Role of Arrival Time Difference Between Lesions and Lung Tissue on Contrast-Enhanced Sonography in the Differential Diagnosis of Subpleural Pulmonary Lesions.

Objectives-The purpose of this study was to explore the diagnostic value of the arrival time difference between lesions and surrounding lung tissue on contrast-enhanced sonography of subpleural pulmonary lesions. Methods-A total of 110 patients with subpleural pulmonary lesions who underwent both conventional and contrast-enhanced sonography and had a definite diagnosis were enrolled. After contrast agent injection, the arrival times in the lesion, lung, and chest wall were recorded. The arrival time differences between various tissues were also calculated. Results-Statistical analysis showed a significant difference in the lesion arrival time, the arrival time difference between the lesion and lung, and the arrival time difference between the chest wall and lesion (all P<.001) for benign and malignant lesions. Receiver operating characteristic curve analysis revealed that the optimal diagnostic criterion was the arrival time difference between the lesion and lung, and that the best cutoff point was 2.5 seconds (later arrival signified malignancy). This new diagnostic criterion showed superior diagnostic accuracy (97.1%) compared to conventional diagnostic criteria. Conclusions-The individualized diagnostic method based on an arrival time comparison using contrast-enhanced sonography had high diagnostic accuracy (97.1%) with good feasibility and could provide useful diagnostic information for subpleural pulmonary lesions.