• Elastography is a medical imaging procedure that allows doctors to examine an individual’s body for various diseases, such as liver or breast diseases, thyroid, and prostate cancer.
  • Researchers used elastography to determine how many young adults have features indicating nonalcoholic fatty liver disease (NAFLD)(1). Another study showed that elastography as a noninvasive tool may help evaluate hepatic fibrosis among chronic hepatitis C patients(2).
  • Clinicians may not recommend ultrasound and magnetic resonance elastography for individuals with acute hepatitis, abdominal fluids, heart conditions, obesity, or iron deposits in the liver.

What Is Elastography?

Elastography, sometimes called liver elastography, is an imaging test that checks the liver for fibrosis.

Liver fibrosis is a medical condition described by abnormally large scar tissue formation in the liver when the organ repairs and replaces damaged cells.

This condition damages the liver, and severe scarring can lead to cirrhosis (chronic liver disease leading to permanent liver damage).

If fibrosis is left untreated, it can cause serious liver problems, such as liver cancer and liver failure. Early diagnosis and treatment can lower or even reverse the effects of fibrosis.

Liver elastography has two types of tests(3):

  • Ultrasound elastography: This test is also known as FibroScan, the brand name of the ultrasound equipment.

This elastography type uses ultrasonic frequency sound waves to measure liver tissue stiffness. Stiffness is one of the indications of fibrosis.

  • Magnetic resonance elastography (MRE): An MRE test combines ultrasound with magnetic resonance imaging (MRI) technology.

MRI is an imaging procedure that uses radio waves and powerful magnets to produce images of organs and the internal body structure. During an MRE exam, the computer software creates a visual map showing liver stiffness.

Uses or Applications of Elastography

Doctors use elastography to examine various organs like liver, breast, thyroid, and prostate for possible diseases, such as cancer.

The procedure also provides additional diagnostic information compared to a basic anatomical image.

Elastography can be used to guide clinicians in performing biopsies. Doctors can also recommend elastography testing on individuals in place of a liver biopsy, an invasive test involving the removal of a piece of soft tissue in the liver for testing.

Biopsies can be painful and present a hemorrhage or infection risk compared to elastography, which is completely noninvasive.

Hepatology is an area of medical study concerning liver conditions. 

When used in hepatology to investigate the possibility of liver diseases, elastography is used to detect liver stiffness that can lead to fibrosis or steatosis (fatty liver disease).

 These diseases, in turn, can also indicate numerous medical conditions, including hepatitis.

Elastography is particularly helpful, especially when fibrosis is considered diffuse and a biopsy may be insufficient.

The diffuse effect typically results in the fibrosis spreading around the tissue in clumps instead of continuous scarring. This effect can cause a biopsy sampling to miss the diseased tissue, resulting in a false negative diagnosis.

Other types of elastography are also applicable for musculoskeletal imaging, and they can determine the mechanical properties and state of muscles and tendons.

Elastography can detect conditions in various parts of the body. Thus, this procedure does not have the same limitations manual palpation has. Elastography has potential application in areas without a diagnosis history that used manual palpation.

For example, magnetic resonance elastography can assess the stiffness of the brain.

Palpation is a method of checking for potential diseases or illnesses by using the hands or fingers to feel the texture, size, location, and tenderness of a body part or organ.

Elastography is a method that estimates tissue stiffness as a physical property known as Young’s modulus. This modulus is a constant that relates stress (applied force per unit area) and strain (resultant relative change in tissue dimension).

Ultrasound elastography has two categories: strain-based or shear wave-based imaging systems.

Population Studies

In a study named Children of the 90s conducted by Bristol University, researchers used elastography to determine the number of young adults who have features suggestive of nonalcoholic fatty liver disease (NAFLD)(4).

The study evaluated 4,021 young adults for NAFLD using ultrasound and showed that the prevalence of the disease among the subjects was 2.5%.

The researchers revisited the same cohort of subjects and used transient elastography to evaluate the subjects for fibrosis and steatosis.

Out of the 3,277 individuals analyzed, 680 (20.8%) had steatosis, indicative of NAFLD. Less than half of this number (331 or 10.1% of the cohort) were considered severe.

Additionally, 76 of 3,128 subjects (2.4%) had fibrosis.

Thus, elastography has a practical medical application for detecting various liver conditions.

Another study analyzed the usefulness of ultrasound elastography as a noninvasive tool to evaluate hepatic fibrosis among patients with chronic hepatitis C(5).

Researchers conducted the study on 310 patients and showed that real-time tissue elastography may help diagnose fibrosis in the presence of inflammation.

Individuals with long-term infection of chronic hepatitis C may have an increased risk for hepatocellular carcinoma and hepatic fibrosis.

Chronic hepatitis C is an infection that causes liver damage, cirrhosis, cancer, or death.

Meanwhile, hepatic fibrosis is an excessive tissue buildup in the liver resulting from wound healing due to chronic injury.

Hepatocellular carcinoma is liver cancer common among individuals with chronic liver diseases such as hepatitis B, cirrhosis, or hepatitis C.

Individuals interested in other elastography-related population studies can search the PubMed.gov database or access the study online using the article’s digital object identifier (DOI) link.

Benefits, Risks, and Complications

Elastography benefits applicable for ultrasound elastography and MR elastography are as follows(6):

  • Elastography is a noninvasive imaging technique that does not involve ionizing radiation exposure.
  • Doctors can assess a larger portion of the liver through elastography than a biopsy.
  • The procedure can detect liver diseases earlier than other imaging exams.
  • Elastography may minimize or eliminate the need to perform a liver biopsy.
  • This imaging method can help doctors predict potential liver complications, such as ascites or fluid buildup within the abdomen.

Elastography is not without disadvantages. The complications and risks of this procedure, especially for MR elastography, are as follows(7):

  • The MRI exam may pose a risk to the average patient unless they follow the appropriate safety guidelines.
  • Elastographic procedures requiring sedatives may risk using too much sedation on an individual. Hence, monitoring the patient’s vital signs can help minimize this risk.
  • Although the magnetic field the equipment produces is not harmful to humans, it may affect implanted medical devices and cause them to malfunction. The magnetic field may also distort the images produced by the medical imaging equipment.
  • Nephrogenic systemic fibrosis is a complication that can occur due to the presence of gadolinium contrast medium in the body. This disease can affect individuals with advanced kidney failure characterized by a thickening and darkening of the skin.

Gadolinium contrast media, also called MRI contrast agents, are chemicals injected into the body to enhance the quality of MRI images.

Newer gadolinium contrast agents may minimize the chance of the disease happening(8). However, complications can still occur in patients with severe kidney disease.

To reduce the likelihood of this risk happening, doctors will typically assess the individual’s kidney function before considering a contrast injection.

  • Contrast media can cause a slight risk of an allergic reaction among individuals administered with this media.

Such reactions are usually mild, and individuals can take medications to control these reactions. A doctor should be available for immediate assistance if an allergic reaction occurs.

  • Individuals undergoing multiple MRI exams that require gadolinium contrast doses are likely to have small amounts of the medium remain in the body, especially in the brain.

The contrast agent is mostly removed from the body through the kidneys.

However, patients requiring this procedure should consult their doctor regarding gadolinium retention. Notably, the effects of this medium can vary from one patient to another.

Tests and Procedures

To conduct an elastographic test on the specific organ being examined, such as the liver, the technologist or technician places an ultrasound (US) probe or magnetic resonance (MR) driver on the surface of the patient’s skin.

The driver or probe transmits painless, low-frequency vibrations through the body and the organ undergoing analysis.

MR or US elastography techniques measure and record the speed of the vibrations moving through the organ. Meanwhile, a computer processes this information to produce a visual map showing tissue elasticity or stiffness.


Individuals about to undergo an elastography examination should consider the following guidelines to prepare for the test:

  • Clothing should be comfortable, like loose-fitting garments. Individuals may either remove all clothing and jewelry or change into a gown to prepare for the procedure.
  • Certain items are typically not allowed in the testing room since they can interfere with the MRI equipment’s magnetic field.

Such prohibited items include:

    • Jewelry, hearing aids, and credit cards
    • Pins, metal zippers, hairpins, and other metallic items that can distort MRI images
    • Pens, eyeglasses, and pocket knives
    • Body piercings
    • Removable dental items
    • Watches, mobile phones, and tracking devices

When placed near the scanning equipment, these items can cause burns or become dangerous projectiles.

  • An MRI exam in most clinical applications is safe for patients with metal implants(9).

However, there are some cases where individuals with the following implants may not be allowed to enter the MRI imaging area without undergoing a safety evaluation:

    • Cochlear (ear) implants
    • Certain types of clips for brain aneurysms
    • Certain pacemakers and old cardiac defibrillators
    • Metal coils placed within blood vessels
    • Vagal nerve stimulators

Individuals with medical or electronic implants should inform the technologist about these devices before the examination, especially since some devices may pose a risk or interfere with the exam.

Implanted devices often come with a pamphlet explaining the device’s potential MRI risks. Individuals should bring that pamphlet to the scheduler’s attention before the exam.

They should also carry the pamphlet during the examination should the technologist or radiologist has any questions, especially about the device’s safety when exposed to a strong magnetic field.

Meanwhile, doctors and technologists cannot perform an MRI examination without documentation and confirmation of the implant type and its compatibility with MRI.

  • Food and sugary beverages can affect liver stiffness measurements. Thus, individuals should consider avoiding such food and drinks before the exam.

This fasting method allows better visualization of the gallbladder. Fasting instructions may vary depending on the facility or clinic. Thus, individuals should ask their doctor for specific instructions.

The doctor can recommend avoiding eating for six to eight hours before the exam or eating a fat-free meal in the evening before the test.

  • Women should immediately inform if they are pregnant to their doctor and technologist.

MRI has been used on pregnant women since the 1980s without any reported ill effects on them or their unborn babies. Still, the child will be exposed to a strong magnetic field.

Thus, pregnant women should not undergo an MRI test in their first trimester unless the exam’s benefits outweigh any potential risks.

Additionally, expectant mothers should not take gadolinium contrast unless their doctor deems it necessary.

  • Individuals with claustrophobia or fear of enclosed spaces should ask a doctor for a mild sedative prescription before undergoing the examination.
  • If the individual to be scanned has questions or is uncertain about metal objects in their body, they may opt for an X-ray to detect and identify these objects.

Some individuals who underwent orthopedic surgery may have metal objects in their bodies. However, these objects generally do not pose any risk during an MRI exam.

However, individuals who have a recently placed artificial joint may need to undergo a different imaging exam.

  • Aside from implanted electronic or metal devices, there may also be a presence of bullets, shrapnel, or other foreign objects in the body that the individual may or may not know.

Individuals who know about the presence of such objects should tell their technologist or radiologist about these objects prior to the exam.

Meanwhile, individuals unsure of such objects should undergo a different imaging procedure, such as an X-ray, to identify such items.

Individuals with foreign objects lodged near or in the eyes should take precautions because these objects may heat up or move during the scan and cause blindness.

  • Some individuals may have tattoos that use dyes with iron content, which can heat up during an MRI scan. Although this situation is rare during exams, it can still happen.
  • The magnetic field will usually not affect braces, tooth fillings, eyeshadows, or cosmetics.

However, these items can distort the images of the facial area or brain. Thus, the individual should inform the radiologist or technologist about these items before the exam.

Ultrasound Elastography

Ultrasound imaging uses a similar concept as sonar that ships, fishers, and bats use. Sonar is a system that utilizes sound pulses or waves to detect or measure objects, such as those located underwater.

Sound waves hit an object and echo or bounce back in this system. By measuring the time these echoes bounce back, an individual can determine the object’s distance, size, shape, and consistency.

Some systems can also determine whether the object is solid or filled with liquid.

Doctors use ultrasound to observe changes in the appearance of tissues, organs, and vascular structures and detect lesions, such as tumors and nodules or abnormal tissue growth in these body parts.

In an ultrasound exam, the technologist uses a transducer on the individual to be examined. When the technologist presses the transducer against the skin, the device sends small pulses of high-frequency but inaudible sound waves into the body.

When the sound waves bounce off internal organs, tissues, and fluids, the transducer’s sensitive receiver records the changes in the sound’s pitch and direction.

A computer to which the transducer is connected measures these bounced sound waves and displays them on a monitor as real-time pictures.

While the screen displays these moving pictures, the technologist will capture one or more frames of those moving pictures as still images.

The technologist can also produce short video clips or loops of the images.

MR Elastography

MRI does not use radiation for imaging, unlike X-ray and computed tomography (CT) examinations. Instead, MR uses radio waves to realign hydrogen atoms naturally existing within the body.

This procedure does not create any chemical changes in the tissues. Instead, the hydrogen atoms affected by the scan return to their usual alignment and emit different amounts of energy depending on the tissue type these molecules are in.

The scanner captures and converts this energy into electronic signals to create a picture based on this information.

Most MRI units produce a magnetic field using wire coils that pass an electric current. These coils are usually inside the machine. In some cases, the coils are placed around the body part to be scanned.

The electric current produced by the machine does not come into contact with the individual’s body. The coils emit and receive radio waves, which produce signals detected by the machine.

Afterward, the scanning equipment sends the data to a computer, which processes the signals to create several images. Each image shows a thin slice of the body.

The radiologist (ARRT-certified), a doctor who interprets radiology exams and other medical imaging results, analyzes these images from various angles to provide the patient with the appropriate diagnosis and treatment.

An MRI procedure is usually more capable of telling the difference between normal and diseased tissues than X-ray, CT, and ultrasound exams(10).

Strain Elastography (SE)

SE measures tissue stiffness through the application of external tissue pressure.

Strain elastography falls into two categories of tissue excitation (application of energy): external manual excitation or excitation with internal physiological movement(11).

Excitation through manual pressure measures the elasticity in superficial tissues. One disadvantage of this method is that manual stress does not typically transmit efficiently to deeper tissues.

Another mechanism to generate tissue stress is excitation through natural physiologic motion, such as respiration or cardiac pulsation.

In strain imaging, translucent colored elastograms (quantitative elasticity images) or strain images can be superimposed on B-mode images (two-dimensional grayscale ultrasound images) to produce complementary anatomic information.

The monitor typically displays strain maps as colored pixels on a red-blue scale or grayscale.

Shear Wave Elastography

Conventional ultrasound using B-mode image generation produces compressive acoustic waves traveling at high speeds through soft tissue (1,450 to 1,550 meters per second)(12).

In comparison, mechanical shear waves used in shear wave elastography travel slower (1 to 10 meters per second). The velocity of shear wave propagation also depends on the tissue stiffness.

A variation of the shear imaging procedure called point shear wave elastography (pSWE) uses focused ultrasound in a process called acoustic radiation force impulse imaging or ARFI.

In this process, the equipment tracks the resulting shear waves, yielding a shear wave speed estimate to calculate the tissue stiffness.

Several ultrasound imaging systems utilizing this technique include the Philips Shear Wave Elastography, Siemens VirtualTouch Imaging Quantification (VTIQ), SuperSonic Imagine Shear Wave Elastography, and GE Healthcare 2D-SWE.

In another study on transient elastography reproducibility, researchers suggested that transient elastography, another variation of shear wave imaging, may have high reproducibility for evaluating liver fibrosis in patients with CLD(13).

Two different operators during the study conducted 800 transient elastography examinations on 200 patients. The interobserver agreement result for the two raters was 0.98, indicating high reproducibility.

Stiffness values measured through transient elastography are presented in kilopascals (kPa). This unit measures stress and pressure.


Despite elastography, whether by magnetic resonance (MR) or ultrasound (US), being a widely used method to determine liver fibrosis or other health conditions, the procedure still has the following limitations:

  • US elastography may not be advisable for patients with narrowly spaced ribs.

The technologist usually places the transducer close to the liver to achieve accurate results. Thus, spaces smaller than the probe can prevent an individual from seeing the desired results.

  • US and MR elastography procedures are usually not recommended for the following situations:
    • Ascites or abdominal fluid buildup: This fluid can interfere with the transmission of vibrations to the liver.
    • Acute hepatitis: This condition can lead to increased stiffness, which makes it difficult for doctors to determine if any stiffness is associated with fibrosis.
    • Heart failure: This condition can cause increased stiffness. Thus, the doctor may need further assessment to tell if fibrosis or another condition is causing the stiffness.
    • Obesity: An individual who is severely obese may be unable to lie flat on their back.
    • Iron deposits within the liver: Iron deposits can interfere with the results of MRI elastography and affect the procedure’s accuracy.

Expected Results

Individuals undergoing elastography may expect the following results depending on the modality or procedure:

MR Elastography

During the procedure, the technologist will advise the individual being scanned to hold their breath for a few seconds while the scanning device sends vibrations into the liver.

Holding one’s breath during the scan also helps produce clear images(14).

While the device emits the vibrations, the scanned individual will also feel those vibrations. However, such an effect should not cause pain.

Ultrasound Elastography

US imaging is typically fast, painless, and well tolerated among individuals undergoing the procedure.

In this procedure, the technologist places the probe between the lower chest wall and the ribs on the right side. Some procedures require a series of 10 vibrations directed through the body and into the liver.

One study suggested that transient elastography has a sensitivity value of 0.79 and a specificity value of 0.78(15). These values indicate the accuracy of the procedure in detecting fibrosis.

In comparison, the values of perfect sensitivity and specificity levels are 1.

The study also showed that the same procedure has a sensitivity of 0.83 and a specificity of 0.89 for cirrhosis.

In most cases, individuals can resume their normal activities immediately after undergoing an exam.

After the procedure, a radiologist will analyze the test results and report their findings.

The doctor who ordered the test will receive the radiologist’s report and share the results with the individual who underwent the exam. In some facilities, the radiologist can also speak with the individual after the test.

How Elastography Equipment Looks Like

Various types of elastography equipment have the following features:

MR Elastography

A typical MRI equipment is composed of a large cylindrical structure surrounded by a circular magnet. An individual lies on a table that slides into the structure and towards the magnet’s center.

Some MRI machines are designed so that the magnet does not surround the individual. These units are called short-bore systems.

Some MRI units are open on the sides. This structure can be more comfortable and easier for patients with claustrophobia or large bodies.

Open MRI units can produce high-quality images for various exam types. However, open MRI may not be applicable for all exams. By having one side open, this equipment may be unable to scan certain body parts.

Individuals may ask a radiologist for more information about the procedure.

There are also MRI machines with a large diameter bore. These machines are beneficial in examining larger patients or those with claustrophobia.

Ultrasound Elastography

An ultrasound machine consists of a computer console, video monitor, and transducer.

The transducer or probe is a hand-held device that appears similar to a microphone. A single procedure can comprise several exams and use different transducers, each with different capacities.

The technologist applies gel to the area to be examined during the procedure and places the transducer on that part. The gel allows sound waves to travel between the transducer and the examined area.

A video monitor immediately shows the ultrasound image produced by the scan. The image shown on the monitor is based on the pitch (frequency), loudness (amplitude), and time the ultrasound signal takes to bounce back to the transducer.

Locations and Appointments

Many facilities provide elastography services in the United States. For example, in Philadelphia, PA, individuals can request an elastography appointment in the following hospitals(16):

  • Thomas Jefferson University Hospital
    111 South 11th Street, Philadelphia, PA 19107
  • Jefferson Hospital for Neuroscience
    900 Walnut Street, Philadelphia, PA 19107
  • Methodist Hospital
    2301 South Broad Street, Philadelphia, PA 19148

Costs to undergo a liver elastography procedure may vary depending on the facility. However, the average cost for a FibroScan procedure is estimated at $447(17).

Some insurance providers offer individuals with discounted elastography costs.


Before advanced medical imaging and diagnostic equipment existed, practitioners performed palpation to feel the stiffness in an individual’s tissues.

The practice of manual palpation goes back to around 1550 BC. The Egyptian Ebers Papyrus, which contains information on ancient Egyptian medical practices, provides instructions on diagnosing health conditions through palpation.

In ancient Greece, Hippocrates, a physician of the classical period, gave instructions on using palpation as a method to perform various diagnoses. These methods include palpating the breasts, bowels, ulcers, skin, wounds, uterus, and tumors.

Palpation has also been an essential element in traditional Chinese medicine and is considered a highly refined art dating back to around 500 BC(18). By touching the body, one can detect pulses in the radial artery.

Thus, a practitioner during that time may diagnose disease conditions depending on the characteristics of the pulsations.

During the 1930s, palpation was considered a reputable diagnostic method in the scope of Western medicine(19). Since then, palpation has become a widely practiced method to detect tumors and other pathologies.

However, manual palpation has several limitations, such as being limited to tissues the physician’s hand can access, distorted by other intervening tissues, and a qualitative rather than a quantitative procedure.

Scientists developed elastography to help measure tissue stiffness quantitatively and address the limitations of manual palpation, especially in areas difficult to access with the hands.

  1. Nonalcoholic Fatty Liver Disease Found in Large Numbers of Teenagers and Young Adults
  2. Novel Image Analysis Method Using Ultrasound Elastography for Noninvasive Evaluation of Hepatic Fibrosis in Patients With Chronic Hepatitis C
  3. Elastography
  4. Nonalcoholic Fatty Liver Disease Found in Large Numbers of Teenagers and Young Adults
  5. Novel Image Analysis Method Using Ultrasound Elastography for Noninvasive Evaluation of Hepatic Fibrosis in Patients With Chronic Hepatitis C
  6. Elastography
  7. Ibid.
  8. Ibid.
  9. Ibid.
  10. Ibid.
  11. Principles of Ultrasound Elastography
  12. Ibid.
  13. Reproducibility of Transient Elastography in the Evaluation of Liver Fibrosis in Patients With Chronic Liver Disease
  14. Elastography
  15. Principles of Ultrasound Elastography
  16. MR & Ultrasound Elastography
  17. FibroScan
  18. Medical Ultrasound: Imaging of Soft Tissue Strain and Elasticity
  19. Ibid.
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