Simultaneous Multiparameter Mapping of the Liver in a Single Breath-Hold or Respiratory-Triggered Acquisition Using...

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Physics
• Radiology

Background:

• Quantitative parametric mapping is crucial for noninvasive assessment of chronic liver disease.
• Conventional techniques require multiple breath-holds and have limited coverage.
• Novel methods are needed to improve efficiency and coverage.

Purpose of the Study:

• To evaluate a multi-inversion spin and gradient echo (MI-SAGE) technique.
• To assess its capability for simultaneous estimation of liver T1, T2, and T2*.
• To compare MI-SAGE with conventional parametric mapping sequences.

Main Methods:

• Prospective study involving 16 participants (adult and pediatric) with and without liver disease.
• Utilized 1.5T MRI with single breath-hold and respiratory-triggered MI-SAGE sequences.
• Compared MI-SAGE with breath-hold MOLLI (T1), GRASE (T2), and mGRE (T2*) sequences.
• Statistical analysis included Bland-Altman analysis and intraclass correlation coefficients (ICC).

Main Results:

• MI-SAGE T1, T2, and T2* estimates showed good agreement with conventional methods, with minor biases.
• Mean biases for T1, T2, T2* were (72, -3, 2) msec for breath-hold and (36, -3, 4) msec for respiratory-triggered MI-SAGE.
• All MI-SAGE estimates demonstrated strong repeatability and reproducibility (ICC > 0.72).

Conclusions:

• The MI-SAGE technique yields hepatic T1, T2, and T2* estimates comparable to conventional MRI methods.
• A slight underestimation of T1 values was observed compared to MOLLI.
• Both breath-hold and respiratory-triggered MI-SAGE parameter maps exhibit robust repeatability and reproducibility.