Vendor-Specific Correction Software for Apparent Diffusion Coefficient Bias Due to Gradient Nonlinearity in Breast...

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Physics
• Biomedical Engineering

Background:

• Gradient nonlinearity in MRI scanners can introduce bias in apparent diffusion coefficient (ADC) measurements.
• This bias is particularly relevant in diffusion-weighted imaging (DWI) of the breast, affecting diagnostic accuracy.
• Accurate ADC values are crucial for characterizing breast lesions.

Purpose of the Study:

• To evaluate a vendor-specific software designed to correct ADC bias caused by gradient nonlinearity.
• To assess the software's effectiveness using an ice-water phantom in a 3.0-T MRI scanner.
• To determine if the correction improves ADC accuracy at off-center positions.

Main Methods:

• An ice-water phantom with five tubes was used for data acquisition.
• Diffusion-weighted images were acquired using an echo-planar imaging sequence with four b-values.
• ADC maps were generated with and without vendor-specific correction software.
• Mean ADCs were measured at various positions, including off-center locations and the magnet isocenter.

Main Results:

• Before correction, ADC values showed directional variations (increase in AP/RL, decrease in SI) with increasing distance from the isocenter.
• After correction, ADC values at off-center positions were within 5% of the expected values.
• Significant differences in ADC were observed between corrected and uncorrected off-center measurements (P < 0.001).
• ADC at the magnet isocenter remained consistent after correction.

Conclusions:

• The vendor-specific software successfully corrected ADC bias due to gradient nonlinearity in all tested directions (AP, RL, SI).
• This correction is vital for accurate ADC assessment in breast DWI.
• The software is expected to enhance the reliability of quantitative ADC measurements in clinical breast MRI.