Ground glass patchy shadows with clear borders may be benign or malignant and need to be evaluated in conjunction with imaging and other tests. Frosted glass refers to a cloudy, slightly dense image on chest CT, and patchy image refers to a frosted glass image with a patchy shape. Ground glass shadows can be caused by benign lung diseases such as inflammation and tuberculosis, or by malignant tumors such as lung cancer. Lung shadows caused by benign lung diseases often have clear boundaries, while malignant tumors such as lung cancer and metastatic cancer lesions are invasive, and thus the boundaries of the lesions are often unclear. Generally speaking, the clear border of ground-glass patchy shadow is more likely to be caused by benign diseases such as inflammatory lung lesions, but it does not exclude the risk of lung cancer, which needs to be judged with the combination of the lesion size, location, clinical symptoms and other examination results, and it is recommended to consult the doctor in time and follow the doctor’s instructions for further examination and treatment.