CCI Study Guide 2026

The Valsalva maneuver (straining against a closed glottis) significantly increases intra-thoracic and intra-abdominal pressure. This pressure is transmitted down the venous system. In a patient with competent valves, this will cause flow to slow or cease. If the valves are incompetent, the increased proximal pressure will cause blood to flow backward (reflux) past the faulty valve, which can be detected by Doppler.

Explanation: Arterial wall infections such as Staphylococcus, Tuberculosis, and Syphilis can contribute to the development of aneurysms by weakening the arterial wall. However, Measles is not typically associated with arterial wall infections that lead to aneurysms.

Explanation: Contrast echocardiography involves the use of contrast agents to enhance the visibility of cardiac structures during echocardiography. It can aid in the detection of various conditions, including left ventricular opacification (option A), providing a refined definition of left ventricular (LV) structural abnormalities (option B), and identifying intracardiac shunts (option C). Therefore, option D, all of the above, is the correct choice.

There is a fundamental trade-off in ultrasound physics between image resolution and penetration. Higher frequency transducers produce shorter wavelengths, which provide better axial and lateral resolution (finer detail). However, higher frequency sound waves are attenuated more rapidly by tissue, which limits their ability to penetrate to deeper structures.

When imaging from the posterior aspect of the knee (the popliteal fossa), the popliteal vein is typically located superficial to the popliteal artery. Therefore, on the ultrasound display, the vein will appear closer to the top of the screen than the artery.

The Bernoulli equation is based on the law of conservation of energy, which states that the total energy of a fluid (composed of pressure energy and kinetic energy) remains constant. As blood accelerates through a stenosis, its velocity (kinetic energy) increases, which must be accompanied by a corresponding decrease in pressure (pressure energy). The simplified equation relates this change in velocity directly to the pressure gradient.