What is " no definite liver lesion seens" on non contrast CT scan means? Us followed 3 mn later says no masses " why CT impression so vague

Vague reports. The amount of vagueness in a report varies from radiologist to radiologist, but it is common. Generally, they are careful to use language that won't create any legal troubles for them down the road. In this case it is clear that both the ct and the ultrasound were negatie.
Non-contrast CT. The vagueness may have been due to the absence of contrast on the ct scan. Contrast enhances sensitivity in detection of liver masses - some are completely invisible without contrast.