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Objective To investigate CT and MRI findings of giant cell tumors of the temporal bone(GCTTB).Methods CT and MRI features of 5 cases pathologically proven GCTTB were retrospectively reviewed.The lesion characteristics,including location, size,shape,margin,attenuation on CT scans,signal intensity on MR images,and enhancement pattern were documented and analyzed.Results In all 5 patients,the lesions were located adj acent to the mandibular fossa.These lesions were round or oval in shape,predominantly demonstrated as expansive lytic bone destruction containing hyperattenuating septa,calcifications,non-sclerotic borders,and discontinuous bony shells,with“boundary angle”sign.No soft tissue masses were found around the lesions.These lesions with different content demonstrated various MRI signal intensity,and the solid component enhanced intensely.Conclusion GCTTB is rare.Features such as expansive growing pattern,discontinuous bony shell,intralesional septa,calcification,and “boundary angle”sign are common,which may help in the radiographic diagnosis of giant cell tumor.
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Objective To prepare dual?modality single?photon emission computed tomography (SPECT)?MRI molecular nanoprobes targeting HAb18G/CD147 expressed on breast cancer cell membranes and investigate the physicochemical and biological properties in vitro. Methods Superparamagnetic iron oxide nanoparticles (SPIOs) were prepared by one?pot reaction method as described. The single?chain antibody fragments HAb18F(ab')2 were conjugated to SPIOs via chemical method and then labeled with 125I using Iodogen method. The final 125I?SPIO?HAbF18(ab')2 nanoprobes were purified. SPIOs or 125I?HAb18F(ab')2 were used as control. We carried preliminary evaluation on their physicochemical properties and biological characteristics in vitro: transmission electron microscope (TEM) and dynamic light scattering (DLS) were used to measure these nanoparticle sizes and the hydrodynamic diameters. The MRI T2 transverse relaxation efficiency of these nanoprobes at different Fe2+concentrations were measured with 1.5 T clinical MR scanner. The 125I?SPIO?HAb18F(ab')2 and 125I?HAb18F(ab')2 radiochemical purity were measured by thin layer chromatography and the radio chemical yield was calculated. We also conducted stability tests in vitro and octanol/water partition coefficient experiments. Two breast tumor cell lines, MDA?MB?231 (HAb18G?overexpressing cells,experimental group) and MDA?MB?468 (control), were used for assessment of cells viability at different Fe2 + concentrations (1, 5, 10, 20, 40 μg/ml) by methyl thiazolyl tetrazolium assay. Specific binding experiments in vitro included two parts:magnetic resonance imaging and radionuclide tests, the above?mentioned breast cancer cell lines were incubated with 125I?SPIO?HAb18F(ab')2 nanoprobes respectively and took MDA?MB?231 cells which were not treated as blank group. First comparing the MR signal intensity differences among experimental group, the control group and blank group, then calculated the rate of MRI signal changes;Two breast tumor cell lines, MDA?MB?231 and MDA?MB?468 were incubated with 125I?SPIO?HAb18F(ab')2 nanoprobes too, then measured radioactivity counting byγcounter at different time and calculated the cell binding rates, and did statistical analysis by using one?way ANOVA. Results The SPIOs were fairly homogeneous with an average core size of (10.32±1.30) nm;the SPIO and 125I?SPIO?HAb18F(ab')2 hydrodynamic diameter of 44.80 and 52.64 nm, and MRI scanning showed that the transverse relaxation efficiency of SPIO and 125I?SPIO?HAb18F(ab')2 were 38.79 and 106.73 mM-1 · s-1, respectively. The radio chemical yield of 125I?SPIO?HAbF18(ab')2 and 125I?HAb18F(ab')2 were 41.90% and 85.50%, respectively. The radio chemical yield of the two groups were >95%, suggesting well stability in vitro. The lipo?hydro partition coefficient values were -0.99 ± 0.03 and-1.49 ± 0.08, respectively, which demonstrated that they were both water?soluble substances. Different Fe2+concentrations (1,5,10,20,40μg/ml) of 125I?SPIO?HAb18F(ab')2 on breast cancer cell lines MDA?MB?231 and MDA?MB?468 showed no significant inhibition of cell proliferation (F values were 0.78, 0.66; P values were 0.58, 0.66). The cell?specific binding experiment showed: MRI signal intensity values on experimental group, the control group and the blank group were (1 670 ± 5), (1 930 ± 8), (2 349 ± 14), respectively, significant differences existed among these groups (F=4 408.48,P=0.000), the rate of signal intensity change of experimental group and the control group were 28.87%,17.78%. SPECT:MDA?MB?231 could uptake 125I?SPIO?HAb18F(ab')2, the cell binding rates were (6.52 ± 0.60)% and (10.52 ± 2.04)% in 20 min and 4 h, respectively.Conclusions Our results suggested that the dual?modality SPECT?MRI nanoprobes 125I?SPIO?HAb18F(ab')2 were prepared successfully with good physicochemical properties and biological characteristics in vitro. These dual?modality molecular imaging nano?probes may have potential to improvearly detection and diagnosis of HAb18G/CD147?expressing cancers and to facilitate the development of HAb18G/CD147?directed interventions.
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Objective To investigate the early diagnosis value of MR by detecting spinal inflammatory lesions in ankylosing spon-dylitis (AS).Methods Forty patients were involved in this study,including 20 cases with short inflammatory back pain (IBP)histo-ry (duration ≤18 months)and 20 cases with long IBP history (duration ≥24 months).MR images were analyzed retrospectively. Results Patients with a short history of IBP had 7 lesions in vertebral bodies (anterior/posterior spondylitis and spondylodiscitis) and 33 lesions in posterior spinal structures (arthritis of costovertebral joints,costotransversal joints,zygapophyseal joints and en-thesitis of spinal ligaments).Patients with a long history of IBP had 27 lesions in vertebral bodies and 24 lesions in posterior spinal structures.Patients with a short history of IBP had significantly more lesions in posterior spinal structures than in vertebral bodies with 82.5% (33/40)vs 1 7.5% (7/40),respectively (P <0.01).In contrast,patients with a long history of IBP had significantly more inflammation in vertebral bodies with 79.4% (27/34)vs 20.6% (7/34),respectively (P <0.01).Conclusion Inflammatory spinal lesions in patients with a short history of IBP are seen more often in the posterior structures.Early detection of inflammatory spinal lesions by MRI is useful for early diagnosis of AS.
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Objective To develop an MR optical dual-modality probe targeting angiogenesis of gastric cancer and to study its physical characteristics , in vitro cytotoxicity and magnetic effects of different pulse sequences on 3 T clinical MR scanner.Methods We conjugated GX1-Cy5.5, a novel gastric cancer neo-vasculature targeted peptide labeled with Cy 5.5, to the surface functionalized magnetic nanoparticles according to different molecular weights (1∶100, 1∶500),resulting in dual-modality probe DPs100 and DPs500 (named DPs).The hydrodynamic size and zeta potential of DPs and DPs 500 were analyzed by nano-ZS.The human umbilical vein endothelial cells (HUVECs) and BGC-823 cells were treated with DPs for 24 h, and methyl thiazol tetrazolium ( MTT) method was used to detect the survival rate of cells.DPs with different concentrations were scanned on different MR sequences , and then the relative signal intensity was observed.The absorbance of HUVECs and BGC823 cells treated with DPs of different concentration (0.00, 1.25, 2.50, 15.00, 50.00, 100.00 and 150.00 μg/ml) were compared with single factor analysis of variance.Relative signal intensity of different MR sequences was compared using a paired Wilcoxon signed-rank test.Results The dual-modality probe targeting angiogenesis of gastric cancer was successfully constructed.The hydrodynamic size of iron oxide nanoparticles , DPs100 and DPs500 was (35.23 ±0.07), (39.49 ±0.16) and (40.43 ±1.70) nm and the Zeta potential was (0.31 ±0.20), ( -4.15 ±0.79) and ( -10.51 ± 2.37) mV.The coupled rates of DPs 100 and DPs500 with polypeptide were 92%and 94% respectively.The absorbance of HUVECs and BGC823 cells treated with DPs of different concentrations were 0.76 ±0.04, 0.80 ±0.03, 0.79 ±0.05, 0.75 ±0.06, 0.74 ±0.05, 0.77 ±0.01,0.71 ±0.04 and 0.38 ±0.04, 0.43 ±0.04, 0.41 ±0.03, 0.43 ±0.07, 0.44 ±0.04, 0.41 ±0.07 and 0.40 ±0.04, there was no statistical significance ( F=0.94, 0.51;P>0.05).The signal intensity increased first and then decreased following the increasing concentrations of DPs on T 1WI,especially on FSPGR T1WI (Z =-3.294,P 10μg/ml( Z=-7.110,P>0.05).With iron concentration≤10 μg/ml,the signal intensity on SSFSE T 2*WI was significantly decreased compared to FSE T2 WI ( Z =-2.023, P <0.05 ) .Conclusions DPs may be potential dual-modal probes for characterization of tumor angiogenesis by MR and optical imaging noninvasively , without causing significant effects on the cell activity in vitro , and SSFSE T2*WI may be the most sensitive sequence for DPs evaluation on MR.
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Objective To study the MR imaging characteristics of benign cerebellar astrocytomas(BCAs) in children. Methods The clinical and MR imaging data of twelve patients with BCAs were reviewed and analyzed retrospectively.Results Of 12 tumors, 7 cases were located in the cerebellar hemisphere, 4 in the vermis, and 1 in the IV ventricle. All children were in company with hydrocephalus rated as extensive (n=9) or moderate (n=3). The tumors ranged in diameter from 23 mm to 68 mm, mean diameter 42 mm. Solid tumors were found in 5 children, and cystic areas occurred in 7 of 12 patients.BCAs were hypointense on T 1-weighted in 10 cases, and hyperintense on T 2WI in 9 cases compared with that of normal brain parenchyma. After contrast injection, BCAs marked (n=2), moderate (n=5), or absent (n=5) enhancement. Hemorrhage and calcification were not common (n=1,0, respectively).Conclusion BCAs has relative characteristic features on MRI in children, and MRI plays an important role in diagnosing and evaluating these tumors preoperatively.
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Objective To prepare the Target-directed probe(Hab18-SPIO) and to test its phisichemical characteristics. Methods The McAb Target-directed probe(Hab18-SPIO) was prepared through hepatocellular carcinoma(HCC) McAb(Hab18) conjugated toSPIO using chemical method,while negative McAb probe(SED-SPIO) was also prepared using the same method.These agents weretested by high-performance liquid chromatography(HPLC) and electron microscope. Results The results of HPLC and electronmicroscope proved that Hab18 was conjugated SPIO effectively.The diameter of particles was between 50 and 70 nm.The binding rate of Hab18 was 97.5%. Conclusion The probe targeted to membrane-associated antigen of HCC(Hab18g) has been successfully prepared,which has novel physiochemical property.It is of great value in specific MR diagnosis of early HCCs.