Liver Imaging at 3.0 T: Diffusion-induced Black-Blood Echo-planar Imaging with Large Anatomic Volumetric Coverage as an Alternative for Specific Absorption Rate–intensive Echo-Train Spin-Echo Sequences: Feasibility Study

Radiology ◽  
2008 ◽  
Vol 248 (1) ◽  
pp. 264-271 ◽  
Author(s):  
Indra C. van den Bos ◽  
Shahid M. Hussain ◽  
Gabriel P. Krestin ◽  
Piotr A. Wielopolski
2019 ◽  
Author(s):  
Mahdi Khajehim ◽  
Thomas Christen ◽  
J. Jean Chen

AbstractPurposeTo introduce a novel magnetic-resonance fingerprinting (MRF) framework with single-shot echo-planar imaging (EPI) readout to simultaneously estimate tissue T2, T1 and T2*, and integrate B1 correction.MethodsSpin-echo EPI is combined with gradient-echo EPI to achieve T2 estimation as well as T1 and T2* quantification. In the dictionary matching step, the GE-EPI data segment provides estimates of tissue T1 and T2* with additional B1 information, which are then incorporated into the T2-matching step that uses the SE-EPI data segment. In this way, biases in T2 and T2* estimates do not affect each other.ResultsAn excellent correspondence was found between our T1, T2, and T2* estimates and results obtained from standard approaches in both phantom and human scans. In the phantom scan, a linear relationship with R2>0.96 was found for all parameter estimates. The maximum error in the T2 estimate was found to be below 6%. In the in-vivo scan, similar contrast was noted between MRF and standard approaches, and values found in a small region of interest (ROI) located in the grey matter (GM) were in line with previous measurements (T2MRF=88±7ms vs T2Ref=89±11ms, T1MRF=1153±154ms vs T1Ref=1122±52ms, T2*MRF=56±4ms vs T2*Ref=53±3ms).ConclusionAdding a spin echo data segment to EPI based MRF allows accurate and robust measurements of T2, T1 and T2* relaxation times. This MRF framework is easier to implement than spiral-based MRF. It doesn’t suffer from undersampling artifacts and seems to require a smaller dictionary size that can fasten the reconstruction process.


2017 ◽  
Vol 27 (3) ◽  
pp. 193-201 ◽  
Author(s):  
Fabian Hilbert ◽  
Tobias Wech ◽  
Henning Neubauer ◽  
Simon Veldhoen ◽  
Thorsten Alexander Bley ◽  
...  

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