Image: An example of Shear Wave Elastography (SWE) images of the liver (Photo courtesy of MGH Department of Radiology).
While histopathology is still the overall standard for assessing and staging chronic liver fibrosis, researchers in the US have started using a new ultrasound technique called Shear Wave Elastography (SWE), and found that it is just as reliable, and can prevent the need for patient to undergo a painful biopsy.
Every year chronic liver diseases, especially cirrhosis of the liver and chronic liver fibrosis, are responsible for 1.2% of deaths in the US alone. Early detection and staging of fibrosis, and inflammation enable clinicians to determine prognoses and can help them predict the outcome of treatments. Liver fibrosis can even be reversed if detected early enough and treated on time.
The researchers from the Lahey Hospital and Medical Center (Burlington, MA, USA) used the SWE ultrasound technique to supplement, and often to replace liver biopsies in approximately 50 interventions per month. They presented their findings at annual Radiological Society of North America (RSNA 2016) meeting in Chicago, in the US. According to the researchers, most healthcare facilities could use the new SWE technology with their existing ultrasound equipment, after performing a software upgrade.
SWE is used to quantify tissue stiffness and to find diseased, and potentially malignant tissue. Liver tissue stiffness is measured in kilopascals (kPA), which is then converted to the METAVIR scale (F0 to F4) used for grading histopathology specimens. SWE is non-invasive and fast, and can be used to sample much larger areas than a biopsy.
According to the researchers, SWE will be useful for regular follow-up screening without exposing patients to ionizing radiation from Computed Tomography (CT) exams, performing costly Magnetic Resonance Imaging (MRI) scans, or painful invasive biopsies.
Pauley Chea, MD, radiology resident at Lahey Clinic, who presented the study, said, "Switching over can happen fairly quickly — it's just a matter of deciding whether it's what a facility needs. The beauty is that it's simple to read. Essentially, you place the probe in a particular position and press a button."
Lahey Hospital and Medical Center