Quantitative MRI

We developed an MRI pulse sequence that fairly rapidly gathers a lot of information about the imaged object. It is a multi-pathway multi-echo (MPME) pulse sequence, and an example is shown in Fig. 1 for a neuro acquisition. Note how images from different magnetization pathways have very different tissue contrasts, and how this contrast changes with echo time (TE). The overall goal of this project is to gather enough information in one relatively-short MPME 3D scan to possibly replace lengthy brain MR exams.

Quantitative MRI
            FIG. 1

3D quantitative map

       FIG. 2

In a first step, we developed a mathematical framework to convert such MPME datasets into 3D maps of the main parameters that determine contrast in MRI: T1, T2, T2*, M0, B0 and B1+. Examples are shown in Fig. 2 (for the whole 3D volume) and in Fig. 3 (for one slice within the 3D volume). The quantitative information represented in Fig. 2 and 3 was acquired here in a single minimally-accelerated 3D scan of about 12 min.

2D quantitative maps
            FIG. 3
In a second step, we have now started using neural networks as 'contrast translators' to convert MPME datasets into quantitative as well as synthetic contrasts. In Fig. 4, data from a 7-min MPME acquisition was converted into full-brain quantitative T1 and T2 maps, along with synthetic FLAIR and T1-weighted contrasts, for example.
3D translated contrasts
            FIG. 4

So far, applications to MR thermometry (Madore et alAksit Ciris et al) and cartilage imaging have been pursued (Duryea et al), while ongoing work focuses primarily on neuro applications. In summary, MPME acquisitions can rapidly gather much information about the imaged 3D anatomy, and 'contrast translation' can be performed through neural networks to generate a variety of different quantitative and qualitative image types.

 

Publications

  1. Cheng C-C, Hoge WS, Kuo TH, Preiswerk F, Madore B. Multi-pathway multi-echo (MPME) imaging: all main MR parameters mapped based on a single 3D scan. Magn Reson Med 2019; 81: 1699-1713.
  2. P Aksit Ciris, C-C Cheng, C-S Mei, LP Panych, B Madore. “Dual-Pathway sequences for MR thermometry: When and where to use them.” Mag Reson Med 2017; 77:1193–1200.
  3. C-C Cheng, C-S Mei, J Duryea, H-W Chung, T-C Chao, LP Panych, B Madore. “Dual-pathway multi-echo sequence for simultaneous frequency and T2 mapping.” J Magn Reson 2016; 265:177-87.
  4. C-S Mei, R Chu, WS Hoge, LP Panych, B Madore. “Accurate field mapping in the presence of B0 inhomogeneities, applied to MR thermometry.” Mag Reson Med 2015; 73:2142-51.
  5. B Madore, LP Panych, C-S Mei, J Yuan, R Chu. “Multipathway sequences for MR thermometry.” Magn Reson Med 2011; 66:658-68.

 

Abstracts

  1. C-C Cheng, F Preiswerk, and B Madore. 2019. “Quantitative and synthetic MRI using a Multi-Pathway Multi-Echo (MPME) acquisition followed by machine-learning contrast translation.” International Society of Magnetic Resonance in Medicine. Montréal, Québec, Canada.
  2. C-C Cheng, WS Hoge, T-H Kuo, and B Madore. “Quantitative MRI method, a multi-pathway multi-echo approach.” Proceedings of the International Society of Magnetic Resonance in Medicine 2017. Honolulu, USA, p. 5044.
  3. B Madore, WS Hoge, T-H Kuo, and C-C Cheng. “Quantitative MR imaging method: All of the main MR parameters can be obtained in little more than a single scan.” Proceedings of the International Society of Magnetic Resonance in Medicine 2015. Toronto, Canada, p. 1665.
  4. B Madore, C-C Cheng, and C-S Mei. “Quantitative MR imaging method.” Proceedings of the International Society of Magnetic Resonance in Medicine 2014. Milan, Italy, p. 0336.