Imaging Pearls ❯ Liver ❯ Cirrhosis
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- Focal Lesions in the Cirrhotic Liver
- Regenerative nodules (RN)
- Dysplastic nodules
- Hepatocellular carcinoma (HCC) - Regenerating Nodules
Usually too small to detect by imaging
- May be surrounded by fibrotic septa
- May contain iron, copper
Siderotic nodules
- Hyperdense on NCCT, disappear on HAP & PVP
- Hypointense on T2 MR, “bloom” on GRE
Larger or vascular/enhancing RN
- Can not be distinguished from dysplastic nodule or HCC - Dysplastic Nodules
- “Adenomatous hyperplasia” (old term)
- Are premalignant (larger, high-grade DNs)
- Rarely diagnosed by US or CT - Dysplastic Nodules
Small, low-grade DNs are often indistinguishable from regenerative nodules (by imaging + histology)
- Usually <1.5 cm diameter, minimal vascularity
- Usually hypointense on T2WI
Larger, high grade DNs are often indistinguishable from HCC
- Usually >2cm, moderate vascularity
- May be hyperintense on T2WI - Primary Criteria for Dx of HCC
- Mass-like arterial phase hyperenhancement with “washout” (becomes hypodense to liver)
- Tumor within the portal (or hepatic) vein
- Increase in size by > 10 mm within one year - HCC - Helical CT Pitfalls
THAD (transient hep. attenuation differences)
- Small peripheral wedge-shaped
- Ignore, usually due to AP shunt or aberrant veins
Larger segmental or lobar
- Often due to tumor occlusion of portal vein
Arterioportal shunt
- Common in cirrhosis
- Usually benign if small, peripheral, non-spherical, isodense on PVP, visible vessels into + out - Screening Recommendation for Known Cirrhosis
1. AFP and PIVKA II – every 3 months
2. Ultrasonography – every 3 or 4 months
- Most useful in less advanced cirrhosis
- Very nodular/coarse liver is difficult
3. CT or MR ~ every 12 months
- (For chronic hepatitis without cirrhosis, extend intervals)
4. For high clinical suspicion or indeterminate lesion, shorten intervals