Quantitative evaluation of fatty liver disease by ultrasound attenuation imaging: A comparison with MRİ

OBJECTİVE: Ultrasound attenuation imaging is liver fat quantification technique which has come into clinical use in recent years and become rather widespread. In this research ATI values in adult patients will be compared to proton density fat fraction of magnetic resonance imaging. MATERIALS AND METHODS: 257 number of patients were evaluated by two different operators with attenuation ultrasound technique and underwent MRI-PDFF examination in 1.5T MR scanner. Afterwards 49 number of randomly choosen patients are called back to repeat ATI. MR-PDFF – ATI correlation, interobserver correlation and test-retest reliability are calculated. MR-PDFF values are confirmed with MR spectroscopy. Attenuation values are repeated 5 times for each patient and median values are used for calculations. In our research, demographical and clinical datas of the patients are also compared. Besides descriptive statistics; Pearson correlation coefficient, intraclass correlation coefficient, ANOVA, receiver operating characteristics and logistic regretion analysis are used. RESULTS: ATI and MRI datas follow normal distribution. There is strong correlation betweeen ATI and MR-PDFF (with 0.88 as Pearson Correlation coefficient). There is also strong correlation between two operators and between test-re-test group ( interclass correlation coefficients are 0.91 and 0.92 respectively). Areas under curve are calculated for grade 1 and above (%5.2), grade 2 and above(%11.3) and grade 3 and above (%17.1) as 0.97, 0.97 and 0.95 respectively. CONCLUSIONS: Ultrasound attenuation imaging is a promising technique for liver fat quantification considering its high accordance with MR-PDFF values. It shows high correlation with MR-PDFF, a good interobserver agreement and succesful results in test-retest reliability. Even without sufficient litterateur data, ATI appears to be playing a big role in the forthcoming years for liver fat quantification due to its practicality, cost-efficiency and applicability compared to MRI.