Fat-containing liver lesions: a pictorial review

<div><p>Abstract The aim of this pictorial essay is to review the spectrum of fat-containing liver lesions and their characterisation on magnetic resonance imaging with focus on the radiological features that aid in the differential diagnoses. Fat-containing liver lesions comprise a heterogeneous group of tumours with variable imaging findings. Magnetic resonance imaging clearly displays the micro- and macroscopic fat components of the lesions and other characteristic features that are helpful tools to make the differential diagnosis.</p></div

Pure molecular diffusion (D), perfusion-related diffusion (D*), and perfusion fraction (f) in histological fibrosis stage groups (F0 to F4).

<p>D, pure molecular diffusion; D*, perfusion-related diffusion; f, vascular fraction; SD; Standard deviation; IQR; interquartil range; NA, not assigned</p><p>Pure molecular diffusion (D), perfusion-related diffusion (D*), and perfusion fraction (f) in histological fibrosis stage groups (F0 to F4).</p

IVIM diffusion-weighted MR image (b = 0 s/mm²) from a 62 year-old woman with type 2 diabetes and steatohepatitis.

<p>ROI was manually drawn at segment V, as shown (in the same region where biopsies were performed). This is a representative figure to demonstrate ROI positioning at the liver. Diffusion images have low signal-to-noise ratio, therefore the “blurred” appearance. IVIM, intravoxel incoherent-motion; MR, magnetic resonance; ROI, region of interest.</p

Comparison among D, D*, and f for the detection of NASH and fibrosis.

<p>NASH, non-alcoholic steatohepatitis; D, pure molecular diffusion; D*, perfusion-related diffusion; f, perfusion fraction; AUC, area under the curve</p><p>Comparison among D, D*, and f for the detection of NASH and fibrosis.</p

Comparison of D, D*, and f between patients without vs. with NASH and between patients without vs. with fibrosis (F0 vs. F1–F4).

<p>D, pure molecular diffusion; D*, perfusion-related diffusion; f, vascular fraction; NASH; non-alcoholic steatohepatitis; SD; Standard deviation; IQR; interquartil range</p><p>Comparison of D, D*, and f between patients without vs. with NASH and between patients without vs. with fibrosis (F0 vs. F1–F4).</p

Diagnostic performance for D, D*, and f for the diagnosis of fibrosis using histopathology as the gold standard.

<p>The best cut-off point was identified using the Youden index.</p

Triple- and Multi-echo MRI and MRS medians for no steatosis, mild, moderate, and severe steatosis using biopsy evaluations as reference values.

<p>MRI, magnetic resonance imaging; MRS, magnetic resonance spectroscopy; IQR, interquartile range;</p><p>All the groups were compared by 2×2 independent sample tests and the p values were <0.05 in all the analyses.</p><p>Triple- and Multi-echo MRI and MRS medians for no steatosis, mild, moderate, and severe steatosis using biopsy evaluations as reference values.</p

Univariable linear regressions analyses for each one of the imaging techniques.

<p>S.E., standard error; ROC, receiver operating characteristic; AUC, area under the curve; MRS, magnetic resonance spectroscopy.</p><p>Univariable linear regressions analyses for each one of the imaging techniques.</p

Diagnostic performance for triple- and multi-echo sequences, and MRS using histopathology as the gold standard.

<p>The best cut-off point was identified using the Youden index.</p

Correlations between triple- and multi-echo sequences and MR spectroscopy versus histopathology examination.

<p>Correlations between triple- and multi-echo sequences and MR spectroscopy versus histopathology examination.</p