A nighthawk or preliminary read is often done for urgent studies performed during the evenings or the night, frequently from the emergency room. This type of read is done by a board certified radiologist who usually does not work for the hospital but an outside company that provides this type of coverage.
Many hospitals and practices hire a company to cover the times when the on site radiologists are not providing coverage. This happens between the hours of 10 pm and 7 am in my practice. Other practices may start earlier or not use night hawk at all. They may have a dedicated group of on site radiologists who cover the night.
A nighthawk or preliminary read means that the read is not final. That the case will be read again when the dedicated on site radiologists begin work in the morning. Frequently, The diagnosis and treatment decisions will have already been made by the time the on site radiologist reads the case.
A preliminary read is often just that. The emphasis is on urgent conditions that need to be taken care of. Many preliminary reads that I see however include many non urgent findings. The reads are very important because your treatment will depend on the report. The radiologists providing these reads is board certified and focuses their practice on emergency radiology.
Occasionally, the dedicated onsite radiologist who reads the case in the morning may see additional findings. Most of the time, these are non urgent findings that may need follow up or findings that can be ignored. Rarely, there may be an additional finding that is urgent and significant. In these cases, the on site morning radiologist will call the treating physician and let him know.
If your in the hospital, then the radiologist will let your doctor know about the finding. If you have been discharged, you will be contacted by phone to either return to the emergency room or receive treatment from your doctor. Some important and urgent findings are hard to see and easy to miss. Other findings are subjective and depend on the interpreting radiologist. This does not mean that you necessarily received poor care.
It is important to follow up with your regular doctor once the final reading of your test is available. Sometimes there are important findings that need to be followed or treated. You can obtain a copy of your test and report to take to your regular doctor.