Liver mass CT
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American Roentgen Ray Society Images of Liver mass CT |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Maria Fernanda Villarreal, M.D. [2]
Overview
Computed tomography may be useful for the evaluation and diagnosis of liver masses. The evaluation of liver mass should be performed with a triphasic CT, this modality includes 3 phases: non-contrast, arterial phase, and portal venous phase. On CT, characteristic findings of liver mass, may include: solitary or multiple lesion, solid or cystic consistency, and normally a rounded lesion. The evaluation of liver mass will depend on several characteristics, such as: vascular pattern, size, location, size, distribution, margins, attenuation, and contrast enhancement.[1]
CT
- Computed tomography may be useful for the evaluation and diagnosis of liver masses.
- The evaluation of liver mass should be performed with a triphasic CT, this modality includes 3 phases:
- Non-contrast
- Arterial phase
- Portal venous phase
- On CT, characteristic findings of liver mass, include:[2]
- Solitary or multiple lesion
- Solid or cystic
- Rounded lesion
- Most common hypervascular primary liver malignancy
- Early arterial phase enhancement and then rapid wash out
- Rim enhancement of capsule may persist
- Malignant liver mass, particularly hepatocellular carcinoma, can have a variety of appearances, such as:
- Massive (focal)
- Large mass
- May have necrosis, fat and /or calcification
- Nodular (multifocal)
- Multiple masses of variable attenuation
- May also have central necrosis
- Infiltrative (diffuse)
- May be difficult to distinguish from associated cirrhosis
- Benign; most common liver tumor overall
- Discontinuous, nodular, peripheral enhancement starting in arterial phase
- Gradual central filling in
- Enhancement must match blood pool in each phase, or not a hemangioma (i.e. similar to aorta in arterial, portal vein in portal phase, etc)
- Small hemangiomas (< ~1.5 cm) may demonstrate "flash filling" - complete homogenous enhancement in arterial phase (no gradual filling in)
- Bright arterial phase enhancement except central scar
- Isodense/isointense to liver on portal venous phase
- Central scar enhancement on delayed phase
- Large, well circumscribed encapsulated tumors
- The distribution of hepatic adenoma
- 80% solitary
- 20% multiple
- Arterial phase: transient homogenous enhancement
- Returns to near isodensity on portal venous and delayed phase image
- Hypodense and enhance less than the surrounding liver
- Metastases from certain primaries demonstrate an increase in the number of vessels
- Rim enhancement is a feature of malignant lesions, especially metastases.
On CT, radiological signs of liver mass, include:[2]
- Bright dot sign: Presence of a bright dot within a lesion which remains hyper-attenuating on arterial and portal venous phase CT, corresponding to early nodular enhancement seen on liver hemangioma.
Gallery
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Liver hemangioma: discontinuous, nodular, peripheral enhancement starting in arterial phase -
Bright dot sign: Bright dot within a lesion which remains hyper-attenuating on arterial and portal venous phase CT, corresponding to early nodular enhancement seen on liver hemangioma -
Focal nodular hyperplasia: bright arterial contrast enhancement except for the central scar which remains hypoattenuating -
Hepatic abscess: peripheral enhancement, centrally hypoattenuating lesions. Occasionally they appear solid, or contain gas. Segmental perfusion abnormalities, with early enhancement, may be seen.
References
- ↑ Bonder A, Afdhal N (2012). "Evaluation of liver lesions". Clin Liver Dis. 16 (2): 271–83. doi:10.1016/j.cld.2012.03.001. PMID 22541698.
- ↑ 2.0 2.1 Oliver JH, Baron RL: State of the art, helical biphasic contrast enhanced CT of the liver: Technique, indications, interpretation, and pitfalls. Radiology 1996; 201:1-14.