Fajin Lv

Evaluation of 64-Section CT Angiography for Detection and Treatment Planning of Intracranial Aneurysms by Using DSA and Surgical Findings

PURPOSE To investigate the diagnostic performance of 64-section computed tomographic (CT) angiography in the detection of intracranial aneurysms. MATERIALS AND METHODS This study was approved by the institutional review board; written informed consent was obtained. One hundred eight consecutive patients suspected of having intracranial aneurysms were recruited. All patients underwent both 64-detector CT angiography and digital subtraction angiography (DSA) for the detection of intracranial aneurysms. CT angiograms were reviewed by two independent blinded readers. Sensitivity, specificity, and positive and negative predictive values for aneurysm detection with CT angiography were calculated by using DSA and surgical findings as the reference standard. RESULTS One hundred seven aneurysms were seen in 96 patients. Of those, DSA helped detect 106. On a per-aneurysm basis, the sensitivity, specificity, and positive and negative predictive values for CT angiography were 99%, 100%, and 100% and 92.3%, respectively. For aneurysms smaller than 3 mm, sensitivity was 93.7% for reader 1 and 96.8% for reader 2. However, the sensitivity and specificity were both 100% for aneurysms larger than 3 mm. Therapeutic decisions could be made on the basis of information provided by CT angiography. CONCLUSION Sixty-four-detector CT angiography is an accurate imaging method for the detection of aneurysms. It may be used as the initial imaging technique in the diagnostic work-up of patients suspected of having intracranial aneurysms.

Neurogenesis and major depression: implications from proteomic analyses of hippocampal proteins in a rat depression model

Major depression is one of the most disabling disorders. Yet, the pathogenesis of this mental disorder is poorly understood. Hippocampus is generally believed to be associated with pathogenesis of depression. In this study, we adopted a proteomic approach to examine possible alterations of protein expression in the hippocampus of a rat depression model. Our results suggest that neurogenesis in hippocampus may play an important role in the pathogenesis of major depression.

Blend Sign on Computed Tomography Novel and Reliable Predictor for Early Hematoma Growth in Patients With Intracerebral Hemorrhage

Background and Purpose— Early hematoma growth is not uncommon in patients with intracerebral hemorrhage and is an independent predictor of poor functional outcome. The purpose of our study was to report and validate the use of our newly identified computed tomographic (CT) blend sign in predicting early hematoma growth. Methods— Patients with intracerebral hemorrhage who underwent baseline CT scan within 6 hours after onset of symptoms were included. The follow-up CT scan was performed within 24 hours after the baseline CT scan. Significant hematoma growth was defined as an increase in hematoma volume of >33% or an absolute increase of hematoma volume of >12.5 mL. The blend sign on admission nonenhanced CT was defined as blending of hypoattenuating area and hyperattenuating region with a well-defined margin. Univariate and multivariable logistic regression analyses were performed to assess the relationship between the presence of the blend sign on nonenhanced admission CT and early hematoma growth. Results— A total of 172 patients were included in our study. Blend sign was observed in 29 of 172 (16.9%) patients with intracerebral hemorrhage on baseline nonenhanced CT scan. Of the 61 patients with hematoma growth, 24 (39.3%) had blend sign on admission CT scan. Interobserver agreement for identifying blend sign was excellent between the 2 readers (&kgr;=0.957). The multivariate logistic regression analysis demonstrated that the time to baseline CT scan, initial hematoma volume, and presence of blend sign on baseline CT scan to be independent predictors of early hematoma growth. The sensitivity, specificity, positive and negative predictive values of blend sign for predicting hematoma growth were 39.3%, 95.5%, 82.7%, and 74.1%, respectively. Conclusions— The CT blend sign could be easily identified on regular nonenhanced CT and is highly specific for predicting hematoma growth.

Subtraction CT angiography for evaluation of intracranial aneurysms: comparison with conventional CT angiography

The purpose of our study was to compare the diagnostic performance of subtraction computed tomography angiography (CTA) with conventional nonsubtracted CTA and digital subtraction angiography (DSA) for the detection of intracranial aneurysms. A total of 76 patients underwent both subtraction CTA and conventional CTA for the detection and therapy planning of suspected intracranial aneurysms. Subtraction and conventional CTA images were independently assessed by two readers in a blinded manner. The possibility of endovascular treatment or surgical clipping was also assessed based on information provided by CT angiograms alone. In 64 patients, 75 aneurysms were present on DSA. On a per-aneurysm basis, the sensitivity of subtraction CTA was 98.6% for reader 1, and 100% for reader 2. However, sensitivity of conventional CTA was 94.6% for reader 1, and 93.3% for reader 2. Therapeutic decisions could be made regarding 63 patients based on information provided by subtraction CTA images. However, conventional CTA provided sufficient information to make this decision for 55 patients. Conventional CTA has limited sensitivity in detecting very small aneurysms as well as aneurysms adjacent to bone. Subtraction CTA performed on a 64-row multidetector CT is an accurate and promising diagnostic tool that seems to be equivalent to 2D DSA for the detection and pretreatment planning of intracranial aneurysms.

A multidetector CT angiography study of variations in the circle of Willis in a Chinese population

The circle of Willis is a major collateral circulation that has an important role in ischemic events. The purpose of our study was to investigate the collateral circulation in a Chinese population with 64-section multidetector CT angiography (CTA). A total of 170 patients who underwent 64-section CT angiography at The First Affiliated Hospital of Chongqing Medical University were included in our study. The morphological variations in the anterior and posterior circle of Willis were assessed in each patient. A total of 160 patients were included in the final analysis, of whom 126 (79%) demonstrated a complete anterior circle of Willis, and 50 (31%) had a complete posterior circle of Willis. A complete circle of Willis was seen in 43 of 160 participants (27%). A fetal-type posterior circle of Willis was seen in 15 (9.4%) patients. This is the first report of a CTA study of collateral circulation in a Chinese population. A higher prevalence of compromised posterior collaterals was observed in this Chinese population compared to Western and Japanese populations.

Abnormal Regional Homogeneity in Patients with Essential Tremor Revealed by Resting-State Functional MRI

Essential tremor (ET) is one of the most common movement disorders in human adults. It can be characterized as a progressive neurological disorder of which the most recognizable feature is a tremor of the arms or hands that is apparent during voluntary movements such as eating and writing. The pathology of ET remains unclear. Resting-state fMRI (RS-fMRI), as a non-invasive imaging technique, was employed to investigate abnormalities of functional connectivity in ET in the brain. Regional homogeneity (ReHo) was used as a metric of RS-fMRI to assess the local functional connectivity abnormality in ET with 20 ET patients and 20 age- and gender-matched healthy controls (HC). The ET group showed decreased ReHo in the anterior and posterior bilateral cerebellar lobes, the bilateral thalamus and the insular lobe, and increased ReHo in the bilateral prefrontal and parietal cortices, the left primary motor cortex and left supplementary motor area. The abnormal ReHo value of ET patients in the bilateral anterior cerebellar lobes and the right posterior cerebellar lobe were negatively correlated with the tremor severity score, while positively correlated with that in the left primary motor cortex. These findings suggest that the abnormality in cerebello-thalamo-cortical motor pathway is involved in tremor generation and propagation, which may be related to motor-related symptoms in ET patients. Meanwhile, the abnormality in the prefrontal and parietal regions may be associated with non-motor symptoms in ET. These findings suggest that the ReHo could be utilized for investigations of functional-pathological mechanism of ET.

Iron deposition of the deep grey matter in patients with multiple sclerosis and neuromyelitis optica: A control quantitative study by 3D-enhanced susceptibility-weighted angiography (ESWAN)

PURPOSE Previous studies have detected abnormal iron deposition in the deep grey matter (DGM) of multiple sclerosis (MS). The regional specificity of the DGM iron deposition in neuromyelitis optica (NMO) is still unclear. We compared the differences in the DGM iron concentration between MS and NMO patients. METHODS We enrolled 42 relapsing-remitting MS (RRMS) patients, 42 NMO patients and 42 healthy controls undergoing brain conventional MRI and three-dimensional (3D)-enhanced T(2)*-weighted angiography (ESWAN) sequences. We obtained the mean phase values (MPVs) for ESWAN-filtered phase images. An analysis of covariance (ANCOVA) was used to compare MPVs among three groups. The correlations of MPVs changes with disease duration and expanded disability status scale (EDSS) were analyzed. RESULTS The RRMS patients had higher DGM iron concentration than did the NMO and control groups, but only the bilateral substantia nigra (SN) showed a significant statistical difference among three groups (p<0.05). In the RRMS group, the iron concentration in the bilateral head of the caudate nucleus (HCN) (left: p<0.0001; right: p=0.0134) and the dentate nucleus (DN) (p<0.05 for both) were correlated with disease duration. In the NMO group, no correlation was found between the DGM iron concentration and disease duration (p>0.05). Furthermore, no correlations were found between the DGM iron concentration and EDSS (p>0.05). CONCLUSIONS We confirm the iron concentration in the DGM iron content of MS patients is more than NMO patients and healthy controls in the same age range. Furthermore, the disease duration was found to be a significant contributor to patients with MS.

Essential tremor is associated with disruption of functional connectivity in the ventral intermediate Nucleus—Motor Cortex—Cerebellum circuit

The clinical benefits of targeting the ventral intermediate nucleus (VIM) for the treatment of tremors in essential tremor (ET) patients suggest that the VIM is a key hub in the network of tremor generation and propagation and that the VIM can be considered as a seed region to study the tremor network. However, little is known about the central tremor network in ET patients. Twenty‐six ET patients and 26 matched healthy controls (HCs) were included in this study. After considering structural and head‐motion factors and establishing the accuracy of our seed region, a VIM seed‐based functional connectivity (FC) analysis of resting‐state functional magnetic resonance imaging (RS‐fMRI) data was performed to characterize the VIM FC network in ET patients. We found that ET patients and HCs shared a similar VIM FC network that was generally consistent with the VIM anatomical connectivity network inferred from normal nonhuman primates and healthy humans. Compared with HCs, ET patients displayed VIM‐related FC changes, primarily within the VIM‐motor cortex (MC)‐cerebellum (CBLM) circuit, which included decreased FC in the CBLM and increased FC in the MC. Importantly, tremor severity correlated with these FC changes. These findings provide the first evidence that the pathological tremors observed in ET patients might be based on a physiologically pre‐existing VIM ‐ MC ‐ CBLM network and that disruption of FC in this physiological network is associated with ET. Further, these findings demonstrate a potential approach for elucidating the neural network mechanisms underlying this disease. Hum Brain Mapp 37:165–178, 2016.

Early-Stage Psychotherapy Produces Elevated Frontal White Matter Integrity in Adult Major Depressive Disorder

Background Psychotherapy has demonstrated comparable efficacy to antidepressant medication in the treatment of major depressive disorder. Metabolic alterations in the MDD state and in response to treatment have been detected by functional imaging methods, but the underlying white matter microstructural changes remain unknown. The goal of this study is to apply diffusion tensor imaging techniques to investigate psychotherapy-specific responses in the white matter. Methods Twenty-one of forty-five outpatients diagnosed with major depression underwent diffusion tensor imaging before and after a four-week course of guided imagery psychotherapy. We compared fractional anisotropy in depressed patients (n = 21) with healthy controls (n = 22), and before-after treatment, using whole brain voxel-wise analysis. Results Post-treatment, depressed subjects showed a significant reduction in the 17-item Hamilton Depression Rating Scale. As compared to healthy controls, depressed subjects demonstrated significantly increased fractional anisotropy in the right thalamus. Psychopathological changes did not recover post-treatment, but a novel region of increased fractional anisotropy was discovered in the frontal lobe. Conclusions At an early stage of psychotherapy, higher fractional anisotropy was detected in the frontal emotional regulation-associated region. This finding reveals that psychotherapy may induce white matter changes in the frontal lobe. This remodeling of frontal connections within mood regulation networks positively contributes to the “top-down” mechanism of psychotherapy.

Iron deposition in the precentral grey matter in patients with multiple sclerosis: A quantitative study using susceptibility-weighted imaging

PURPOSE Several studies suggest that iron deposition may play a role in multiple sclerosis (MS) pathology. Three-dimensional (3D) enhanced T2*-weighted angiography (ESWAN) at 3T was used to quantify iron deposition in the precentral grey matter in MS and its relationship with disease duration, atrophy and Expanded Disability Status Scale (EDSS) scores. METHODS We recruited 33 patients with diagnosis of clinically definite MS and 31 age- and sex-matched healthy controls who underwent conventional brain MRI, 3D-ESWAN and 3D T1sequences. We obtained the mean phase values (MPVs) of the precentral grey matter on ESWAN-filtered phase images and volume of the precentral gyrus on 3D T1 images. We investigated the correlation between precentral grey matter MPVs, precentral gyrus volume, disease duration and EDSS scores of MS patients and healthy controls. RESULTS The precentral grey matter MPVs in MS patients and controls were 1870.83 ± 56.61 and 1899.22 ± 51.73 respectively and had significant difference in the MS group vs. the control group (t=-2.09, P=0.04). There was significant negative correlation between precentral grey matter MPVs and disease duration (r=-0.365, P=0.03). No correlation was found between MPVs and EDSS scores. Mean precentral gyrus volume in MS patients was 4368.55 ± 867.78 whereas in controls was 5701.00 ± 1184.03 with significant difference between volume of the precentral gyrus in MS patients compared to healthy controls (t=-5.167, P<0.001). There was a positive correlation between MPVs and precentral gyrus volume (r=0.291, P=0.020). CONCLUSIONS Our study demonstrated that quantitative assessment of abnormal iron deposition in the precentral grey matter in MS patients can be measured using 3D-ESWAN.