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Non-invasive detection of liver fibrosis: Is superparamagnetic iron oxide particle-enhanced MR imaging a contributive
Olivier Lucidarme1, Florence Baleston, Mehdi Cadi
1Department of Radiology, Université Paris VI, Hôpital de la Pitié-Salpêtrière Assistance Publique-Hôpitaux de Paris, 47, boulevard de l'Hôpital, 75651 Paris Cedex 13, France. olivier.lucidarme@psl.ap-hop-paris.fr
Abstract:
The purpose of our study was to evaluate the ability of superparamagnetic iron oxide (SPIO)-enhanced MR imaging to detect liver fibrosis in patients with chronic liver disease and to compare the findings with histopathological data. Sixty-seven patients with chronic hepatitis ( n=58) or focal nodular hyperplasia (FNH; n=9) were studied using a 1.5-T MR system. The protocol included proton density-weighted, T2-weighted spin-echo (SE) and fast SE (FSE) sequences before and after SPIO administration and T2*-weighted gradient-recalled-echo (GRE) sequences after SPIO. Pre- and post-contrast T2-weighted and T2*-weighted sequences were retrospectively evaluated by three independent observers for evidence of non-tumor hypersignal intensities. Three liver patterns were considered: thick reticulations; thin reticulations; and/or multiple areas of hypersignal intensities. Unenhanced or enhanced patterns were compared with histopathological specimens, which had been obtained by percutaneous biopsy of the right lobe within a maximum of 12 months of MR examination. Liver fibrosis was histologically graded using a five-level scale (F0-F4), according to the METAVIR classification. Histopathology demonstrated significant fibrosis (F2-F4) in 57 patients, non-significant fibrosis in 1 patient (F1), and normal liver surrounding FNH in 9 patients (F0). After SPIO administration, at least one pattern of non-tumor hypersignal intensities was seen in 43 (76%) of the 57 patients with F>/=2 with good agreement (kappa=0.68) compared with 2 (20%) of the 10 F0/1 patients ( p<0.01). Attenuated non-homogeneous liver-signal intensities with persistent thick reticulations, thin reticulations, or multiple areas of hypersignals were observed in, respectively, 30, 52, and 56% of patients with F>/=2 with moderate agreement (kappa=0.51). Before SPIO, MR images were positive in 21 of 57 (37%) F>/=2 and zero F0/1 patients. Post-contrast proton-density-weighted and T2*-weighted GRE were the most sensitive sequences for detecting non-tumor hypersignal intensities. In patients with chronic liver diseases, SPIO-enhanced MR imaging exhibits non-tumor hypersignal intensities indicative of liver fibrosis by decreasing the signal from the non-fibrotic areas where Kupffer cells are present.
Insights
Superparamagnetic iron oxide (SPIO)-enhanced MR imaging effectively detects liver fibrosis in chronic liver disease patients. This advanced imaging technique shows non-tumor hypersignal intensities, correlating with histopathological findings of fibrosis.
Area of Science:
- Radiology
- Hepatology
- Medical Imaging
Background:
- Liver fibrosis is a significant complication of chronic liver disease.
- Accurate detection and grading of liver fibrosis are crucial for patient management.
- Non-invasive imaging methods are sought to complement or replace liver biopsy.
Purpose of the Study:
- To evaluate superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging for detecting liver fibrosis.
- To compare SPIO-enhanced MR imaging findings with histopathological data in patients with chronic liver disease.
- To assess the sensitivity and specificity of different MR sequences in identifying fibrosis patterns.
Main Methods:
- Sixty-seven patients with chronic hepatitis or focal nodular hyperplasia underwent 1.5-T MR imaging.
- Imaging protocols included pre- and post-SPIO administration sequences (proton density-weighted, T2-weighted SE/FSE, T2*-weighted GRE).
- MR findings were compared with histopathology (METAVIR classification) obtained via percutaneous biopsy.
Main Results:
- SPIO-enhanced MR imaging detected non-tumor hypersignal intensities in 76% of patients with significant fibrosis (F≥2) versus 20% in controls (p<0.01).
- Specific patterns (thick/thin reticulations, hypersignal areas) showed moderate agreement with fibrosis grade (kappa=0.51).
- Post-contrast proton-density-weighted and T2*-weighted GRE sequences were most sensitive for detecting fibrosis indicators.
Conclusions:
- SPIO-enhanced MR imaging is a valuable tool for detecting liver fibrosis in chronic liver disease.
- The technique identifies fibrosis by revealing non-tumor hypersignal intensities due to Kupffer cell activity changes.
- This imaging approach offers a non-invasive method for assessing liver fibrosis, potentially reducing the need for biopsies.