This study evaluated quantitative ultrasound features for assessing hepatic fibrosis in a rat model of cirrhosis induced by diethylnitrosamine (DEN). Rats received DEN (n=12) or served as controls (n=4). Ultrasound images were analyzed for echo-intensity and heterogeneity at 0, 10, and 13 weeks. Both features increased significantly with time in DEN rats compared to controls. Histological analysis found DEN rats developed METAVIR grades F2-F4 fibrosis while controls were F0. Echo-intensity and heterogeneity correlated strongly with METAVIR grade. Ultrasound could non-invasively track fibrotic changes and distinguish fibrosis grades, suggesting potential for assessing liver fibrosis.

1. Quantitative Assessment of
Diethylnitrosamine-induced Hepatic Fibrosis
by
Non-Invasive Ultrasound
Laith R Sultan MD, Julia C D’Souza BSE, Susan M Schultz RDMS, Tong Wu PhD,
Terrence Gade MD PhD,Sean D Carlin PhD, Stephen J Hunt MD PhD,
Chandra M Sehgal PhD

2. ❖ All authors have
no financial
disclosures

3. Cirrhosis: Diagnosis
▪ Cirrhosis and liver disease represent
the 12th leading cause of death
overall, and 5th leading cause of
death for 45 - 54 year olds in US
▪ Liver biopsy is the gold standard for
assessing fibrosis and cirrhosis
▪ Shortcomings of liver biopsy:
▪ Invasive
▪ Sampling error:
▪ Complications

4. Objective
To evaluate fibrotic changes in a preclinical model using
B-mode ultrasound
Approach:
▪ Quantitative, computer-extracted features
▪ Diethylnitrosamine (DEN)-induced rat model

5. Experimental Design
Arms:
DEN (n=12)
Control (n=4)

6. Materials & Methods
Image and Statistical Analysis
▪ Sampling: 6 image acquisitions throughout liver
4 - 6 ROIs/image
▪ Echo-intensity = mean brightness of ROIs
▪ Heterogeneity = variance of 1st order histogram
▪ Intragroup Δ (temporal progression): ANOVA with
subsequent t-tests between three timepoints
▪ Intergroup Δ (DEN vs control): Two-sided t-tests
at each timepoint

7. ▪ Preparation of H&E and trichrome stains
▪ METAVIR grading by veterinary pathologist
▪ Spearman correlation between sonographic
parameters and METAVIR score
Materials & Methods
Pathologic Validation

8. DENControl
10 weeks0 weeks 13 weeks
Results
Echointensity
*
*
* p = 0.001
0w 10w 13w
Control 38.1 38.2 38.4
DEN 38.1 56.5 59.6
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
Echointensity

9. Echo-intensity:
10 weeks (p = 0.0013), 13 weeks (p = 0.0002)
DENControl
10 weeks0 weeks 13 weeks
Results
Heterogeneity
**
*
*
** p = 0.005
0w 10w 13w
Control 275.3 247.8 245.5
DEN 246.6 524.9 480.7
0.0
100.0
200.0
300.0
400.0
500.0
600.0
700.0
Heterogeneity

10. ▪ DEN rats: METAVIR grades F2-F4
▪ Control rats: F0
F3 F4F2
Results
Histology

11. Results
Correlation of 13w sonographic data with METAVIR
score
Echointensity vs. Fibrosis grade Heterogeneity vs. Fibrosis grade
Rho = 0.8242
p = 0.0003
Rho = 0.8287
p = 0.0002

12. Different grades of fibrosis show separate populations based on echointensity and heterogeneity
Results
Population grouping of METAVIR grades by sonographic measures
F
4
F
0
F
2
F
3

13. Limitations
◼ Limited data for intermediate stages of fibrosis→ Image
and sacrifice at earlier time points
◼ Similarities in characterization of F2/F3 lesions→
Further characterization with additional computerized
features

14. Conclusion
◼ B-mode US tracks fibrotic changes in a rat model.
◼ Sonographic features correlate to histology.
◼ Potential role for B-mode US for the non-invasive
measurement of liver fibrosis.

15. Future Directions
◼ Preclinical correlation of sonographic features to HCC
development
◼ Rat model comparison to fibroscan results
◼ Comparison of biopsy-proven METAVIR fibrosis scoring with
clinical ultrasound measurements

16. Thank you!
Contact:
lsultan@pennmedicine.upenn.edu
julia.dsouza@uphs.upenn.edu
Stephen.hunt@uphs.upenn.edu
Chandra.sehgal@uphs.upenn.edu
Penn Ultrasound Research Lab
Penn Small Animal Imaging Facility