[CT-Like MRI and Calcium-Suppressed Spectral CT Imaging of Multifocal Bone Infarcts in Both Lower Extremities:Report of One Case].

Bone infarction has a low incidence in clinical practice and mostly occurs in the metaphysis and diaphysis.Few studies report the advanced imaging technique for bone infarction.Here we reported the fast field echo resembling a CT using restricted echo-spacing and calcium-suppressed spectral CT imaging for a case of multifocal bone infarcts in both lower extremities,aiming to provide diagnostic experience for clinical practice.

[Optimal Parameters for Virtual Mono-Energetic Imaging of Liver Solid Lesions].

Objective To explore the optimal parameters for virtual mono-energetic imaging of liver solid lesions. Methods A retrospective analysis was performed on 60 patients undergoing contrast-enhanced spectral CT of the abdomen.The iodine concentration values of hepatic arterial phase images and the CT values of different mono-energetic images were measured.The correlation coefficient and coefficient of variation were calculated. Results The average correlation coefficients between iodine concentrations and CT values of hepatic solid lesion images at 40,45,50,55,60,65,and 70 keV were 0.996,0.995,0.993,0.989,0.978,0.970,and 0.961,respectively.The correlation coefficients at 40(P=0.007),45(P=0.022),50 keV (P=0.035)were higher than that at 55 keV,and the correlation coefficients at 40 keV(P=0.134) and 45 keV(P=0.368) had no significant differences from that at 50 keV.The coefficients of variation of the CT values at 40,45,and 50 keV were 0.146,0.154,and 0.163,respectively. Conclusion The energy of 40 keV is optimal for virtual mono-energetic imaging of liver solid lesions in the late arterial phase,which is helpful for the diagnosis of liver diseases.

[MRI Findings of the Uterine Tumors Resembling Ovarian Sex Cord Tumors:Report of Two Cases].

Uterine tumors resembling ovarian sex cord tumors are rarely reported with limited imaging findings.The current study reported two case of uterine tumors resembling ovarian sex cord tumors and described the detailed MRI findings,which would provide valuable imaging evidence for the diagnosis of such tumors.

[Atypical Cystic Meningioma:Report of One Case].

The diagnosis of atypical cystic meningioma is difficult because of the atypical MRI findings.This paper reported a case of atypical cystic meningioma and described the detailed MRI findings,which would provide valuable imaging evidence for the localization and classification of cystic meningioma.

[Two Cases of Hypovascular Pituitary Metastases and Literature Review].

Pituitary metastasis,a rare kind of intracranial malignant tumor,is characterized by metastasis from all parts of the body to the pituitary.The common tumors metastatic to pituitary are abundant with blood supply,located in the posterior pituitary lobe and/or the pituitary stalk.The lesion shows infiltrative growth,and mainly demonstrates low signal on T1 weighted imaging and high signal on T2 weighted imaging.It is usually enhanced significantly after iodinated contrast administration.The metastatic tumor with poor blood supply is similar to pituitary macroadenoma on magnetic resonance image,which makes it difficult to be differentiated.We reported two cases of pathologically diagnosed pituitary metastasis with poor blood supply and reviewed related papers,aiming to provide the imaging differentiation points of hypovascular pituitary metastasis.

[Papillary Tumor of the Pineal Region:Report of One Case].

We report a case of papillary tumor in the pineal region.The imaging findings mainly included:(1)slight high density on CT images;(2)short T1 signal,cystic changes,and evident enhancement on magnetic resonance imaging.

[CT and Magnetic Resonance Imaging Findings of the Intracranial Extra-cerebral Chondroma:A Case Report].

Intracranial intradural chondroma is a rare disorder,the imaging findings of which have been rarely reported.The current study reported a case of intracranial extra-cerebral chondroma and described the detailed CT and magnetic resonance imaging findings,which would provide valuable imaging evidence for the diagnosis of intracranial extra-cerebral chondroma.

[Evaluation of Lateral Pterygoid Muscle Contraction in Patients with Temporomandibular Disorders Based on 3D-T2 Weighted Imaging].

Objective To evaluate lateral pterygoid muscle(LPM)contraction in the patients with temporomandibular disorders(TMD)based on 3D-T2 weighted imaging(3D-T2WI).Multiplanar reconstruction(MPR)was employed to measure the length of LPM in the images taken in closed-and open-mouth positions. Methods Seventeen TMD patients [age of(29.82±10.70)years,males/females=8/9] and 13 normal volunteers [control,age of(23.54±3.31)years,males/females=6/7] received 3D-T2WI of the temporomandibular joints in closed-and open-mouth positions from November 2019 to April 2020 in Department of Radiology,Hainan Hospital of Chinese PLA General Hospital.According to the position of the discs,the subjects were classified into the following groups:TMD with disc displacement without reduction(TMD-DDwoR),TMD with disc displacement with reduction(TMD-DDwR),TMD without disc displacement(TMDwoDD),and normal control without disc displacement(NCwoDD).MPR was employed to measure the maximal length of the superior belly of LPM.One-way analysis of variance,receiver operating characteristic curve,and permutation test were employed for the statistical analyses. Results The contraction of LPM was significantly shorter in TMD-DDwoR group [(3.36±1.96)mm] than in TMDwoDD group [(7.90±3.95)mm],NCwoDD group [(8.77±3.13)mm](F=12.891,P=0.000),and TMD-DDwR group[(7.12±3.69)mm](χ2=5.314,P=0.031). Conclusion This study confirmed that the contraction of LPM decreased in patients with TMD-DDwoR,which provided imaging evidence for the study of disc displacement mechanism in TMD patients.

[Reproducibility Analysis of Iodine Concentrations of Abdominal Parenchymal Organs Based on Spectral CT].

Objective To investigate the intra-and inter-observer reproducibility of iodine concentrations of abdominal parenchymal organs based on spectral CT.Methods The water-free iodine images of the venous phase were retrospectively obtained from 50 patients with abdominal dynamic spectral CT scans.The iodine concentrations were measured in the left,right and caudate lobes of liver,spleen,pancreas and bilateral kidneys.Intraclass correlation coefficient(ICC)and Bland-Altman plot were employed to analyze the intra-and inter-observer reproducibility.Results The intra-observer ICCs of the left,right and caudate lobes of liver,spleen,pancreas,and left and right kidneys were 0.938(0.894,0.965),0.932(0.884,0.961),0.939(0.895,0.965),0.947(0.909,0.970),0.912(0.851,0.949),0.946(0.906,0.969)and 0.907(0.842,0.946),which indicated good intra-observer reproducibility.The inter-observer ICCs of the left,right and caudate lobes of liver,spleen,pancreas,and left and right kidneys were 0.947(0.909,0.970),0.927(0.875,0.958),0.943(0.902,0.968),0.956(0.924,0.975),0.934(0.887,0.962),0.927(0.875,0.958)and 0.892(0.818,0.937),which indicated good inter-observer reproducibility.Bland-Altman plots presented that more than 95% points of the intra-observer differences located within 95% CI of limits of agreement for the caudate lobe of liver,spleen,pancreas and bilateral kidneys,which was same as inter-observer differences of the caudate lobe of liver,spleen and right kidney.Conclusion The iodine concentration measurement based on the spectral CT presented good intra-and inter-observer reproducibility for the caudate lobe of liver and spleen.

Alterations of regional homogeneity in Parkinson's disease with mild cognitive impairment: a preliminary resting-state fMRI study.

PURPOSE: Mild cognitive impairment (MCI) is commonly observed in Parkinson's disease (PD), even in the early stages. However, the neural substrates of cognitive impairment in PD remain unclear. The aim of the current study was to investigate the change of local brain function in PD patients with MCI. METHODS: Fifty patients with PD, including 25 PD patients with MCI (PD-MCI) and 25 PD patients with normal cognition (PD-NC), and 25 age- and sex-matched healthy controls (HC) were enrolled. Conventional magnetic resonance imaging (MRI), 3D structural images, and resting state-functional MRI (rs-fMRI) were performed in all subjects. Regional homogeneity (ReHo) was measured based on the rs-fMRI images to investigate the altered local brain functions. RESULTS: Brain regions with decreased ReHo were located in the left posterior cerebellar lobe in PD sub-groups compared to the HC group, and the brain regions with increased ReHo were located in the limbic lobe (right precuneus/bilateral middle cingulate cortex) in PD-MCI compared with HC group. PD-MCI presented with increased ReHo in the bilateral precuneus/left superior parietal lobe and decreased ReHo in the left insula compared to PD-NC. ReHo values for the left precuneus were negatively related to neuropsychological scores, and ReHo values for the left insula were positively related to neuropsychological scores in PD subjects. CONCLUSION: The present study demonstrated abnormal spontaneous synchrony in the left insula and left precuneus in patients with PD-MCI compared to PD-NC, which might provide a novel insight into the diagnosis and clinical treatment of cognitive impairment in PD.

Effect of MR Field Strength on the Texture Features of Cerebral T2-FLAIR Images: A Pilot Study.

Objective To investigate effect of MR field strength on texture features of cerebral T2 fluid attenuated inversion recovery (T2-FLAIR) images. Methods We acquired cerebral 3D T2-FLAIR images of thirty patients who were diagnosed with ischemic white matter lesion (WML) with MR-1.5T and MR-3.0T scanners. Histogram texture features which included mean signal intensity (Mean), Skewness and Kurtosis, and gray level co-occurrence matrix (GLCM) texture features which included angular second moment (ASM), Contrast, Correlation, Inverse difference moment (IDM) and Entropy, of regions of interest located in the area of WML and normal white matter (NWM) were measured by ImageJ software. The texture parameters acquired with MR-1.5T scanning were compared with MR-3.0T scanning. Results The Mean of both WML and NWM obtained with MR-1.5T scanning was significantly lower than that acquired with MR-3.0T (P<0.001), while Skewness and Kurtosis between MR-1.5T and MR-3.0T scanning showed no significant difference (P>0.05). ASM, Correlation and IDM of both WML and NWM acquired with MR-1.5T revealed significantly lower values than those with MR-3.0T (P<0.001), while Contrast and Entropy acquired with MR-1.5T showed significantly higher values than those with MR-3.0T (P<0.001). Conclusion MR field strength showed no significant effect on histogram textures, while had significant effect on GLCM texture features of cerebral T2-FLAIR images, which indicated that it should be cautious to explain the texture results acquired based on the different MR field strength.

[Hypovascular Pituitary Metastasis from Poorly Differentiated Lung Adenocarcinoma:Report of One Case].

Pituitary metastasis is a rare intracranial malignant tumor originated from other malignant tumors at other parts of the body.Pituitary metastases are typically hypervascular,while hypovascular pituitary metastasis is rare.Radiologically,hypovascular pituitary metastasis is difficult to be distinguished from pituitary adenoma.This article reports one case of pathologically confirmed hypovascular pituitary metastasis,with the main diagnostic clues including history of malignant tumor,presence of normal pituitary in the intrasellar region,and isointensity on T1 and T2 sequence.

[Optimal Mono-energy in Mono-energetic Spectral Computed Tomography of Enhanced Renal Cortex in Cortical Phase Based on Iodine Concentration].

Objective To identify the optimal mono-energetic enhanced spectral CT for renal cortex in cortical phase based on the iodine concentration. Methods Fifty patients with normal renal function received the abdominal enhanced spectral CT examination.The iodine concentration and CT values of the multiple mono-energetic spectral images were measured on renal cortex in cortical phase,and the correlation between the iodine concentration and the CT values and the coefficient of variation(CV)were analyzed. Results The correlation analysis demonstrated that the correlation coefficient was 0.994,0.994,0.993,0.987,0.976,0.960,and 0.938 between mono-energetic spectral CT images(40-100 keV with interval 10 keV,respectively)and iodine concentration(all P <0.001).The correlation coefficients of 40 keV,50 keV(P=0.007)and 60 keV(P=0.030)were significantly higher compared with that of 70 keV,and the correlation coefficients were not significantly among 40 keV,50 keV and 60 keV(P =0.590).The CV of renal cortex in cortical phase was 0.21,0.20,and 0.19 for 40 keV,50 keV,and 60 keV,respectively. Conclusion 60 keV is the optimal mono-energy for the enhanced spectral CT of the renal cortex in cortical phase.

[Fibrous Meningioma with Ring Enhancement in Cerebellopontine Angle Region:Report of One Case].

Fibrous meningioma is a common subtype of meningioma. Contrast-enhanced scan typically shows evident homogeneous enhancement,while ring enhancement has not been described. In this article,we report a case of fibrous meningioma with ring enhancement in cerebellopontine angle region.

Altered functional connectivity of the marginal division in Parkinson's disease with mild cognitive impairment: A pilot resting-state fMRI study.

BACKGROUND: The marginal division (MrD) is an important subcortical center involved in learning and memory. Mild cognitive impairment (MCI) is commonly seen in patients with Parkinson's disease (PD), but the neurobiological basis is yet to be elucidated. PURPOSE: To use resting-state functional magnetic resonance imaging (rs-fMRI) to explore the altered functional connectivity (FC) of the MrD in patients with PD-MCI. STUDY TYPE: Prospective pilot study. POPULATION: Twenty-five patients with PD-MCI; 25 PD patients and no cognitive impairment (PD-NCI); and 25 healthy control (HC) participants. SEQUENCE: 3.0 T GE Healthcare MRI scanner; three-dimensional T1 -weighted fast spoiled gradient recalled echo (3D T1 -FSPGR); rs-fMRI. ASSESSMENT: The MrD was defined using manual delineation, which was the seed point to compute the FC to examine correlations between low-frequency fMRI signal fluctuations in MrD and the whole brain. STATISTICAL TESTS: Between-group comparisons of the rs-fMRI data were computed using two-sample t-tests in a voxelwise manner after controlling for age and sex, to determine the brain regions that showed significant differences in FC with the bilateral MrDs. Correlation analyses were performed for FC values and cognitive abilities in patients with PD. RESULTS: In the PD-MCI group, compared with the PD-NCI group, we observed lesser FC between the MrD bilaterally and right putamen, left insula, left cerebellum, and left thalamus; greater FC between the MrD bilaterally and left middle cingulate cortex, left middle frontal gyrus, left superior frontal gyrus, left supplementary motor area, and left middle/inferior occipital gyrus. Moreover, the strength of FC between the MrD and regions that showed differences between the PD-MCI and PD-NCI groups was significantly correlated with neuropsychological scores in patients with PD. DATA CONCLUSION: The current study suggests that MrD dysfunction may contribute to MCI in PD. However, the mechanisms underlying this process require further investigation. Level of Evidence 1. Technical Efficacy Stage 2. J. Magn. Reson. Imaging 2019;50:183-192.

Differential Diagnostic Value of Texture Feature Analysis of Magnetic Resonance T2 Weighted Imaging between Glioblastoma and Primary Central Neural System Lymphoma.

Objective To investigate the difference in tumor conventional imaging findings and texture features on T2 weighted images between glioblastoma and primary central neural system (CNS) lymphoma.Methods The pre-operative MRI data of 81 patients with glioblastoma and 28 patients with primary CNS lymphoma admitted to the Chinese PLA General Hospital and Hainan Hospital of Chinese PLA General Hospital were retrospectively collected. All patients underwent plain MR imaging and enhanced T1 weighted imaging to visualize imaging features of lesions. Texture analysis of T2 weighted imaging (T2WI) was performed by use of GLCM texture plugin of ImageJ software, and the texture parameters including Angular Second Moment (ASM), Contrast, Correlation, Inverse Difference Moment (IDM), and Entropy were measured. Independent sample t-test and Mann-Whitney U test were performed for the between-group comparisons, regression model was established by Binary Logistic regression analysis, and receiver operating characteristic (ROC) curve was plotted to compare the diagnostic efficacy.Results The conventional imaging features including cystic and necrosis changes (P=0.000), 'Rosette' changes (P=0.000) and 'incision sign' (P=0.000), except 'flame-like edema' (P=0.635), presented significantly statistical difference between glioblastoma and primary CNS lymphoma. The texture features, ASM, Contrast, Correlation, IDM and Entropy, showed significant differences between glioblastoma and primary CNS lympoma (P=0.006, 0.000, 0.002, 0.000, and 0.015 respectively). The area under the ROC curve was 0.671, 0.752, 0.695, 0.720 and 0.646 respectively, and the area under the ROC curve was 0.917 for the combined texture variables (Contrast, cystic and necrosis, 'Rosette' changes, and 'incision sign') in the model of Logistic regression. Binary Logistic regression analysis demonstrated that cystic and necrosis changes, 'Rosette' changes and 'incision sign' and texture Contrast could be considered as the specific texture variables for the differential diagnosis of glioblastoma and primary CNS lymphoma.Conclusions The texture features of T2WI and conventional imaging findings may be used to distinguish glioblastoma from primary CNS lymphoma.

MRI Histogram Texture Feature Analysis of the Optic Nerve in the Patients with Optic Neuritis.

Objective To evaluate the optic nerve impairment using MRI histogram texture analysis in the patients with optic neuritis.Methods The study included 60 patients with optic neuritis and 20 normal controls. The coronal T2 weighted imaging (T2WI) with fat saturation and enhanced T1 weighted imaging (T1WI) were performed to evaluate the optic nerve. MRI histogram texture features of the involved optic nerve were measured on the corresponding coronal T2WI images. The normal optic nerve (NON) was measured in the posterior 1/3 parts of the optic nerve. Kruskal-Wallis one-way ANOVA was used to compare the difference of texture features and receiver operating characteristic (ROC) curve were performed to evaluate the diagnostic value of texture features for the optic nerve impairment among the affected optic nerve with enhancement (ONwEN), affected optic nerve without enhancement (ONwoEN), contralateral normal appearing optic nerve (NAON) and NON.Results The histogram texture Energy and Entropy presented significant differences for ONwEN vs. ONwoEN (both P=0.000), ONwEN vs. NON (both P=0.000) and NAON vs. NON (both P<0.05). ROC analysis demonstrated that the area under the curve (AUC) of histogram texture Energy were 0.758, 0.795 and 0.701 for ONwEN vs. ONwoEN, ONwEN vs. NON and NAON vs. NON, AUC of Entropy were 0.758, 0.795 and 0.707 for ONwEN vs. ONwoEN, ONwEN vs. NON and NAON vs. NON.Conclusions The altered MRI histogram texture Energy and Entropy could be considered as a surrogate for MRI enhancement to evaluate the involved optic nerve and normal-appearing optic nerve in optic neuritis.

Value of Texture Analysis of Intravoxel Incoherent Motion Parameters in Differential Diagnosis of Pancreatic Neuroendocrine Tumor and Pancreatic Adenocarcinoma.

Objective To evaluate the value of texture features derived from intravoxel incoherent motion (IVIM) parameters for differentiating pancreatic neuroendocrine tumor (pNET) from pancreatic adenocarcinoma (PAC).Methods Eighteen patients with pNET and 32 patients with PAC were retrospectively enrolled in this study. All patients underwent diffusion-weighted imaging with 10 b values used (from 0 to 800 s/mm 2). Based on IVIM model, perfusion-related parameters including perfusion fraction (f), fast component of diffusion (Dfast) and true diffusion parameter slow component of diffusion (Dslow) were calculated on a voxel-by-voxel basis and reorganized into gray-encoded parametric maps. The mean value of each IVIM parameter and texture features [Angular Second Moment (ASM), Inverse Difference Moment (IDM), Correlation, Contrast and Entropy] values of IVIM parameters were measured. Independent sample t-test or Mann-Whitney U test were performed for the between-group comparison of quantitative data. Regression model was established by using binary logistic regression analysis, and receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic efficiency.Results The mean f value of the pNET group were significantly higher than that of the PAC group (27.0% vs. 19.0%, P = 0.001), while the mean values of Dfast and Dslow showed no significant differences between the two groups. All texture features (ASM, IDM, Correlation, Contrast and Entropy) of each IVIM parameter showed significant differences between the pNET and PAC groups (P=0.000-0.043). Binary logistic regression analysis showed that texture ASM of Dfast and texture Correlation of Dslow were considered as the specific imaging variables for the differential diagnosis of pNET and PAC. ROC analysis revealed that multiple texture features presented better diagnostic performance than IVIM parameters (AUC 0.849-0.899 vs. 0.526-0.776), and texture ASM of Dfast combined with Correlation of Dslow in the model of logistic regression had largest area under ROC curve for distinguishing pNET from PAC (AUC 0.934, cutoff 0.378, sensitivity 0.889, specificity 0.854).Conclusions Texture analysis of IVIM parameters could be an effective and noninvasive tool to differentiate pNET from PAC.

Value of Magnetic Resonance Imaging Texture Analysis in the Differential Diagnosis of Benign and Malignant Breast Tumors.

Objective To investigate the difference in texture features on diffusion weighted imaging (DWI) images between breast benign and malignant tumors.Methods Patients including 56 with mass-like breast cancer, 16 with breast fibroadenoma, and 4 with intraductal papilloma of breast treated in the Hainan Hospital of Chinese PLA General Hospital were retrospectively enrolled in this study, and allocated to the benign group (20 patients) and the malignant group (56 patients) according to the post-surgically pathological results. Texture analysis was performed on axial DWI images, and five characteristic parameters including Angular Second Moment (ASM), Contrast, Correlation, Inverse Difference Moment (IDM), and Entropy were calculated. Independent sample t-test and Mann-Whitney U test were performed for intergroup comparison. Regression model was established by using Binary Logistic regression analysis, and receiver operating characteristic curve (ROC) analysis was carried out to evaluate the diagnostic efficiency.Results The texture features ASM, Contrast, Correlation and Entropy showed significant differences between the benign and malignant breast tumor groups (PASM=0.014, Pcontrast=0.019, Pcorrelation=0.010, Pentropy=0.007). The area under the ROC curve was 0.685, 0.681, 0.754, and 0.683 respectively for the positive texture variables mentioned above, and that for the combined variables (ASM, Contrast, and Entropy) was 0.802 in the model of Logistic regression. Binary Logistic regression analysis demonstrated that ASM, Contrast and Entropy were considered as the specific imaging variables for the differential diagnosis of breast benign and malignant tumors.Conclusions The texture analysis of DWI may be a simple and effective tool in the differential diagnosis between breast benign and malignant tumors.

[Atypical Cavernous Hemangioma of the Trigeminal Nerve:Report of One Case].

Extracerebral cavernous hemangioma typically occurs in cavernous sinus in middle cranial fossa,showing iso-or hypointensity on T1WI,obvious hyperintensity on T2WI,and evident enhancement after contrast administration during magnetic resonance imaging(MRI).In this article we report one case of atypical cavernous hemangioma of the trigeminal nerve,with atypical MRI findings including isotense or slight long T2 signal,dotty short T1 signal,and non-enhancement on T1WI.