Swirl sign score system: a novel and practical tool for predicting hematoma expansion risk after spontaneous intracerebral hemorrhage.

OBJECTIVE: To methodically analyze the swirl sign and construct a scoring system to predict the risk of hematoma expansion (HE) after spontaneous intracerebral hemorrhage (sICH). METHODS: We analysed 231 of 683 sICH patients with swirl signs on baseline noncontrast computed tomography (NCCT) images. The characteristics of the swirl sign were analyzed, including the number, maximum diameter, shape, boundary, minimum CT value of the swirl sign and the minimum distance from the swirl sign to the edge of the hematoma. In the development cohort, univariate and multivariate analyses were used to identify independent predictors of HE, and logistic regression analysis was used to construct the swirl sign score system. The swirl sign score system was verified in the validation cohort. RESULTS: The number and the minimum CT value of the swirl sign were independent predictors of HE. The swirl sign score system was constructed (2 points for the number of swirl signs > 1 and 1 point for the minimum CT value ≤ 41 Hounsfield units). The area under the curve of the swirl sign score system in predicting HE was 0.773 and 0.770 in the development and validation groups, respectively. CONCLUSIONS: The swirl sign score system is an easy-to-use radiological grading scale that requires only baseline NCCT images to effectively identify subjects at high risk of HE. ADVANCES IN KNOWLEDGE: Our newly developed semi-quantitative swirl sign score system greatly improves the ability of swirl sign to predict HE.

Atomic-scale observation of calcium occupation in spinel cobalt ferrite towards the regulation of intrinsic magnetic properties.

Spinel ferrites have drawn intensive attention because of their adjustable magnetic properties by ion doping, among which calcium (Ca) is an essential dopant that is widely employed in massive production. However, its exact lattice occupation and relationship with intrinsic magnetic properties remain unclear. Here, we successfully prepared Ca-doped cobalt ferrite (CoFe2O4) nanoparticles by electrospinning. Ca2+ is observed to occupy both the tetrahedral Fe site and the octahedral Co site using spherical aberration correction transmission electron microscopy (TEM) and prefers to occupy the octahedral site at a high doping level. Such dual occupation behavior affects the tetrahedral and octahedral sublattices differently, resulting in nonmonotonic saturation magnetization variation, reduced magnetocrystalline anisotropy and negative magnetization in the zero field cooling (ZFC) process. By controlling the Ca doping amount, increased saturation magnetization and reduced coercivity can be obtained simultaneously. Our findings establish the relationship between the atomic-scale structural change and the macroscopic magnetic properties of spinel ferrites, promoting the development of new ferrite materials.

A novel clinical-radscore nomogram for predicting ruptured intracranial aneurysm.

Objectives: Our study aims to find the more practical and powerful method to predict intracranial aneurysm (IA) rupture through verification of predictive power of different models. Methods: Clinical and imaging data of 576 patients with IAs including 192 ruptured IAs and matched 384 unruptured IAs was retrospectively analyzed. Radiomics features derived from computed tomography angiography (CTA) images were selected by t-test and Elastic-Net regression. A radiomics score (radscore) was developed based on the optimal radiomics features. Inflammatory markers were selected by multivariate regression. And then 4 models including the radscore, inflammatory, clinical and clinical-radscore models (C-R model) were built. The receiver operating characteristic curve (ROC) was performed to evaluate the performance of each model, PHASES and ELAPSS. The nomogram visualizing the C-R model was constructed to predict the risk of IA rupture. Results: Five inflammatory features, 2 radiological characteristics and 7 radiomics features were significantly associated with IA rupture. The areas under ROCs of the radscore, inflammatory, clinical and C-R models were 0.814, 0.935, 0.970 and 0.975 in the training cohort and 0.805, 0.927, 0.952 and 0.962 in the validation cohort, respectively. Conclusion: The inflammatory model performs particularly well in predicting the risk of IA rupture, and its predictive power is further improved by combining with radiological and radiomics features and the C-R model performs the best. The C-R nomogram is a more stable and effective tool than PHASES and ELAPSS for individually predicting the risk of rupture for patients with IA.

Comparison of Ruptured Intracranial Aneurysms Identification Using Different Machine Learning Algorithms and Radiomics.

Different machine learning algorithms have different characteristics and applicability. This study aims to predict ruptured intracranial aneurysms by radiomics models based on different machine learning algorithms and evaluate their differences in the same data condition. A total of 576 patients with intracranial aneurysms (192 ruptured and 384 unruptured intracranial aneurysms) from two institutions are included and randomly divided into training and validation cohorts in a ratio of 7:3. Of the 107 radiomics features extracted from computed tomography angiography images, seven features stood out. Then, radiomics features and 12 common machine learning algorithms, including the decision-making tree, support vector machine, logistic regression, Gaussian Naive Bayes, k-nearest neighbor, random forest, extreme gradient boosting, bagging classifier, AdaBoost, gradient boosting, light gradient boosting machine, and CatBoost were applied to construct models for predicting ruptured intracranial aneurysms, and the predictive performance of all models was compared. In the validation cohort, the area under curve (AUC) values of models based on AdaBoost, gradient boosting, and CatBoost for predicting ruptured intracranial aneurysms were 0.889, 0.883, and 0.864, respectively, with no significant differences among them. Of note, the performance of these models was significantly superior to that of the other nine models. The AUC of the AdaBoost model in the cross-validation was within the range of 0.842 to 0.918. Radiomics models based on the machine learning algorithms can be used to predict ruptured intracranial aneurysms, and the prediction efficacy differs among machine learning algorithms. The boosting algorithms might be superior in the application of radiomics combined with the machine learning algorithm to predict aneurysm ruptures.

Prediction of short-term prognosis of patients with hypertensive intracerebral hemorrhage by radiomic-clinical nomogram.

Hypertensive intracerebral hemorrhage (HICH) is the most common type of spontaneous intracerebral hemorrhage in China which is associated with high mortality and disability. We sought to develop and validate a noncontrast computed tomography (NCCT)-based nomogram model to achieve short-term prognostic prediction for patients with HICH. We retrospectively studied 292 patients with HICH from two medical centers, and they were divided into training (n = 151), validation (n = 66), and testing cohorts (n = 75). Based on radiomics, univariate and multivariate, and logistic regression analyses, four models (black hole sign, clinical, radiomics score, and combined models) were established to predict the prognosis of patients with HICH 30 days after the onset. The results suggested that the combined model had the best predictive performance with the area under the receiver operating characteristic curve (AUC) of 0.821, 0.816, and 0.815 in the training, validation, and testing cohorts, respectively. In addition, a radiomics-clinical (R-C) nomogram was visualized. A calibration curve analysis showed that the R-C nomogram had satisfactory calibration in the three cohorts. A decision curve analysis demonstrated that the R-C nomogram was clinically valuable. Our results suggest that the R-C nomogram can accurately and reliably predict the short-term prognosis of patients with HICH and provide a useful evaluation for making individualized treatment plans.

FTLD-TDP assemblies seed neoaggregates with subtype-specific features via a prion-like cascade.

Morphologically distinct TDP-43 aggregates occur in clinically different FTLD-TDP subtypes, yet the mechanism of their emergence and contribution to clinical heterogeneity are poorly understood. Several lines of evidence suggest that pathological TDP-43 follows a prion-like cascade, but the molecular determinants of this process remain unknown. We use advanced microscopy techniques to compare the seeding properties of pathological FTLD-TDP-A and FTLD-TDP-C aggregates. Upon inoculation of patient-derived aggregates in cells, FTLD-TDP-A seeds amplify in a template-dependent fashion, triggering neoaggregation more efficiently than those extracted from FTLD-TDP-C patients, correlating with the respective disease progression rates. Neoaggregates are sequentially phosphorylated with N-to-C directionality and with subtype-specific timelines. The resulting FTLD-TDP-A neoaggregates are large and contain densely packed fibrils, reminiscent of the pure compacted fibrils present within cytoplasmic inclusions in postmortem brains. In contrast, FTLD-TDP-C dystrophic neurites show less dense fibrils mixed with cellular components, and their respective neoaggregates are small, amorphous protein accumulations. These cellular seeding models replicate aspects of the patient pathological diversity and will be a useful tool in the quest for subtype-specific therapeutics.

Abnormal corpus callosum induced by overt hepatic encephalopathy impairs interhemispheric functional coordination in cirrhosis patients.

BACKGROUND: Although overt hepatic encephalopathy (OHE) patients were shown to have bilaterally symmetrical structural and functional abnormalities in the whole brain, few studies have focused on the bilateral cerebral hemisphere commissural fibers and measured functional coordination between bilateral hemispheres. This study aimed to investigate the structural changes of the corpus callosum (CC) and interhemispheric functional coordination in patients with OHE and to test the hypothesis that abnormal CC induced by OHE impairs interhemispheric functional coordination in cirrhosis patients. METHODS: The microstructural integrity and the volumes of each subregion of the CC were analyzed by diffusion tensor imaging (DTI) and three-dimensional T1-weighted imaging. Voxel-mirrored homotopic connectivity (VMHC) was derived from resting-state functional magnetic resonance imaging (MRI). RESULTS: Compared with the healthy controls (HCs) and patients without hepatic encephalopathy (noHE), the OHE group showed decreased volumes in all subregions of the CC. In OHE patients, the decreased fractional anisotropy (FA) of CC-5 correlated with decreased VMHC in the middle occipital gyrus (MOG) and precuneus. The value of FA in CC-5 and the volumes of CC-3, CC-4, and CC-5 showed correlations with neuropsychological performance in patients with OHE. CONCLUSIONS: These findings suggest that impairment of interhemispheric white matter pathways may disturb the functional connectivity associated with coordination and neurocognitive performance.

An individualized prediction of time to cognitive impairment in Parkinson's disease: A combined multi-predictor study.

BACKGROUND: Cognitive impairment (CI) is important for the prognosis of Parkinson's disease (PD). Early prediction whether and when cognitive decline from normal cognition (NC) will occur is crucial for preventing or delaying the progression timely. The current study aimed to provide a personalized risk assessment of CI by using baseline information and establishing a multi-predictor nomogram. METHODS: 108 patients with PD were collected from the Parkinson's Progression Markers Initiative (PPMI), of whom 58 had progressed to CI and 50 remained NC during 5-year follow up. Radiomics signatures were obtained by using least absolute shrinkage and selection operator (LASSO) Cox regression algorithm. Clinical factors and laboratory biomarkers were selected by multivariate Cox regression analysis. The combined model of radiomics signatures and clinical risk factors was developed by a multivariate Cox proportional hazard model. A multi-predictor nomogram derived from the combined model was established for individualized estimation of time to progress (TTP) of CI. We analyzed the risk of two subgroups of the combined model by Kaplan-Meier (KM) analysis. RESULTS: The combined model showed the best performance with a C-index of 0.988 and 0.926 in the training and validation datasets. KM analysis verified significant TTP of CI (P＜0.05) between two subgroups stratified by the cutoff value (-0.058). CONCLUSION: The combined model and its multi-predictor nomogram can be used to perfectly and individually predict the TTP of CI for patients with PD. Stratification of PD will benefit its timely clinical intervention and the delay and prevention of CI.

Differentiating Parkinson's disease motor subtypes: A radiomics analysis based on deep gray nuclear lesion and white matter.

OBJECTIVE: To investigate the feasibility of radiomics analysis of brain MR images to differentiate Parkinson's disease motor subtypes. METHODS: 42 postural instability gait difficulty (PIGD) patients, 92 tremor-dominant (TD) patients and 96 healthy controls were included from the Parkinson's Progressive Marker Initiative public database. For each subject, 4850 radiomic features from 148 cortical and 14 subcortical brain regions were extracted. The variance threshold and the least absolute shrinkage and selection operator were used to select the optimal features. Classification models based on Support Vector Machine, Logistic Regrcession, and Multi-Layer Perceptron were constructed to assess the performance of optimal features in the discrimination of the two subtypes. Correlations between radiomic features and clinical scores of the two subtypes were estimated. RESULTS: The Support Vector Machine demonstrated the best performance in discriminating between the two subtypes, and the mean area under the curve was 0.833 (specificity = 83.3%, sensitivity = 75.0%, and accuracy = 80.7%). For the postural instability gait difficulty patients, these optimal features in the hippocampal showed closed correlations with the Montreal Cognitive Assessment scores (P < 0.05). CONCLUSION: The results of our study provide preliminary evidence that radiomics analysis of brain MR images could allow discrimination between patients with TD, PIGD and control subjects and has great potential value in the clinical practice.

Radiomics-based classification models for HBV-related cirrhotic patients with covert hepatic encephalopathy.

INTRODUCTION: The significant abnormalities of precuneus (PC), which are associated with brain dysfunction, have been identified in cirrhotic patients with covert hepatic encephalopathy (CHE). The present study aimed to apply radiomics analysis to identify the significant radiomic features in PC and their subregions, combine with clinical risk factors, then build and evaluate the classification models for CHE diagnosis. METHODS: 106 HBV-related cirrhotic patients (54 had current CHE and 52 had non-CHE) underwent the three-dimensional T1-weighted imaging. For each participant, PC and their subregions were segmented and extracted a large number of radiomic features and then identified the features with significant discriminative power as the radiomics signature. The logistic regression analysis was employed to develop and evaluate the classification models, which are constructed using the radiomics signature and clinical risk factors. RESULTS: The classification model (R-C model) achieved best diagnostic performance, which incorporated radiomics signature (4 radiomic features from right PC), venous blood ammonia, and the Child-Pugh stage. And the area under the receiver operating characteristic curve values (AUC), sensitivity, specificity, and accuracy values were 0.926, 1.000, 0.765, and 0.848, in the testing set. Application of the radiomics nomogram in the testing set still showed a good predictive accuracy. CONCLUSIONS: This study presented the radiomic features of the right PC, as a potential image marker of CHE. The radiomics nomogram that incorporates the radiomics signature and clinical risk factors may facilitate the individualized prediction of CHE.

Aberrant brain structural network and altered topological organization in minimal hepatic encephalopathy.

PURPOSE: We aimed to investigate the multilevel impairments of brain structural network in patients with minimal hepatic encephalopathy (MHE). METHODS: Twenty-two patients with MHE and 22 well-matched healthy controls (HC) underwent structural magnetic resonance imaging (MRI) brain scans and neuropsychological evaluations. Individual brain structural networks were constructed using diffusion tensor imaging. Comparing with HC, we investigated the possible impairments of brain structural network in MHE, by applying graph-theory approaches to analyze the topological organization at global, modular, and local levels. The correlations between altered brain structural network and neuropsychological tests scores and venous ammonia levels were also examined in MHE patients. RESULTS: In the MHE group, small-worldness showed significant decrease and normalized characteristic path length showed increase at the global level. In the modular section, six modules were identified. The inter-modular connective strengths showed significant increase between modules 2 and 4 and between modules 4 and 5. The results of node analysis showed similar hub distributions in the MHE and HC groups except for the right postcentral gyrus, which was only found in the MHE group. No significant differences were found in connective strength of edges between MHE and HC groups using network-based statistics. CONCLUSION: The altered brain structural networks with reduced network integration and module segregation were demonstrated in patients with MHE. The dysconnectivity of brain structural network could provide an explanation for the brain dysfunctions of MHE.

Structural Brain Network Alteration and its Correlation With Structural Impairments in Patients With Depression in de novo and Drug-Naïve Parkinson's Disease.

Purpose: Depression is common in Parkinson's disease (PD) and is correlated with the severity of motor deficits and quality of life. The present study aimed to investigate alterations in the structural brain network related to depression in Parkinson's disease (d-PD) and their correlations with structural impairments of white matter (WM). Materials and Methods: Data were acquired from the Parkinson Progression Markers Initiative (PPMI) database. A total of 84 de novo and drug-naïve PD patients were screened and classified into two groups according to the 15-item Geriatric Depression Scale (GDS-15): d-PD (n = 28) and nondepression in PD (nd-PD, n = 56). Additionally, 37 healthy controls (HC) were screened. All subjects underwent DTI and 3D-T1WI on a 3.0 T MR scanner. Individual structural brain networks were constructed and analyses were performed using graph theory and network-based statistics (NBS) at both global and local levels. Differences in global topological properties were explored among the three groups. The association models between node and edge changes and the GDS-15 were constructed to detect regions that were specifically correlated with d-PD. Tract-based spatial statistics (TBSS) was used to detect structural impairments of WM between the d-PD and nd-PD groups. The correlations between altered global topological properties and structural impairments were analyzed in the d-PD group. Results: The global efficiency and characteristic path length of the structural brain network were impaired in the d-PD group compared with those in the nd-PD and HC groups. Thirteen nodes and 1 subnetwork with 10 nodes and 12 edges specifically correlated with d-PD were detected. The left hippocampus, left parahippocampal, left lingual, left middle occipital, left inferior occipital, left fusiform, left middle temporal, and left inferior temporal regions were all involved in the results of node and edge analysis. No WM microstructural impairments were identified in the d-PD group. Conclusion: Our study suggests that the integration of the structural brain network is impaired with disrupted connectivity of limbic system and visual system in the de novo and drug-naïve d-PD patients.The topological properties assessing integration of the structural brain network can serve as a potential objective neuroimaging marker for early diagnosis of d-PD.

Abnormal spontaneous brain activity in minimal hepatic encephalopathy: resting-state fMRI study.

PURPOSE: We aimed to assess the abnormality of baseline spontaneous brain activity in minimal hepatic encephalopathy (MHE) by amplitude of low frequency fluctuation (ALFF) and fraction ALFF (fALFF). METHODS: A total of 14 MHE patients and 14 healthy controls were included in our study. Both ALFF and fALFF of functional magnetic resonance imaging were calculated for statistical analysis. RESULTS: Compared with healthy controls, patients with MHE had significantly decreased ALFF in the bilateral medial prefrontal cortex (MPFC), left superior frontal gyrus, right precentral gyrus, left opercular part of inferior frontal gyrus, left gyrus rectus, bilateral precuneus, and the posterior lobe of right cerebellum; and they had significantly decreased fALFF in the bilateral MPFC, right middle frontal gyrus, right superior temporal gyrus, and the posterior lobe of left cerebellum. CONCLUSION: ALFF and fALFF changes in many brain regions demonstrate abnormality of the spontaneous neuronal activity in MHE. Especially the impairment of right precuneus and left MPFC may play a critical role in manifestation of MHE. Changes of ALFF and fALFF in the precuneus and the MPFC can be used as a potential marker for MHE.

The Value of Proton Magnetic Resonance Spectroscopy in High-Intensity Focused Ultrasound Treatment of Experimental Liver Cancer.

High-intensity focused ultrasound (HIFU) is a rapidly developing, non-invasive technique for local treatment of solid tumors that produce coagulative tumor necrosis. This study is aimed to investigate the feasibility of proton magnetic resonance spectroscopy (MRS) on early assessing treatment of HIFU ablation in rabbit with VX2 liver tumor. HIFU ablation was performed on normal liver and VX2 tumor in rabbit, and MRS was performed on normal liver and VX2 tumor before and 2 days after 100% HIFU ablation or 80% ablation in tumor volume. Choline (Cho) and choline/lipid (Cho/Lip) ratios between complete and partial HIFU ablation of tumor were compared. Tissues were harvested and sequentially sliced to confirm the necrosis. In normal liver, the Cho value liver was not obviously changed after HIFU (P > .05), but the Cho/Lip ratio was decreased (P < .05). Cho in liver VX2 tumor was much higher than that in normal liver (P < .001). Cho and Cho/Lip ratio were significantly decreased in tumor after complete HIFU ablation and partial HIFU ablation, and the Cho value in complete HIFU tumor ablation did not show any difference from that in normal liver after HIFU (P > .05); however, the Cho value in partial ablation was still higher than that in normal liver before or in tumor after complete HIFU treatment due to the residual part of tumors, and Cho/Lip ratio is lower than that in complete HIFU treatment (P < .001). The changes in MRS parameters were consistent with histopathologic changes of the tumor tissues after treatment. MRS could differentiate the complete tumor necrosis from residual tumor tissue, when combined with magnetic resonance imaging. We conclude that MRS may be applied as an important, non-invasive biomarker for monitoring the thoroughness of HIFU ablation.

[1H magnetic resonance spectroscopy in the evaluation of high intensity focused ultrasound ablation for primary liver cancer].

To investigate the clinical value of 1H magnetic resonance spectroscopy (1H MRS) in the evaluation of high intensity focused ultrasound (HIFU) ablation for primary liver cancer. Routine magnetic resonance sequences, contrast-enhanced magnetic resonance imaging and respiratory-triggered single voxel point resolved spectroscopy sequence (PRESS) were performed on 24 patients with primary liver cancer before and after HIFU ablation. A respiratory-triggered axial T2 weighted imaging (T2WI) was used as localizer for PRESS. Spectroscopy data was transmitted to a personal computer and was post-processed with a custom software (Saker, provided by Ning Jing, an engineer in GE Healthcare). It would be considered "technical success" if the baselines of spectra were stable and main metabolites were without overlapping and could be identified. Integral areas of choline (Cho) peak at 3.2 parts per million (ppm) and lipid (Lip) peak at 1.3 ppm were measured, and the choline to lipid (Cho/Lip) ratios were calculated. The differences of areas of Cho, Lip peak and Cho/Lip ratios before and after HIFU ablation were compared by using paired samples t test, and a P value of less than 0.05 was considered statistically significant. The technical success rate of 1H-MRS was 87.50% (42/48). Integral areas of Cho peak and Lip peak of 20 patients with satisfied spectra were measured, and the Cho/Lip ratios were calculated. The Integral area of Cho peak decreased from 34 597+/-6 802 before HIFU ablation to 6 372+/-2 466 after HIFU ablation (t = 18.02, P less than 0.01). The Integral area of Lip peak increased from 147 948+/-16 317 before HIFU ablation to 149 069+/-16 345 after HIFU ablation (t = -15.11, P less than 0.01). The Cho/Lip ratio decreased from 0.23+/-0.03 before HIFU ablation to 0.04+/-0.02 after HIFU ablation (t = 25.32, P less than 0.01). 1H-MRS could provide information of metabolites changes of primary liver cancer after HIFU ablation and could be used as a complementary sequence to other magnetic resonance sequences to evaluate all around primary liver cancer after HIFU ablation.

Evaluation of short-term response of high intensity focused ultrasound ablation for primary hepatic carcinoma: utility of contrast-enhanced MRI and diffusion-weighted imaging.

OBJECTIVE: To explore the significance of contrast-enhanced MRI (CE-MRI) and diffusion-weighted imaging (DWI) in evaluating the short-term response of high intensity focused ultrasound (HIFU) ablation for primary hepatic carcinoma (PHC). METHODS: Thirty-nine lesions in the livers of 27 patients were performed HIFU ablation. Conventional MRI sequences, CE-MRI and DWI were performed 1 week before HIFU and 1 week, 3 months after the therapy, respectively. The short-term responses of HIFU for all lesions were evaluated with MRI. RESULTS: 28 of the 39 lesions (28/39, 71.8%) showed complete necrosis with no enhancement 1 week and 3 months after HIFU. The apparent diffusion coefficient (ADC) values 1 week and 3 months after HIFU were significantly higher than those 1 week before treatment (p<0.05). The tumor recurrence was detected in 7 of the 39 lesions (7/39, 17.9%) which had no significant enhancement 1 week after HIFU. On the 3 months follow-up, focal nodules were found on the inner aspects of the treated areas. The ADC values had no significant difference between 1 week before and after treatment (p>0.05), however, they were significantly higher 3 months after HIFU (p<0.05). The tumor residuals were detected in 4 of the 39 lesions (4/39, 10.3%) showing enhancement 1 week after treatment and increased size 3 months after HIFU. The ADC values had no significant difference among 1 week before HIFU, 1 week and 3 months after treatment (p>0.05). CONCLUSION: CE-MRI and DWI can be employed to evaluate the short-term response of HIFU ablation for PHC and to guide the patient management.

Accuracy and reliability of thyroid volumetry using spiral CT and thyroid volume in a healthy, non-iodine-deficient Chinese adult population.

OBJECTIVE: The purpose of this study was to assess the accuracy and reliability of thyroid volumetry using spiral CT and to investigate thyroid volumes for a healthy, non-iodine-deficient adult population in southwestern region of China. MATERIALS AND METHODS: Spiral CT was performed in phantoms and adult subjects with normal thyroid, and the volumes were measured by observers with 5 years or more of CT experience. The phantom volumes and the thyroid volumes of all subjects were noted. RESULTS: For the thyroid phantoms, there was no significant difference between the true and CT calculated volumes (t = 0.862, P = 0.399), and the correlation was excellent (ICC = 0.9995, P = 0.000). In the subjects for reliability analysis, the intraobserver or interobserver differences for CT volumetric measurement of thyroid were not significant (P > 0.05). The intraobserver or interobserver correlations were very high (ICC > 0.99, P < 0.001). In the subjects for population analysis, the median of the thyroid volumes was 11.45 cm(3). The nonparametric Mann-Whitney U-test showed no significant difference for the thyroid volume between sexes (U = 4388.00, Z = -1.118, P = 0.264). The nonparametric Kruskall-Wallis test showed no significant difference in all age groups (χ(2) = 13.466, P = 0.062). There was a slight negative correlation between the thyroid volume and age (r(s) = -0.166, P = 0.019). CONCLUSION: The accuracy and reliability of multi-slice spiral CT in measuring thyroid volume are very high. The thyroid volumes are not significantly difference between genders or among decades for the healthy, non-iodine-deficient adult population in southwestern region of China.

[The application of 3D liver acquisition volume acceleration integrated with array spatial sensitivity encoding technique in liver dynamic-enhancement scanning].

OBJECTIVE: To evaluate the application of 3D liver acquisition volume acceleration (3D-LAVA) integrated with array spatial sensitivity encoding technique (ASSET) in liver dynamic-enhancement scanning. METHODS: One hundred forty-seven patients underwent conventional plain and contrast enhancement liver MR imaging. 3D-LAVA and 2D fast spoiled gradient recalled echo were used for contrast enhancement liver MR scanning in 90 and 57 patients respectively. In the 3D-LAVA group, integrated ASSET was used in 72 out of the 90 patients. Of the 57 patients who underwent examinations using 2D fast spoiled gradient recalled echo, portal vein CE-MRA was performed on 20. The ability of 3D-LAVA to detect the lesions and the advantage to shorten the acquisition time after integrating with ASSET were analyzed. Original images of 60 patients in the 3D-LAVA group were processed using MIP to illustrate the anatomy of the portal vein. They were compared with those shown by CE-MRA to evaluate the illustration abilities of the two approaches. RESULTS: 3D-LAVA is more sensitive than 2D-FSPGR in detecting metastatic hepatic carcinomas. In the 3D-LAVA group integrated with ASSET, earlier and peak arterial phase images were acquired in 34 cases; and earlier, peak and late arterial phase images were acquired in 23 cases. The illustrations of the portal vein anatomy by 3D-LAVA were similar to those shown by portal vein CE-MRA. CONCLUSION: 3D-LAVA integrated with ASSET can obtain higher quality multi-phase dynamic enhancement images of the liver in a shorter time, and in the meantime also shows the vascular anatomy.