Management of nonalcoholic fatty liver disease in the Middle East

Table 2 Key diagnostic modalities for nonalcoholic fatty liver disease and nonalcoholic steatohepatitis[11,35,85,86]

Diagnostic Tests	Advantages	Limitations
Liver enzymes and other blood tests for fibrosis
Platelet count; APRI; AST; ALT; AST/ALT ratio; Hyaluronic acid; ELF; Hepascore; FibroSpect; FibroTest/FibroSure	Simple and easy; AST/ALT of > 1 is predictive of fibrosis; ELF can predict stage of fibrosis and outcomes	AST and ALT can be normal in some patients with NAFLD; ELF is not widely available; Some tests initially developed for HCV; Limited published data on external validation
Radiology
Ultrasonography	Easily available; Safe; Overall scanning of abdominal organs	Cannot detect mild degree of steatosis (< 30% of hepatocytes); Does not distinguish between steatosis and NASH; Operator dependent
MRI	More sensitive than ultrasonography	Cost and availability; Does not distinguish between steatosis and NASH
Transient; Elastography	Can detect fibrosis	Cost and availability
MRE	Can detect fibrosis and MRI-PDFF can quantify steatosis	Cost and availability
Fibrosis scoring systems
NAFLD fibrosis score (NFS), Fibro Meter Fibrosis-4 (FIB-4)	Allow a more targeted use of liver biopsy by reliably excluding advanced fibrosis in a high proportion of NAFLD patients; Potentially predict liver-related and cardiovascular complications and death	Significant number with indeterminate scores; Limited external validation in NASH
Liver biopsy	Gold standard for diagnosis of NAFLD and NASH; Allows staging of the disease	Invasive; Associated with complications – pain, intraperitoneal bleeding; Cost

ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; APRI: AST-to-platelet ratio index; CT: Computerized tomographic; ELF: Enhanced liver fibrosis; MRE: Magnetic resonance elastography; MRI: Magnetic resonance imaging; MRI-PDFF: MRI-based proton density fat fraction; NAFLD: Nonalcoholic fatty liver disease; NASH: Nonalcoholic steatohepatitis.