Esthesioneuroblastoma methods of intracranial extension: CT and MR imaging findings.

INTRODUCTION: Esthesioneuroblastoma (ENB) is an aggressive neuroectodermal malignancy in the upper nasal cavity with local infiltration and lymphatic or hematogenous metastasis. The purpose of this paper is to document three types of direct intracranial extensions by ENB using computed tomography (CT) and magnetic resonance imaging (MRI). METHODS: Eleven patients with pathologically confirmed ENB were admitted in our hospital between December 2002 and December 2008. Their magnetic resonance (MR; n = 10) and CT (n = 8) images were retrospectively reviewed, and particular attention was paid to tumor location and extension, enhancement pattern, cervical lymph node metastasis, and Kadish stage. RESULTS: The majority of patients were male (8/11) with Kadish stage C tumor (10/11). Three types of direct intracranial extension by ENBs were put forward according to their MR and CT findings. The primary tumors were well-defined soft-tissue masses centered in the roof of the nasal cavity eroding into the paranasal sinuses (11/11), the contralateral nasal cavity (4/11), the cranial cavity (5/11), and the fossa orbitalis (3/11). The tumor parenchyma were hypointensity on T1-weighted images, heterogeneous hyperintensity on T2-weighted images, and isodensity or slight hyperdensity on CT images with scattered necroses (4/11) and marginal cysts(4/11). Their enhancements were significant and inhomogeneous. Cervical lymph nodes metastases were observed in four patients (4/11), but no pathologically proved distant metastasis was observed. CONCLUSION: Three types of direct intracranial extensions by ENB can be found on CT and MRI: cranio-orbital-nasal-communicating ENB, cranio-nasal-communicating ENB, and orbital-nasal-communicating ENB.

[Synthesis of Gal-BSA-SPIO and magnetic resonance imaging of ASG receptors in rabbits bearing liver VX2 tumor and human liver].

OBJECTIVE: To synthesize Gal-BSA-SPIO as the magnetic resonance imaging (MRI) contrast agent targeting asialoglycoprotein (ASG) receptors in the liver and observe its role in MRI detection of hepatocellular carcinomas (HCCs). METHODS: Gal-BSA was synthesized by means of reductive amination and mixed with SPIO in ice bath to prepare Gal-BSA-SPIO complex. Twenty rabbits bearing VX2 liver tumor underwent MRI enhanced by SPIO (n=10) and Gal-BSA-SPIO (n=10), and the T2 values of the liver and tumor before and after the contrast imaging were measured. Fresh human normal hepatic tissues (n=3), cirrhotic tissues (n=4) and HCC tissues (n=6) were obtained and incubated with Gal-BSA-SPIO followed by Perl's Prussian blue staining to observe the distribution of ASG receptors. RESULTS: The size of the Gal-BSA-SPIO particles was 34.4 nm. The 20 rabbits bearing VX2 tumor, with tumor size ranging from 3 mm to 12 mm, showed isointense signal in the liver and hypointense signal in the tumor on T1WI, and isointense signal in the liver and slightly hyperintense signal in the tumor on GRE T2*WI. The signal intensity of the liver decreased slightly or moderately after administration of SPIO in the rabbits, and administration Gal-BSA-SPIO resulted in obvious reduction in the signal intensity of the liver. The signal intensities of the tumors did not exhibit obvious changes after the administration of SPIO or Gal-BSA-SPIO. Histological examination revealed numerous blue iron deposits in the Kupffer cells in SPIO group and in the hepatocytes in Gal-BSA-SPIO group, but not in the tumors in either of the groups. The human liver specimens incubated with Gal-BSA-SPIO contained numerous blue iron deposits in the hepatocyte cytoplasm and cell membrane in normal liver tissue, but the deposits were reduced in the cirrhotic tissue and almost absent in the HCC tissue. CONCLUSION: Gal-BSA-SPIO can specifically bind to ASG receptors on hepatocyte membrane to improve the tumor-liver contrast-to-noise ratio.