Evaluation of calculation processes of apparent diffusion coefficient subtraction method (ASM) imaging

Area of Science:

• Radiology
• Medical Imaging
• Biophysics

Background:

• Restricted diffusion (RD) imaging techniques like diffusion kurtosis (DK) imaging are vital for diagnosing neurological conditions such as cerebral gliomas and infarction.
• Apparent diffusion coefficient (ADC) subtraction method (ASM) imaging is a novel RD technique utilizing differences in ADC values from varying diffusion times.

Purpose of the Study:

• To evaluate and compare the diagnostic potential of different ASM imaging techniques against the established gold-standard DK imaging.
• To investigate the impact of varying calculation methods on ASM image characteristics.

Main Methods:

• Three distinct ASM imaging variations (ASM/A, ASM/S, PASM/A) were developed and analyzed using phantom models.
• ASM image calculations involved dividing the difference between ADC basic (ADCb) and ADC modify (ADCm) by ADCb or its standard deviation.
• Image comparisons were performed against DK imaging to assess sensitivity and characteristics.

Main Results:

• All tested ASM variations exhibited similar tendencies in their imaging characteristics.
• Increasing the number of divisions by ADCb in ASM/A from three to five times shifted images from mimicking DK to becoming more sensitive to RD.
• ASM/A demonstrated a transformation towards enhanced RD sensitivity compared to DK imaging.

Conclusions:

• ASM/A imaging, particularly with an increased number of divisions, shows potential for enhanced sensitivity in restricted diffusion imaging.
• These findings suggest that ASM/A may become a valuable tool in future clinical RD imaging protocols for disease diagnosis.