Contrast-enhanced power Doppler sonography and helical computed tomography for assessment of vascularity of small hepatocellular carcinomas before and after percutaneous ablation.
OBJECTIVE
We compared the usefulness of Levovist-enhanced power Doppler imaging (PDI) and helical CT in the depiction of tumor vascularity before and after percutaneous ablation of small hepatocellular carcinomas (HCCs).


METHODS
Thirty-one cirrhotic patients with solitary unresectable HCCs smaller than 5 cm (mean size, 2.7 +/- 0.8 cm; range, 1.5-5.0 cm) recruited over a 15-month period were treated with percutaneous ethanol injection (n = 9) or radiofrequency ablation (n = 22). PDI, contrast-enhanced PDI (using Levovist), and multiphase contrast-enhanced helical CT were performed before and after percutaneous ablation, and vascularity findings were compared.


RESULTS
Levovist significantly increased baseline intratumoral Doppler signals on PDI compared to non-contrast PDI. The most frequent tumor vascularity pattern was heterogeneous (45%). Vascularity was identified in all tumors by both contrast-enhanced PDI and helical CT before ablation. After percutaneous ablation, intratumoral vascularity was detected in 11 tumors by contrast-enhanced PDI and in 15 tumors by CT. The sensitivity, specificity, and diagnostic accuracy of contrast-enhanced PDI in demonstrating intratumoral vascularity, with CT being the gold standard, were 66%, 93%, and 81%, respectively. There was significant agreement between the 2 modalities in the depiction of tumor vascularity after ablation (kappa = 0.6, p = 0.001). However, there were 5 false negatives and 1 false positive with contrast-enhanced PDI. Complete tumor necrosis was achieved in 21 patients (68%).


CONCLUSIONS
There was a good concordance between contrast-enhanced PDI and helical CT in the depiction of HCC vascularity before and after percutaneous ablation. However, although contrast-enhanced PDI may be useful for real-time guidance of treatment, its low sensitivity makes it inadequate to accurately assess the completeness of ablation.
Vilana
Ramon
R
Radiology Department, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Hospital Clínic, University of Barcelona, Calle Villarroel, 170, 08036 Barcelona, Spain.
Llovet
Josep M
JM
Bianchi
Luis
L
Sanchez
Marcelo
M
Pagés
Mario
M
Sala
Margarita
M
Gilabert
Rosa
R
Nicolau
Carlos
C
Garcia
Angeles
A
Ayuso
Carmen
C
Bruix
Jordi
J
Bru
Concepció
C
D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000628:therapy; D017115:Catheter Ablation; D003287:Contrast Media; D000431:Ethanol / Q000008:administration & dosage; D005260:Female; D006801:Humans; D015552:Injections, Intralesional; D008113:Liver Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000628:therapy; D008297:Male; D011134:Polysaccharides; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed; D018608:Ultrasonography, Doppler
D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508; D000431:Ethanol