Ultrasound Equipment: Types and Their Clinical Applications

Image: Assorted ultrasound machines for medical use.
21 December 2023

A non-invasive imaging technology that allows to easily navigate in medicine. This equipment has multiple types and modes, that are dedicated to efficiently tracking and diagnosing multiple medical conditions. With that, here are some of the ultrasound types.

Types of ultrasound: Doppler ultrasound

This type of ultrasound uses high-quality sound waves, similar to traditional ultrasound. 

During the procedure, the waves return as echoes when they come into contact with moving blood cells. The Doppler effect causes the frequency of the echoes to alter as blood cells travel through the blood vessels. The direction and speed of blood flow are connected to this variation in frequency.

After processing, the data obtained from the Doppler effect is shown as waveforms or color-coded pictures. Usually, the colors indicate which way the blood is flowing—for example, red indicates blood moving toward the transducer and blue indicates blood moving away.

High-Intensity Focused Ultrasound (HIFU)

This one has a therapeutic effect and uses a focused ultrasound effect to deliver energy to the examined part of the body. The high intensity of these waves helps them increase the heat and cause tissue destruction.

This equipment can be used for discovering different types of medical conditions, for example:

  • Tumor ablation: In many cases, medicine uses HIFU to deliver non-invasive treatment for several tumors, especially in the prostate, uterus, liver, kidney, and breast. HIFU precisely targets and ablates the cancerous tissues without the necessity for surgical interventions.
  • Bone Metastases: The HIFU treatment also includes the treatment of painful bone metastases, where the intense waves spot and destroy the nerve endings in the bone.

Intravascular Ultrasound (IVUS)

This is a medical imaging technique that uses ultrasound in blood vessels to have detailed images of vessel walls and structures. With this technology, it is possible to assist with the evaluation and diagnosis of different cardiovascular conditions since it provides real-time, high-resolution images. Here are some cases where IVUS can be used.

  • Coronary artery images: IVUS can visualize the inside of coronary arteries (the blood vessels supplying the heart muscles). Meaning, that health providers can have more detailed images of the vessel walls, the size of the arterial wall, the presence of plaque, and so on.
  • Guidance during Coronary interventions: IVUS provides immediate results. It helps interventional cardiologists to precisely position and deploy stents. 

Portable Ultrasound

Due to their compact sizes portable ultrasound devices are used in different medical cases. They are easy to transport while also providing real-time imaging, here are some cases where they can efficiently help.

  • Emergency medicine: These devices are effectively used in emergency medicine to help trauma patients, abdominal pain, and so on. It quickly provides diagnostic data with no need to transport the traumatized patient.
  • Home health care: There are many cases when the patient cannot leave the house or the bed due to their health condition. These devices enable access to professional diagnostics, they monitor certain conditions and perform basic assessments without moving the patient too much.

Transesophageal Echocardiography (TEE)

A specialized imaging technique that uses ultrasound to receive detailed images of the heart. The process includes inserting a probe into the tube that connects the mouth to the stomach the purpose of which is to get more detailed and closer images of the heart structures. 

It is often used during cardiac surgeries and provides real-time imaging guidance to the doctors holding the procedure. 

Endoscopic Ultrasound (EUS)

Another sonography equipment that provides detailed images of the gastrointestinal (GI) tract and surrounding structures by combining endoscopy and ultrasound. An endoscope fitted with an ultrasound transducer must be inserted into the digestive tract to complete the procedure.

  • Biliary Tract Imaging: EUS helps to visualize the bile ducts and gallbladder, as well as in diagnosing conditions such as gallstones, strictures, and tumors in the biliary system.
  • Liver imaging: When combined with other imaging techniques, EUS can assess certain liver conditions such as Portal Hypertension, Focal Liver Lesions, Biliary Tract Disorders, and more. 

Ultrasound modes types

Alongside the variety of ultrasound device types, there are also a couple of modes that vary with their functionalities. Here they are:

  • 2D Ultrasound (also as Brightness Mode): The most commonly used ultrasound mode, which provides two-dimensional, grayscale images of the internal structures of the body. It helps to detect abnormalities and guide medical procedures.
  • 3D Ultrasound: This mode adds an extra layer of dimension to the imaging, and produces three-dimensional volumetric images of the scanned area. It provides a more realistic visual, therefore it has high popularity in pregnancy cases.
  • 4D Ultrasound (Real-time 3D): 4D mode extends the capabilities of 3D imaging, providing real-time, moving, and dynamic three-dimensional images. 

In conclusion, each ultrasound mode is used for a specific diagnostic procedure.