Do I need to fast before a vascular ultrasound examination?

Planner: Chinese Medical Association

Reviewer: Wang Yandong, Chief Physician, Tianjin University Central Hospital

Vascular ultrasound is a non-invasive medical imaging technology that uses ultrasound to generate images of the body's vascular system and detects the health of blood vessels by analyzing the speed, direction and other characteristics of blood flow. Whether fasting is required before a vascular ultrasound examination depends on the specific part of the examination and the purpose of the examination.

For example, you may need to fast before performing an ultrasound examination of abdominal blood vessels (especially the abdominal aorta, inferior vena cava, and renal artery), because after eating, the gas and contents in the gastrointestinal tract may interfere with the penetration of ultrasound, thereby affecting the image quality and reducing the accuracy of ultrasound diagnosis; some special types of vascular ultrasound examinations (such as abdominal ultrasound angiography that requires injection of contrast agents) may require fasting. In addition, for most routine ultrasound examinations of blood vessels (such as carotid arteries, limb blood vessels, etc.), special dietary restrictions are usually not required. Of course, if the purpose of the ultrasound examination is to observe the hemodynamic situation, avoid drinking alcohol and coffee before the examination, otherwise it will cause tachycardia and accelerated blood flow, which will affect the examination results. In short, whether fasting is required before a vascular ultrasound examination, the ultrasound physician will give specific instructions based on the examination items and personal health status.