Hepatic Vein Contrast-Enhanced Ultrasound Subharmonic Imaging Signal as a Screening Test for Portal Hypertension

Portal hypertension is the underlying cause of most complications associated with cirrhosis, with the hepatic venous pressure gradient (HVPG) used for diagnosis and disease progression. Subharmonic imaging (SHI) is a contrast-specific imaging technique receiving at half the transmit frequency resulting in better tissue suppression.

To determine whether the presence of optimized SHI signals inside the hepatic vein can be used as a screening test for portal hypertension.

This prospective trial had 131 patients undergoing SHI examination of portal and hepatic veins using a modified Logiq 9 scanner (GE, Waukesha, WI). Images acquired after infusion of the ultrasound contrast agent Sonazoid (GE Healthcare, Oslo, Norway) were assessed for the presence of optimized SHI signals in the hepatic vein and compared to the HVPG values obtained as standard of care.

Of 131 cases, 64 had increased HVPG values corresponding to subclinical (n = 31) and clinical (n = 33) portal hypertension (> 5 and > 10 mmHg, respectively), and 67 had normal HVPG values (< 5 mmHg). Two readers performed independent, binary qualitative assessments of the acquired digital clips. Reader one (experienced radiologist) achieved for the subclinical subgroup sensitivity of 98%, specificity of 88%, and ROC area of 0.93 and for the clinical subgroup sensitivity of 100% and specificity of 61%, with an ROC area of 0.74. Reader two (less experienced radiologist) achieved for the subclinical subgroup sensitivity of 77%, specificity of 76%, and ROC area of 0.76 and for the clinical subgroup sensitivity of 88% and specificity of 63%, with an ROC area of 0.70. Readers agreement was of 83% with kappa value of 0.66.

The presence of optimized SHI signals inside the hepatic vein can be a qualitative screening test for portal hypertension, which could reduce the need for invasive diagnostic procedures.