Possible use of Digital Variance Angiography in Liver Transarterial Chemoembolization: A Retrospective Observational Study

PURPOSE: Digital variance angiography (DVA), a recently developed image processing technology, provided higher contrast-to-noise ratio (CNR) and better image quality (IQ) during lower limb interventions than digital subtraction angiography (DSA). Our aim was to investigate whether this quality improvement can be observed also during liver transarterial chemoembolization (TACE). MATERIALS AND METHODS: We retrospectively compared the CNR and IQ parameters of DSA and DVA images from 25 patients (65% male, mean ± SD age: 67.5 ± 11.2 years) underwent TACE intervention at our institute. CNR was calculated on 50 images. IQ of every image set was evaluated by 5 experts using 4-grade Likert scales. Both single image evaluation and paired image comparison were performed in a blinded and randomized manner. The diagnostic value was evaluated based on the possibility to identify lesions and feeding arteries. RESULTS: DVA provided significantly higher CNR (mean CNR(DVA)/CNR(DSA) was 1.33). DVA images received significantly higher individual Likert score (mean ± SEM 3.34 ± 0,08 vs. 2.89 ± 0.11, Wilcoxon signed-rank p < 0.001) and proved to be superior also in paired comparisons (median comparison score 1.60 [IQR:2.40], one sample Wilcoxon p < 0.001 compared to equal quality level). DSA could not detect lesion and feeding artery in 28 and 36% of cases, and allowed clear detection only in 22% and 16%, respectively. In contrast, DVA failed only in 8 and 18% and clearly revealed lesions and feeding arteries in 32 and 26%, respectively. CONCLUSION: In our study, DVA provided higher quality images and better diagnostic insight than DSA; therefore, DVA could represent a useful tool in liver TACE interventions. LEVEL OF EVIDENCE: III Non-consecutive study.