Assessment of low signal adjacent to the falciform ligament on contrast-enhanced MRI.

OBJECTIVE

Geographic low signal in the medial segment of the liver seen on contrast-enhanced MRI has been attributed to focal fatty infiltration. Using in- and opposed-phase gradient-recalled echo (GRE) T1-weighted MRI, we attempted to determine if this finding represents focal fatty infiltration.

MATERIALS AND METHODS

From a radiology information system, we identified 174 consecutive patients who underwent contrast-enhanced abdominal MRI. Subjects with diffuse liver disease were excluded. The presence of geographic low signal adjacent to the falciform ligament in the anterior medial aspect of the medial segment of the liver during dynamic gadolinium-enhanced imaging was assessed during the arterial, portal venous, and equilibrium phases of enhancement. If this finding was present on any contrast-enhanced sequence, in- and opposed-phase images were qualitatively evaluated to determine if signal loss occurred on opposed-phase imaging.

RESULTS

Fifty-three patients were excluded because of diffuse liver disease. Twenty-one (17.4%) of the remaining 121 patients showed focal low signal during gadolinium-enhanced MRI. This finding was present in all 21 patients during the portal venous phase and in seven and five during the arterial and equilibrium phases of enhancement, respectively. Of the 21 patients, three showed signal loss on opposed-phase imaging and 18 (85.7%) did not.

CONCLUSION

Although low attenuation or signal adjacent to the falciform ligament may represent focal fat, it usually does not and is likely related to anomalous venous drainage into the liver.