There's some truth to that statement. But there are other factors as well. For example, ultrasound imaging depends on the person taking the ultrasound, too. This is called operator-dependent imaging. Ultrasound results do depend in large part on the skill of the operator. It takes a long time to learn this skill. Not all centers have experienced operators.

The patients also affect results. Someone with limited motion might not be able to get into the best position needed for the test. Large or obese patients don't get as good of results.

The doctor who reads the imaging results is called a radiologist. The radiologist is more accurate reading tests he or she is familiar with and sees often. There is a learning curve here, too. Some hospitals and clinics have a second reading done when new staff is in training. This can help reduce errors and improve accuracy.

You can always ask for a second reading or second opinion if you're in doubt about the results of any tests done.