ISMRM2012 Review

Jun 4, 2012Jason Su

Outline• Parametric Mapping

– Kumar et al. A Bayesian Algorithm Using Spatial Priors for Multi-Exponential T2 Relaxometry from Multi-Echo Spin Echo MRI. [0360]

– Ott et al. Phase sensitive PC-bSSFP: simultaneous quantification of T1, T2 and spin density M0. [2387]

– Rudrapatna et al. Robust estimation of T1 and T2 parameters from complex datasets. [3418]

• Image Reconstruction and Acceleration Methods– Kayvanrad et al. T1 Map Reconstruction from Under-sampled KSpace Data

using a Similarity Constraint. [0015]– Weavers et al. Optimal Apportionment of Acceleration in 2D SENSE. [2224]

• Myelin Sensitive Sequences– Bluestein et al. Can T1-Differentiation in a Magnetization Prepared Turbo Field

Echo Sequence at 7T Predict "Persistent Black Hole” White Matter Lesions in Multiple Sclerosis? [3115]

Parametric Mapping

A Bayesian Algorithm Using Spatial Priors for Multi-Exponential T2 Relaxometry from Multi-Echo Spin Echo MRI [0360]

• Dushyant Kumar et al. University of Hamburg• Goal is to improve noisiness of MWF maps in qT2

• The first term is the data fidelity term• The second term is the conventional temporal regularization

term which penalizes large values in inferred T2 distributions• The third term imposes spatial constraints: first difference

smoothness• Resulting maps are reminiscent of mcDESPOT MWF and

values are similar– However vanilla qT2 MWF values seem overestimated

A Bayesian Algorithm Using Spatial Priors for Multi-Exponential T2 Relaxometry from Multi-Echo Spin Echo MRI [0360]

Phase sensitive PC-bSSFP: simultaneous quantification of T1, T2 and spin density M0 [2387]

• Martin Ott et al. Magnetic Resonance Bavaria e.V, Würzburg, Bayern, Germany

• Goal is a new mapping sequence using phase cycled SSFP at two angles, don’t need a T1 map like DESPOT2

• Solution is approximately to fit an ellipse to the data

• Still need to compare it against reference techniques

Phase sensitive PC-bSSFP: simultaneous quantification of T1, T2 and spin density M0 [2387]

Image Reconstruction and Acceleration Methods

Optimal Apportionment of Acceleration in 2D SENSE. [2224]

• Weaver et al. Mayo Clinic, Rochester, MN• Goal is to optimize the selection of Ry and Rz

for a SENSE acquisition given coil sensitivities• Choose Ry and Rz that minimizes the cost:

maximum g-factor * scan time• Simple, effective abstract, shouldn’t we have

been doing this all along?

Optimal Apportionment of Acceleration in 2D SENSE. [2224]

Myelin Sensitive Sequences

Can T1-Differentiation in a Magnetization Prepared Turbo Field Echo Sequence at 7T Predict "Persistent Black Hole” White

Matter Lesions in Multiple Sclerosis? [3115]

• Bluestein et al. The Ohio State University, Columbus, Ohio• Goal was to develop a better sequence parameters for a T2w

scan that better shows different types of lesions• Simulated behavior of some lesion types with multicomponent

signals and then chose parameters• Compared against:

– FLAIR (TR = 11000 ms, TI = 2800 ms, TE = 125 ms, TSE factor = 31)– WHAT (TS/TI = 4550/500 ms

• “That simulation showed that setting TS = 4500 ms and TI ranging from 880-980 ms, results in images with the long T1 WMLs brighter and short T1 WMLs darker than surrounding NAWM.”

Can T1-Differentiation in a Magnetization Prepared Turbo Field Echo Sequence at 7T Predict "Persistent Black Hole” White

Matter Lesions in Multiple Sclerosis? [3115]