My concern is that if we are going to be both super cautious and assume that X-rays are copyrightable than we will need to get permission from all 9 potential copyright holders (ordering physician, patient, radiologist, hospital, government, X-ray tech, machine manufacturer, software programmer and the Queen of English in my jurisdiction, shareholders of hospitals in other jurisdictions). This will eliminate all radiological images from Wikipedia. Last time I wrote the Queen asking her to release content under a CC BY SA license she didn't respond. If the Wikimedia movement takes this stance I will go elsewhere.