MRI T2 Mapping of Knee Articular Cartilage Using Different Acquisition Sequences and Calculation Methods at 1.5 Tesla

Area of Science:

• Radiology
• Biomedical Imaging
• Orthopedics

Background:

• T2 mapping is crucial for assessing knee cartilage integrity.
• Standardization of T2 values is needed across different MRI sequences and calculation methods.
• Optimizing MRI protocols can improve diagnostic accuracy and efficiency.

Purpose of the Study:

• To evaluate the impact of various MRI acquisition techniques and calculation methods on T2 values in knee cartilage at 1.5 tesla.
• To identify MRI sequences suitable for high-resolution T2 mapping within reduced scanning times.

Main Methods:

• Phantom and patient (n=29) knee MRI scans were performed at 1.5 tesla.
• T2 mapping sequences included Single-Echo Spin Echo (SESE), Multi-Echo Spin Echo (MESE), Fast Spin Echo (FSE), and Turbo Gradient Spin Echo (TGSE).
• T2 relaxation times were quantified using MapIt, Syngo Offline, and mono-exponential fitting; signal-to-noise ratios (SNR) were also measured.

Main Results:

• No significant differences in T2 values were observed between MESE, FSE, and TGSE compared to the SESE reference sequence (p > 0.05).
• T2 values in phantoms ranged from 41.7 ± 13.8 ms (SESE) to 44 ± 14.5 ms (TGSE).
• No significant differences were found between the three calculation methods or between SNR values across all sequences.

Conclusions:

• T2 values in knee cartilage are influenced by both MRI sequence type and calculation method.
• No tested sequence showed significant deviation from the SESE reference.
• Turbo Gradient Spin Echo (TGSE) is recommended for high-resolution T2 mapping due to its efficient, short scanning time.