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The human ear cannot distinguish between two sources of sound if they happen to reach within a specific time interval, typically 0.1 seconds apart. More than this, and they are perceived as separate sources.
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Respiratory-triggered spin-echo echo-planar imaging-based mr elastography for evaluating liver stiffness.

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Magnetic resonance elastography (MRE) can assess liver disease without breath-holding. A new respiratory-triggered (RT) MRE technique shows excellent agreement with breath-holding MRE, offering a feasible alternative for patients unable to hold their breath.

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Area of Science:

  • Medical Imaging
  • Biophysics
  • Hepatology

Background:

  • Magnetic resonance elastography (MRE) is valuable for diagnosing chronic liver disease.
  • Breath-holding (BH) MRE acquisition minimizes motion artifacts but poses challenges for some patients.

Purpose of the Study:

  • To develop and validate a respiratory-triggered (RT) spin-echo echo-planar imaging (SE-EPI) MRE technique.
  • To compare the performance of RT SE-EPI MRE against the established BH SE-EPI MRE.

Main Methods:

  • A prospective feasibility study involving 23 adult volunteers (18 healthy, 5 with liver disease).
  • Acquisition of four axial liver images using both RT and BH SE-EPI MRE sequences on a 1.5 T Philips Ingenia scanner.
  • Liver stiffness measurements (kPa) were obtained and compared using statistical analyses, including Lin's concordance coefficient and Bland-Altman analysis.

Main Results:

  • Excellent agreement (rc = 0.98) was observed between RT and BH SE-EPI MRE techniques.
  • Mean liver stiffness values were comparable (2.40 ± 1.15 kPa for BH vs. 2.37 ± 1.06 kPa for RT, P = 0.54) with no significant bias.
  • Slightly smaller measurable regions of interest were noted with the RT technique (mean difference 1.91 cm2, P = 0.04).

Conclusions:

  • Respiratory-triggered (RT) SE-EPI MRE is a feasible technique for liver stiffness assessment.
  • RT SE-EPI MRE provides results comparable to the conventional breath-holding (BH) SE-EPI MRE technique.
  • This RT approach offers a viable alternative for patients who find breath-holding difficult.