Kibo Yoon MD, Presenter: Nothing to Disclose

Woo Kyoung Jeong MD, Abstract Co-Author: Nothing to Disclose

Yong-Soo Kim MD, PhD, Abstract Co-Author: Nothing to Disclose

Min Yeong Kim MD, Abstract Co-Author: Nothing to Disclose

Soon-Young Song, Abstract Co-Author: Nothing to Disclose

On-Koo Cho MD, PhD, Abstract Co-Author: Nothing to Disclose

Byung-Hee Koh MD, Abstract Co-Author: Nothing to Disclose

To evaluate reproducibility of liver stiffness (LS) measurement by Supersonic shear wave elastography (SSWE) in patients with long-term use of methotrexate (MTX) for treatment of rheumatoid arthritis

This prospective study was approved by our institutional review board. After obtaining written informed consent, 148 consecutive patients were enrolled in the study. All subjects who had taken MTX underwent SSWE along with liver ultrasonography. SSWE was performed twice by two of three different radiologists each of whom had at least 100 cases of clinical experience with SSWE. The measurement was repeated 5 times by each examiner and each examiner was blinded to the results of other examiners. The median value (considered as LS) and interquartile range divided by the median value (IQR/M; representing intraobserver variability) were calculated from 5 measurements. Body mass indexes (BMI) of the patients (n=139) were also investigated. Intraclass correlation coefficient (ICC) was used for statistical analysis, and z-test for comparison of correlation coefficient.

Mean values of LS and IQR/M in the overall subject were 5.82 kPa (range, 3.96–9.31 kPa) and 0.12 (range, 0.02–0.32). ICC(2,1) of overall LS was 0.593 (95% confidence interval (CI), 0.477–0.688; P<.001), and ICC(2,1) of overall IQR/M was -0.041 (95% CI, -0.197–0.118; P=.695). In the obese group (BMI>25; n=34), ICC(2,1) of LS and IQR/M was 0.669 (95% CI, 0.430–0.820; P<.001) and -0.106 (95% CI, -0.437–0.243; P=.723), respectively. In the lower BMI group (BMI≤25; n=105), ICC(2,1) of LS and IQR/M was 0.441 (95% CI, 0.273–0.583; P<.001) and -0.014 (95% CI, -0.197–0.173; P=.558), respectively. The difference between two correlation coefficients of obese and lower BMI groups was not statistically significant (P=.102).

LS measurement by SSWE may be reproducible moderately for measurement of liver stiffness irrespective of BMI. Intraobserver variability did not show any significant difference between examiners.

This preliminary result shows SSWE to be moderately reproducible among different examiners in patients with liver stiffness of ≤10 kPa even with little clinical experience.

Yoon, K, Jeong, W, Kim, Y, Kim, M, Song, S, Cho, O, Koh, B, Reproducibility of Liver Stiffness Measurement by Supersonic Shear Wave Elastography in Patients with Long-term Use of Methotrexate.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12043432.html