An astute future doc on the SDN forums noticed recently that the opening sequence of Scrubs (a sitcom which I confess I haven't seen yet) features an incorrectly oriented chest X-ray. In accordance with the universal standard for viewing X-ray images (or "plain films" as radiologists seem to prefer these days), you're supposed to imagine viewing a patient that is facing you, so the left side of the film is the patient's right side. The Scrubs title shot (see below) clearly shows a heart pointing the wrong way (i.e., to the right instead of left). Also, the diaphragm bulges higher on the wrong side (left instead of right). Flip the image and everything looks normal.
It turns out that the gaffe was intentional:
The chest X-ray in the title sequence was hung backwards during the first season, then corrected briefly for season 2, but then returned to being backwards. Bill Lawrence states that having the X-ray backwards was intentional as it signified that the new interns were inexperienced. This error was parodied in "My Cabbage" (original airdate: February 28, 2006), with Cabbage (an Intern), attempting to read a chest X-ray backwards.
Sounds reasonable. But there is another, much less likely but much more anatomically interesting possibility. Perhaps the patient in the chest film has situs inversus. In this rare (1 in 10,000) congenital condition, an individual's internal organs appear to be the mirror image of the normal arrangement. The liver is on the left instead of the right, the spleen is on the right instead of the left, the left lung has 3 lobes instead of 2, etc. There is also some evidence that brain anatomy in situs inversus is inverted too.
For me, the most curious thing about situs inversus is that people with it usually have a normal life expectancy. Apparently in most people it's just an uncommon but normal variation, kind of like red hair or left-handedness. Indeed, the only real risk of situs inversus is confusing a clinician! For example, appendicitis normally causes pain in the right lower quadrant of the abdomen. In patients with situs inversus...you guessed it, left lower quadrant. There's always something to keep doctors on their toes.
P.S. For more information, check out this blog entry on situs inversus. It has a link to a nice New York Times article, and many comments by readers with situs inversus.