What Nurses Need to Know About Ultrasound Scans

Ultrasound imaging, also known as sonography, is a cornerstone of non-invasive diagnostic evaluation. Used widely across disciplines from obstetrics to emergency medicine, ultrasound offers a radiation-free method for assessing internal structures in real time.  

This guide provides nurses with an in-depth understanding of ultrasound technology and how these tools can assist them in providing safe and effective patient care. 

What is an ultrasound? 

An ultrasound scan is a tool that uses high-frequency sound waves to produce real-time images of organs, tissues, and blood flow inside the body. A transducer sends sound waves into the body and records the echoes as they bounce back.  

These echoes are translated by computer software into visual images that clinicians use for diagnosis, monitoring, and procedural guidance. Ultrasound can assess dynamic physiological functions, such as cardiac ejection fraction or fetal movement, in real time. It is also instrumental in guiding needle placements for biopsies, catheter insertions, and fluid drainage.  

Unlike CT or MRI, ultrasound can be performed at the bedside, making it ideal for critically ill or immobile patients. Its non-invasive, radiation-free nature also makes it suitable for serial evaluations and pediatric care. 

How long does an ultrasound take? 

The duration of an ultrasound exam varies based on the area being evaluated. Most scans take between 15 and 45 minutes.  

For example, a focused FAST exam in trauma may take under 10 minutes, while a detailed abdominal or obstetric scan can take longer. Time may also increase with patient preparation, repositioning, or the need for repeat imaging. 

Is ultrasound considered radiology? 

Yes, ultrasound is a part of diagnostic radiology. Although it does not use ionizing radiation like CT or X-rays, it falls under the purview of medical imaging. Radiologists often interpret ultrasound images, and in some settings, advanced practice providers or trained specialists perform point-of-care ultrasounds (POCUS) with immediate clinical application. 

When was ultrasound invented? A brief history 

Ultrasound technology for medical use began in the 1940s and 1950s, inspired by sonar used in naval operations to detect submarines. Dr. Karl Dussik, an Austrian neurologist, is credited with pioneering early ultrasound studies of the brain in the late 1940s.  

These early studies used A-mode (amplitude modulation) and later B-mode (brightness modulation) to enhance image representation. During the 1950s and 1960s, researchers in Scotland and Sweden expanded its use to obstetrics and gynecology, laying the groundwork for fetal imaging.  

By the 1960s, obstetric ultrasound had gained popularity as a routine prenatal tool, helping clinicians monitor fetal development and detect anomalies. In the 1970s and 1980s, the introduction of real-time imaging and Doppler ultrasound allowed for dynamic visualization of internal structures and vascular flow.  

Advances in microelectronics, digital processing, and portable transducers have since transformed ultrasound into a versatile and indispensable clinical tool used in nearly every medical specialty today. 

What degree do you need to be an ultrasound tech? 

Ultrasound technicians, or diagnostic medical sonographers, typically complete an accredited associate degree or postsecondary certificate in diagnostic medical sonography. These programs include didactic coursework, anatomy and physiology, and extensive clinical training.  

Some choose to pursue a bachelor's degree for advanced practice or leadership roles. Certification through the American Registry for Diagnostic Medical Sonography (ARDMS) is widely recognized and often required. 

What can an ultrasound detect? 

Ultrasound is used to assess a variety of clinical conditions, including: 

• Pregnancy and fetal development: This is the most well-known and frequent application, where ultrasound is used to confirm gestational age, assess fetal anatomy and growth, monitor placental location, and detect congenital anomalies. Routine ultrasounds in pregnancy are pivotal for evaluating fetal well-being and are typically performed at various gestational milestones. 
• Gallbladder disease 
• Liver pathology (e.g., cirrhosis, masses) 
• Kidney stones or hydronephrosis 
• Abdominal aortic aneurysms 
• Deep vein thrombosis (DVT) 
• Cardiac function via echocardiography 
• Pelvic disorders (e.g., ovarian cysts, uterine fibroids) 

While its primary use remains in obstetric imaging, ultrasound's utility spans emergency medicine, cardiology, and musculoskeletal diagnostics. Its ability to provide immediate, real-time data without radiation makes it invaluable in time-sensitive or patient-sensitive scenarios. 

Compared to CT or MRI, ultrasound excels in real-time imaging, portability, and safety in populations like pregnant individuals. However, it is limited by body habitus and bone or air interference. It is not ideal for detecting gas-filled structures or deep tissue masses where resolution is critical. 

What do nurses need to know about ultrasound techs? 

Nurses frequently collaborate with sonographers and should understand their workflow to optimize patient care: 

• Assist with patient positioning and education about the procedure. 
• Prepare the patient according to scan requirements (e.g., full bladder, NPO status). 
• Communicate relevant clinical information or patient concerns to the sonographer. 
• Recognize findings that may require urgent follow-up or further imaging. 
• Understand infection control protocols for probe handling and gel use. 
• Support patients during bedside or intraoperative ultrasounds.