Apparent Diffusion Coefficient (ADC) as a quantitative parameter in diffusion weighted MR imaging in gynecologic...

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Radiology
• Oncology

Background:

• Diffusion-weighted imaging (DWI) is increasingly used for tumor assessment and treatment response.
• Accurate Apparent Diffusion Coefficient (ADC) calculation is vital for quantitative analysis.
• Standardizing ADC measurements across patients and institutions is a clinical challenge.

Purpose of the Study:

• To evaluate the impact of b-value selection on ADC calculations in locally advanced gynecological cancer.
• To identify a stable range of diffusion gradients for reliable ADC comparisons.

Main Methods:

• High-resolution, single-shot EPI DWI scans were performed on six patients using 16 b-values.
• Data were analyzed using monoexponential and biexponential models.
• The biexponential model accounted for both perfusion and diffusion effects.

Main Results:

• ADC values varied up to 40% depending on the b-value used.
• Using b-values ≥ 150 s/mm² and ≥ 700 s/mm² limited ADC variation to <10%.
• Eliminating perfusion effects significantly reduced quantitative ADC uncertainty.

Conclusions:

• The choice of b-values significantly influences ADC measurements in gynecological cancer.
• A specific b-value range (≥ 150 and ≥ 700 s/mm²) enhances ADC measurement stability.
• Accounting for perfusion improves the reliability of quantitative ADC values.