Time-dependent diffusion MRI to distinguish malignant from benign head and neck tumors

Area of Science:

• Magnetic Resonance Imaging
• Biomedical Engineering
• Oncology

Background:

• Growing interest exists in diffusion time's effect on apparent diffusion coefficient (ADC) values in cancers.
• Limited evidence currently addresses its utility in differentiating malignant from benign head and neck tumors.

Purpose of the Study:

• To investigate the utility of ADC value changes in distinguishing between malignant and benign head and neck tumors.
• Utilized different diffusion times from oscillating gradient spin-echo (OGSE) and pulsed gradient spin-echo (PGSE) MRI sequences.

Main Methods:

• Prospective study involving 31 patients with suspected head and neck tumors and a phantom.
• 3T MRI with diffusion-weighted imaging (DWI) using OGSE (4.3 msec) and PGSE (82.6 msec) sequences.
• Assessed ADC values (ADC_OGSE, ADC_PGSE) and relative ADC changes.

Main Results:

• Malignant tumors showed significantly lower ADC_OGSE and ADC_PGSE values than benign tumors (P < 0.001 and < 0.0001).
• Significantly larger relative ADC changes were observed in malignant compared to benign tumors (P < 0.0001).
• Relative ADC change and ADC_PGSE demonstrated higher diagnostic performance (AUC 0.97 and 0.96).

Conclusions:

• ADC values obtained with PGSE were lower than OGSE, with a more pronounced difference in malignant tumors.
• Observed differences suggest variations in tissue structure or cell permeability influenced by diffusion time.
• Reporting diffusion time is crucial for interpreting head and neck diffusion MRI findings.