Impression is like the conclusion of a report. It should be the place where the bottom line is. Where the radiologist gives his most likely diagnosis. Sometimes radiologists will give recommendations for what to do next.
What else can an impression have other then the diagnosis?
This may include further testing so we can reach a diagnosis. Other times it may be a specialist consult that may work up the finding or diagnosis. The impression should be concise and to the point. This should direct the referring physician to provide the appropriate treatment for the patient.
The impression may include a short sentence with a diagnosis. Other times the impression may include multiple sentences or impression points. There may be more then one diagnosis. There may be an explanation of the findings.
The impression is often longer when the findings are inconclusive or need further workup. The radiologist may use the impression to explain the findings and what the possibilities may be. He may provide a differential diagnosis which is a set of possibilities.
The radiologist will also often provide a way to reach a more confident diagnosis. He may recommend another test like an MRI. He may suggest a biopsy to reach a diagnosis. Sometimes he can even suggest a referral to a specialist like a urologist.
The impression can also state that a report is normal or has benign findings. In these cases it will often be short and to the point. This does not mean that there is no diagnosis. This just means that the test did not identify a problem and the workup should continue.
The impression can be seen for all types of studies from X-rays to MRIs. The impression follows a description of all the findings in a report. Often impressions for more advanced imaging will be longer because they provide more information then an X-ray.
The impression of a report is therefore the last part of the report. It is where the radiologist gives his conclusion and most likely diagnosis. There will also often be recommendations for further workup. The impression is the most important part of the report. Many referring doctors turn to the impression to receive guidance on treatment.