Spleen Stiffness measured by point Shear Wave Elastography (pSWE) – Comparison between VTTQ/Acoustic Radiation Force Impulse (ARFI) and ElastPQ

K Schall; W Kratzer; T Gräter; M Hänle; S Tasdemir; H Jäger

doi:10.1055/s-0036-1587805

Ultraschall in der Medizin - European Journal of Ultrasound, Inhaltsverzeichnis

Spleen Stiffness measured by point Shear Wave Elastography (pSWE) – Comparison between VTTQ/Acoustic Radiation Force Impulse (ARFI) and ElastPQ

K Schall ¹, W Kratzer ¹, T Gräter ², M Hänle ¹, S Tasdemir ¹ H Jäger ³, Elasto-Study Group Ulm

¹Universitätsklinikum Ulm, Klinik für Innere Medizin I, Ulm, Germany
²Universitätsklinikum Ulm, Klinik für Diagnostische und Interventionelle Radiologie, Ulm, Germany
³Universität Ulm, Division of Neurophysiology, Ulm, Germany

Abstract

Purpose: A comprehensive comparison between Acoustic Radiation Force Impulse (Siemens Acuson S3000) and ElastPQ (Philips EPIQ 7) by means of spleen stiffness (SS) measurement. Standard values of spleen stiffness measured with pSWE until today have been generated solely by means of ARFI. In former studies, measurement of SS is recommended in the lower pole of the spleen.

Material and methods: In 200 healthy subjects (78 male/122 female, mean BMI 22.56 ± 2.57 kg/m², mean age 27.93 ± 8.13 years, mean fasting time = 3.74 ± 1.84 hours) SS was measured in 3 defined regions of the spleen using VTTQ/ARFI and ElastPQ (lower pole LP, mid region MR, upper pole UP). Shear wave velocities (SWV) were compared between both techniques, furthermore regarding region of measurement, probands gender, BMI, alcohol intake and fasting time.

Results: Values measured with ElastPQ are significantly lower than measured with VTTQ/ARFI (mean SWV in m/s: ElastPQ: UP 2.30 ± 0.87, MR 1.89 ± 0.38, LP 1.88 ± 0.40; VTTQ/ARFI: UP 2.53 ± 0.58, MR 2.53 ± 0.44, LP 2.05 ± 0.54). There is no significant correlation between the values measured with both techniques in the LP (p = 0.3799) or in the MR (p = 0.0618). Correlation can be verified in the UP (p < 0.0001). However, correlation in the UP is not verifiable when BMI is > 25 kg/m² or age > 30y.

Conclusion: Standard values for spleen stiffness generated with VTTQ/ARFI do not equally apply to ElastPQ, which should be considered when diagnosing patients with portal hypertension and during their follow-up. Due to the lack of correlation, no valid conversion factor can be calculated.