Limits...
Diagnostic value of MRI proton density fat fraction for assessing liver steatosis in chronic viral C hepatitis.

Paparo F, Cenderello G, Revelli M, Bacigalupo L, Rutigliani M, Zefiro D, Cevasco L, Amico M, Bandelloni R, Cassola G, Forni GL, Rollandi GA - Biomed Res Int (2015)

Bottom Line: The median MRI PDFF showed a strong correlation with the histological fat fraction (FF) (r = 0.754, 95% CI 0.637 to 0.836, P < 0.0001), and the correlation was influenced by neither the liver stiffness nor the T2* decay.The median MRI PDFF result was significantly lower in the F4 subgroup (P < 0.05).Our MRI technique of PDFF estimation allowed discriminating with a good diagnostic accuracy between different grades of hepatic steatosis.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, E.O. Ospedali Galliera, Mura della Cappuccine 14, 16128 Genoa, Italy.

ABSTRACT

Objective: To assess the diagnostic performance of a T1-independent, T2*-corrected multiecho magnetic resonance imaging (MRI) technique for the quantification of hepatic steatosis in a cohort of patients affected by chronic viral C hepatitis, using liver biopsy as gold standard.

Methods: Eighty-one untreated patients with chronic viral C hepatitis were prospectively enrolled. All included patients underwent MRI, transient elastography, and liver biopsy within a time interval <10 days.

Results: Our cohort of 77 patients included 43/77 (55.8%) males and 34/77 (44.2%) females with a mean age of 51.31 ± 11.27 (18-81) years. The median MRI PDFF showed a strong correlation with the histological fat fraction (FF) (r = 0.754, 95% CI 0.637 to 0.836, P < 0.0001), and the correlation was influenced by neither the liver stiffness nor the T2* decay. The median MRI PDFF result was significantly lower in the F4 subgroup (P < 0.05). The diagnostic accuracy of MRI PDFF evaluated by AUC-ROC analysis was 0.926 (95% CI 0.843 to 0.973) for S ≥ 1 and 0.929 (95% CI 0.847 to 0.975) for S = 2.

Conclusions: Our MRI technique of PDFF estimation allowed discriminating with a good diagnostic accuracy between different grades of hepatic steatosis.

Show MeSH

Related in: MedlinePlus

Example of ROI positioning for the calculation of MRI PDFF (a), T2* (b), and R2* decay (reciprocal of T2*, expressed in Hz) (c) in a 52-year-old male patient with chronic viral C hepatitis. The histological FF of this patient was 10%, corresponding to a steatosis grade 1 (S1). Images (d), (e), and (f) show the histogram of pixel distribution with mean values ± standard deviation and medians.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4383409&req=5

fig1: Example of ROI positioning for the calculation of MRI PDFF (a), T2* (b), and R2* decay (reciprocal of T2*, expressed in Hz) (c) in a 52-year-old male patient with chronic viral C hepatitis. The histological FF of this patient was 10%, corresponding to a steatosis grade 1 (S1). Images (d), (e), and (f) show the histogram of pixel distribution with mean values ± standard deviation and medians.

Mentions: A color-coded map reflecting the estimated PDFF values in each pixel of the image is displayed and juxtaposed on the corresponding axial MRI slice. The histogram of pixel distribution with mean, median, and standard deviation of the PDFF values is computed in a freehand, elliptical, or rectangular user-adjustable ROI. A single abdominal radiologist, blind to the results of both TE and histology, performed ROI positioning. A single freehand ROI was drawn in a midhepatic axial slice including the right lobe of the liver and systematically excluding large blood vessels, biliary ducts, and focal lesions. The mean area of the ROIs was of about 40–60 cm2, depending on patient's anthropometric features (Figure 1). MRI PDFF and T2* decay were calculated in the same ROI. Clinically significant hepatic iron overload was defined by MRI T2* values less than 6.3 ms, corresponding to a liver iron concentration in dry tissue (LIC dry weight) of 4.2 mg/g [29, 30].


Diagnostic value of MRI proton density fat fraction for assessing liver steatosis in chronic viral C hepatitis.

Paparo F, Cenderello G, Revelli M, Bacigalupo L, Rutigliani M, Zefiro D, Cevasco L, Amico M, Bandelloni R, Cassola G, Forni GL, Rollandi GA - Biomed Res Int (2015)

Example of ROI positioning for the calculation of MRI PDFF (a), T2* (b), and R2* decay (reciprocal of T2*, expressed in Hz) (c) in a 52-year-old male patient with chronic viral C hepatitis. The histological FF of this patient was 10%, corresponding to a steatosis grade 1 (S1). Images (d), (e), and (f) show the histogram of pixel distribution with mean values ± standard deviation and medians.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4383409&req=5

fig1: Example of ROI positioning for the calculation of MRI PDFF (a), T2* (b), and R2* decay (reciprocal of T2*, expressed in Hz) (c) in a 52-year-old male patient with chronic viral C hepatitis. The histological FF of this patient was 10%, corresponding to a steatosis grade 1 (S1). Images (d), (e), and (f) show the histogram of pixel distribution with mean values ± standard deviation and medians.
Mentions: A color-coded map reflecting the estimated PDFF values in each pixel of the image is displayed and juxtaposed on the corresponding axial MRI slice. The histogram of pixel distribution with mean, median, and standard deviation of the PDFF values is computed in a freehand, elliptical, or rectangular user-adjustable ROI. A single abdominal radiologist, blind to the results of both TE and histology, performed ROI positioning. A single freehand ROI was drawn in a midhepatic axial slice including the right lobe of the liver and systematically excluding large blood vessels, biliary ducts, and focal lesions. The mean area of the ROIs was of about 40–60 cm2, depending on patient's anthropometric features (Figure 1). MRI PDFF and T2* decay were calculated in the same ROI. Clinically significant hepatic iron overload was defined by MRI T2* values less than 6.3 ms, corresponding to a liver iron concentration in dry tissue (LIC dry weight) of 4.2 mg/g [29, 30].

Bottom Line: The median MRI PDFF showed a strong correlation with the histological fat fraction (FF) (r = 0.754, 95% CI 0.637 to 0.836, P < 0.0001), and the correlation was influenced by neither the liver stiffness nor the T2* decay.The median MRI PDFF result was significantly lower in the F4 subgroup (P < 0.05).Our MRI technique of PDFF estimation allowed discriminating with a good diagnostic accuracy between different grades of hepatic steatosis.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, E.O. Ospedali Galliera, Mura della Cappuccine 14, 16128 Genoa, Italy.

ABSTRACT

Objective: To assess the diagnostic performance of a T1-independent, T2*-corrected multiecho magnetic resonance imaging (MRI) technique for the quantification of hepatic steatosis in a cohort of patients affected by chronic viral C hepatitis, using liver biopsy as gold standard.

Methods: Eighty-one untreated patients with chronic viral C hepatitis were prospectively enrolled. All included patients underwent MRI, transient elastography, and liver biopsy within a time interval <10 days.

Results: Our cohort of 77 patients included 43/77 (55.8%) males and 34/77 (44.2%) females with a mean age of 51.31 ± 11.27 (18-81) years. The median MRI PDFF showed a strong correlation with the histological fat fraction (FF) (r = 0.754, 95% CI 0.637 to 0.836, P < 0.0001), and the correlation was influenced by neither the liver stiffness nor the T2* decay. The median MRI PDFF result was significantly lower in the F4 subgroup (P < 0.05). The diagnostic accuracy of MRI PDFF evaluated by AUC-ROC analysis was 0.926 (95% CI 0.843 to 0.973) for S ≥ 1 and 0.929 (95% CI 0.847 to 0.975) for S = 2.

Conclusions: Our MRI technique of PDFF estimation allowed discriminating with a good diagnostic accuracy between different grades of hepatic steatosis.

Show MeSH
Related in: MedlinePlus