Does motion affect liver stiffness estimates in shear wave elastography? Phantom and clinical study. Issue 9 (September 2016)

• Record Type: Journal Article
• Authors: Pellot-Barakat, Claire; Chami, Linda; Correas, Jean Michel; Lefort, Muriel; Lucidarme, Olivier
• Is Part Of: European journal of radiology. Volume 85:Issue 9(2016)
• Page Start: 1645
• Page End: 1650
• Publication Date: 2016-09
• Subjects: Ultrasound imaging -- Elasticity -- Fibrosis -- Respiration -- Apnea -- Feasibility; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2016.07.001
• Languages: English
• ISSNs: 0720-048X

Abstract

Highlights: Liver-stiffness measurements under free breathing are lower than those under apnea. Stiffness discrepancies might be due to elevated central venous pressure during apnea. Quality indexes of free breathing SWE image were generally poorer than that of apnea. Under unfavorable clinical conditions free breathing SWE measurement is not reliable. Abstract: This study was undertaken to evaluate the impact of free-breathing (FB) vs. Apnea on Shear-wave elastography (SWE) measurements. Quantitative liver-stiffness measurements were obtained during FB and Apnea for 97 patients with various body-morphologies and liver textures. Quality indexes of FB and Apnea elasticity maps (percentage of non-filling (PNF), temporal (TV) and spatial (SV) variabilities) were computed. SWE measurements were also obtained from an homogeneous phantom at rest and during a mechanically-induced motion. Liver-stiffness values estimated from FB and Apnea acquisitions were correlated, particularly for homogeneous livers ( r = 0.76, P < 0.001) and favorable body-morphologies ( r = 0.68, P < 0.001). However FB values were consistently 20–25% lower than Apnea ones ( P < 0.001). FB also systematically resulted in degradation of TV ( P < 0.005) and PNF ( P < 0.001) compared to Apnea but had no impact on SV. With the phantom, no differences between SWE measurements at rest and during motion were observed. Apnea and FB measurements are highly correlated, although FB data quality is degraded compared to Apnea and estimated stiffness in FB is systematically lower than in Apnea. These discrepancies between rest and motion states were observed for patients but not for phantom data, suggesting that patient breath-holding impacts liver stiffness.