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

Abstract

Purpose: 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. Methods: 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 pre-defined 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. Results: 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). Conclusion: 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.