Task: Question Answering
Input (English): Context: To investigate the relationship between tissue elasticity before and after antiviral therapy and shear wave as well as strain elastography.', 'FibroScan and real-time tissue elastography were performed before and after antiviral therapy for chronic hepatitis C, and treatment efficacy and elastographic findings were comparatively analyzed. Elasticity was evaluated by measuring liver stiffness (LS) in kilopascals using FibroScan, and the liver fibrosis index (LFI) was assessed by real-time tissue elastography.', 'LS and LFI correlated well before and after therapy (r = 0.567, p = 0.003 and r = 0.576, p = 0.002, respectively). In the group without a sustained virological response (SVR), LS increased in 4 of 5 patients. Patients with an increase in both LS and LFI were all in the non-SVR group (3/3, 100%). In addition, LS increased in all patients except 1 in the non-SVR group (4/5, 80%). In the SVR group, both LS and LFI decreased in all patients except 1 (18/19, 94.7%). In the patient with an increase in LS despite achieving SVR, LS decreased quickly after alcohol cessation.\Question: Does ultrasound elastography correlate treatment response by antiviral therapy in patients with chronic hepatitis C?
Output (English): With a few exceptions, SVR improved LS. All patients with an increase in LFI were in the non-SVR group, even though LFI decreased in 2 patients. Our findings suggest that an LFI increase indicates lack of treatment efficacy with antiviral therapy. LFI may be useful for the assessment of treatment efficacy in patients with worsening of LS despite achieving SVR with antiviral therapy.