The use of ultrasound to diagnose hepatic steatosis in type 2 diabetes: Intra- and interobserver variability and comparison with magnetic resonance spectroscopy

• Published in: Clinical radiology Vol. 66; no. 5; pp. 434 - 439
• Main Authors: Williamson, R.M, Perry, E, Glancy, S, Marshall, I, Gray, C, Nee, L.D, Hayes, P.C, Forbes, S, Frier, B.M, Johnston, G.I, Lee, A.J, Reynolds, R.M, Price, J.F, Strachan, M.W.J
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01-05-2011; Elsevier
• Subjects: Aged; Biological and medical sciences; Diabetes Mellitus, Type 2 - diagnosis; Diabetes Mellitus, Type 2 - diagnostic imaging; Diabetes. Impaired glucose tolerance; Disease Progression; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Fatty Liver - diagnosis; Fatty Liver - diagnostic imaging; Fatty Liver - pathology; Female; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Magnetic Resonance Spectroscopy - methods; Male; Medical sciences; Middle Aged; Observer Variation; Other diseases. Semiology; Radiology; Sensitivity and Specificity; Ultrasonography; United Kingdom; Endocrinopathy; Sonography; Type 2 diabetes; Human; Metabolic diseases; Hepatic disease; NMR spectrometry; Fatty liver; Intraindividual comparison; Interindividual comparison; Echography; Digestive diseases; Diagnosis; Comparative study
• DOI: 10.1016/j.crad.2010.09.021
• EISSN: 1365-229X
• ISSN: 0009-9260

Aim To compare ultrasound gradings of steatosis with fat fraction (FF) on magnetic resonance spectroscopy (MRS; the non-invasive reference standard for quantification of hepatic steatosis), and evaluate inter- and intraobserver variability in the ultrasound gradings. Materials and methods Triple grading of hepatic ultrasound examination was performed by three independent graders on 131 people with type 2 diabetes. The stored images of 60 of these individuals were assessed twice by each grader on separate occasions. Fifty-eight patients were pre-selected on the basis of ultrasound grading (normal, indeterminate/mild steatosis, or severe steatosis) to undergo1 H-MRS. The sensitivity and specificity of the ultrasound gradings were determined with reference to MRS data, using two cut-offs of FF to define steatosis, ≥9% and ≥6.1%. Results Median (intraquartile range) MRS FF (%) in the participants graded on ultrasound as normal, indeterminate/mild steatosis, and severe steatosis were 4.2 (1.2–5.7), 4.1 (3.1–8.5) and 19.4 (12.9–27.5), respectively. Using a liver FF of ≥6.1% on MRS to denote hepatic steatosis, the unadjusted sensitivity and specificity of ultrasound gradings (severe versus other grades of steatosis) were 71 and 100%, respectively. Interobserver agreement within one grade was observed in 79% of cases. Exact intraobserver agreement ranged from 62 to 87%. Conclusion Hepatic ultrasound provided a good measure of the presence of significant hepatic steatosis with good intra- and interobserver agreement. The grading of a mildly steatotic liver was less secure and, in particular, there was considerable overlap in hepatic FF with those who had a normal liver on ultrasound.