Rorschach

The Rorschach inkblot test (example shown above) is a psychological test where a subject is asked to interpret an inkblot. His response reveals something about his personality, emotional state, and thought process. What do you see in the image? What aspects of the image do you focus on? How easy is it to create a shape or figure or description? And what could this possibly reveal to an outside observer about your psychological state?

In some ways, and perhaps unfairly so, radiology to a beginner feels like an inkblot test. We look at complex images with an overwhelming amount of information and it's hard to know where to begin. What's normal? What's abnormal? Often, findings are subtle yet significant. CTs and MRIs have hundreds of slices to look through, and watching experienced radiologists scroll through this wealth of data is both intimidating and impressive.

For example, the CT angiogram above shows a life-threatening pulmonary embolus. But it can also be "windowed" (adjusting the contrast/display) to examine the bones, soft tissues, vessels, heart, and lungs. How do you pick up on what stands out? How do you know you aren't just imaging a finding in a Rorschach inkblot test?

The residents always seem to return to a systematic method to ensure they look at everything. It's really easy for me to identify an outrageously abnormal finding and forget to examine everything else in the image. I think the other element is simply practice. After looking at enough normal and abnormal pictures, the differences start to become instinct. Radiology in some ways reminds me of that game in childhood of examining two images and finding the differences.

Image of Rorschach ink blot is in the public domain, from Wikipedia. Image of the CT angiogram is also in the public domain, from Wikipedia.