RESUMO
Disease monitoring in nonalcoholic steatohepatitis (NASH) is limited by absence of noninvasive biomarkers of disease regression or progression. We aimed to examine the role of multiparametric three-dimensional magnetic resonance elastography (3D-MRE) and magnetic resonance imaging proton density fat fraction (MRI-PDFF) in the detection of NASH regression after interventions. This is a single-center prospective clinical trial of 40 patients who underwent bariatric surgery. Imaging and liver biopsies were obtained at baseline and 1 year after surgery. The imaging protocol consisted of multifrequency 3D-MRE to determine the shear stiffness at 60 Hz and damping ratio at 40 Hz, and MRI-PDFF to measure the fat fraction. A logistic regression model including these three parameters was previously found to correlate with NASH. We assessed the model performance in the detection of NASH resolution after surgery by comparing the image-predicted change in NAFLD activity score (delta NAS) to the histologic changes. A total of 38 patients (median age 43, 87% female, 30 of 38 with NAS ≥ 1, and 13 of 38 with NASH) had complete data at 1 year. The NAS decreased in all subjects with NAS ≥ 1 at index biopsy, and NASH resolved in all 13. There was a strong correlation between the predicted delta NAS by imaging and the delta NAS by histology (r = 0.73, P < 0.001). The strength of correlation between histology and the predicted delta NAS using single conventional parameters, such as the fat fraction by MRI-PDFF or shear stiffness at 60 Hz by MRE, was r = 0.69 (P < 0.001) and r = 0.43 (P = 0.009), respectively. Conclusion: Multiparametric 3D-MRE and MRI-PDFF can detect histologic changes of NASH resolution after bariatric surgery. Studies in a nonbariatric setting are needed to confirm the performance as a composite noninvasive biomarker for longitudinal NASH monitoring.
RESUMO
OBJECTIVE: Percutaneous liver biopsy is an essential diagnostic tool utilized in the management of patients with liver disease. This procedure is generally performed by a physician and has a small but well-defined complication rate. We report on the complication rate and efficiency of ultrasound-assisted percutaneous liver biopsy performed by an experienced physician assistant. METHODS: One thousand eighty-six consecutive outpatient liver biopsies (847 hepatic allografts and 239 native livers) were performed at a single center by a physician assistant between June, 1996 and June, 2000. Patients with hepatic mass lesions, unusual hepatic anatomy, and uncorrectable coagulopathy (international normalized ratio > 1.7, platelet count < 50 x 10(9)/L) were excluded. Bedside ultrasonography was used to determine the optimal site for the liver biopsy. Liver biopsies were performed with a 15-gauge Jamshidi aspiration biopsy needle. Patients were observed for 3 h after biopsy, followed by dismissal with subsequent contact in 24 h to assess outcome and complications. RESULTS: Adequate tissue was obtained in 1084 cases (99.8%), with a mean tissue length of 3.2 cm. After the procedure, narcotic analgesia was necessary in 116 (10%) of the patients undergoing liver biopsies. The overall complication rate requiring hospitalization was 0.6%. Major complications requiring intervention occurred in four patients (0.4%). There were no deaths resulting from liver biopsies. CONCLUSION: We conclude that outpatient percutaneous liver biopsy can be safely and effectively performed by a trained physician assistant.
