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Objective To evaluate the accuracy of measurements of atherosclerotic middle cerebral artery (MCA) stenosis with 3.0 T high-resolution magnetic resonance imaging (HR-MRI).Methods Forty patients with symptomatic atherosclerotic stenosis of middle cerebral artery (MCA) confirmed by digital subtraction angiography (DSA) in the Affiliated Hospital of Binzhou Medical College from September 2017 to May 2018 were enrolled in the study.Patients were scanned by HR-MRI sequence (including T1WI,T2WI,PDWI).The MCA M1 stenosis rate on HR-MR images was assessed by warfarin-aspirin symptomatic intracranial artery disease (WASID) method and area measurement algorithm,respectively,and based on the stenosis rate the degree of stenosis (semi-quantitative measurement) was determined.The accuracy of the two measurement methods was evaluated with DSA results as the gold standard.Results The HR-MRI images showed the structure of the vessel wall clearly in 30 patients meeting the measurement requirements.The inner edge of the vessel was clearly distinguishable and smooth,showing eccentric stenosis.The stenosis rate of MCA measured by DSA,WASID method and area measurement algorithm were (82± 17)％,(70± 12)％,(81 ± 16)％,respectively (P＞0.05).The result of area measurement algorithm was better correlated with DSA (r=0.893);and the coincidence of the stenosis degree rate of two measurement method was 90％(27/30).Conclusion The area measurement algorithm based on the HS-MRI has high accuracy in measuring the degree of MCA stenosis,which is of high clinical application value.
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Objective To investigate the clinical application of SWI in detecting calcifications of vertebral artery wall.Methods 1 95 patients who accepted craniocerebral CT scans,and MRI scans (includingT1 WI,T2 WI,T2 GFLAIR,SWI)in recent three years in the Affiliated Hospital of Binzhou Medical University were reviewed.Taking CT as a standard,the calcification of intracranial vertebral artery wall was analyzed using conventional MRI and SWI sequences,and their sensitivities and specificities were calculated.Correlations among various imaging modalities were assessed by measuring the maximum diameter of calcifications.Results The sensitivity of SWI was 93%, and the specificity of SWI was 9 9%.The sensitivity of conventional MRI was 3 1%,and the specificity of conventional MRI was 9 1%. The correlation between SWI and CT was R2＝0.77 (0.60－0.89),while the correlation between conventional MRI and CT was R2＝0.22 (0.02－0.80).Conclusion SWI has high sensitivity and specificity in detecting calcification of intracranial vertebral artery wall,and has a good correlation with CT in measuring calcification,which can be a inspection method to detect calcification of intracranial vertebral artery wall.
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Objective To evaluate the changes of diffusion kurtosis imaging (DKI) parameters with time in cerebral in farction patients,and contrast with diffusion tensor imaging (DWI).Methods DWI and DKI scans were performed in 95 patients of cerebral infarction.The patients were divided into five groups according to the time of cerebral infarction:Hyperacute phase (n=10),acute phase (n=12),early subacute phase (n =33),late subacute phase (n =20) and chronic phase (n =20).Parameters of DKI were obtained,and the parameters and percentage change of diffusion metrics from normal to ischemic tissue were compared.The evolution rule of parameter with time was analyzed.Results Mean kurtosis (MK),axial kurtosis (K//),radial kurtosis (K⊥) of DKI parameters increased after infarction,and reached the peak at acute phase,and decreased gradually with the prolonging of time.Mean diffusion (MD),axial diffusion (D//),radial diffusion (D⊥) of DTI parameters decreased after infarction,and reached the lowest at the acute phase,and increased gradually with the prolonging of time.The percentage change of MK,K//,K⊥ were higher than those of MD,D//,D⊥,and percent change along the axial direction were significantly larger than that along the radial direction.Conclusion DKI is superior to DTI in evaluating cerebral infarction,and can analyze the changes of microstructure of cerebral infarction comprehensively.
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Objective To explore the imaging features of appendiceal mucinous neoplasms and their correlation with the pathology results.Methods The imaging data of 1 6 patients with histopathology proved appendiceal mucinous neoplasms were analyzed retrospectively including mucinous adenoma in 2,low-grade appendiceal mucinous neoplasm (LAMN)in 10,and appendiceal adenocarcinoma in 4. The imaging features were correlated with the result of pathology.Results Mucinous cystadenoma was usually a long oval or strip low density cystic structures with smooth capsule wall and well defined border.Mucinous adenocarcinoma usually presented as a irregular solid-cystic mass with ill-defined border and nodular or separation enhancement.The tumor often infiltrated adjacent bowels,and some of them were accompanied with pseudomyxoma peritonei (PMP)and abdominal implantation metastasi.LAMN had low potential malignancy.The imaging features were between cystadenoma and cystadenocarcinoma.Most cases were similar to mucinous cystadenoma, and some were like to mucinous cystadenocarcinoma.Conclusion The appendiceal mucinous neoplasms have various imaging manifestations. Some cases show some CT and MRI characteristics,which are benefit to the diagnosis of these diseases.
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Objective To investigate the value of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) based on ISHIM sequence in the grading of astrocytic tumor.Methods We collected excised tumors confirmed by histological diagnosis from 42 patients including high-grade astrocytic tumors (10 WHO grade Ⅲ,18 WHO grade Ⅳ),and 14 low-grade astrocytic tumors (1 WHO grade Ⅰ and 13 WHO grade Ⅱ).All patients underwent conventional MR imaging,ISHIM IVIM-DWI,and contrast-enhanced MR imaging.Parameters of tumor parenchyma region,peripheral edema regions and the contralateral normal brain white matter sites were measured,and the statistical analysis was conducted.Results The D value in tumor parenchyma region was significantly lower,but the D* and f values were higher in high-grade astrocytic tumor when compared with lowgrade one and all had statistical significance;in tumor peripheral edema region,D value was lower in high-grade astrocytic tumor than that in low-grade one,and the difference had statistical significance but there was no significant difference in terms of the D* and f values.There was no significant difference of the D,D* and f values in contralateral normal brain white matter sites in both high-and low-grade astrocytic tumor.Conclusion The D,D* and f values measured by ISHIM IVIM-DWI are helpful to the judgment of tumor grade and it has greatapplication value in the differential diagnosis of high-and low-grade astrocytic tumor.
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Objective To investigate the variation of multivoxel 1 H magnetic resonance spectroscopy(1 H-MRS)before and after continuous positive airway pressure(CPAP)treatment in obstructive sleep apnea hypopnea syndrome(OSAHS).Methods Brain multivoxel 1 H-MRS examinations were performed in 25 cases of moderate or severe OSAHS patients before and after CPAP treat-ment,and 25 cases of healthy.The ratios of brain metabolites of the frontal lobe were recorded and analyzed respectively.To observe whether the lactate(Lac)peak appeared or not.Results In the frontal lobe,the NAA/Cr,NAA/Cho of the patients before treatment (2.021 2±0.231 2 and 1.608 8±0.257 1,respectively)was decreased compared with the healthy (2.726 8±0.607 1 and 2.445 6± 0.437 5).The NAA/Cr,NAA/Cho of the patients after treatment (2.314 0±0.312 8 and 2.01 6 4±0.424 0,respectively)was in-creased compared with the patients before treatment (2.021 2±0.231 2 and 1.608 8±0.257 1).The NAA/Cr,NAA/Cho of the pa-tients after treatment (2.314 0±0.312 8 and 2.01 6 4±0.424 0,respectively)was decreased compared with the healthy (2.726 8± 0.607 1 and 2.445 6±0.437 5),and the difierences were statistically significant (P <0.01).The Cho/Cr of the patients before treatment (1.293 2±0.261 5)was increased compared with the healthy (1.129 2±0.157 7),the difference was statistically significant(P <0.05).Lac peak was not detected in all.Conclusion Multivoxel 1 H-MRS can demonstrate sensitively the changes of brain metabolism in pa-tients with OSAHS before and after CPAP treatment,and may provide imaging evidence for clinical therapeutic effect and prognostic evaluation.
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Objective To investigate CT and MRI imaging of Warthin tumor of parotid gland.Methods CT and MRI character-istics of 5 1 patients confirmed as Warthin tumor by operation and pathology were analyzed retrospectively.Results Among 5 1 cases, 43 patients were males,and 8 patients were females.A total of 84 lesions were found in all cases,20 cases had at least 2 lesions.The margins of lesions were well-defined.68 lesions were round or elliptical.45 lesions located in the posterior and inferior quadrant of the parotid gland completely or premodinantly.The density and signal of most lesions were homogeneous.The parenchymal area of most lesions showed an early moderate-remarkable enhancement.Small blood vessels surrounded the lesions in 1 9 cases.Conclusion CT and MRI are important and valuable for the diagnosis of Warthin tumor.
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Objective To evaluate the clinical value of susceptibility weighted imaging (SWI)in full-term neonatal hypoxic ische-mic encephalopathy (HIE).Methods Sixty-three neonates with HIE were collected and scanned by Siemens 3.0T superconducting MR scanner.Routine axial conventional MRI scan and axial SWI scan were conducted.Results In 63 neonates,a total of 29 cases with different degree of intracranial hemorrhage were scanned with SWI sequence.A total of 1 5 1 intracranial hemorrhages were found.Conventional MRI sequences were performed in 1 5 cases with different degree of intracranial hemorrhage.Only 78,43 and 88 hemorrhages were found by T1 WI,T2 WI and T2 Flair sequences,respectively.SWI were significantly superior to conventional MRI sequences in displaying the scope and boundary definition of hemorrhage.Conclusion SWI sequence is obviously better than the con-ventional MRI sequences in bleeding detection and displaying hemorrhage stove,and it provides a powerful imaging method for the clinical diagnosis and treatment.
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Objective To investigate the value of magnetic resonance (MR)diffusion kurtosis imaging (DKI)in diagnostic classi-fication of astrocytic tumors.Methods 31 patients with astrocytic tumors confirmed by operation and pathology were collected,in-cluding low-grade tumors (WHO gradeⅠ and Ⅱ)in 14 and high-grade ones (WHO grade Ⅲ and Ⅳ)in 1 7.Routine MRI and DKI scan were preoperatively conducted using Siemens 3.0T MR scanner.Mean kurtosis (MK),radial kurtosis (RK)and axial kurtosis (AK)values were calculated in the solid portion of the tumors and the contralateral normal white matter.Results The MK,RK and AK values in tumors were lower than those in contralateral normal white matter,and were significantly higher in high-grade tumors than those in low-grade ones (P <0.05).Conclusion The MK,RK and AK values obtained by DKI reflect the histological structure changes of the astrocytic tumors.DKI is helpful for the diagnostic classification of astrocytic tumors,exhibiting more value in optimi-zing the treatment.
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Objective To investigate the characteristic of MRS in patients suffered diffuse axonal injury (DAI)in acute and suba-cute stage,and the correlation between MRS changes and the severity of disease.Methods We reported MRI and proton magnetic resonance spectroscopy studies of 3 6 head-inj ured patients in acute and subacute stage.Proton magnetic resonance spectra were ac-quired from the white matter and gray matter of bibateral frontal lobe that on conventional MRI appeared normal by using 2D MRSI at 3.0T MRI .30 volunteers as contronl were studied at the same time.Results In patient group,N-acetylaspartate/creatine ratios were (2.14±0.15)and (1.71±0.08)choline/creatine ratios were(1.35±0.13)and (1.03±0.08)for the white matter and the gray matter,respectivily.The brain N-acetylaspartate/creatine ratio was reduced and the choline/creatine ratio was increased in pa-tient group compared with the controls.The increase in the choline/creatine ratio was significant even in the moderate and severe in-j ured groups.Furthermore,there was a significantly correlation between the severity of head inj ury and the N-acetylaspartate/cho-line ratio,and changes in patients with metabolite ratios of the GCS score had a strong correlation.Conclusion We conclude that DAI patients with normal conventional imaging manifestations of the frontal lobe appear metabolite ratio change,suggesting the existence of local cerebral inj ury,and it has a strong correlation between the prognosis and MRS changes.MRS may provide an useful method that can tell us the severity of the brain inj ury in patients with DAI .
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Objective To determine whether the different pathological types of astrocytic tumours can be differentiated by diffusion tensor MR imaging. Methods In this study, diffusion tensor MR imaging was performed preoperatively in 67 patients with different pathological types of astrocytic tumours. Furthermore , T1WI, T2WI, FLAIR and T1WI enhancement scanning by GD-DTPA were performed preoperatively in all patients. The Mean diffusivity (ADC) values in the tumor parenchyma and normal white matter from different pathological types of astrocytic tumours were measured and analyzed. The ADC with the tumor parenchyma and normal white matter from the tumours were statistically analyzed by SPSS 19.0. The results were expressed as ± s and P < 0.05 was regarded as statistically significant differences. Results There were many differences with ADC (< 10-9 mm2/s) in the tumor parenchyma between fibrillary astrocytoma (1.48 ± 0.12、0.72 ± 0.05) from fat cell astrocytoma (1.31 ± 0.07, 0.69 ± 0.03), There were also many differences with ADC ( < 10-9 mm2/s) in the tumor parenchyma between fibrillary and fat cell astrocytoma from anaplastic astrocytoma (1.06 ± 0.11, 0.71 ± 0.04) and giant cell glioblastoma (0.98 ± 0.09, 0.73 ± 0.04). There were not differences with ADC in the tumor parenchyma between anaplastic astrocytoma from giant cell gliobastona. Conclusion Measurement of tumor parenchyma′s ADC values can identify different pathological types of astrocytic tumours , but not between anaplastic astrocytoma and giant cell glioblastoma. DTI is essential to preoperative evalution of astrocytic tumours.
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Objective To evaluate the effect of non-linear blending function for dual-energy CT on image of pulmonary angiogra-phy.Methods 27 patients underwent dual energy CT pulmonary angiography(CTPA).Data obtained with 100 kVp,140kVp,and non-linear blending were divided into group A,B,and C respectively.CT value of emboli were measured.Corresponding signal to noise ratio(SNR )and contrast to noise ratio(CNR)were calculated.One-way Anova analysis and Friedman test were used to ana-lyze statistical significance among these values.Results On quantitative analysis of 27 patients,there was no statistical difference for CT value of CTPA among the three groups(P >0.05).For the noise,CNR and SNR,there were statistically significant among the three groups(P <0.05).Conclusion The non-linear blending function has certain advantages in improved image signal-to-noise ratio and it can be used in CT pulmonary angiography examination for patients suspected pulmonary embolism clinically .