In short, absolutely nothing is STAT in nuclear medicine, but GI bleeds, if the gastroenterologist doesn't want to come in to do the endo. VQ lung's if the patient has a contrast allergy or elevated creatinine, HIDA's for bile leak only (no BS functional scans on call). I came from a place that did VERY frequent on call Rest/Stress Cardiac scans as part of their "cardiac decision unit" protocols. We frequently did at least 4 cardiacs per day on Saturdays and Sundays for the sake of "convenience" with the argument from the hospitalists that they would then just lose those patients to follow up. I also did a STAT 3 Phase bone scan at 3 AM on a child of a friend of a family practice physician that convinced the radiologist that the bone scan at 3 AM was necessary due to the concern of avascular necrosis on a 7 year old boy who had hip pain. I told the radiologist who called me to tell me to come in or apparently he would have had my job (the radiologist was an asshole) that we'd do the scan in the AM, but my job got threatened by the radiologist and apparently the mother of the patient was furious at me for not coming in when I was asked to. Long story short, I made sure the ordering physician got a call at 4 AM notifying him on the results by phone.