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Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality worldwide. Transcatheter arterial chemoembolization (TACE) has been performed as a palliative treatment for patients with HCC. However, HCC is easy to recur after TACE. Magnetic resonance imaging (MRI) has clinical potential in evaluating the TACE treatment effect for patients with liver cancer. However, traditional MRI has some limitations.To explore the clinical potential of diffusion kurtosis imaging (DKI) in predicting recurrence and cellular invasion of the peritumoral liver zone of HCC after TACE.Seventy-six patients with 82 HCC nodules were recruited in this study and underwent DKI after TACE. According to pathological examinations or the overall modified response evaluation criteria in solid tumors (mRECIST) criterion, 48 and 34 nodules were divided into true progression and pseudo-progression groups, respectively. The TACE-treated area, peritumoral liver zone, and far-tumoral zone were evaluated on DKI-derived metric maps. Non-parametricDKI metrics, including mean diffusivity (MD), axial diffusivity (DA), radial diffusivity (DR), axial kurtosis (KA), and anisotropy fraction of kurtosis (Fak), showed statistically different values between the true progression and pseudo-progression groups (DKI has been demonstrated with robust performance in predicting the therapeutic response of HCC to TACE. Moreover, DKI might reveal cellular invasion of the peritumoral zone by molecular diffusion-restricted change.

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, accounting for about 90% of liver cancer cases. It is currently the fifth most common cancer in the world and the third leading cause of cancer-related mortality. Moreover, recurrence of HCC is common. Microvascular invasion (MVI) is a major factor associated with recurrence in postoperative HCC. It is difficult to evaluate MVI using traditional imaging modalities. Currently, MVI is assessed primarily through pathological and immunohistochemical analyses of postoperative tissue samples. Needle biopsy is the primary method used to confirm MVI diagnosis before surgery. As the puncture specimens represent just a small part of the tumor, and given the heterogeneity of HCC, biopsy samples may yield false-negative results. Radiomics, an emerging, powerful, and non-invasive tool based on various imaging modalities, such as computed tomography, magnetic resonance imaging, ultrasound, and positron emission tomography, can predict the HCC-MVI status preoperatively by delineating the tumor and/or the regions at a certain distance from the surface of the tumor to extract the image features. Although positive results have been reported for radiomics, its drawbacks have limited its clinical translation. This article reviews the application of radiomics, based on various imaging modalities, in preoperative evaluation of HCC-MVI and explores future research directions that facilitate its clinical translation.

Background In this study, we explored whether the proposed short-echo-time magnitude (setMag) image derived from quantitative susceptibility mapping (QSM) could resemble NM-MRI image in substantia nigra (SN), by quantitatively comparing the spatial similarity and diagnosis performances for Parkinson’s disease (PD). Methods QSM and NM-MRI were performed in 18 PD patients and 15 healthy controls (HCs). The setMag images were calculated using the short-echo-time magnitude images. Bilateral hyperintensity areas of SN (SNhyper) were manually segmented on setMag and NM-MRI images by two raters in a blinded manner. The inter-rater reliability was evaluated by the intraclass correlation coefficients (ICC) and the Dice similarity coefficient (DSC). Then the inter-modality (i.e. setMag and NM-MRI) spatial similarity was quantitatively assessed using DSC and volume of the consensual voxels identified by both of two raters. The performances of mean SNhyper volume for PD diagnosis on setMag and NM-MRI images were evaluated using receiver operating characteristic (ROC) analysis. Results The SNhyper segmented by two raters showed substantial to excellent inter-rater reliability for both setMag and NM-MRI images. The DSCs of SNhyper between setMag and NM-MRI images showed substantial to excellent voxel-wise overlap in HCs (0.80 ~ 0.83) and PD (0.73 ~ 0.76), and no significant difference was found between the SNhyper volumes of setMag and NM-MRI images in either HCs or PD (p > 0.05). The mean SNhyper volume was significantly decreased in PD patients in comparison with HCs on both setMag images (77.61 mm3 vs 95.99 mm3, p 3 vs 96.00 mm3, p hyper volume for PD diagnosis were 0.904 on setMag and 0.906 on NM-MRI images. No significant difference was found between the two curves (p = 0.96). Conclusions SNhyper on setMag derived from QSM demonstrated substantial spatial overlap with that on NM-MRI and provided comparable PD diagnostic performance, providing a new QSM-based multi-contrast imaging strategy for future PD studies.

To investigate whether an improved U2-Net model could be used to segment the median nerve and improve segmentation performance, we performed a retrospective study with 402 nerve images from patients who visited Huashan Hospital from October 2018 to July 2020; 249 images were from patients with carpal tunnel syndrome, and 153 were from healthy volunteers. From these, 320 cases were selected as training sets, and 82 cases were selected as test sets. The improved U2-Net model was used to segment each image. Dice coefficients (Dice), pixel accuracy (PA), mean intersection over union (MIoU) and average Hausdorff distance (AVD) were used to evaluate segmentation performance. Results revealed that the Dice, MIoU, PA and AVD values of our improved U2-Net were 72.85%, 79.66%, 95.92% and 51.37 mm, respectively, which were comparable to the actual ground truth; the ground truth came from the labeling of clinicians. However, the Dice, MIoU, PA and AVD values of U-Net were 43.19%, 65.57%, 86.22% and 74.82 mm, and those of Res-U-Net were 58.65%, 72.53%, 88.98% and 57.30 mm. Overall, our data suggest our improved U2-Net model might be used for segmentation of ultrasound median neural images.

Context Chronic excess of growth hormone (GH) often leads to systemic complications. The reversibility of these complications after GH resolution is not fully understood. Objective To investigate when and to what extent will the comorbidities be ameliorated. Design We conducted a prospective study comprising 24 patients with acromegaly, who achieved remission after transsphenoidal surgery. The dynamic changes of endocrine, cardiovascular, respiratory, sleep, bone and morphology parameters were evaluated at enrollment and 1 week, 1 month, 3 months, 6 months and 12 months after surgery. Results Random GH dropped by 98.4% at the first day postoperatively. IGF-I index dropped by 50% and 64% at 1 week and 1 month respectively and remained unchanged onwards. Glucose metabolism improved significantly at 1 week and stabilized at 1 month. Testosterone in male patients recovered to normal range since 1 month. Systolic blood pressures dropped markedly at 3 months while diastolic blood pressures fell mildly at later visits. Abnormal lung function showed no improvement. The decrease of bone formation and resorption markers occurred at 1 week and 3 months, respectively. At 1 month, the tongue area declined while the airway volume increased significantly, accompanied with improved obstructive sleep apnea syndrome. Extremities, lips and nasal ala became smaller since 1 week. Liver, kidney and spleen volumes declined by 6.4, 15.9, 9.2%, respectively at 1 month. The volumes of pancreas and adrenal showed no change. Conclusions The rapid resolution of excessive GH led to the reversible changes of systemic comorbidities in a time-dependent and organ-specific manner.

Purposes The aims of the study were to analyze the conventional and diffusion-weighted MRI (DWI) of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) and to investigate underlying mechanisms. Methods Features of 58 acute and 68 chronic stroke-like lesions as well as global brain abnormalities of 40 Chinese MELAS patients were analyzed. Results Gyriform DWI hyperintensity with decreased apparent diffusion coefficient (ADC) and patchy DWI hyperintensity with normal ADC were noted in 56 of 58 and 2 of 58 cortical regions of acute lesions, respectively. High ADC and mix of low and high ADC were observed in 51 of 58 and 5 of 58 affected subcortical white matters, respectively. Lacunar infarcts existed in 23 of 40 patients. Among 17 patients who have been followed, recurrence, progression, and progressive atrophy were noted in 8, 9, and 4 cases, respectively. Conclusions This study demonstrates the conventional and diffusional MRI features of MELAS, suggesting a model of acute stroke-like lesions in which the cortex manifest with cytotoxic edema and the subcortical area with vasogenic edema.

Background Diffusion kurtosis imaging (DKI) has the potential to provide microstructural insights into myelin and axonal pathology with additional kurtosis parameters. To our knowledge, few studies are available in the current literature using DKI by tract-based spatial statistics (TBSS) analysis in patients with multiple sclerosis (MS). The aim of this study is to assess the performance of commonly used parameters derived from DKI and diffusion tensor imaging (DTI) in detecting microstructural changes and associated pathology in relapsing remitting MS (RRMS). Methods Thirty-six patients with RRMS and 49 age and sex matched healthy controls underwent DKI. The brain tissue integrity was assessed by fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (Da), radial diffusivity (Dr), mean kurtosis (MK), axial kurtosis (Ka) and radial kurtosis (Kr) of DKI and FA, MD, Da and Dr of DTI. Group differences in these parameters were compared using TBSS (P Kr (76.7%) > Ka (53.5%) and Dr (78.8%) > MD (76.7%) > FA (74.1%) > Da (28.3%) for DKI, and Dr (79.8%) > MD (79.5%) > FA (68.6%) > Da (40.1%) for DTI. DKI-derived diffusion parameters (FA, MD, and Dr) were sensitive for detecting abnormality in WM regions with coherent fiber arrangement; however, the kurtosis parameters (MK and Kr) were sensitive to discern abnormalities in WM regions with complex fiber arrangement. Conclusions The diffusion and kurtosis parameters could provide complementary information for revealing brain microstructural damage in RRMS. Dr and DKI_Kr may be regarded as useful surrogate markers for reflecting pathological changes in RRMS.

Cushing's disease, also known as adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas (PAs) that cause excess cortisol production, accounts for up to 85% of corticotrophin-dependent Cushing's syndrome cases. However, the genetic alterations in this disease are unclear. Here, we performed whole-exome sequencing of DNA derived from 12 ACTH-secreting PAs and matched blood samples, which revealed three types of somatic mutations in a candidate gene, USP8 (encoding ubiquitin-specific protease 8), exclusively in exon 14 in 8 of 12 ACTH-secreting PAs. We further evaluated somatic USP8 mutations in additional 258 PAs by Sanger sequencing. Targeted sequencing further identified a total of 17 types of USP8 variants in 67 of 108 ACTH-secreting PAs (62.04%). However, none of these mutations was detected in other types of PAs (n = 150). These mutations aggregate within the 14-3-3 binding motif of USP8 and disrupt the interaction between USP8 and 14-3-3 protein, resulting in an elevated capacity to protect EGFR from lysosomal degradation. Accordingly, PAs with mutated USP8 display a higher incidence of EGFR expression, elevated EGFR protein abundance and mRNA expression levels of POMC, which encodes the precursor of ACTH. PAs with mutated USP8 are significantly smaller in size and have higher ACTH production than wild-type PAs. In surgically resected primary USP8-mutated tumor cells, USP8 knockdown or blocking EGFR effectively attenuates ACTH secretion. Taken together, somatic gain-of-function USP8 mutations are common and contribute to ACTH overproduction in Cushing's disease. Inhibition of USP8 or EGFR is promising for treating USP8-mutated corticotrophin adenoma. Our study highlights the potentially functional mutated gene in Cushing's disease and provides insights into the therapeutics of this disease.

OBJECTIVE Our purpose was to evaluate the diagnostic performance of diffusion-weighted imaging, the relative minimum apparent diffusion coefficient (rADCmin) in differentiating primary central nervous system lymphomas (PCNSLs) from glioblastomas (GBMs) and inflammatory demyelinating pseudotumors (IDPs). MATERIALS AND METHODS Magnetic resonance images were reviewed retrospectively in 82 patients including 39 PCNSLs, 35 GBMs, and 8 IDPs. Regions of interest were drawn around the tumor on contrast-enhanced axial images; these images were transferred onto coregistered ADC maps to obtain the ADCmin, and the normalized ADCmin ratios (rADCmin) were calculated using the formula rADCmin = ADCmin of the lesion / ADCmin of the normal white matter. The rADCmin values were compared between PCNSLs, GBMs, and IDPs using the analysis of variance test. Receiver operating characteristic curves were constructed to evaluate the diagnostic performance of rADCmin values and to determine the optimum thresholds. Simple logistic regression was analyzed to evaluate the relationship between ADCs and tumor cellularity. RESULTS The rADCmin value was significantly lower in PCNSLs (0.675 ± 0.113) than GBMs (0.765 ± 0.059) and IDPs (0.834 ± 0.067) (PCNSL vs GBM, P < 0.001; PCNSL vs IDP, P < 0.001). Relative ADCmin was a significant assessor for differentiating PCNSLs from non-PCNCLs (P < 0.001). The optimal cutoff value was 0.722 (sensitivity, 74.5%; specificity, 74.1%; area under the curve, 0.803) on receiver operating characteristic analysis. A stronger negative correlation (r = -0.755, P = 0.000) was obtained between the cytoplasm and rADCmin. CONCLUSIONS Relative ADCmin value is helpful in differentiating PCNSL from GBM and IDP. Thus, ADC values may provide a useful supplement to the information obtained from conventional contrast-enhanced magnetic resonance imaging and assist in future treatment planning.

To prospectively evaluate and compare the potential of various diffusion metrics obtained from mono-exponential model (MEM), bi-exponential model (BEM), and stretched exponential model (SEM)-based diffusion-weighted imaging (DWI) in the grading of meningiomas.Consecutive 93 patients with histopathologically confirmed meningiomas received DWI of multiple b-values. Apparent diffusion coefficient (ADC), pure molecular diffusion (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), water molecular diffusion heterogeneity index (alpha), and distributed diffusion coefficient (DDC) were calculated and compared between low-grade and high-grade meningiomas. Receiver operating characteristic and multivariable stepwise logistic regression analyses were performed to evaluate the diagnostic performance of different parameters.The mean and normalised ADC, D, f, and DDC values were significantly lower in high-grade meningiomas than those in low-grade meningiomas (all p0.05). The AUCs of D and DDC were significantly higher than that of f in the differentiation (all p0.05). D was the only variable that could be used to independently differentiate high-grade and low-grade meningiomas (p0.001).Different models of DWI, including MEM, BEM, and SEM, are useful in the differentiating high-grade and low-grade meningiomas; however, D obtained from BEM is the most promising diffusion parameter for predicting the grade of meningiomas.

Purpose This study aimed to perform an evaluation of 4 perfusion computed tomographic (PCT) parameters (relative cerebral blood flow, cerebral blood volume, mean transit time [MTT], and delay time [DT]) in a series of patients with acute ischemic stroke to find optimal parameters to predict infarct core and penumbra. Methods Twenty-six patients with symptoms suggesting stroke less than 7 hours from onset were enrolled in this study. They all underwent admission and 24-hour PCT and a 24-hour diffusion-weighted imaging. Perfusion computed tomographic maps were assessed for relative reduced cerebral blood flow and cerebral blood volume and increased MTT and DT. Receiver operating characteristic curve analysis was performed to locate the optimal threshold for each parameter, using diffusion-weighted imaging as the gold standard. Results The PCT parameter that most accurately describes the penumbra is the relative MTT of 150% or greater (area under the curve, 0.827; 95% confidence interval, 0.826-0.827), whereas the parameter that most accurately describes the infarct core is the relative DT of + 2.0 seconds or greater (area under the curve, 0.879; 95% confidence interval, 0.878-0.879). Conclusions The optimal parameters to define the infarct core and the penumbra are relative DT (≥+ 2.0 seconds) and relative MTT (≥ 150%).

Background: Neoadjuvant chemotherapy (NAC) is generally an effective method of reducing locally advanced malignant breast lesions before surgery; assessing the tumor response to NAC is crucial for patient management. T2 relaxation times can reflect biological state of lesions, may prove useful to assess the response to NAC. Objectives: To investigate the lesion T2 relaxation times change in breast cancer neoadjuvant chemotherapy (NAC). Patients and Methods: In total, 26 patients underwent NAC. Magnetic resonance imaging (MRI) T2 mapping was performed before and after NAC. The T2 relaxation times were obtained by using Functool software on an AW 43 workstation. The treatment response was assessed according to the pathological response classification. We aimed to analyze the changes in the T2 relaxation times before and after NAC as well as to study the relationship between the response and the lesion T2 relaxation times after NAC. Results: In 26 cases with NAC, the mean lesion T2 relaxation time before NAC was 81.34 ± 13.68 ms, compared with 64.50 ± 8.71 ms after NAC. Significant differences in the lesion T2 relaxation times existed between the pre- and post-NAC (P < 0.001) ; based on the pathology results, the mean lesion T2 relaxation times in 23 of the 26 responders (63.18 ± 8.37 ms) was shorter than in 3 of the 26 nonresponders (74.62 ± 2.32 ms) after NAC (P = 0.029). Conclusion: In breast cancer after NAC, the lesion T2 relaxation time was reduced in the responders, and this finding is potentially useful to assess the response to NAC.

To determine whether the apparent diffusion coefficient (ADC) correlates with histopathologic findings and whether ADC values can be used to differentiate benign from atypical/malignant meningiomas.MR images were reviewed retrospectively in 138 patients with meningiomas treated between September 1997 and July 2003. The ADC values were measured in the lesions and peritumoral edema, and the normalized ADC (NADC) ratios were calculated using the formula NADC=ADC of the tumor/ADC of the normal white matter. The ADC findings were compared with the histopathologic findings after resection using the World Health Organization criteria (2007).Meningiomas were histologically graded as malignant (9%), atypical (14%) and benign (77%). Of the 138 meningiomas, 32 (23%) were atypical (n=19) or malignant (n=13), whereas 106 (77%) were typical. The mean ADC values were statistically different between typical and atypical/malignant meningiomas (0.97 ± 0.21 × 10(-3)mm(2)/s vs 0.85 ± 0.17 × 10(-3)mm(2)/s). The mean NADC ratios were also significantly lower in the atypical/malignant group (1.09 ± 0.23) than in the benign group (1.24 ± 0.25; P=0.0020.05). The mean ADC values and NADC ratios did not differ significantly among fibrous, meningothelial, transitional and atypical tumors (P0.05). The mean ADC values and NADC ratios were higher in the angiomatous and secretory subgroups than in the fibrous, meningothelial, transitional, atypical and malignant subgroups (P0.05). The ADC values and NADC ratios were the lowest in the malignant subgroup, and the difference between atypical and malignant meningiomas was statistically significant (P0.05).Meningioma subgroups displayed different ADC values from each other. Thus, ADC values may provide a useful supplement to the information obtained from conventional contrast-enhanced MR imaging, enhancing the ability of medical professionals to differentiate among the subgroups of meningiomas.

OBJECTIVE: To investigate the features of pathologically confirmed gliosarcomas using computed tomography (CT) and magnetic resonance (MR) imaging. METHODS: We retrospectively reviewed the cross-sectional CT and MR images of 54 patients (37 males and 17 females; mean age, 44.5 years; range, 13-74 years) with gliosarcomas confirmed by histopathology. RESULTS: Across all patients, there were 59 lesions. On nonenhanced CT and MR images, tumors were predominantly inhomogeneous. On the postcontrast CT and MR images, 50 (84.7%) irregular lesions had thick walls with a strong rim- and ringlike enhancement, whereas the remaining 9 (15.3%) round or oval lesions had even thin walls with an enhanced peripheral ring. Magnetic resonance spectroscopy showed increased choline and lactate values, along with decreased N-acetylaspartate and creatine values. On diffusion-weighted imaging, the tumor was slightly or markedly hyperintense compared with the white matter. CONCLUSION: A well-demarcated mass located peripherally, with rimlike or ring enhancement, is a common presentation of gliosarcoma on CT and MR images. In addition, magnetic resonance spectroscopy and diffusion-weighted imaging can be used to make a differential diagnosis.

Isocitrate dehydrogenase (IDH) mutations are frequently present in oligodendroglial tumors (OTs) and have prognostic value. We assessed whether diffusion tensor imaging (DTI) metrics could aid the noninvasive detection of IDH mutations and their correlations with tumor proliferation and microvascular density (MVD) in OTs.Ninety patients with OTs who underwent conventional magnetic resonance imaging (MRI) and DTI were retrospectively reviewed (3T). IDH mutations were determined by immunohistochemical staining or direct sequencing. MVD and cell proliferation were evaluated by immunohistochemical staining with anti-CD31 and Ki-67, respectively. The Mann-Whitney U-test was applied to each of the imaging parameters. Spearman correlation analysis and receiver operating characteristic curve analysis were performed.The maximal fractional anisotropy (FA), ratio of maximal FA (rmFA), minimal ADC, and ratio of minimal (rmADC) values were demonstrated to be significantly different between the OTs with IDH1/2 mutations and those without mutations (P0.05). The areas under the curve (AUCs) for the maximal FA, rmFA, minimal ADC, and rmADC were 0.79, 0.82, 0.77, and 0.80, respectively. A combination rmFA and rmADC for the diagnosis of IDH1/2 mutations led to sensitivity, specificity, and AUC of 91.5%, 76.5%, and 0.86, respectively. The Ki-67 and MVD levels in the IDH-mutated samples were lower than those in the IDH wildtype cases (P0.05).DTI metrics may provide a noninvasive method for assessing the IDH statuses of OTs. Significantly higher minimal ADC and lower maximal FA in OTs with IDH mutations may suggest that IDH mutations lead to proliferation inhibition and an angiogenesis decrease.

Pituitary adenoma is one of the most common intracranial neoplasms, and its genetic basis remains largely unknown. To identify genetic susceptibility loci for sporadic pituitary adenoma, we performed a three-stage genome-wide association study (GWAS) in the Han Chinese population. We first analyzed genome-wide SNP data in 771 pituitary adenoma cases and 2,788 controls and then carried forward the promising variants for replication in another 2 independent sets (2,542 cases and 3,620 controls in total). We identified three new susceptibility loci below the genome-wide significance threshold (P < 5 × 10(-8)) in the combined analyses: 10p12.31 (rs2359536, P(meta) = 2.25 × 10(-10) and rs10828088, P(meta) = 6.27 × 10(-10)), 10q21.1 (rs10763170, P(meta) = 6.88 × 10(-10)) and 13q12.13 (rs17083838, P(meta) = 1.89 × 10(-8)). This study is the first GWAS to our knowledge on sporadic pituitary adenoma, and our results provide insight into the genetic basis of this disease.

Objective The purpose of this study was to characterize the magnetic resonance imaging (MRI), and computed tomographic (CT) findings in a series of 8 patients with papillary glioneuronal tumor (PGNT). Methods The routine MRI (n = 8), DWI (n = 7), and CT (n = 4) of 8 PGNTs verified by pathologic examination were reviewed. The location, internal architecture, calcification, attenuation value on CT; and signal features and degree of enhancement of the lesions on MRI were evaluated. Results Papillary glioneuronal tumor showed relatively characteristic imaging features as well-demarcated masses with cystic degeneration, calcification, and inhomogeneous enhancement. Six of the 8 cases were located in the periventricular area. The solid part of the lesion was isointense (n = 5/8) or hypointense (n = 3/8) to gray matter on T1-weighted imaging. Diffusion-weighted imaging presented heterogeneous hypointensity and isointensity (n = 4/7) or homogeneous hypointensity (n = 3/7) in the solid part of the lesion. Conclusions The location adjacent to lateral ventricle, isointensity on T1-weighted imaging, and low signal on DWI may be of some specificity to PGNT.

The degree of pathological microvascular proliferation is an important element in evaluation of the astrocytoma grade. This study was aimed to quantitatively assess the microvascular permeability of brain astrocytoma with the volume transfer constant (K(trans)) and volume of extravascular extracellular space per unit volume of tissue (Ve) from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and to evaluate the effectiveness of the K(trans) and Ve in the grading of astrocytoma.The highest values of the K(trans) and Ve of 67 patients with astrocytoma (27 with grade II, 12 with grade III, and 28 with grade IV) were obtained. The comparisons of the differences of the K(trans) and Ve between the different grades were conducted using the Mann-Whitney rank-sum tests. Spearman's rank correlation coefficients were determined between K(trans) values, Ve values and astrocytoma grades. Receiver operating characteristic (ROC) curve analyses were performed to determine the cut-off values for the K(trans) and Ve to distinguish between the different grades of astrocytoma.There were significant differences (P0.001) between the different grades in the K(trans) values and Ve values, except for grades III and IV. The K(trans) values and Ve values were both correlated with astrocytoma grades (both P0.001). The ROC curve analyses showed that the cut-off values for the K(trans) and Ve provided the best combination of sensitivity and specificity in distinguishing between grade II and grade III or IV astrocytomas.DCE-MRI can play an important role in assessing the microvascular permeability and the grading of brain astrocytoma.

Fenestrations involving aneurysms have been well documented. Only sporadic papers have been reported on fenestrations associated with AVMs (arteriovenous malformations) with few cases. Our study is to determine the rate of co-occurrence of fenestrations and AVMs and to analyze the possible relationship between them by CTA.Between January 2006 and February 2012, the CTA data of 5,657 consecutive patients were retrospectively reviewed.A total of 12 cases (.21%) of fenestrations associated with AVMs were found. Of these, single-fenestrations were identified in 9 cases, and multifenestrations were found in 3 cases. Among 349 fenestrations, there were 15 cases of multifenestrations. The frequency of multifenestrations among fenestrated patients without AVMs was 3.6%. There was no significant difference in the incidence of AVMs in cases with and without fenestrations (3.4% and 2.7%), and there was no significant difference in the incidence of fenestration in cases with and without AVMs (7.7% and 6.1%, χ(2) = .643, P = .423).CTA may play a vital role in assessing the anomalies of co-occurring AVM and fenestration, with an incidence of .21%. The frequency of multifenestrations in fenestrated cases with AVMs was higher than those without AVMs, though there is no significant association between fenestrations and AVMs.

This study aimed to determine whether the use of apparent diffusion coefficient (ADC) values can improve the diagnostic efficacy of magnetic resonance imaging (MRI) to differentiate hemangiopericytoma (HPC) from angiomatous and anaplastic meningioma.Preoperative diffusion-weighted imaging (DWI) studies of 38 patients with pathologically proven intracranial HPC (n = 12) and angiomatous (n = 13) or anaplastic meningioma (n = 13) were retrospectively reviewed. ADC values were measured in the tumor parenchyma and peritumoral edema, and used to obtain normalized ADC (NADC) ratios (ADC of tumor/ADC of normal white matter).Mean ADC values were significantly different between HPC and anaplastic meningioma (1.17 ± 0.30 × 10(-3) mm(2)/s and 0.75 ± 0.11 × 10(-3) mm(2)/s, respectively). Mean NADC ratios were also significantly lower in the malignant cases (0.95 ± 0.13) compared with the benign HPCs (1.53 ± 0.39; P0.05). Mean ADC values and NADC ratios did not differ significantly between angiomatous meningioma and HPC (P0.05), whereas mean ADC values and NADC ratios were lower for anaplastic meningioma than for either angiomatous meningioma or HPC (P0.05). Mean ADC value in peritumoral edema in HPC (1.48 ± 0.11 × 10(-3) mm(2)/s) was lower than in either angiomatous (1.73 ± 0.28 × 10(-3) mm(2)/s) or anaplastic (1.72 ± 0.25 × 10(-3) mm(2)/s) meningioma (P0.05), and there was no significant difference between ADC values in anaplastic versus angiomatous meningioma (P0.05).ADC values in tumor parenchyma and peritumoral edema can provide helpful information that is otherwise not available from conventional MRI to differentiate HPC from angiomatous and anaplastic meningioma.

Aim To present the neuroradiological and clinical findings of fourth-ventricular meningiomas to increase awareness of this entity. Materials and methods The computed tomography (CT; n = 5), magnetic resonance imaging (MRI; n = 9) features and clinical presentations of 10 patients with pathologically documented fourth-ventricular meningiomas were retrospectively analysed. Results All tumours appeared as well-demarcated masses in the fourth ventricle at CT and MRI. The tumour shape was round in eight cases (80%) and irregular in two cases (20%). The CT images of five cases showed predominantly isoattenuation in three cases and high attenuation in two cases, with a mean attenuation value of 52 HU. In addition, calcifications were seen in three cases. At MRI, nine masses were isointense (n = 6) or hypointense (n = 3) to grey matter on T1-weighted images and mildly hyperintense (n = 4), isointense (n = 3), hypointense (n = 1), and of mixed signal intensity (n = 1) on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images. Signal voids were visible in two cases. Enhancement after injection of contrast material was marked homogeneous (n = 5) or heterogeneous (n = 5) on CT or T1-weighted images. Three tumours had mild peritumoural oedema. Three tumours were associated with obstructive hydrocephalus. The pathological subtype of the 10 meningiomas was fibromatous (n = 5), atypical (n = 2), and one each of transitional, psammomatous, and clear-cell type. Conclusion Although fourth-ventricular meningioma is quite rare, it should be considered in differential diagnosis of neoplasms within the fourth ventricle. The relatively typical radiological appearance, combined the age and sex of patients, can suggest the diagnosis of fourth-ventricular meningioma.

Retroperitoneal hemangiopericytoma is a kind of uncommon tumor. We report a case of 41-year-old man who was diagnosed retroperitoneal tumor without significant symptoms by abdominal ultrasonography. Abdominal CT and MRI scans show a 6 cm × 5 cm solid tumor delineated clearly from adjacent organs. Excision of the tumor was performed and the histopathological examination confirmed the diagnosis of hemangiopericytoma.

AIM To evaluate the value of three-dimensional (3D) whole brain perfused volume computed tomography (3D PBV CT) based on CT angiography (CTA) data in patients with hyperacute cerebral infarction. METHODS Thirty-five patients who had suffered stroke with anterior circulation within 3 hours underwent nonenhanced CT (NECT) scanning and CTA. Neuro PBV, a 3D software, was utilized to process the raw CTA data and a PBV image of the brain was obtained. Magnetic resonance imaging (MRI) was performed 6 hours after CT imaging. The volume and quantity of the ischemic lesion on 3D PBV and NECT were compared with MR-diffuse-weighted imaging (DWI). RESULTS The numbers of cerebral infarcts detected by MRI, PBV, and NECT were 40, 38 and 16, respectively. The results of kappa analysis between NECT and PBV with MR were −.0128 and .7622, and a paired t-test analysis for the measurement of infarct volume between PBV and MRI was t = 7.249, P > .05. The lesions that were not detected by PBV volumes less than 4.5 cm3. CONCLUSION 3D PBV CT has the potential to assess the full extent of an ischemic stroke at an early stage, whereas PBV is limited to the detection of small infarcts. The 3D PBV CT technique based on CTA data requires no additional radiation exposure or contrast medium injection, and can be performed in a short period of time. J Neuroimaging 2012;22:149-154.

Hemangiopericytomas (HPCs) have a relentless tendency for local recurrence and metastases, differentiating between benign meningiomas and HPCs before surgery is important for both treatment planning and the prognosis appraisal. The purpose of this study was to evaluate the correlations between CT perfusion parameters and microvessel density (MVD) in extra-axial tumors and the possible role of CT perfusion imaging in preoperatively differentiating benign meningiomas and HPCs.Seventeen patients with benign meningiomas and peritumoral edema, 12 patients with HPCs and peritumoral edema underwent 64-slice CT perfusion imaging pre-operation. Perfusion was calculated using the Patlak method. The quantitative parameters, include cerebral blood volume (CBV), permeability surface (PS) of parenchyma, peritumoral edema among benign meningiomas and HPCs were compared respectively. CBV and PS in parenchyma, peritumoral edema of benign meningiomas and HPCs were also compared to that of the contrallateral normal white matter respectively. The correlations between CBV, PS of tumoral parenchyma and MVD were examined.The value of CBV and PS in parenchyma of HPCs were significantly higher than that of benign meningiomas (P0.05), while the values of CBV and PS in peritumoral edema of benign meningiomas and HPCs were not significantly different (P0.05). MVD in parenchyma of HPCs were significantly higher than that of benign meningiomas (P0.05). There were positive correlations between CBV and MVD (r = 0.648, P0.05), PS and MVD (r = 0.541, P0.05) respectively. Furthermore, the value of CBV and PS in parenchyma of benign meningiomas and HPCs were significantly higher than that of contrallateral normal white matter (P0.05), the value of CBV in peritumoral edema of benign meningiomas and HPCs were significantly lower than that of contrallateral normal white matter (P0.05), while the value of PS in peritumoral edema of benign meningiomas and HPCs were not significantly different with that of contrallateral normal white matter (P0.05).CT perfusion imaging can provide critical information on the vascularity of HPC and benign meningiomas. Determination of maximal CBV and corresponding PS values in the parenchyma may be useful in the preoperative differentiating HPC from benign meningiomas.

To explore the relationship between clinical ischemic events and carotid calcification detected by 64 slices CT angiography.We retrospectively analyzed the carotid calcified plaques in 116 patients underwent the 64 slices CT angiography. The relationship between the carotid calcification and the clinical ischemic events was analyzed.A total of 377 plaques were detected and the incidence of carotid plaque calcification was 63.40%. Incidence of plaque calcification was significantly lower in patients with ages50 years than that in patients with ages 51 - 59 years, 60 - 69 years and higher than 70 years (P = 0.003, P = 0.002, P = 0.000, respectively). The incidence of plaque calcification in the common carotid artery was significantly lower than the carotid bifurcation (P = 0.000) and the internal carotid artery (P = 0.000). The incidences of calcification in the mild, moderate and severe degree of stenosis and occlusion were 46.54%, 33.33%, 26.67% and 0% respectively. The distribution of intraplaque calcium was similar between patients with ischemic event and non-ischemic event group. However, the incidence of calcification was significantly lower patients with ischemic event than that in patients without ischemic event (30.34% vs. 43.10%, P = 0.013). Calcified plaque was negatively associated with ischemic event (beta = -0.688, P = 0.006).64 slices CT angiography can analyze the characterization of carotid plaque calcium.

In this report, we separately performed dynamic computed tomographic perfusion and dynamic susceptibility contrast-T2* magnetic resonance perfusion imaging on 2 cases of brain tumors (one was a glioblastoma, and the other was a central neurocytoma). Between the 2 methods, we saw the discrepancy in values of cerebral blood volume and cerebral blood flow, differences in location of the maximal cerebral blood volume, and regions with abnormal increased cerebral blood flow besides the solid part of the tumors. Both differences and similarities of the 2 techniques with their advantages and pitfalls were analyzed in detail. The developing trends in the near future were also discussed.

OBJECTIVE: Parkinson's disease (PD) is associated with well-documented morphological changes in substantia nigra and basal ganglia nuclei. This study evaluates the ability of magnetic resonance imaging to detect these changes and investigates the relationship between severity of clinical findings and degree of morphological change. This correlation may provide valuable information in early diagnosis of PD. METHODS: Sixteen patients with early stage PD, eight patients with advanced PD, and eight normal controls were studied by 3T magnetic resonance imaging. The whole brain volume and the volumes of the caudate, putamen, globus pallidus, and substantia nigra were calculated on three-dimensional reconstructed images. RESULTS: Putamen volume was significantly diminished in patients with early PD and advanced PD compared with that in controls (P < 0.05), and the percentage of atrophy was 12.5 and 26.5%, respectively. The putamen volume was negatively correlated with Hoehn and Yahr staging (r = -0.720, P < 0.001). Pallidal volume was reduced only in advanced PD (P = 0.023). There were no significant differences in total brain, caudate, or substantia nigra among these three groups CONCLUSION: Magnetic resonance imaging-based volumetric measurement is a sensitive method in the assessment of morphological changes of PD in vivo. The putamen atrophy was correlated with the severity of clinical findings. The volumetric measurement of putamen could potentially be a useful indicator of PD in the early stage.

To map dynamic changes of primary motor cortex after total brachial plexus traction injury by using functional magnetic resonance imaging, and to explore underlying probable mechanisms.Five patients with total traumatic root avulsions of the brachial plexus underwent varied kinds of nerve transfer to restore partially shoulder or elbow function. Four of them (cases 1, 3, 4, 5) accepted the first fMRI examination prior to surgery treatment, and four of them (cases 2, 3, 4, 5) accepted second or third or fourth fMRI follow-up re-examinations after surgery treatment. Maps of neuronal activation within the motor cortex were generated for both hands in each patient by using BOLD-fMRI and the cluster size and position were recorded. The motor tasks consisted of simple hand grasping of both hands respectively. Patients with paralytic hand were asked to complete task under "virtual" condition. The cluster size and intensity as well as location of motor activation within the primary motor cortex of the affected hand generated were compared with those of unaffected hand generated as reference in single subject, and the resultant maps of follow-up re-examinations were also compared with those of the prior examinations.All patients' unaffected hand movement generated strong signal change within the contralateral primary motor cortex. In contrast, the clusters generated by affected hand showed very small and lower intensity than usual (2 cases) or could not be induced (2 case) in the first examination that prior to surgery treatment and seemed larger gradually in the following re-examination with time increasing.Peripheral nerve injury can produced significant changes in the motor cortex of human brain. fMRI is a valuable tool to evaluate neural plasticity in motor cortex after peripheral nerve injury.

The degree of malignancy in brain glioma needs to be assessed by MRI findings and clinical data before operations. There have been previous attempts to solve this problem with a fuzzy rule extraction algorithm based on fuzzy min-max neural networks. We utilize support vector machines with floating search method to select relevant features and to predict the degree of malignancy. Computation results show that the feature subset selected by our techniques can yield better classification performance. In contrast with the base line method, which generated two rules and obtained 83.21% accuracy on the whole data set, our method generates one rule to yield 88.21% accuracy.