What is a Protocol for An Imaging Test?

Protocol is a way of doing a particular imaging test.   A protocol can vary based on the particular test, the location where the test is done, the preference of the radiologists where the test is done, and the expertise of the facility where you are having it done.  Despite the variability, the same information and diagnosis is reached most of the time.  It’s just another way of getting the information in many cases.

Are protocols for imaging the same for all patients?

Many imaging tests have a generic protocol which applies to the majority of exams done at a facility.   Occasionally a more focused protocol has to be done because of a specific question that is asked or if a certain diagnosis is suspected.    Some facilities have multiple protocols for different conditions and clinical scenarios.    Sometimes these protocols have to be done by radiologists for individual patients.

Protocols are done for many types of tests

Protocols are done for many different kinds of tests like X-ray, ultrasound, CT and MRI.   Protocols for X-ray can mean what kinds of views you do for a knee or shoulder X-ray for example.   These protocols are usually given to the technologists who do the exam.  They follow this protocol every time.

For ultrasound, this may mean what the expectation is for showing different structures that are being looked at.  For example, each ovary in a pelvic ultrasound must be measured in 3 planes and blood flow must be shown.    For the uterus, this may mean showing it in two planes.  Showing pictures of the cervix and endometrium.

For CT, protocols are usually standard.   Some modifications are made when looking at different organs or body parts to get a more focused exam.  For example, a CT urogram is done for patients when they have blood in their urine or to exclude a tumor of the urinary tract.  A pancreatic CT is focused on the pancreas.

MRI protocols are usually standard for the majority of exams and indications.  There are also more focused protocols for specific indications or organs.  Radiologists get involved in protocol design when there are specific questions involved.  Sometimes there are another challenges like artifacts where the radiologist has to modify the exam.  Usually the radiologist also has to specify what anatomy is covered and  how closely we look at the structures.

A protocol is therefore a way of doing an imaging test.  This varies from facility to facility.  There are multiple ways to get the information and diagnosis.  Sometimes focused protocols need to be done for specific reasons.  These standard and focused protocols are usually specified in advance.  Rarely, radiologists have to provide an individualized protocol for a patient when there is a specific question or unusual circumstance.