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Focal hepatic lesions: detection and characterization with combination gadolinium- and superparamagnetic iron
Myeong-Jin Kim1, Joo Hee Kim, Jae-Joon Chung
1Department of Diagnostic Radiology, Research Institute of Radiological Science, Severance Hospital, and Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seodaemun-ku, Shinchon-dong 134, Seoul 120-752, Republic of Korea.
Purpose:
To compare gadolinium- and superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging for detection and characterization of focal hepatic lesions when different contrast agent administration sequences are used.
Materials And Methods:
Unenhanced, dynamic gadolinium-enhanced, and SPIO-enhanced hepatic MR images were obtained in 134 patients. SPIO-enhanced MR imaging was performed immediately after gadolinium-enhanced dynamic MR imaging in 50 patients, 1 day after gadolinium-enhanced dynamic MR imaging in 40 patients, and before gadolinium-enhanced dynamic MR imaging in 44 patients. Two radiologists independently reviewed the gadolinium image set (unenhanced and gadolinium-enhanced dynamic MR images) and the SPIO image set (unenhanced and SPIO-enhanced MR images) in random order. Lesion detection sensitivity and lesion characterization accuracy were compared by analyzing the area under the receiver operating characteristic curve (Az).
Results:
Overall lesion detection accuracy for pooled data was significantly higher with the SPIO set (Az = 0.903) than with the gadolinium set (Az = 0.857) (P <.05). When hypovascular lesions were excluded, the detection rate was similar with the two sets. When hepatocellular carcinomas were excluded, the detection rate was significantly higher with the SPIO set (P <.01). Readers were more accurate in differentiating benign from malignant lesions with the gadolinium set (Az = 0.915) than with the SPIO set (Az = 0.847) (P <.01). Detection accuracy tended to be better with the images obtained after the second contrast agent was used.
Conclusion:
Hypovascular lesion detection was better with SPIO-enhanced MR images than with gadolinium-enhanced MR images. Detection and characterization of hypervascular lesions were improved with gadolinium-enhanced MR images.
Insights
Superparamagnetic iron oxide (SPIO)-enhanced MRI improved detection of hypovascular liver lesions. Gadolinium-enhanced MRI was superior for characterizing hypervascular lesions and differentiating benign from malignant tumors.
Area of Science:
- Radiology
- Medical Imaging
- Hepatology
Background:
- Focal hepatic lesions require accurate detection and characterization for effective management.
- Magnetic Resonance Imaging (MRI) is a key modality for liver lesion assessment.
- Different contrast agents, gadolinium and superparamagnetic iron oxide (SPIO), offer distinct imaging properties.
Purpose of the Study:
- To compare the efficacy of gadolinium-enhanced MRI versus SPIO-enhanced MRI in detecting and characterizing focal hepatic lesions.
- To evaluate the impact of contrast agent administration sequences on imaging performance.
Main Methods:
- 134 patients underwent unenhanced, dynamic gadolinium-enhanced, and SPIO-enhanced hepatic MRI.
- SPIO-enhanced imaging was performed in different sequences relative to gadolinium enhancement.
- Two radiologists independently assessed lesion detection sensitivity and characterization accuracy using ROC curve analysis (Az).
Main Results:
- Overall lesion detection accuracy was significantly higher with SPIO-enhanced MRI (Az = 0.903) compared to gadolinium-enhanced MRI (Az = 0.857).
- SPIO-enhanced MRI showed superior detection rates for non-hypovascular lesions, excluding hepatocellular carcinomas.
- Gadolinium-enhanced MRI provided higher accuracy in differentiating benign from malignant lesions (Az = 0.915 vs. Az = 0.847).
Conclusions:
- SPIO-enhanced MRI is advantageous for detecting hypovascular liver lesions.
- Gadolinium-enhanced MRI demonstrates superior performance in detecting and characterizing hypervascular lesions.
- Contrast agent choice and administration sequence influence diagnostic performance in liver MRI.