Microflow imaging versus color Doppler imaging for differentiating malignant from non-neoplastic peripheral lung lesions

This study aimed to compare microflow imaging (MFI) with conventional color Doppler imaging (CDI) for differentiating malignant from non-neoplastic peripheral lung lesions on the basis of vascular grading and vascular morphology.

This retrospective single-center study included 124 patients with pleura-based peripheral lung lesions who underwent thoracic ultrasound between January 2024 and January 2026. Each lesion was examined with B-mode ultrasound, CDI, and MFI during the same session. Vascularity was graded according to the Adler classification, and vascular morphology was assigned to one of five predefined patterns. Histopathological findings or clinical and radiological follow-up served as the reference standard. Receiver operating characteristic curve analysis and multivariable logistic regression were performed.

Among the 124 lesions, 77 (62.1%) were malignant and 47 (37.9%) were non-neoplastic. Vascularity scores obtained with both MFI and CDI were significantly higher in malignant lesions than in non-neoplastic lesions (P<0.001). The MFI morphology score achieved the highest diagnostic performance (area under the curve [AUC], 0.933; 95% confidence interval [CI], 0.888 to 0.979), followed by the MFI Adler score (AUC, 0.899), CDI Adler score (AUC, 0.847), and CDI morphology score (AUC, 0.828). At a cutoff of ≥3, the MFI morphology score yielded 94% sensitivity and 83% specificity. In multivariable analysis, only the MFI morphology score remained an independent predictor of malignancy (odds ratio, 6.13; 95% CI, 2.02 to 18.56; P=0.001).

MFI, particularly vascular morphology assessment, showed better diagnostic performance than CDI for differentiating malignant from non-neoplastic peripheral lung lesions and may improve routine thoracic ultrasound evaluation.