhancing tumor (arrows) that washes out.

Dynamic contrast enhancement with gadoxetic acid, again with view sharing. High temporal resolution imaging is critical with this agent to capture transiently enhancing tumors (arrows).



Proc. Intl. Soc. Mag. Reson. Med. 24 (2016)