Preoperative prediction of pituitary macroadenoma consistency using diffusion-weighted MRI: A prospective study with surgical correlation

Background Preoperative knowledge of pituitary macroadenoma consistency holds considerable importance in guiding surgical strategy and optimizing patient outcomes. The mechanical properties of the tumor may determine both the feasibility of complete resection and the most appropriate operative technique. This study was designed to examine the utility of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) quantification as preoperative tools for characterizing pituitary macroadenoma consistency. Results Among the studied macroadenomas, the mean ADC value was 0.937 ± 0.261 ×10 ‒3 mm 2 /s. A statistically significant relationship was established between ADC measurements and intraoperative tumor consistency ( p < .001). Soft tumors demonstrated the lowest mean ADC (0.780 ± 0.074 × 10 ‒3 mm 2 /s), firm tumors showed intermediate values (0.871 ± 0.09 × 10 ‒3 mm 2 /s), and hard tumors exhibited the highest ADC (1.270 ± 0.268 × 10 ‒3 mm 2 /s). The optimal ADC cutoff for discriminating hard from firm adenomas was 1.08 × 10 ‒3 mm 2 /s (sensitivity 90%, specificity 100%, accuracy 94.4%), and 0.88 × 10 ‒3 mm 2 /s for firm versus soft discrimination (sensitivity 62.5%, specificity 88.9%, accuracy 80.8%). Conclusion Quantitative ADC measurements obtained through DWI may serve as a useful non-invasive imaging parameter for the preoperative assessment of pituitary macroadenoma consistency and could provide supportive information for surgical planning.