Correlation between acoustic radiation force impulse (ARFI)-based tissue elasticity measurements and perfusion parameters acquired by perfusion CT in cirrhotic livers: a proof of principle
To investigate whether liver stiffness measured by acoustic radiation force impulse (ARFI) sonoelastography always correlates with the liver perfusion parameters quantified by perfusion CT in patients with known liver cirrhosis.
Sonoelastography and perfusion CT were performed in 50 patients (mean age 65.5; range 45–87 years) with liver cirrhosis, who were classified according to Child–Pugh into class A (30/50, 60%), B (17/50, 34%), and C (3/50, 6%). For standardized ARFI measurements in the left liver lobe at a depth of 4 cm, a convex 6-MHz probe was used. CT examinations were performed using 80 kV, 100 mAs, and 50 ml of iodinated contrast agent injected at 5 ml/s. Using standardized region-of-interest measurements, we quantified arterial, portal venous, and total liver perfusion.
There was a significant linear correlation between tissue stiffness and arterial liver perfusion (p = 0.015), and also when limiting the analysis to patients with histology (p = 0.019). In addition, there was a positive correlation between the total blood supply (arterial + portal-venous liver perfusion) to the liver and tissue stiffness (p = 0.001; with histology, p = 0.027). Shear wave velocity increased with higher Child–Pugh stages (p = 0.013).
The degree of tissue stiffness in cirrhotic livers correlates expectedly—even if only moderately—with the magnitude of arterial liver perfusion and total liver perfusion. As such, liver elastography remains the leading imaging tool in assessing liver fibrosis.
KeywordsLiver cirrhosis Elasticity imaging techniques Perfusion imaging Spiral computed tomography
Compliance with ethical standards
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Conflict of interest
Michael Esser, Michael Bitzer, Manuel Kolb, Jan Fritz, Mustafa Kurucay, and Christer Ruff declare that they have no conflicts of interest. Marius Horger declares that the institution has received national grants financed by the “Bundesministerium für Bildung und Forschung” (BMBF), Germany.