A short-TR single-echo spin-echo breath-hold method for assessing liver T2

Area of Science:

• Magnetic Resonance Imaging
• Medical Physics
• Radiology

Background:

• Conventional single-echo spin-echo T2 mapping for liver iron quantification requires long scan times, exceeding typical breath-hold durations.
• This limitation hinders accurate assessment in clinical settings, particularly for patients with iron overload.

Purpose of the Study:

• To investigate a novel, accelerated single-echo spin-echo T2 mapping technique suitable for breath-hold acquisition.
• To evaluate the accuracy and reliability of this short TR (~100 ms) T2 mapping method for liver iron quantification.

Main Methods:

• A short TR (~100 ms) single-echo spin-echo T2 mapping sequence was developed, acquiring each echo time (TE) image in ~17 seconds.
• To mitigate T1 bias, the repetition time (TR) was incremented with each TE, maintaining a constant TR-TE interval.
• Validation was performed using phantoms, 9 healthy volunteers, and 5 iron overload patients at 1.5T, comparing results against conventional methods and FerriScan.

Main Results:

• In phantoms, the constant TR-TE technique yielded unbiased T2 estimates, unlike the conventional constant TR approach which underestimated T2.
• Healthy volunteers showed no significant discrepancy between constant TR-TE T2 values and reference T2 values.
• In iron overload patients, a high correlation (r² = 0.95) was observed between constant TR-TE T2 values and FerriScan, with a small discrepancy (0.6 ± 1.4 ms).

Conclusions:

• The developed short-TR single-echo breath-hold spin-echo T2 mapping technique provides unbiased T2 estimates.
• This accelerated method is accurate and reliable for liver iron quantification in both phantoms and clinical liver applications.