Dynamic alternations of interhemispheric functional connectivity in brachial plexus avulsion injury patients with nerve transfer: a resting state fMRI study.

Brachial plexus avulsion injury (BPAI) is a severe peripheral nerve injury that leads to functional reorganization of the brain. However, the interhemispheric coordination following contralateral cervical 7 nerve transfer remains unclear. In this study, 69 BPAI patients underwent resting-state functional magnetic resonance imaging examination to assess the voxel-mirrored homotopic connectivity (VMHC), which reveals the interhemispheric functional connection. The motor function of the affected upper extremity was measured using the Fugl-Meyer Assessment of Upper Extremity (FMA-UE) scale. The VMHC analysis showed significant differences between the bilateral precentral gyrus, supplementary motor area (SMA), middle frontal gyrus (MFG), and insula. Compared to the preoperative group, the VMHC of the precentral gyrus significantly increased in the postoperative short-term group (PO-ST group) but decreased in the postoperative long-term group (PO-LT group). Additionally, the VMHC of the SMA significantly increased in the PO-LT group. Furthermore, the VMHC of the precentral gyrus in the PO-ST group and the SMA in the PO-LT group were positively correlated with the FMA-UE scores. These findings highlight a positive relationship between motor recovery and increased functional connectivity of precentral gyrus and SMA, which provide possible therapeutic targets for future neuromodulation interventions to improve rehabilitation outcomes for BPAI patients.

MR Diffusion Kurtosis Imaging (DKI) of the Normal Human Uterus in Vivo During the Menstrual Cycle.

BACKGROUND: The uterus undergoes dynamic changes throughout the menstrual cycle. Diffusion kurtosis imaging (DKI) is based on the non-Gaussian distribution of water molecules and can perhaps represent the changes of uterine microstructure. PURPOSE: To investigate the temporal changes in DKI-parameters of the normal uterine corpus and cervix during the menstrual cycle. STUDY TYPE: Prospective. POPULATION: 21 healthy female volunteers (26.64 ± 4.72 years) with regular menstrual cycles (28 ± 7 days). FIELD STRENGTH/SEQUENCE: Readout segmentation of long variable echo-trains (RESOLVE)-based DKI and fast spin-echo T2-weighted sequences at 3.0T. ASSESSMENT: Each volunteer was scanned during the menstrual phase, ovulatory phase, and luteal phase. Regions of interest (ROI) were manually delineated in the endometrium, junctional zone, and myometrium of the uterine body, and in the mucosal layer, fibrous stroma layer, and loose stroma layer of the cervix. The mean Kapp (diffusion kurtosis coefficient), Dapp (diffusion coefficient), and ADC (apparent diffusion coefficient) values were measured in the ROI. STATISTICAL TESTS: ANOVA with Bonferroni or Tamhane correction. Intraclass correlation coefficient (ICC) for assessing agreement. P < 0.05 was considered statistically significant. RESULTS: During the menstrual cycle, the highest Kapp (0.848 ± 0.184) and lowest Dapp (1.263 ± 0.283 *10-3 mm2 /sec) values were found in the endometrium during the menstrual phase. The Dapp values for the myometrium were significantly higher than those of the endometrium and the junctional zone in every phase. Meanwhile, the Dapp values for the three zonal structures of the cervix during ovulation were significantly higher than those during the luteal phase. However, there was no significant difference in the ADC values of the loose stroma between ovulation and the luteal phase (P = 0.568). The reproducibility of DKI parameters was good (ICC, 0.857-0.944). DATA CONCLUSION: DKI can show dynamic changes of the normal uterus during the menstrual cycle. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

Differences in Cortical Activation During Dorsiflexion and Plantarflexion in Chronic Ankle Instability: A Task-fMRI Study.

BACKGROUND: Chronic ankle instability is a common sports injury that often presents with increased plantarflexion and restricted dorsiflexion. The cumulative effect of peripheral injuries may induce neuroplasticity in the central nervous system. However, the relationship between dorsiflexion or plantarflexion and the central nervous system in patients with chronic ankle instability remains unknown. QUESTIONS/PURPOSES: (1) Is there a difference in region and voxel (volume pixel) of cortical activation during plantarflexion and dorsiflexion between patients with chronic ankle instability and a control group with normal ankle function? (2) Is there a correlation between activation of sensorimotor-related brain regions and three clinical measurement scales of ankle function and disease severity in patients with chronic ankle instability? METHODS: Between December 2020 and May 2022, we treated 400 patients who had chronic ankle instability. Ten percent (40 patients; mean ± standard deviation age 29 ± 7 years; 17 male patients) were randomly selected to participate in this study. We recruited 42 volunteers with normal ankle function (mean age 28 ± 5 years; 21 male participants) matched by age and education level. A total of 2.5% (1 of 40) of patients with bilateral chronic ankle instability and 30% (12 of 40) with left-sided chronic ankle injury did not meet our inclusion criteria and were excluded from the study. The control group underwent MRI with good image quality. Finally, 27 patients with chronic ankle instability (mean age 26 ± 5 years; 10 male patients) and 42 participants with normal ankle function were enrolled. Ankle function and disease severity were assessed using three clinical scales: the Cumberland Ankle Instability Tool, Karlsson-Peterson Ankle Function Score, and the American Orthopedic Foot and Ankle Society Score. A uniplanar and nonweightbearing ankle dorsiflexion-plantarflexion paradigm (a recognized model or pattern) was performed using a short-block design during the functional MRI scan. This experimental design included a series of on-off periods consisting of movement and a rest period. From 15° of plantarflexion to 15° of dorsiflexion, the manipulator allowed 30° of ankle rotation. The cerebral excitability patterns between patients with chronic ankle instability and controls were analyzed using t-tests. We retained voxels with p values less than 0.05 in a voxel-level family-wise error correction. Clusters with voxel numbers greater than 10 were retained. The Cohen d coefficient was used to calculate between-group effect sizes. Spearman analysis was performed to explore the correlation between activation regions and the three clinical assessment scales. RESULTS: In the patient group, cortical activation was greater during plantarflexion than during dorsiflexion, which was different from that in the control group. The between-group comparison showed that patients with chronic ankle instability had reduced activation in the ipsilateral precuneus (cluster size = 35 voxels [95% CI -0.23 to 0.07]; p < 0.001) during dorsiflexion, whereas during plantarflexion, chronic ankle instability caused increased activation in the ipsilateral superior temporal gyrus (cluster size = 90 voxels [95% CI -0.73 to -0.13]; p < 0.001), precuneus (cluster size = 18 voxels [95% CI -0.56 to -0.19]; p < 0.001), supplementary motor area (cluster size = 57 voxels [95% CI -0.31 to 0.00]; p < 0.001), superior frontal gyrus (cluster size = 43 voxels [95% CI -0.82 to -0.29]; p < 0.001), medial part of the superior frontal gyrus (cluster size = 39 voxels [95% CI 0.41 to 0.78]; p < 0.001), and contralateral postcentral gyrus (cluster size = 100 voxels [95% CI -0.32 to 0.02]; p < 0.001). Patients with chronic ankle instability showed a large effect size compared with controls (Cohen d > 0.8). During plantarflexion, the number of activated voxels in the supplementary motor area had a modest, positive correlation with the Karlsson-Peterson Ankle Function Score (r = 0.52; p = 0.01), and the number of activated voxels in the primary motor cortex (M1) and primary sensory cortex (S1) had a weak, positive correlation with the American Orthopedic Foot and Ankle Society Score in patients with chronic ankle instability (M1: r = 0.45; p = 0.02, S1: r = 0.49; p = 0.01). CONCLUSION: Compared with volunteers with normal ankle function, patients with chronic ankle instability had increased cortical activation during plantarflexion and decreased cortical activation during dorsiflexion. We analyzed the central neural mechanisms of chronic ankle instability in patients with sports injuries and provided a theoretical basis for the development of new central and peripheral interventions in the future. CLINICAL RELEVANCE: Because there was a positive correlation between the neural activity in sensorimotor-related regions during plantarflexion and clinical severity, clinicians might one day be able to help patients who have chronic ankle instability with neuromuscular rehabilitation by applying electrical stimulation to specific targets (such as S1M1 and the supplementary motor area) or by increasing activation of sensorimotor neurons through ankle movement.

Solitary Fibrous Tumor of the Spine: Imaging Grading Diagnosis and Prognosis.

OBJECTIVE: This study aimed to investigate the imaging features and prognosis of spinal solitary fibrous tumors (SFTs) of different pathological grades. METHODS: The clinical features, computed tomography and magnetic resonance (MR) images, and follow-up data of 23 patients with SFTs were reviewed. The patients were divided into 3 groups according to their pathological manifestations: grade 1 (n = 3), grade 2 (n = 14), and grade 3 (n = 6). The following imaging features were recorded: location, computed tomography density/MR intensity, enhancement pattern, dural tail sign, adjacent bone remodeling, lobulation, and tumor size. The immunohistochemical (Ki-67/MIB-1) levels were also investigated. All parameters were statistically analyzed between grade 2 and 3 tumors. RESULTS: The Ki-67/MIB-1 index was markedly higher in grade 3 tumors than in grade 2 tumors ( P < 0.001). All grade 1 lesions appeared hypointense on T2-weighted image, whereas grade 2 and 3 lesions appeared isointense or mildly hyperintense. There were significant differences in enhancement type and osteolytic bony destruction between grade 2 and 3 tumors ( P < 0.05). However, no marked differences were found in the distribution of age, sex, location, MR signal, degree of enhancement, compressive bony absorption, dural tail sign, or maximum vertical/traverse diameter ratio. Malignant progression occurred less frequently in patients with grade 2 tumors than in those with grade 3 tumors, but the difference was not statistically significant. CONCLUSIONS: Different grades of spinal SFTs have different degrees of proliferation and imaging features, especially grade 3 tumors, which show a heterogeneous enhancement pattern, osteolytic bony destruction, and a higher possibility of recurrence and metastasis.

Attenuation of brain grey matter volume in brachial plexus injury patients.

Brachial plexus injury (BPI) causes functional changes in the brain, but the structural changes resulting from BPI remain unknown. In this study, we compared grey matter volume between nine BPI patients and ten healthy controls by means of voxel-based morphometry. This was the first study of cortical morphology in BPI. We found that brain regions including the cerebellum, anterior cingulate cortex, bilateral inferior, medial, superior frontal lobe, and bilateral insula had less grey matter in BPI patients. Most of the affected brain regions of BPI patients are closely related to motor function. We speculate that the loss of grey matter in multiple regions might be the neural basis of the difficulties in the motor rehabilitation of BPI patients. The mapping result might provide new target regions for interventions of motor rehabilitation.

Exploring low- and high-order functional connectivity in chronic ankle instability through resting-state fMRI.

BACKGROUND: The functional connectivity (FC) has emerged as a valuable tool for comprehending the cerebral operational mechanism. Understanding the FC changes in patients with chronic ankle instability (CAI) helps reveal the underlying central nervous system mechanisms of the disease and provides clues for developing personalized treatment plans. OBJECTIVES: To explore differences between low- and high-order FC in patients with CAI and healthy controls, as well as the correlation among the feature connections and clinical data. METHODS: In our study, we recruited 40 patients with CAI and 42 healthy individuals who had not experienced ankle injuries. All participants underwent clinical assessments of ankle joints, collected the number of ankle sprains within the past 6 months, and performed resting-state functional magnetic resonance imaging (rs-fMRI) scans. Pearson correlation and matrix variate normal distribution (MVND) were used to construct low-order and high-order FC networks, respectively. Feature selections between groups were performed by two-sample t-tests, and a multi-kernel support vector machine (MK-SVM) was subsequently applied to combine the multiple connection patterns for the classification. Using leave-one-out cross-validation (LOOCV) to assess classification performance and identify the consensus connections contributing most to classification. RESULTS: FC was reduced in certain brain regions of CAI patients. More consensus connections were recognized in low-order FC network than in high-order FC network. The highest classification accuracy of 91.30% was achieved by combining three connection patterns. The most discriminating functional connections were primarily centered on the default mode network and spanned the visual network, sensorimotor network, ventral attention network, and central executive network. In addition, FC strength in the left cingulate and paracingulate gyrus (DCG.L) and right superior temporal gyrus (STG.R) was negatively correlated with the number of ankle sprains in the past 6 months in all FC networks (p < 0.05). CONCLUSIONS: Abnormalities in connectivity in patients with CAI were observed in both low- and high-order FC networks. The adaptive changes in the brain related to CAI may extend beyond the sensorimotor networks, primarily involving higher-level default mode networks associated with attention. Moreover, the FC strength between DCG.L and STG.R may predict the risk of ankle re-sprains and help clinicians develop personalized treatment plans.

Epidemiological Insights into Autoimmune Bullous Diseases in China: A Comprehensive Analysis.

OBJECTIVE: This study aims to conduct an extensive analysis of autoimmune bullous diseases, particularly pemphigus vulgaris and bullous pemphigoid, in Shanghai, China, from 2016 to 2023. It seeks to understand the demographic profiles, comorbidities, mortality rates, risk factors, and socioeconomic impacts associated with autoimmune bullous disease. METHODS: A cross-sectional study design was employed, enrolling 1,072 patients. Diagnostic measures included clinical manifestations, histopathology, direct immunofluorescence, and serologic tests. The study also involved a detailed socioeconomic analysis and evaluation of occupational risks. RESULTS: The findings highlight a significant occupational risk in industries requiring enhanced safety measures, with a notable prevalence of autoimmune bullous disease among workers in these sectors. A considerable portion of the patients were from low-income backgrounds with limited literacy, indicating the economic burden of autoimmune bullous disease. A key discovery of the study is the potential pathological link between autoimmune bullous disease and interstitial lung disease. CONCLUSION: This research, one of the first comprehensive studies on autoimmune bullous disease in China, underscores the need for targeted healthcare strategies and further investigation into autoimmune bullous disease, particularly its relationship with interstitial lung disease.

Multi-b-value diffusion stretched-exponential model parameters correlate with MIB-1 and CD34 expression in Glioma patients, an intraoperative MR-navigated, biopsy-based histopathologic study.

Background: To understand the pathological correlations of multi-b-value diffusion-weighted imaging (MDWI) stretched-exponential model (SEM) parameters of α and diffusion distribution index (DDC) in patients with glioma. SEM parameters, as promising biomarkers, played an important role in histologically grading gliomas. Methods: Biopsy specimens were grouped as high-grade glioma (HGG) or low-grade glioma (LGG). MDWI-SEM parametric mapping of DDC1500, α1500 fitted by 15 b-values (0-1,500 sec/mm2)and DDC5000 and α5000 fitted by 22 b-values (0-5,000 sec/mm2) were matched with pathological samples (stained by MIB-1 and CD34) by coregistered localized biopsies, and all SEM parameters were correlated with these pathological indices pMIB-1(percentage of MIB-1 expression positive rate) and CD34-MVD (CD34 expression positive microvascular density for each specimen). The two-tailed Spearman's correlation was calculated for pathological indexes and SEM parameters, as well as WHO grades and SEM parameters. Results: MDWI-derived α1500 negatively correlated with CD34-MVD in both LGG (6 specimens) and HGG (26 specimens) (r=-0.437, P =0.012). MDWI-derived DDC1500 and DDC5000 negatively correlated with MIB-1 expression in all glioma patients (P<0.05). WHO grades negatively correlated with α1500(r=-0.485; P=0.005) and α5000(r=-0.395; P=0.025). Conclusions: SEM-derived DDC and α are significant in histologically grading gliomas, DDC may indicate the proliferative ability, and CD34 stained microvascular perfusion may be an important determinant of water diffusion inhomogeneity α in glioma.

MR neurography of lumbosacral nerve roots for differentiating chronic inflammatory demyelinating polyneuropathy from acquired axonal polyneuropathies: a cross-sectional study.

Background: Magnetic resonance (MR) neurography is an imaging technique focused on the peripheral nerves. Its role in the diagnosis and differential diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) has yet to be investigated. This study explored the value of MR neurography in identifying CIDP and differentiating it from acquired axonal polyneuropathies. Methods: In this study, 20 patients with CIDP, 10 patients with acquired axonal polyneuropathies, and 20 healthy controls were prospectively enrolled. Three-dimensional T2-weighted image fat-suppressed and diffusion tensor imaging sequences of the lumbosacral plexus were completed in all participants. The cross-sectional area (CSA) and diffusion parameters, including the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the L3 to S1 nerve roots, were measured and compared across the 3 groups using Kruskal-Wallis 1-way analysis of variance. Receiver operating characteristic (ROC) curves were plotted to determine the value of CSA and diffusion parameters in the diagnosis and differential diagnosis of CIDP. Results: CSA and ADC increased in CIDP patients but didn't differ between patients with axonal polyneuropathies and healthy controls [CAS: 45.35±23.889, 22.25±3.878, 22.81±4.079 mm2, ADC: (1.64±0.269)×10-3, (1.37±0.204)×10-3 and (1.39±0.156)×10-3 mm2/s, in CIDP, axonal polyneuropathies and healthy controls, respectively, both P<0.001]. Compared with healthy controls, FA reduced in patients with CIDP and axonal polyneuropathies but no difference was observed in the two groups (FA: 0.24±0.053, 0.27±0.014 and 0.32±0.045, in CIDP, axonal polyneuropathies and healthy controls, respectively, P<0.001). To identify CIDP, ROC analysis showed that FA had better efficiency with cut-off value of 0.278 and sensitivity and specificity of 85% and 90% respectively. To differentiate CIDP from axonal polyneuropathies, CSA had better diagnostic accuracy with cut-off value of 29.46 mm2 and sensitivity and specificity of 75% and 100% respectively. Conclusions: CSA and ADC values of lumbosacral nerve roots can help to identify patients with CIDP and further distinguish them from patients with axonal polyneuropathies. FA decreased in both types of polyneuropathies and may thus have limited value in the discrimination of the 2 types of neuropathies.

Microstructural Alteration of Lumbosacral Nerve Roots in Chronic Inflammatory Demyelinating Polyradiculoneuropathy: Insights From DTI and Correlations with Electrophysiological Parameters.

RATIONALE AND OBJECTIVES: To detect the diffusion characteristics of lumbosacral nerve roots in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and further to explore their correlations with electrophysiological parameters of lower extremity nerves. MATERIALS AND METHODS: Eighteen CIDP patients and 18 age and sex-matched healthy volunteers were enrolled in this study from August 2019 to August 2020. Axial diffusion tensor imaging (DTI) of lumbosacral plexus was performed in all subjects and fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) of lumbosacral nerve roots were measured. Two-sample t test or Mann-Whitney U test was used to compare the difference of DTI parameters between two groups. Receiver operating characteristic curves were plotted to determine the diagnostic accuracy. All patients also underwent nerve conduction studies. Correlations between DTI parameters of lumbosacral nerve roots and electrophysiological parameters were analyzed with Pearson or Spearman coefficients. RESULTS: CIDP patients showed significantly lower FA as well as higher AD, RD, and MD values of lumbosacral nerve roots (FA:0.24±0.054, 0.32±0.044; AD:2.31±0.256, 2.11±0.230 (×10-3mm2/s); RD:1.28±0.189, 1.13±0.106 (×10-3mm2/s); MD:1.68±0.268, 1.45±0.186 (×10-3mm2/s) in CIDP and control group, respectively, all p < 0.05). Receiver operating characteristic analysis showed among all DTI parameters, FA had the best diagnostic accuracy with an area under the curve of 0.914 and optimal cut-off value of 0.27. FA showed a positive correlation while RD showed a negative correlation with a conduction velocity of tibial and common peroneal nerves. RD also correlated positively with F-wave minimal latency of tibial nerves. CONCLUSION: DTI can be used to assess the microstructure alterations of lumbosacral nerve roots in CIDP patients. FA and RD may serve as potential markers reflecting the conduction function of tibial and common peroneal nerves.

Not Only in Sensorimotor Network: Local and Distant Cerebral Inherent Activity of Chronic Ankle Instability-A Resting-State fMRI Study.

BACKGROUND: Increasing evidence has proved that chronic ankle instability (CAI) is highly related to the central nervous system (CNS). However, it is still unclear about the inherent cerebral activity among the CAI patients. PURPOSE: To investigate the differences of intrinsic functional cerebral activity between the CAI patients and healthy controls (HCs) and further explore its correlation with clinical measurement in CAI patients. MATERIALS AND METHODS: A total of 25 CAI patients and 39 HCs were enrolled in this study. Resting-state functional magnetic resonance imaging (rs-fMRI) was used to detect spontaneous cerebral activity. The metrics of amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), and regional homogeneity (ReHo) of the two groups were compared by two-sample t-test. The brain regions that demonstrated altered functional metrics were selected as the regions of interest (ROIs). The functional connectivity (FC) was analyzed based on the ROIs. The Spearman correlation was calculated between rs-fMRI metrics and clinical scale scores. RESULTS: Compared with HCs, CAI patients showed higher ALFF and ReHo values in the right postcentral gyrus, the right precentral gyrus, and the right middle frontal gyrus, while lower fALFF values in the orbital-frontal cortex (OFC, p < 0.01 after correction). Increasing FC between the right precentral gyrus and the right postcentral gyrus while decreasing FC between the right precentral gyrus and the anterior cingulum cortex (ACC), the right middle frontal gyrus and the left middle temporal gyrus, and the OFC and left inferior parietal lobule (IPL) was observed. In addition, in the CAI group, the ReHo value negatively correlated with the Cumberland Ankle Instability Tool score in the right middle frontal gyrus (r = -0.52, p = 0.007). CONCLUSION: The CAI patients exhibited enhanced and more coherent regional inherent neuronal activity within the sensorimotor network while lower regional inherent activity in pain/emotion modulation related region. In addition, the information exchanges were stronger within the sensorimotor network while weaker between distant interhemispheric regions. Besides, the increased inherent activity in the right middle frontal gyrus was related to clinical severity. These findings may provide insights into the pathophysiological alteration in CNS among CAI patients.

A Numerical Study on 3D Printed Cementitious Composites Mixes Subjected to Axial Compression.

Aptly enabled by recent developments in additive manufacturing technology, the concept of functionally grading some cementitious composites to improve structural compression forms is warranted. In this work, existing concrete models available in Abaqus Finite Element (FE) packages are utilized to simulate the performance of some cementitious composites numerically and apply them to functional grading using the multi-layer approach. If yielding good agreement with the experimental results, two-layer and three-layer models case combinations are developed to study the role of layer position and volume. The optimal and sub-optimal performance of the multi-layer concrete configurations based on compressive strength and sustained strains are assessed. The results of the models suggest that layer volume and position influence the performance of multi-layer concrete. It is observed that when there exists a substantial difference in material strengths between the concrete mixes that make up the various layers of a functionally graded structure, the influence of position and of material volume are significant in a two-layer configuration. In contrast, in a three-layer configuration, layer position is of minimal effect, and volume has a significant effect only if two of the three layers are made from the same material. Thus, a multilayered design approach to compression structures can significantly improve strength and strain performance. Finally, application scenarios on some structural compression forms are shown, and their future trajectory is discussed.

MR neurography of lumbosacral nerve roots: Diagnostic value in chronic inflammatory demyelinating polyradiculoneuropathy and correlation with electrophysiological parameters.

PURPOSE: MR neurography(MRN) is an advanced imaging technique to visualize peripheral nerves. Our aim was to determine the value of morphological features of lumbosacral nerve roots on MRN in diagnosing chronic inflammatory demyelinating polyradiculoneuropathy(CIDP) and analyze their correlations with electrophysiological parameters. METHODS: MRN of lumbosacral plexus was performed in 21 CIDP patients and 21 healthy volunteers. The cross-sectional areas(CSAs) and signal intensities(SI) of L3 to S1 nerve roots were measured and compared between two groups. Receiver operating characteristic(ROC) curves were plotted to assess the diagnostic accuracy. All patients also underwent nerve conduction studies. Correlations between CSAs and SI of lumbosacral nerve roots and electrophysiological parameters were analyzed. RESULTS: Compared with control group, CIDP patients showed significantly increased CSAs and SI from L3 to S1 nerve root (P < 0.001 and P < 0.05 respectively for all nerve roots). The CSAmean and SImean were 28.04 ± 8.55mm2, 1.314 ± 0.199 for patient group and 14.91 ± 2.36mm2,1.155 ± 0.094 for control group. ROC analysis revealed the best diagnostic accuracy for the CSAmean with an area under the curve of 0.968 and optimal cut-off value of 19.20 mm2. CSAs of L5 or S1 nerve root correlated positively with central latency and negatively with conduction velocity of tibial nerve. SI of L5 also had a positive correlation with latency of sural nerve. CONCLUSIONS: Evaluation of lumbosacral nerve roots on MRN in a quantitative manner may serve as an important tool to support the diagnosis of CIDP.

Nonrigid Image Registration Using Spatially Region-Weighted Correlation Ratio and GPU-Acceleration.

OBJECTIVE: Nonrigid image registration with high accuracy and efficiency remains a challenging task for medical image analysis. In this paper, we present the spatially region-weighted correlation ratio (SRWCR) as a novel similarity measure to improve the registration performance. METHODS: SRWCR is rigorously deduced from a three-dimension joint probability density function combining the intensity channels with an extra spatial information channel. SRWCR estimates the optimal functional dependence between the intensities for each spatial bin, in which the spatial distribution modeled by a cubic B-spline function is used to differentiate the contribution of voxels. We also analytically derive the gradient of SRWCR with respect to the transformation parameters and optimize it using a quasi-Newton approach. Furthermore, we propose a GPU-based parallel mechanism to accelerate the computation of SRWCR and its derivatives. RESULTS: The experiments on synthetic images, public four-dimensional thoracic computed tomography (CT) dataset, retinal optical coherence tomography data, and clinical CT and positron emission tomography images confirm that SRWCR significantly outperforms some state-of-the-art techniques such as spatially encoded mutual information and Robust PaTch-based cOrrelation Ration. CONCLUSION: This study demonstrates the advantages of SRWCR in tackling the practical difficulties due to distinct intensity changes, serious speckle noise, or different imaging modalities. SIGNIFICANCE: The proposed registration framework might be more reliable to correct the nonrigid deformations and more potential for clinical applications.

Decreased Distance between Representation Sites of Distinct Facial Movements in Facial Synkinesis-A Task fMRI Study.

This study aimed to investigate the cortical functional alterations in patients with unilateral facial synkinesis using the task-designed functional magnetic resonance imaging. Fourteen unilateral synkinesis followed by peripheral facial nerve palsy patients and eighteen healthy adults were recruited in this study. Four facial motor tasks, i.e. left/right blinking and left/right smiling, were performed by each subject during the scans. Based on the activation maps, the spatial distance between the representation sites in the contralateral pre-/post-central gyrus of left or right blinking and smiling tasks (i.e. left/right B-S-distance) were calculated. Patients with unilateral facial synkinesis showed decreased B-S-distances during blinking and smiling tasks on the affected half face (9.68 ±â€¯3.92 mm) compared to both average distances in healthy controls (14.95 ±â€¯5.55 mm; p = 0.002) and unaffected half face tasks in patients (16.19 ±â€¯7.87 mm; p = 0.011). These findings demonstrated cortical reorganization in facial synkinesis and suggested a conceivable mechanism corresponding to the simultaneous facial movement. This potentially provides a new modulation target for preventive, therapeutic and rehabilitative maneuver of this disease.

MRI in cerebral schistosomiasis: characteristic nodular enhancement in 33 patients.

OBJECTIVE: The purpose of our study was to describe the characteristic MRI appearance of cerebral infection with Schistosoma japonicum. CONCLUSION: Cerebral infection with S. japonicum can cause a characteristic MRI pattern of a large mass comprising multiple intensely enhancing nodules, sometimes with areas of linear enhancement. The typical appearance may be useful for diagnosis in endemic regions and may potentially be useful in cases imported into countries in which the disease is not endemic.

Patterns of cortical reorganization in facial synkinesis: a task functional magnetic resonance imaging study.

Facial synkinesis, a sequela of peripheral facial nerve palsy, is characterized by simultaneous involuntary facial movement during a voluntary desired one. Maladaptive cortical plasticity might be involved in the dysfunction of facial muscles. This cohort study investigated the cortical functional alterations in patients with unilateral facial synkinesis, using the task functional magnetic resonance imaging. Facial motor tasks, including blinking and smiling, were performed by 16 patients (aged 30.6 ± 4.5 years, 14 females/2 males) and 24 age- and sex-matched healthy controls (aged 29.1 ± 4.2 years, 19 females/5 males). Results demonstrated that activation in the cortico-facial motor representation area was lower during tasks in patients with facial synkinesis compared with healthy controls. Facial movements on either side performed by patients caused more intensive activation of the supplementary motor area on the contralateral side of the affected face, than those on the unaffected side. Our results revealed that there was cortical reorganization in the primary sensorimotor area and the supplementary motor area. This study was registered in Chinese Clinical Trial Registry (registration number: ChiCTR1800014630).

The plasticity of the corticospinal tract in children with obstetric brachial plexus palsy after Botulinum Toxin A treatment.

Botulinum neurotoxin A (BTX-A) intervention has long-term benefits for children with obstetric brachial plexus palsy (OBPP). Although cortical plasticity has been widely studied, plasticity in white matter has not received as much attention. Here, six children with OBPP underwent functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) before and 6 months after BTX-A treatment. Surface electromyography (EMG) was recorded. The aim was to investigate changes in the corticospinal tract (CST) as an example longitudinal observation of white matter plasticity. Deterministic fiber tracking with a Fiber Assignment by Continuous Tracking algorithm was used to reconstruct the CST. Fiber tracts passing through a region of interest (ROI) in the posterior limb of the internal capsule and a target ROI in the upper-limb representation of M1 (defined by task-related fMRI) were selected as the CST. Motor performances were improved while EMG showed no significant difference 6 months after the treatment. We observed a significant increase in mean fractional anisotropy and a significant decrease in fiber number after treatment. We analyzed the correlations between DTI metrics and clinical motor assessments. Although the correlation results were not statistically significant, they support the notion that BTX-A treatment causes white matter plasticity and has a positive long-term outcome. Peripheral deafferentation may lead to altered information flow, resulting in the positive adaptation of white matter. This study provides novel insight into cerebral plasticity following peripheral nerve regeneration and indicates that a combination of relatively non-invasive therapies can accelerate plasticity of sensorimotor circuits and promote functional recovery in OBPP.