--- a +++ b/docs/source/scans.rst @@ -0,0 +1,84 @@ +.. _scans: + +Scans (dosma.scan_sequences) +================================================================================ +DOSMA currently supports 4 MRI scan types: + +1. Quantitative DESS (qDESS) +2. CubeQuant +3. MAPSS +4. UTE Cones + +Each scan implements a subset of the following actions: + +1. **Segment** tissues from scan +2. **Interregister** to register between lower resolution (moving) and higher resolution (target) scans +3. **Quantitative fitting** for voxel-wise parameter maps. + +.. automodule:: + dosma.scan_sequences + +.. autosummary:: + :toctree: generated + + dosma.scan_sequences.ScanSequence + dosma.scan_sequences.QDess + dosma.scan_sequences.CubeQuant + dosma.scan_sequences.Mapss + dosma.scan_sequences.Cones + +Below we briefly discuss the different scan types and associated actions. + +qDESS +-------------------------------------------------------------------------------- +Quantitative double echo in steady state (qDESS) is a high-resolution scan that has shown high efficacy for analytic +|T2| mapping :cite:`sveinsson2017simple`. Because of its high resolution, qDESS scans have been shown to be good candidates for automatic +segmentation. + +DOSMA supports both automatic segmentation and analytical |T2| solving for qDESS scans. Automated segmentation uses +pre-trained convolutional neural networks (CNNs). + + +CubeQuant (3D FSE) +-------------------------------------------------------------------------------- +Cubequant is a 3D fast-spin-echo (FSE) |T1rho|-weighted sequence. Acquisitions between spin-locks are +susceptible to motion, and as a result, volumes within the scan have to be registered to each other +(i.e. *intra*-registered). + +Moreover, CubeQuant scans often have lower resolution to increase SNR in practice. Because of the +low-resolution, these scans are often registered to higher resolution target scans :cite:`jordan2014variability`. + +By default, DOSMA intraregisters volumes acquired at different spin-locks to one another. This framework also supports +both registration between scan types (interregistration) and |T1rho| fitting. + +Because registration is sensitive to the target scan type, different registration approaches may work better with +different scan types. By default, the registration approaches are optimized to register CubeQuant scans to qDESS scans. + + +3D MAPSS (SPGR) +-------------------------------------------------------------------------------- +Magnetization‐prepared angle‐modulated partitioned k‐space spoiled gradient echo snapshots (3D MAPSS) is a spoiled +gradient (SPGR) sequence that reduce specific absorption rate (SAR), increase SNR, and reduce the extent of +retrospective correction of contaminating |T1| effects :cite:`li2008vivo`. + +The MAPSS sequence can be used to estimate both |T1rho| and |T2| quantitative values. Like CubeQuant scans, MAPSS scans +must also be intraregistered to ensure alignment between all volumes acquired at different echos and spin-lock times. + +DOSMA automatically performs intraregistration among volumes within the MAPSS scan. |T2| and |T1rho| fitting is also +supported. + + +UTE Cones +-------------------------------------------------------------------------------- +Ultra-short echo time (UTE) Cones (or Cones) is a |T2star|-weighted sequence. In practice, many of these scans are low +resolution. + +DOSMA supports interregistration between Cones and other scan sequences; however, registration files are optimized for +registration to qDESS. |T2star| fitting is also supported. + + +.. Substitutions +.. |T2| replace:: T\ :sub:`2` +.. |T1| replace:: T\ :sub:`1` +.. |T1rho| replace:: T\ :sub:`1`:math:`{\rho}` +.. |T2star| replace:: T\ :sub:`2`:sup:`*` \ No newline at end of file