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Objective To investigate the CT and MRI features of supratentorial primitive neuroectodermal tumors (sPNET)in adults,and to analyze the reasons of misdiagnosis.Methods The CT and MRI features of 1 5 patients with sPNET confirmed by pathology were analyzed retrospective.13 of 15 patients were underwent plain and contrast enhanced MRI,4 patients were also performed CT scan and the other 2 patients were underwent CT plain scan only.Results Nine of 1 5 lesions were located in the temporal and/or frontal lobe,with clear margin in 12 lesions,and mild to moderate peritumoral was noted in most cases.The solid portion of the lesions were hyperdense on CT,isointense or slightly hypointense on T1WI,and isointense or hyperintense on T2WI compared to the gray matter.Calcification (2/6),necrosis or cystic degeneration(1 3/1 5),hemorrhage (8/1 5)and flow void signal (1 1/1 3)were seen.Twelve lesions showed significantly heterogeneous enhancement and 7 lesions showed irregular ring-enhancement.The solid parts in 5 lesions showed hyperintensity on diffusion-weighted imaging. Preoperatively,the lesions were misdiagnosed as glioma in 10 cases,ependymoma in 2 cases,meningioma in 1 case and germ cell tumor in 1 case, respectively;and 1 case was not diagnosed definitely.Conclusion Supratentorial PNET in adults has characteristic CT and MRI features,and the main reasons accounting for misdiagnosis are its extraordinary low incidence and that radiologists do no master its imaging features.
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Objective To investigate the diagnostic value of six MRI characteristic features for diagnosing central neurocytoma (CN).Methods MRI data of 30 cases of CN and 68 cases of non-CN located in lateral ventricles were retrospectively analyzed.Six characteristic MRI features,including scalloping sign,broad-based attachment sign,soapbubble sign,peripheral cyst sign,fluid-fluid level sign and gemstone sign were scored based on a five-point scale.ROC curve was used to assess the diagnostic value of each MRI sign.Results The scalloping sign showed the highest area under the curve (AUC) value (0.82) among all 6 signs (all P＜0.05),followed by broad-based attachment,soap-bubble andperipheral cyst signs (AUC 0.73-0.75),higher than that of fluid-fluid level sign and gemstone sign (all P＜0.05).The scalloping sign exhibited the highest specificity (84.56 ％),followed by fluid-fluid level (77.94 ％),gemstone (74.26 ％) and peripheral cyst (70.34％) sign.The soap-bubble sign (83.89％) was the most sensitive sign,followed by broad-based attachment sign (76.11％) and peripheral cyst sign (75.00％).Conclusion The scalloping sign is the most valuable indicator for CN among six characteristic MRI features.
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Objective To investigate MR findings and analyze the misdiagnosed cases of pituitary macroadenoma.Methods MR features of 1 90 patients of pituitary macroadenoma confirmed by operation and pathology were reviewed.Results 1 6 cases were mis-diagnosed as craniopharyngioma,chordoma,or meningioma.Among the sixteen cases,eight cases with cyst degeneration and hemor-rhage were misdiagnosed as craniopharyngioma;five cases with clival and sphenoid sinus destruction were misdiagnosed as chordo-mas;three cases with suprasellar and anterior cranial fossa extension were misdiagnosed as meningiomas.Conclusion Craniophar-yngioma,chordoma and meningioma should be considered in the differential diagnosis of atypical pituitary macroadenoma.The com-prehensive analysis should be based on a variety of signs.
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Objective To explore the value of pretargeting technology in vitro MRI of L5 peptide guided streptavidin-conjugated and polyethylene glycol modification protected ultra-small superparamagnetic iron oxide(SA-PEG-USPIO) to hepatocellular carcinoma(HCC) via glypican-3(GPC3) receptor.Methods Direct immumofluorescence assay with carboxyfluorescein(FAM) labeled L5 and competitive inhibition was performed in HepG2 and HL-7702 cells.Imaging was obtained from fluorescent microscope.Immunoassay fluorescence images were carried out to determine the expression of GPC3 in HepG2 cell.PEG-USPIO conjugated with streptavidin was made by carbodiimide reaction,and the hydrodynamic diameters,Zeta potential and magnetic relaxivity of SA-PEG-USPIO and PEG-USPIO were measured.HL7702 cells were used for evaluate cells viability of SA-PEG-USPIO and PEG-USPIO.HepG2 and HL-7702 cells were used as experimental and control group respectively.Each of the two cell lines were further divided into three groups:L5-BT united SA-PEG-USPIO group,SA-PEG-USPIO group and control group.Prussian blue staining and MRI was preformed to observe the targeting efficacy of SA-PEG-USPIO respectively,and normalized T2 signal was recorded.The significant changes of normalized T2 signal intensity among groups was deterumine by using One-way analysis of variance.Results There were much more fluorescences on the membrane and cytoplasm of HepG2 cells than those on HL-7702 cells and cells of competition group.And indirect immunofluorescence images show the obvious expression of GPC3 in HepG2 cell.The SA-PEG-USPIO and PEG-USPIO nanoparticles had hydrodynamic diameters of (22.73 ± 3.31) and (35.97±5.19)nm,Zeta potential of them were (4.22±0.53) and (-7.91± 1.22)mV and magnetic relaxivity were 0.139 4× 103 and 0.103 9 × 103 mM-1s1.Although the highest concentration of SA-PEG-USPIO and PEG-USPIO was 2.4 mmol/L,cells viability was greater than 80％.The most iron particle was observed in L5-BT united SA-PEG-USPIO group of HepG2 cells.In vitro MR,the normalized T2 signal intensity of HepG2 cells in L5-BT united SA-PEG-USPIO group,SA-PEG-USPIO group and control group were 39±7,77 ± 12 and 93 ± 4.There was significant difference among those three groups (F=23.96,P＜0.01).The normalized T2 signal intensity of HL-7702 cells in each of three groups were 69± 11,78±8 and 95±5.There was no significant difference among those three groups (F=2.86,P＞0.05).Conclusion By the pretargeting method,L5 peptide guided SA-PEG-USPIO has effective targeting ability to HepG2 cells in vitro.