Reliability and reproducibility of sciatic nerve magnetization transfer imaging and T2 relaxometry

Area of Science:

• Radiology
• Neuroimaging
• Biomarkers

Background:

• Sciatic nerve MR neurography (MRN) is crucial for diagnosing peripheral nerve disorders.
• Quantitative imaging techniques like MTI and T2 relaxometry offer objective assessments.
• Reliability and reproducibility of these techniques are essential for clinical translation.

Purpose of the Study:

• To evaluate the interreader and test-retest reliability of MTI and T2 relaxometry for sciatic nerve imaging.
• To establish the reproducibility of quantitative biomarkers derived from these techniques.
• To provide reference values for measurement imprecision in sciatic nerve MRN.

Main Methods:

• Prospective study involving 21 healthy volunteers.
• Standardized 3 Tesla MRN protocol including MTI and multi-echo T2 relaxometry sequences.
• Two independent readers assessed MTR, T2 relaxation time, and PSD.
• Interreader and test-retest reliability analyzed using ICCs and SEM.

Main Results:

• High interreader reliability (ICCs 0.81-0.94) and test-retest reliability (ICCs 0.75-0.94) were observed for MTR, T2, and PSD.
• Standard error of measurement (SEM) values were established for MTR (1.7%), T2 (2.66-2.67 ms), and PSD (20.1-21.3).
• Mean MTR: 26.75 ± 3.5%, T2: 64.54 ± 8.2 ms, PSD: 340.93 ± 78.8.

Conclusions:

• MTI and T2 relaxometry provide reliable and reproducible quantitative measures of the sciatic nerve.
• Reported SEM values serve as a guide for interpreting measurement imprecision.
• These findings support the use of quantitative MRN biomarkers in future research and clinical practice.