MR features of fluid-fluid levels in ovarian masses

Fluid-fluid level in hepatic metastases: a characteristic sign of metastases of neuroendocrine origin

OBJECTIVES

The aim of this study is to determine MRI characteristics which indicate liver metastases of neuroendocrine tumors (NET) rather than metastases of other origin (non-NET).

METHODS

Sixty-nine patients with histopathologically proven liver metastases from NET and 69 patients with known liver metastases of other origin underwent MRI of the liver using a 1.5 T MR-scanner. Two board certified radiologists assessed presence of fluid-fluid-levels, number and distribution pattern, signal intensity (SI) characteristics, lesion homogeneity, presence of central necrosis and intratumoral hemorrhage in T2w and T1w non-contrast imaging. A multivariate logistic regression analysis was performed to determine the independent association of image findings and occurrence of NET.

RESULTS

Fluid-fluid-levels were identified in 19/69 of patients with NET-metastases, and in none of the patients in the control group (p<0.0001). Hyperintense SI in T1w imaging, markedly hyperintense SI in T2w imaging, a disseminated distribution pattern and intratumoral hemorrhage were indicative of NET metastases (p<0.05). After statistical adjustment for all significant MRI findings, fluid-fluid-levels (OR: 17.6, 95% CI: 1.9-166.5), strongly hyperintense SI in T2w (OR: 4.7, 95% CI: 1.8-12.7) and a disseminated distribution pattern (OR: 2.9, 95% CI: 1.1-7.4) were independent predictors for NET metastases.

CONCLUSIONS

The presence of fluid-fluid-levels is highly indicative of NET liver metastases and can be used as an independent predictor to distinguish them from metastases of other origin.

Fluid levels in pediatric imaging: a pictorial review

Fluid levels appearances are not uncommon findings in different diagnostic modalities including radiography, ultrasound, computed tomography, and magnetic resonance imaging. The significance of such signs varies according to the involved sites and the clinical settings. Familiarity with their imaging features and their diagnostic value as well as their clinical implication are of paramount importance for the radiologist and the clinician. We aim to review a spectrum of examples of fluid levels encountered with different modalities in paediatric imaging and discuss their appearances and clinical significances.