Success rates of liver stiffness measurements using point shear-wave elastography and 2d shear wave elastography using different ultrasound probes. does a new bariatric probe increase liver stiffness measurements success rates in obese?

Objectives To evaluate liver stiffness measurements success rates (SR) by pSWE and 2D-SWE implemented on different ultrasound probes from different vendors and evaluate the input on the success rate of a new bariatric probe (DAX) in obese patients. Materials A prospective study was conducted in which liver stiffness measurements (LSM) were performed in 201 consecutive subjects (60.1% men, average BMI = 28.7 ± 4.9 kg/m2, average age 59 ± 18.4 years, 38% obese) with or without chronic hepatopathies evaluated during the same session by point Shear Wave Elastography (pSWE), 2D Shear Wave Elastography (2D SWE), and Transient Elastography (TE) implemented on the following systems: Siemens ACUSON Sequoia (5C-1 convex transducer with pSWE and 2D SWE, Deep Abdominal Transducer (DAX) with pSWE and 2D SWE, 4V-1 linear transducer with pSWE), Aixplorer Mach 30 (C6-1X convex transducer with 2D SWE) and FibroScan Compact 530 (M and XL probes). Reliable LS measurements were defined as the median value of 10 measurements and an IQR/M<0.3. Results Valid LSM were obtained in 99%(199/201) using TE, 99%(199/201) using 2D SWE (C6-1X), 98.5% (198/201) using 2D SWE (5C-1), 99%(199/201) using 2D SWE (DAX), 97.5%(196/201) using pSWE (5C-1), 97.5%(196/201) using pSWE (DAX) and 91.5% (184/201) using pSWE (4V-1). No significant difference were found between the SR of TE, 2D SWE using C6-1X, 5C-1, DAX and pSWE using C5-1 and DAX (p>0.05. pSWE using the linear probe 4V-1 had significantly lower SR compared to the other probes (p< 0.001). 38% (77/201) of subjects were obese. Valid LSM were obtained in 100% of the obese (77/77) using 2D SWE DAX, in 98.7% (76/77) using TE, 2D SWE C6-1X, and pSWE DAX, in 97.4% (75/77) using pSWE and 2D SWE 5C-1 and in 83.1% (64/77) using pSWE 4V-1. No significant differences were found between the SR of TE, 2D SWE using C6-1X, 5C-1, DAX and pSWE using C5-1 and DAX in obese subjects (p>0.05). pSWE using the linear probe 4V-1 had significantly lower SR compared to the other probes in obese subjects (p<0.001). Conclusions 2D SWE and pSWE implemented on convex ultrasound probes have very high success rates for liver stiffness measurements in general population and in obese, with no significant differences between them. pSWE implemented on 4V-1 linear ultrasound probe has a significantly lower success rate for liver stiffness measurements compared to pSWE and 2D SWE implemented on convex ultrasound probes. 2D SWE DAX probe had the highest SR (100%) in obese, with no significant differences compared to the other 2D SWE and pSWE implemented on convex ultrasound probes.