Real-Time Dynamics of an Extravascular Magnetic Resonance Contrast Medium in Acutely Infarcted Myocardium Using Inversion Recovery and Gradient-Recalled Echo-Planar Imaging

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.

Download Full-text

REAL-TIME ECHO-PLANAR IMAGING BY NMR

British Medical Bulletin ◽

10.1093/oxfordjournals.bmb.a071970 ◽

1984 ◽

Vol 40 (2) ◽

pp. 187-190 ◽

Cited By ~ 83

Author(s):

P MANSFIELD

Keyword(s):

Real Time ◽

Echo Planar Imaging ◽

Planar Imaging ◽

Echo Planar

Download Full-text

Echo planar imaging with a contrast medium in studying brain perfusion

Proceedings of the XIV Symposium Neuroradiologicum ◽

10.1007/978-3-642-49329-4_86 ◽

1991 ◽

pp. 267-268

Author(s):

Nicholas J. Patronas ◽

R. Turner ◽

D. Le Bihan ◽

M. Fulham ◽

D. Schellinger ◽

...

Keyword(s):

Contrast Medium ◽

Brain Perfusion ◽

Echo Planar Imaging ◽

Planar Imaging ◽

Echo Planar

Download Full-text

The clinical potential of ultra-high-speed echo-planar imaging

Philosophical Transactions of the Royal Society of London Series A Physical and Engineering Sciences ◽

10.1098/rsta.1990.0178 ◽

1990 ◽

Vol 333 (1632) ◽

pp. 507-514 ◽

Cited By ~ 7

Keyword(s):

Real Time ◽

High Speed ◽

Echo Planar Imaging ◽

Lesion Detection ◽

Whole Body ◽

Planar Imaging ◽

Cardiac Events ◽

Ultra High Speed ◽

Movement Artefact ◽

Echo Planar

Ultra-high-speed echo-planar imaging (EP1) allows acquisition of a complete twodimensional image in 64 to 128 ms devoid of movement artefact and without sacrifice of contrast due to relaxation time effects. In conventional whole-body MRI, however, obtrusive movement artefact and extended imaging time, resulting from the need to apply multiple sequences to facilitate lesion detection and pathological characterization, remain limitations. Reduced total examination time increases patient tolerance and throughput • furthermore optimization of contrast to achieve maximal conspicuity of particular features in liver or brain pathology is achieved simply and interactively by real time adjustment of the imaging parameters. The method provides the opportunity to study in real time dynamic events such as flow phenomena in the vascular and cerebrospinal fluid compartments of the brain as well as the kinetics of administered contrast agents, EPI is the only means of capturing the irregular motion of aperiodic cardiac events and bowel peristalsis.

Download Full-text