2D shear-wave elastography diagnoses cirrhosis

By Kate Madden Yee, AuntMinnie.com staff writer

December 19, 2018 -- 2D shear-wave elastography (SWE) is an effective tool for ruling out liver fibrosis or cirrhosis in people with chronic liver disease, German researchers wrote in a study published online December 11 in the Journal of Ultrasound in Medicine.

The findings suggest a less-invasive alternative for these patients, wrote the team led by Dr. Golo Petzold from University Medical Center Göttingen.

"In the treatment and monitoring of patients with chronic liver disease, the diagnosis of liver fibrosis or cirrhosis is of great importance," the researchers wrote. "The detection of liver cirrhosis can be challenging at times; early forms of cirrhosis and advanced fibrosis are especially hard to distinguish by imaging studies. The reference standard for the diagnosis of liver fibrosis (staging) and cirrhosis is liver biopsy. This procedure is invasive, is sometimes painful, and has rare but potentially serious complications."

An increasing number of ultrasound device manufacturers are incorporating shear-wave elastography into their scanners, according to Petzold and colleagues. Their study had three goals:

• Use 2D SWE to determine normal liver stiffness values for healthy subjects and compare them with values in patients with liver disease.
• Assess the influence of age, sex, body mass index, and steatosis on liver stiffness measurement.
• Explore whether it's possible to rule out disease based on cutoff values for histologically confirmed cirrhosis.

The study included 167 subjects enrolled between July 2016 and February 2018. Within this group, 56 had a healthy liver but nonhepatic disease (requiring baseline abdominal ultrasound), 45 had liver cirrhosis, and 66 were healthy volunteers. All participants underwent a baseline 2D SWE ultrasound exam to establish a liver stiffness measurement.

Liver stiffness in the patients with healthy livers but nonhepatic disease did not differ significantly from liver stiffness in the healthy volunteers, the researchers found. Male sex was associated with significantly higher liver stiffness in healthy volunteers; however, age, body mass index, mild steatosis, and nonhepatic morbidities had no significant impact on liver stiffness. Liver stiffness was significantly higher in patients with cirrhosis.

Liver stiffness values on SWE by patient group
	Healthy participants	Healthy liver patients with nonhepatic disease	Patients with cirrhosis
Liver stiffness (kPa)	5.19	4.93	13.29
Minimum liver stiffness (kPa)	3.62	3.49	7.38
Maximum liver stiffness (kPa)	8.33	6.66	19.96

2D SWE is a relatively new ultrasound technique, but it appears to be effective for evaluating liver stiffness and, therefore, ruling out cirrhosis, Petzold and colleagues wrote.

"The liver stiffness measurement in patients with histologically confirmed liver cirrhosis was significantly higher than that in the healthy-liver cohort," they concluded. "Importantly, the reference ranges for the cirrhosis and healthy-liver cohorts did not overlap. ... Therefore, on the basis of our data, we can rule out cirrhosis in patients with normal liver stiffness values, but no cutoff values for cirrhosis can be derived at present."

Ultrasound options abound for diagnosing liver disease

By Kate Madden Yee, AuntMinnie.com staff writer

December 12, 2018 -- When it comes to ultrasound, radiologists have a number of options for effectively diagnosing advanced fibrosis in patients with nonalcoholic fatty liver disease (NAFLD) -- as well as "mapping" liver stiffness and tracking liver cancer treatment, according to research delivered at the RSNA 2018 meeting.

Three presentations described the performance of various ultrasound techniques for liver indications, including shear-wave elastography (SWE), MR elastography (MRE), transient elastography (TE), and contrast-enhanced ultrasound.

Take your pick

Dr. Alessandro Furlan of the University of Pittsburgh and colleagues found that SWE, MRE, and TE are all viable alternatives to liver biopsy for diagnosing advanced fibrosis in patients with NAFLD.

"Since determination of liver fibrosis via biopsy is invasive and associated with significant cost, patient discomfort, and potential risks, several alternative approaches have been developed, including elastography," Furlan told session attendees.

The study included 62 patients, all of whom had biopsy-proven disease. The patients underwent SWE, MRE, and TE within one year of the biopsy; the researchers evaluated each type of imaging exam's performance with area under the receiver operating characteristic (ROC) curve analysis.

The area under the ROC curve for identifying advanced fibrosis was 0.89 for SWE, 0.95 for MRE, and 0.86 for TE; for significant fibrosis, the values were 0.80 for SWE, 0.85 for MRE, and 0.77 for TE. When each modality was compared with the others, there was no statistically significant difference in performance, Furlan said.

"2D shear-wave elastography, MR elastography, and transient elastography are valid alternatives to biopsy for the diagnosis of advanced fibrosis in patients with nonalcoholic fatty liver disease," he concluded.

Fewer biopsies

In a related presentation delivered during the same session, Dr. Rolf Reiter of Charité University Medicine Berlin shared study results suggesting that multifrequency MR elastography (mMRE) is a promising tool for mapping the distribution of fibrosis throughout the liver, which could, in turn, reduce the need for liver biopsy.

Reiter and colleagues evaluated mMRE's diagnostic accuracy by using multifrequency MR elastography in 43 patients with hepatic fibrosis. The study also included a group of 16 healthy people for comparison.

Tomoelastography stiffness maps showed high spatial resolution and anatomical details, allowing for high diagnostic accuracy for staging hepatic fibrosis, Reiter reported.

"Tomoelastography [showed] an excellent diagnostic accuracy for staging hepatic fibrosis," he told session attendees. "[Our work suggests that] mMRE-based tomoelastography might reduce the need for invasive liver biopsies and indicate the distribution of fibrosis within the entire liver."

Find cancer with contrast

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