Objective To observe imaging characteristics of carotid body tumor and schwannoma in carotid space. Methods CT, MRI and digital subtraction angiography (DSA) appearances of 16 patients with carotid body tumors and schwannomas in carotid space confirmed pathologically were retrospectively analyzed. There were 8 patients with carotid body tumors and 8 patients with schwannomas. Six patients with carotid body tumors and 5 patients with schwannomas underwent CT plain scan. All the patients underwent MR plain and contrast-enhanced scan. Four patients with carotid body tumors and 2 patients with schwannomas underwent DSA examination. Results CT: Six carotid body tumors were lobulated soft tissue masses. The density of the tumors was similar to neck muscles. Two carotid body tumors involving jugular foramen expanded jugular foramen, and the margin was irregular and erosion-destructive. Five schwannomas were ovoid or fusiform soft tissue masses. The density of the tumors was mixed. Two schwannomas involved jugular foramen expanded jugular foramen, and the margin was smooth. MRI: Eight carotid body tumors were lobulated, well-defined, longitudinal growth masses with characteristic high-velocity flow voids. The tumor splayed and surrounded internal carotid artery and external carotid artery. The diameters of the arteries were normal. The tumors intensely enhanced on contrast-enhanced MRI. Eight schwannomas were ovoid or fusiform, well-defined, longitudinal growth masses with heterogeneous signal, splaying carotid artery and jugular vein. The diameters of the vessels were narrow. The tumors nonuniformly enhanced on contrast-enhanced MRI. DSA: Four carotid body tumors showed intense tumor blush, while 2 schwannomas showed slight tumor blush. Conclusion According to the imaging characteristic of the tumors, carotid body tumor and schwannoma in carotid space can be accurately differentiated.

Purpose To investigate the diameter change of dorsal root ganglion (DRG) in lumbar disc herniation using three-dimensional MR neurography. Materials and Methods Sixty-ifve patients with lumbar disc herniation and 30 healthy volunteers were selected. Bilateral DRG diameter was measured using MR three-dimensional constructive interference steady state (3D-CISS) sequence at the level of L3-S1 in the control group and at the level of herniation disc in patient group including central and lateral subgroups. The relationship between the sagittal index and DRG diameter at the level of herniation disc was analyzed. Results In the control group, the DRG diameters increased from the level of L3 to S1. The DRG diameters of the central subgroup were bigger than those of the control group (t=-2.485--2.253, P<0.05). The DRG diameters of the lateral subgroup were bigger on the diseased side than the contralateral side (t=1.956-2.432, P<0.05). The DRG diameters of the contralateral side in lateral subgroup were slightly bigger than those of control group without statistical signiifcance (t=-1.248--0.981, P>0.05). The sagittal index was not correlated with DRG diameter. Conclusion 3D-CISS sequence clearly demonstrates morphological changes of lumbosacral nerve root and measures its diameter.

Objective:To explore the value of quantitative parameters of dynamic contrast-enhanced MRI(DCE-MRI) in evaluating the biological behavior of soft tissue tumors.Methods:The clinical data of 69 patients with soft tissue tumors confirmed by pathology in the Affiliated Hospital of Qingdao University from January 2017 to December 2019 were analyzed retrospectively, including 29 benign tumors and 40 malignant tumors. All patients were examined by routine MRI and DCE-MRI before the operation. The DCE-MRI parameters including volume transfer constant (K trans), rate constant (K ep) and extracellular space volume fraction (V e) were acquired by post-processing software analysis. Microvessel density (MVD) and Ki-67 labeling index (Ki-67 LI) were detected using immunohistoche mical method. Spearman correlation test was used to analyze the correlation between DCE-MRI quantitative parameters and MVD and Ki-67 LI.Independent sample t-test or Mann-Whitney U test was used to compare the difference of parameters between benign and malignant group, and the receiver operating characteristic (ROC) curves were performed to evaluate the diagnostic value. Results:There was positive correlation between K trans, K ep and MVD ( r=0.633, 0.727, P<0.0l), and positive correlation between K trans, K ep and Ki-67 LI ( r=0.557, 0.612, P<0.01). There was no correlation between V e and MVD, Ki-67 LI ( P>0.05). The K trans, K ep, MVD and Ki-67 LI in the malignant group were higher than those in the benign group, and the differences were significant ( P<0.05).There was no significant difference in V e value between malignant group and benign group. When K trans value of 0.169/min was used, the sensitivity, specificity and area under the ROC curve (AUC) for differentiating benign and malignant soft tissue tumors were 84.6%, 85.8% and 0.859, respectively. When K ep value of 0.367/min was used, the sensitivity, specificity and AUC were 92.3%, 83.3% and 0.846, respectively. Conclusion:The DCE-MRI quantitative parameters K trans and K ep can be used to evaluate the biological behavior of soft tissue tumors.

Objective:To investigate the distribution and morphological characteristics of brain magnetic resonance imaging (MRI) lesions in patients with myelin oligodendrocyte glycoprotein (MOG) antibody related demyelinating diseases and aquaporin-4 (AQP4) antibody positive neuromyelitis optica spectrum disorders (NMOSD) and their clinical value in early diagnosis.Methods:A total of 35 patients with MOG antibody related demyelinating diseases [20 males and 15 females; aged 31 (25, 43) years] and 36 patients with AQP4 antibody positive NMOSD [3 males and 33 females; aged 42 (29, 54) years] were collected retrospectively from September 2018 to June 2021 in Chenzhou First People′s Hospital and the Affiliated Hospital of Qingdao University which were classified as MOG group and AQP4 positive group respectively. All patients underwent routine cranial MRI scanning before treatment and the location, shape and quantity of intracranial lesions were recorded. Wilcoxon rank sum test was used to compare the number of different types of lesions between the two groups. Logistic regression analysis was used to evaluate the significance of different lesions for the two diseases.Results:There were 7 types of lesions with significant differences in different parts and shapes. Stepwise Logistic regression showed that cortical and juxtacortical lesions ( OR=21.91, 95% CI 3.09-61.69, P<0.05) and infratentorial peripheral white matter lesions ( OR=10.48, 95% CI 2.00-18.89, P<0.05) were the most important risk factors in the MOG group. The incidence of cortical and juxtacortical lesions in the MOG group was 51.4% (18/35), which was higher than that in the AQP4 positive group (2.8%, 1/36; χ2=19.02, P<0.01). The incidence of infratentorial peripheral white matter lesions in the MOG group was 31.4% (11/35), which was higher than that in the AQP4 positive group (5.6%, 2/36; χ2=6.31, P<0.05). Receiver operating characteristic (ROC) curve showed that peripheral lesions [including 6 types of lesions such as supratentorial soft meningitis, cortical encephalitis, cortical and juxtacortical lesions, infratentorial soft meningitis, infratentorial soft meningeal demyelination and infratentorial peripheral lesions, area under curve (AUC)=0.93] were more important than cortical and juxtacortical lesions (AUC=0.75) and central lesions (supratentorial paraventricular white matter lesions, diencephalon, infratentorial paraventricular lesions,AUC=0.64), which had higher diagnostic efficiency. Conclusions:The incidence of intracranial lesions in MOG antibody related demyelinating disease was higher than that in AQP4 positive NMOSD, and the distribution and morphology of intracranial MRI lesions in the two diseases had their characteristic manifestations. Identifying the distribution patterns of peripheral lesions (distributed along pia mater) and central lesions (distributed along ependyma) had a certain reference significance for distinguishing the two groups of diseases.