by Dr Hesham Salah El Din

1. Non invasive modalities
for diagnosis of NAFLD
By:
Dr. HeshamSalah El Din

5. Imaging modalities
• Diagnosis at US
• Diagnosis at CT
• Diagnosis at MR Imaging
• Elastography

7. Diagnosis at US
is the first-line imaging test used in clinical practice
Fatty liverNormal Liver
Liver echogenicity
exceeds that of renal
cortex and spleen
Echogenicity of the
normal liver equals or
minimally exceeds that
of the renal cortex or
spleen
Poor delineation of the
intrahepatic architecture
Intrahepatic vessels are
sharply demarcated
Loss of definition of
diaphragm
Posterior aspects of the
liver are well depicted

10. To avoid false-positive interpretations, fatty liver should not be considered present if only
one or two of these criteria are fulfilled

11. Diagnosis at CT
Fatty liverNormal Liver
Attenuation of the liver is
at least 10 HU less than
that of the spleen or
attenuation of fatty liver
is less than 40 HU
The normal liver has
slightly greater
attenuation than the
spleen and blood
• In severe cases,
intrahepatic vessels may
appear hyperattenuated
relative to fat-containing
liver tissue
• Intrahepatic vessels are
visible as
hypoattenuated
structures

13. Diagnosis at Magnetic
resonance based techniques
Chemical shift gradient-echo(GRE) imaging with in-phase and opposed-phase
acquisitions is the most widely used MR imaging technique for the assessment
of fatty liver.
Fatty liverNormal Liver
The signal intensity loss on
opposed-phase images
in comparison with inphase
images.
The signal intensity of the
normal liver
parenchyma is similar
on in-phase and
opposed-phase images
MRI-derived proton density fat fraction (MRI-PDFF)
It uses MRI-visible protons that combine with fat in the liver to quantify steatosis by
dividing all protons in the liver.
MRI-PDFF is significantly associated with the histological steatosis grade
MRI-PDFF is superior to other imaging tools for the assessment of hepatic steatosis
and its performance is not affected by obesity
H-MRS magnetic resonance spectroscopy

24. HSI = 8 x ALT/AST + BMI(+ 2 if type 2 diabetes yes, + 2 if female)