K.3 Definition of a Staged Protocol Exam

A "Staged Protocol Exam" acquires images in two or more distinct time intervals called "Stages" with a consistent set of images called "Views" acquired during each Stage of the exam. A View is of a particular cross section of the anatomy acquired with a specific ultrasound transducer position and orientation. During the acquisition of a Staged Protocol Exam, the modality may also acquire non-Protocol images at one or more Protocol Stages.

A common real-world example of an ultrasound Staged Protocol exam is a cardiac stress-echo ultrasound exam. Images are acquired in distinct time intervals (Stages) of different levels of stress and Views as shown in Figure K.3-1. Typically, stress is induced by means of patient exercise or medication. Typical Stages for such an exam are baseline, mid-stress, peak-stress, and recovery. During the baseline Stage the patient is at rest, prior to inducing stress through medication or exercise. At mid-stress Stage the heart is under a moderate level of stress. During peak-stress Stage the patient's heart experiences maximum stress appropriate for the patient's condition. Finally, during the recovery Stage, the heart recovers because the source of stress is absent.

At each Stage an equivalent set of Views is acquired. Examples of typical Views are parasternal long axis and parasternal short axis. Examination of wall motion between the corresponding Views of different Stages may reveal ischemia of one or more regions ("segments") of the myocardium. Figure K.3-1 illustrates the typical results of a cardiac stress-echo ultrasound exam.

Cardiac Stress-Echo Staged Protocol US Exam

Figure K.3-1. Cardiac Stress-Echo Staged Protocol US Exam