Abstract
Background
This article aims to assess the diagnostic accuracy of Kupffer cell–specific contrast-enhanced
ultrasound (Sonazoid) for characterization of suspicious malignant focal liver lesions
and the diagnostic accuracy of Sonazoid in differentiating tumoral thrombosis of the
portal vein from bland thrombosis.
Materials and Methods
This was a single-center, prospective, cross-sectional study conducted in the Department
of Radiology. Baseline gray-scale ultrasound, along with contrast-enhanced imaging,
was performed in patients who met the inclusion criteria. CEUS images were read by
two radiologists with an experience of 3 and 15 years, respectively. Interobserver
agreement between two observers was calculated. CECT and CEMRI images were read by
a third radiologist with an experience of around 7 years; he was also blinded to the
histopathology and CEUS results. CECT/CEMRI was taken as a gold standard for HCC (based
on the evidence-based practice/AASLD guidelines); for non-HCC lesions, histopathology
was taken as a gold standard. Diagnostic accuracy, sensitivity, and positive predictive
value (PPV) of CEUS were then calculated with respect to the gold standard. In eight
cases included in our study, portal vein thrombosis was present, and so the diagnostic
accuracy of CEUS with Sonazoid for differentiating tumoral and bland thrombosis was
also calculated.
Results
CEUS with Sonazoid has a sensitivity of 90%, an accuracy of 87%, and a PPV of 96%
for characterizing focal liver lesions. CEUS with Sonazoid (with respect to histopathology)
has a sensitivity of 87.5%, specificity of 87.5%, and diagnostic accuracy of 77.8%
for the characterization of lesions. In a limited number of patients included in our
study, CEUS had a sensitivity, specificity, negative predictive value, and PPV of
100% for differentiating between tumoral and bland thrombus.
Conclusion
CEUS is an excellent modality for differentiating tumoral from bland thrombus, and
it can be safely used for lesion characterization in patients where CT/MRI contrast
agent is contraindicated. In cases of diagnostic dilemma, CEUS can be used as an alternative
modality. Since it is radiation free, it can be used in regular surveillance of high-risk
patients.
Keywords
Contrast-enhanced ultrasound - Kupffer cell specific - Sonazoid
