Yikai Xu

Esthesioneuroblastoma methods of intracranial extension: CT and MR imaging findings

IntroductionEsthesioneuroblastoma (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).MethodsEleven 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.ResultsThe 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.ConclusionThree 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.

MRI diagnosis and preoperative evaluation for pure epidural cavernous hemangiomas

IntroductionThe aims of the study were to summarize the characteristics of the spinal epidural cavernous hemangioma, especially for the MRI, and to improve the accurate rate of the preoperative diagnosis.MethodsThe clinical and medical imaging data of six patients with pure spinal epidural cavernous hemangioma proved by operation and pathology were analyzed retrospectively.ResultsThe level was thoracic (n = 2), thoracolumbar (n = 1), lumbar (n = 1), and sacral (n = 2). The tumor showed lobulated contour, and the areas the tumors appeared were dorsal side of spinal cord (n = 2), ventral side (n = 1), and lateral side (n = 3). In all six patients, the lesions were isointense to the spinal cord on T1-weighted images and hyperintense on T2-weighted images and showed homogeneously strong enhancement on contrast-enhanced T1-weighted images. The characteristic MRI features were named as the “wafting-silk” sign. Widening of the intervertebral neural foramen (n = 4) and erosion of the adjacent bones (n = 3) can be observed.ConclusionsMRI of the epidural cavernous hemangioma showed the characteristic lobulated contour, which encircled the spinal cord. T1WI on the MRI presented as isointense and T2WI presented as hyperintense and a homogeneously strong enhancement, so we first proposed the sign of wafting silk. The widening of the intervertebral neural foramen and erosion of the adjacent bones can easily be observed. MR imaging has an important role in the detection and diagnosis of pure spinal epidural cavernous hemangioma.

Expression of folate receptors in nasopharyngeal and laryngeal carcinoma and folate receptor-mediated endocytosis by molecular targeted nanomedicine.

Immunohistochemistry and an immunofluorescence technique was used to detect folate receptor expression in tissue samples and cell lines of head and neck squamous carcinoma, including 20 tissue samples of nasopharyngeal carcinoma, 16 tissue samples of laryngeal carcinoma, and HNE-1, HNE-2, CNE-1, CNE-2, SUNE-1, 5–8F, and Hep-2 cell lines. Iron staining, electron microscopy, and magnetic resonance imaging were used to observe endocytosis of folate-conjugated cisplatin-loaded magnetic nanoparticles (CDDP-FA-ASA-MNP) in cultured cells and transplanted tumors. As shown by immunohistochemistry, 83.3% (30/36) of the head and neck squamous carcinomas expressed the folate receptor versus none in the control group (0/24). Only the HNE-1 and Hep-2 cell lines expressed the folate receptor, and the other five cell lines did not. Endocytosis of CDDP-FA-ASA-MNP was seen in HNE-1 and Hep-2 cells by iron staining and electron microscopy. A similar result was seen in transplanted tumors in nude mice. Magnetic resonance imaging showed low signal intensity of HNE-1 cells and HNE-1 transplanted tumors on T2-weighted images after uptake of CDDP-FA-ASA-MNP, and this was not seen in CNE-2 transplanted tumors. In conclusion, head and neck squamous carcinoma cell strongly expressed the folate receptor, while normal tissue did not. The folate receptor can mediate endocytosis of folate-conjugated anticancer nanomedicines, and lays the foundation for molecular targeted treatment of cancer.

Anti-αvβ3 antibody guided three-step pretargeting approach using magnetoliposomes for molecular magnetic resonance imaging of breast cancer angiogenesis

Purpose Pretargeting of biomarkers with nanoparticles in molecular imaging is promising to improve diagnostic specificity and realize signal amplification, but data regarding its targeting potential in magnetic resonance (MR) imaging are limited. The purpose of this study was to evaluate the tumor angiogenesis targeting efficacy of the anti-αvβ3 antibody guided three-step pretargeting approach with magnetoliposomes. Methods Polyethylene glycol-modified and superparamagnetic iron oxide-encapsulated magnetoliposomes with and without biotin were synthesized and characterized. The cytotoxicity of both probes was evaluated using the methyl thiazdyl tetrazolium assay, and their cellular uptake by mouse macrophage was visualized using Prussian blue staining. Three-step pretargeting MR imaging was performed on MDA-MB-435S breast cancer-bearing mice by intravenous administration of biotinylated anti-αvβ3 monoclonal antibodies (first step), followed by avidin and streptavidin (second step), and by biotinylated magnetoliposomes or magnetoliposomes in the targeted or nontargeted group, respectively (third step). The specificity of αvβ3 targeting was assessed by histologic examinations. Results The developed magnetoliposomes were superparamagnetic and biocompatible as confirmed by cell toxicity assay. The liposomal bilayer and polyethylene glycol modification protected Fe3O4 cores from uptake by macrophage cells. MR imaging by three-step pretargeting resulted in a greater signal enhancement along the tumor periphery, occupying 7.0% of the tumor area, compared with 2.0% enhancement of the nontargeted group (P < 0.05). Histologic analysis demonstrated the targeted magnetoliposomes colocalized with neovasculature, which was responsible for the MR signal decrease. Conclusion These results indicate that our strategy for MR imaging of αvβ3-integrin is an effective means for sensitive detection of tumor angiogenesis, and may provide a targetable nanodelivery system for anticancer drugs.

MRI-based estimation of liver function by intravoxel incoherent motion diffusion-weighted imaging

PURPOSE To explore the usefulness of intravoxel incoherent motion (IVIM) to evaluate the hepatic functional reserve as expressed by the model for Child-Pugh class. MATERIALS AND METHODS IVIM diffusion-weighted imaging (DWI) using 10 different b values were performed on a Philips 3.0T MR scanner in 70 patients with liver cirrhosis and 60 healthy volunteers as the control group. Patients with liver cirrhosis were subdivided into three groups: Child-Pugh class A: 29 cases; Child-Pugh class B: 19 cases; Child-Pugh class C: 22 cases. Pure molecular diffusion (D), pseudo-diffusion (D*), perfusion fraction (f) and apparent diffusion coefficient (ADC) values were calculated, and used to determine liver function, as indicated by the Child-Pugh class. RESULTS The ICC values of D, D*, f and ADC between two radiologists were 0.997, 0.986, 0.985 and 0.995, respectively. D*, f and ADC values of liver cirrhosis group were significantly lower than control group (P<0.001, P=0.016, P=0.042, respectively). D*, f and ADC values significantly decreased with increasing Child-Pugh scores (p<0.05). Child-Pugh scores were inversely correlated with D* and f values (r=-0.423, r=-0.620, respectively). The areas under the curve (AUCs) of D* and f for evaluating liver function were 0.67-0.90 and 0.78-0.89, respectively. CONCLUSION IVIM DWI may be a useful image-based method for assessing liver function.

Role of intratumoral flow void signs in the differential diagnosis of intracranial solitary fibrous tumors and meningiomas

BACKGROUND AND OBJECTIVE An absence of signal on magnetic resonance (MR) images caused by blood or cerebral spinal fluid flow is known as a flow void, and may be related to intracranial tumors such as intracranial solitary fibrous tumor (SFT) or meningioma. However, the differential diagnosis of these neoplasms based on flow void configuration is controversial. This study investigated common intratumoral flow void patterns for differentiating intracranial SFT from meningioma. METHODS From May 2008 to May 2015, 14 patients (10 men, 4 women; 14-63y) received a pathologic diagnosis of primary intracranial SFT, and in 85 patients (23 men, 62 women; 20-76y) a pathologic diagnosis of meningioma was made. Intratumoral flow void signs were retrospectively observed on MR images of all these patients and classified by radiologists blinded to the pathology findings. Statistical significance was established by chi-squared tests. RESULTS In intracranial SFT patients, the sunburst flow void was detected in 1 case (7.1%) and the serpentine in 13 cases (92.9%). In meningioma patients, the sunburst flow void was detected in 82 cases (96.5%) and the serpentine in 3 cases (3.5%). The differences in the prevalence of the flow void types between the 2 groups were significant (χ(2)=64.348; P<0.01). CONCLUSION Intracranial SFTs on MR images were more likely to show a serpentine than a sunburst flow void, while the sunburst pattern was far more typical of meningioma. Thus, the pattern of the intratumoral flow void sign may be a useful tool to assist in differentiating these tumors.

Use of intravoxel incoherent motion diffusion-weighted MR imaging for assessment of treatment response to invasive fungal infection in the lung.

AbstractObjectivesThe purpose of this study was to determine whether intravoxel incoherent motion (IVIM) –derived parameters and apparent diffusion coefficient (ADC) could act as imaging biomarkers for predicting antifungal treatment response.MethodsForty-six consecutive patients (mean age, 33.9 ± 13.0 y) with newly diagnosed invasive fungal infection (IFI) in the lung according to EORTC/MSG criteria were prospectively enrolled. All patients underwent diffusion-weighted magnetic resonance (MR) imaging at 3.0 T using 11 b values (0-1000 sec/mm2). ADC, pseudodiffusion coffiecient D*, perfusion fraction f, and the diffusion coefficient D were compared between patients with favourable (n=32) and unfavourable response (n=14).Resultsf values were significantly lower in the unfavourable response group (12.6%±4.4%) than in the favourable response group (30.2%±8.6%) (Z=4.989, P<0.001). However, the ADC, D, and D* were not significantly different between the two groups (P>0.05). Receiver operating characteristic curve analyses showed f to be a significant predictor for differentiation, with a sensitivity of 93.8% and a specificity of 92.9%.ConclusionsIVIM-MRI is potentially useful in the prediction of antifungal treatment response to patients with IFI in the lung. Our results indicate that a low perfusion fraction f may be a noninvasive imaging biomarker for unfavourable response.Key Points• Recognition of IFI indicating clinical outcome is important for treatment decision-making. • IVIM can reflect diffusion and perfusion information of IFI lesions separately. • Perfusion characteristics of IFI lesions could help differentiate treatment response. • An initial low f may predict unfavourable response in IFI.

Choroid plexus tumours: Classification, MR imaging findings and pathological correlation

Choroid plexus tumours (CPTs) are extremely rare intraventricular neoplasms and are prone to bleeding during surgery. The purpose of this study was to summarise the MR imaging characteristics of 13 CPT cases.

Gd-EOB-DTPA-enhanced T1ρ imaging vs diffusion metrics for assessment liver inflammation and early stage fibrosis of nonalcoholic steatohepatitis in rabbits

To assess the value of T1ρ,T1ρ on hepatobiliary phase (HBP) and diffusion metrics in staging of Non-alcoholic fatty liver disease (NAFLD) activity scores, inflammation, fibrosis in NASH rabbits model. Non-alcoholic steatohepatitis (NASH) rabbits model was induced by feeding a varied duration of high-fat, high-cholesterol diet. T1ρ,T1ρ (HBP) 20min after administration of Gd-EOB-DTPA, and Intravoxel incoherent motion imaging (IVIM) diffusion-weighted imaging were performed on a 3.0T magnetic resonance (MR) imaging unit. The diagnostic value of each parameter for NAS, inflammation and fibrosis severity were determined. T1ρ (r=0.658) and T1ρ (HBP) (r=0.750) have strong association with NASH overall activity, T1ρ (HBP) is strongly relevant to inflammation stage (r=0.812). There was negative association between f and inflammation (r=-0.480), whilst no significant relation between other three parameters (apparent diffusion coefficient (ADC), pseudo-diffusion coefficient (D*) and true diffusion coefficient (D)) and inflammation or overall activity. The areas under the receiver operating characteristic curves (AUCs) of f, ADC, T1ρ and T1ρ-HBP were 0.871, 0.728, 0.849 and 0.949 for differentiating NASH; 0.731, 0.552, 0.925 and 0.922 for G2-3 inflammation; and 0.767, 0.625, 0.816, and 0.882 for S1-2 fibrosis. Comparison of ROC curve showed T1ρ (HBP) had an optimal diagnostic performance for NASH [T1ρ (HBP) vs ADC, AUC:0.949 vs 0.728, P=0.043], inflammation [T1ρ (HBP) vs ADC, AUC:0.922 vs 0.552, P=0.003], fibrosis [T1ρ (HBP) vs ADC, AUC:0.882 vs 0.625, P=0.046]. The combination of T1ρ (HBP)+perfusion fraction (f) showed highest diagnostic value for NASH (AUC:0.971), inflammation (AUC:0.935). Among T1ρ imaging and IVIM diffusion metrics, combination of T1rho (HBP)+f was found to be superior noninvasive imaging biomarker for NASH activity assessment.

Gastrin-releasing peptide receptor-targeted gadolinium oxide-based multifunctional nanoparticles for dual magnetic resonance/fluorescent molecular imaging of prostate cancer

Bombesin (BBN), an analog of gastrin-releasing peptide (GRP), specifically binds to GRP receptors, which are overexpressed in human prostate cancer (PC). Here, we synthesized a BBN-modified gadolinium oxide (Gd2O3) nanoprobe containing fluorescein (Gd2O3-5(6)-carboxyfluorescein [FI]-polyethylene glycol [PEG]-BBN) for targeted magnetic resonance (MR)/optical dual-modality imaging of PC. The Gd2O3-FI-PEG-BBN nanoparticles exhibited a relatively uniform particle size with an average diameter of 52.3 nm and spherical morphology as depicted by transmission electron microscopy. The longitudinal relaxivity (r1) of Gd2O3-FI-PEG-BBN (r1 =4.23 mM−1s−1) is comparable to that of clinically used Magnevist (Gd-DTPA). Fluorescence microscopy and in vitro cellular MRI demonstrated GRP receptor-specific and enhanced cellular uptake of the Gd2O3-FI-PEG-BBN in PC-3 tumor cells. Moreover, Gd2O3-FI-PEG-BBN showed more remarkable contrast enhancement than the corresponding nontargeted Gd2O3-FI-PEG according to in vivo MRI and fluorescent imaging. Tumor immunohistochemical analysis further demonstrated improved accumulation of the targeted nanoprobe in tumors. BBN-conjugated Gd2O3 may be a promising nanoplatform for simultaneous GRP receptor-targeted molecular cancer diagnosis and antitumor drug delivery in future clinical applications.