Quantitative MRI analysis of menisci using biexponential T2* fitting with a variable echo time sequence.

Area of Science:

• Biomedical Engineering
• Radiology
• Orthopedics

Background:

• Meniscal disease involves alterations in the collagen fiber matrix.
• Quantitative MRI techniques like T2* mapping may detect these in vivo changes.
• Differentiating normal, degenerative, and torn menisci is crucial for diagnosis and treatment.

Purpose of the Study:

• To evaluate the efficacy of monoexponentially and biexponentially calculated T2* values in differentiating normal, degenerative, and torn menisci.
• To assess the potential of quantitative T2* mapping for in vivo detection of meniscal disease.

Main Methods:

• A 3D Cartesian spoiled gradient echo technique with variable echo times and asymmetric readout was employed.
• T2* values were calculated using both monoexponential (3-parametric) and biexponential (5-parametric) non-linear fits.
• Receiver operating characteristic (ROC) analysis was used to compare the diagnostic performance of the fitting methods.

Main Results:

• Biexponential T2* fitting showed superior performance in distinguishing normal from degenerated menisci compared to monoexponential fitting.
• Mean T2* values (short and long components) were significantly different across normal, degenerated, and torn menisci.
• Biexponential fitting yielded higher area under the curve, specificity, and sensitivity in ROC analysis.

Conclusions:

• Biexponential fitting of T2* data provides more accurate differentiation of meniscal conditions than monoexponential fitting.
• Changes in T2* values reflect matrix reorganization and altered collagen fiber orientation in degenerative meniscal processes.
• Quantitative T2* mapping, particularly with biexponential analysis, holds promise for non-invasive assessment of meniscal health.