Establishment and validation of multiclassification prediction models for pulmonary nodules based on machine learning.

BACKGROUND: Lung cancer is the leading cause of cancer-related death worldwide. This study aimed to establish novel multiclassification prediction models based on machine learning (ML) to predict the probability of malignancy in pulmonary nodules (PNs) and to compare with three published models. METHODS: Nine hundred fourteen patients with PNs were collected from four medical institutions (A, B, C and D), which were organized into tables containing clinical features, radiologic features and laboratory test features. Patients were divided into benign lesion (BL), precursor lesion (PL) and malignant lesion (ML) groups according to pathological diagnosis. Approximately 80% of patients in A (total/male: 632/269, age: 57.73 ± 11.06) were randomly selected as a training set; the remaining 20% were used as an internal test set; and the patients in B (total/male: 94/53, age: 60.04 ± 11.22), C (total/male: 94/47, age: 59.30 ± 9.86) and D (total/male: 94/61, age: 62.0 ± 11.09) were used as an external validation set. Logical regression (LR), decision tree (DT), random forest (RF) and support vector machine (SVM) were used to establish prediction models. Finally, the Mayo model, Peking University People's Hospital (PKUPH) model and Brock model were externally validated in our patients. RESULTS: The AUC values of RF model for MLs, PLs and BLs were 0.80 (95% CI: 0.73-0.88), 0.90 (95% CI: 0.82-0.99) and 0.75 (95% CI: 0.67-0.88), respectively. The weighted average AUC value of the RF model for the external validation set was 0.71 (95% CI: 0.67-0.73), and its AUC values for MLs, PLs and BLs were 0.71 (95% CI: 0.68-0.79), 0.98 (95% CI: 0.88-1.07) and 0.68 (95% CI: 0.61-0.74), respectively. The AUC values of the Mayo model, PKUPH model and Brock model were 0.68 (95% CI: 0.62-0.74), 0.64 (95% CI: 0.58-0.70) and 0.57 (95% CI: 0.49-0.65), respectively. CONCLUSIONS: The RF model performed best, and its predictive performance was better than that of the three published models, which may provide a new noninvasive method for the risk assessment of PNs.

Application of spectral CT in diagnosis, classification and prognostic monitoring of gastrointestinal cancers: progress, limitations and prospects.

Gastrointestinal (GI) cancer is the leading cause of cancer-related deaths worldwide. Computed tomography (CT) is an important auxiliary tool for the diagnosis, evaluation, and prognosis prediction of gastrointestinal tumors. Spectral CT is another major CT revolution after spiral CT and multidetector CT. Compared to traditional CT which only provides single-parameter anatomical diagnostic mode imaging, spectral CT can achieve multi-parameter imaging and provide a wealth of image information to optimize disease diagnosis. In recent years, with the rapid development and application of spectral CT, more and more studies on the application of spectral CT in the characterization of GI tumors have been published. For this review, we obtained a substantial volume of literature, focusing on spectral CT imaging of gastrointestinal cancers, including esophageal, stomach, colorectal, liver, and pancreatic cancers. We found that spectral CT can not only accurately stage gastrointestinal tumors before operation but also distinguish benign and malignant GI tumors with improved image quality, and effectively evaluate the therapeutic response and prognosis of the lesions. In addition, this paper also discusses the limitations and prospects of using spectral CT in GI cancer diagnosis and treatment.

Differentiating between pulmonary adenocarcinoma and squamous cell carcinoma by spectral CT volumetric quantitative analysis: a comparative study with conventional spectral analysis.

Background: Unlike the conventional spectral analyses of spectral computed tomography (CT) that cannot fully represent the whole lesion, the volumetric quantitative analysis reveals the information of the whole lesion and is of more accurate. So this study sought to evaluate the value of volumetric quantitative analysis in the differential diagnosis of pulmonary adenocarcinoma (ADC) and squamous cell carcinoma (SQCC). Methods: Fifty-seven patients with lung cancer confirmed by pathology, including 35 ADC and 22 SQCC patients, were retrospectively analyzed. Calcium concentration and effective-Z (Eff-Z) in plain scan (PS), iodine concentration, and water concentration in the arterial phase (AP) were measured. The Student t-test or rank-sum test was used to determine the statistically significant parameters. Receiver operating characteristic (ROC) curve was used, and the corresponding area under the curve (AUC), sensitivity and specificity was calculated to evaluate the diagnostic efficacy in differential diagnosis of ADC and SQCC. Results: In the volumetric quantitative analysis of spectral CT, the concentration of calcium [(6.97±2.83) mg/cm3], Eff-Z (7.90±0.14), and iodine [1.42 (0.84) mg/cm3] was significantly higher in ADC than SQCC [(5.14±2.39) mg/cm3, (7.80±0.10), 1.16 (0.65) mg/cm3, t=2.513, 2.860, Z=-2.246, P=0.015, 0.006, 0.025], but the concentration of water was significantly lower in ADC [995.00 (38.70) mg/cm3] than SQCC [1,007.00 (14.38) mg/cm3, Z=-2.082, P=0.037]. Moreover, whether it's ADC or SQCC, the concentrations of calcium [(8.51±4.28) mg/cm3, (5.96±2.50) mg/cm3], Eff-Z (7.97±0.20, 7.86±0.13), and water [1,007.00 (14.38) mg/cm3, 1,029.28 (10.49) mg/cm3] were lower in the volumetric spectral analysis than the conventional spectral analysis, while the concentration of iodine [1.33 (0.80) mg/cm3, 0.94 (0.63) mg/cm3] was significantly higher in the volumetric spectral analysis than the conventional spectral analysis. The ROC curve analysis showed that the areas under the curves (AUC) (0.76, 0.76, 0.75, 0.71), sensitivity (66.7%, 66.7%, 66.7%, 85.2%), and specificity (92.3%, 84.6%, 86.9%, 69.2%) of the volumetric spectral analysis parameters for the differential diagnosis of ADC and SQCC were higher than those of the conventional spectral analysis [(0.65, 0.66, 0.73, 0.63), (44.4%, 48.1%, 59.3%, 66.7%), (69.2%, 69.2%, 84.6%, 53.8%)] parameters. Conclusions: The volumetric quantitative analysis has a promising advantage in the observation range of whole lesions, it may be invaluable in the differential diagnosis of ADC and SQCC, and is worthy of clinical recommendation.

Diagnosis of Subcortical Ischemic Vascular Cognitive Impairment With No Dementia Using Radiomics of Cerebral Cortex and Subcortical Nuclei in High-Resolution T1-Weighted MR Imaging.

Purpose: To investigate whether the combination of radiomics derived from brain high-resolution T1-weighted imaging and automatic machine learning could diagnose subcortical ischemic vascular cognitive impairment with no dementia (SIVCIND) accurately. Methods: A total of 116 right-handed participants involving 40 SIVCIND patients and 76 gender-, age-, and educational experience-matched normal controls (NM) were recruited. A total of 7,106 quantitative features from the bilateral thalamus, hippocampus, globus pallidus, amygdala, nucleus accumbens, putamen, caudate nucleus, and 148 areas of the cerebral cortex were automatically calculated from each subject. Six methods including least absolute shrinkage and selection operator (LASSO) were utilized to lessen the redundancy of features. Three supervised machine learning approaches of logistic regression (LR), random forest (RF), and support vector machine (SVM) employing 5-fold cross-validation were used to train and establish diagnosis models, and 10 times 10-fold cross-validation was used to evaluate the generalization performance of each model. Correlation analysis was performed between the optimal features and the neuropsychological scores of the SIVCIND patients. Results: Thirteen features from the right amygdala, right hippocampus, left caudate nucleus, left putamen, left thalamus, and bilateral nucleus accumbens were included in the optimal subset. Among all the three models, the RF produced the highest diagnostic performance with an area under the receiver operator characteristic curve (AUC) of 0.990 and an accuracy of 0.948. According to the correlation analysis, the radiomics features of the right amygdala, left caudate nucleus, left putamen, and left thalamus were found to be significantly correlated with the neuropsychological scores of the SIVCIND patients. Conclusions: The combination of radiomics derived from brain high-resolution T1-weighted imaging and machine learning could diagnose SIVCIND accurately and automatically. The optimal radiomics features are mostly located in the right amygdala, left caudate nucleus, left putamen, and left thalamus, which might be new biomarkers of SIVCIND.

An unusual tracheal foreign body in a middle-aged male with a 15-year history of coal use: a case report.

BACKGROUND: Long-term exposure to coal dust causes respiratory disease. In chest computer tomography (CT), pulmonary nodules, pulmonary interstitial fibrosis and emphysema manifest themselves. However, tracheal foreign bodies caused by coal dust are rarely reported. In this study, we report a special case of a tracheal coal foreign body, in which the patient has neither a history of coal work nor foreign body inhalation. CASE PRESENTATION: A 49-year-old man was diagnosed with chronic obstructive pulmonary disease (COPD) due to chronic cough and exertional dyspnoea. His symptoms gradually worsened despite treatment for COPD. Chest radiograph and CT images showed an irregular high-density nodule inserting fromthe trachea into the right thyroid at approximately the level of the 7th cervical vertebra. Fiberoptic bronchoscopy revealed that the tracheal lumen was mostly blocked. After the surgery, the energy spectrum CT quantitative analysis showed that the foreign body was likely that of a bituminous coal specimen. CONCLUSIONS: For cases in which a foreign body in the airway is highly suspected, early fiberoptic bronchoscopy and radiographic examinations should be performed as soon as possible to avoid misdiagnosis and ensure timely treatment.

Sentinel lymph node detection using magnetic resonance lymphography with conventional gadolinium contrast agent in breast cancer: a preliminary clinical study.

BACKGROUND: Sentinel lymph node (SLN) mapping is the standard method for axillary lymph node staging in patients with breast cancer. Blue dye and radioisotopes are commonly used agents to localize SLNs, but both have several disadvantages. The purpose of this study was to evaluate magnetic resonance lymphography with a gadolinium-based contrast agent (Gd-MRL) in sentinel lymph node identification and metastasis detection in patients with breast cancer. METHODS: Sixty patients (mean age: 46.2 ± 8.8 years) with stage T1- 2 breast cancer and clinically negative axillary lymph nodes participated in this study. After 0.9 ml of contrast material and 0.1 ml of mepivacaine hydrochloride 1% were mixed and injected intradermally into the upper-outer periareolar areas, axillary lymph flow was tracked and sentinel lymph nodes were identified by Gd-MRL. After SLN biopsy and/or surgery, the efficacy of SLN identification and metastasis detection of Gd-MRL were examined. RESULTS: Ninety-six lymph nodes were identified by Gd-MRL as SLNs (M-SLN), and 135 lymph nodes were detected by blue dye-guided methods as SLNs (D-SLN). There was a strong correlation (P < 0.001) between the SLN numbers found by these two methods. Using blue dye-guided methods as the gold standard, the sensitivity of Gd-MRL was 95.65% and the false-negative rate was 4.3% for axillary lymphatic metastasis detection. With heterogeneous enhancement and enhancement defect as the diagnostic criteria, Gd-MRL gave a sensitivity of 89.29% and specificity of 89.66% in discriminating malignant from benign SLNs. CONCLUSION: Gd-MRL offers a new method for SLN identification and metastasis detection in patients with breast cancer.

Accuracy of 3-T MRI using susceptibility-weighted imaging to detect meniscal tears of the knee.

PURPOSE: To evaluate the diagnostic performance of susceptibility-weighted imaging (SWI) at 3-T magnetic resonance imaging for the assessment of meniscal tears. METHODS: Ninety-four patients with tears in the medial meniscus (31) or lateral meniscus (64) imaged with conventional magnetic resonance imaging and SWI followed by knee arthroscopy within 1 month were selected. The diagnostic values of SWI for the detection of meniscal tears were evaluated using arthroscopy as the reference standard. The sensitivity, specificity and accuracy between spin-echo T1-weighted imaging (T1WI) and fat-suppressed proton density-weighted imaging (FS-PDWI) were compared. The diagnosis consistency with two radiologists was also compared. Receiver operating characteristic curve analyses were performed for each individual sequence to estimate their diagnostic performance in meniscal tear. RESULTS: Analyses from 31 patients of medial meniscus tears showed that SWI achieved comparable performance with T1WI and FS-PDWI with respect to sensitivity (96.8 vs. 93.5 and 89.2%), specificity (66.7 vs. 66.7 and 66.7%) and accuracy (91.9 vs. 89.2 and 93.5%). In 64 patients of lateral meniscus tears, SWI was found to be a superior method over T1WI and FS-PDWI with regard to sensitivity (98.4 vs. 92.2 and 95.3%), specificity (100 vs. 100 and 100%) and accuracy (98.5 vs. 92.5 and 95.5%). Upon combination of these patients, SWI is similar or superior to T1WI and FS-PDWI with sensitivity (97.9 vs. 92.6 and 94.7%), specificity (77.8 vs. 77.8 and 77.8%) and accuracy (96.2 vs. 89.2 and 93.3%). SWI exhibited similar or better results with respect to sensitivity (97.9 vs. 92.6 and 94.7%), specificity (77.8 vs. 77.8 and 77.8%) and accuracy (96.2 vs. 89.2 and 93.3%) over T1WI and FS-PDWI. CONCLUSIONS: These data suggest that SWI can be used for the diagnosis of meniscal tears. The sensitivity, accuracy and negative predictive value were same as those of T1WI and FS-PDWI according to the present study. LEVEL OF EVIDENCE: Diagnostic study, Level II.

Differentiation of bland from neoplastic thrombus of the portal vein in patients with hepatocellular carcinoma: application of susceptibility-weighted MR imaging.

BACKGROUND: Neoplastic and bland portal vein thrombi (PVT) are both common in patients with hepatocellular carcinoma (HCC). The correct discrimination of them is essential for therapeutic strategies planning and survival predicting. The current study aims to investigate the value of susceptibility-weighted imaging (SWI) in differentiating bland from neoplastic PVT in HCC patients. METHODS: 20 HCC patients with bland PVT and 22 HCC patients with neoplastic PVT were imaged with non-contrast SWI at 3.0 Tesla MRI. The signal intensity (SI) of the PVT and HCC lesions in the same patients was compared on SW images. The phase values of the PVT were compared between neoplastic and bland thrombi cohorts. Receiver operator characteristics (ROC) analysis was conducted to evaluate the diagnostic ability of the phase values for neoplastic and bland thrombi discrimination. RESULTS: 20 of 22 neoplastic PVT were judged similar SI and 2 were judged lower SI than their HCC. For 20 bland PVT, 19 were judged lower SI and 1 was judged similar SI as their HCC (P<0.001). The average phase values (0.361 ± 0.224) of the bland PVT were significantly higher than those of the neoplastic PVT (-0.328 ± 0.127, P<0.001). The AUC for phase values in differentiating bland from neoplastic PVT was 0.989. The best cut-off value was -0.195, which gave a sensitivity of 95% and a specificity of 95.5%. CONCLUSIONS: SW imaging appears to be a promising new method for distinguishing neoplastic from bland PVT. The high sensitivity and specificity suggest its high value in clinical practice.

Resting-state functional connectivity abnormalities in patients with obsessive-compulsive disorder and their healthy first-degree relatives.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a common, heritable neuropsychiatric disorder, hypothetically underpinned by dysfunction of brain cortical-striatal-thalamic-cortical (CSTC) circuits; however, the extent of brain functional abnormalities in individuals with OCD is unclear, and the genetic basis of this disorder is poorly understood. We determined the whole brain functional connectivity patterns in patients with OCD and their healthy first-degree relatives. METHODS: We used resting-state fMRI to measure functional connectivity strength in patients with OCD, their healthy first-degree relatives and healthy controls. Whole brain functional networks were constructed by measuring the temporal correlations of all brain voxel pairs and further analyzed using a graph theory approach. RESULTS: We enrolled 39 patients with OCD, 20 healthy first-degree relatives and 39 healthy controls in our study. Compared with healthy controls, patients with OCD showed increased functional connectivity primarily within the CSTC circuits and decreased functional connectivity in the occipital cortex, temporal cortex and cerebellum. Moreover, patients with OCD and their first-degree relatives exhibited overlapping increased functional connectivity strength in the bilateral caudate nucleus, left orbitofrontal cortex (OFC) and left middle temporal gyrus. LIMITATIONS: Potential confounding factors, such as medication use, heterogeneity in symptom clusters and comorbid disorders, may have impacted our findings. CONCLUSION: Our preliminary results suggest that patients with OCD have abnormal resting-state functional connectivity that is not limited to CSTC circuits and involves abnormalities in additional large-scale brain systems, especially the limbic system. Moreover, resting-state functional connectivity strength abnormalities in the left OFC, bilateral caudate nucleus and left middle temporal gyrus may be neuroimaging endophenotypes for OCD.

Dissociable self effects for emotion regulation: a study of Chinese major depressive outpatients.

Reappraisal is an adaptive emotion regulation strategy while the role of self-perspective in reappraisal process of depressed patients is largely unknown in terms of goals (valence/arousal) and tactics (detachment/immersion). In this study, 12 depressed individuals and 15 controls were scanned with MRI during which they either attend naturally to emotional stimuli, or adopt detachment/immersion strategy. Behaviorally, no group differences in self-reported emotion regulation effectiveness were found. In addition, we observed that (1) patients were less able to downregulate amygdala activation with recruitment of more dorsal lateral prefrontal cortex (dlPFC) when adopting detachment strategy regardless of valence, and this preserved ability to regulate emotion was inversely associated with severity of symptoms; (2) patients had deficits in upregulating amygdala activation when adopting immersion strategy, with less inferior frontal gyrus (IFG) activation and strengthening coupling of dlPFC and ventral medial prefrontal cortex (vmPFC) with amygdala; (3) comparison between groups yielded that patients showed stronger vmPFC activation under either self-detached or self-immersed condition. In conclusion, impaired modulatory effects of amygdala in depressed patients are compensated with strengthening cognitive control resources, with dissociable effects for different self-perspectives in reappraisal. These results may help clarify the role of self-perspective underlying reappraisal in major depression.

The pattern of brain gray matter impairments in patients with subcortical vascular dementia.

Though subcortical ischemic vascular dementia (SIVD) is known to initially affect subcortical regions, numerous brain imaging studies have also documented the widespread cortical alternations. Here we collected brain structural magnetic resonance imaging data from 34 SIVD patients and 35 healthy controls. Voxel-based morphometry (VBM), cortical thickness (and surface area) analysis and deep gray matter volume measurements were performed. VBM analysis showed gray matter volume reduction in lateral and medial temporal lobes, as well as orbitofrontal cortex in SIVD patients. The surface-based analyses revealed more subtle structural differences in the perisylvian area, medial temporal lobe, anterior and posterior cingulate, as well as prefrontal areas. Furthermore, analyses of deep gray matter demonstrated significant atrophy of the hippocampus, amygdala, nucleus accumbens and other nuclei. Finally, we found that thinning in the hippocampus and anterior cingulate cortex, as well as the volume decline in thalamus, caudate nucleus and amygdala was correlated with the cognitive impairment in patients. In conclusion, our study showed the structural abnormalities of the hippocampus and its associated outflow areas, as well as cortices implicated in cholinergic circuits in SIVD. These findings may bring new insights into the dysfunction of brain gray matter in SIVD.

Abnormal intrinsic brain activity patterns in patients with subcortical ischemic vascular dementia.

OBJECTIVES: To investigate the amplitude of low-frequency fluctuations (ALFF) alteration of whole brain in patients with subcortical ischemic vascular dementia (SIVD). MATERIALS AND METHODS: Thirty patients with SIVD and 35 control subjects were included in this study. All of them underwent structural MRI and rs-fMRI scan. The structural data were processed using the voxel-based morphometry 8 toolbox (VBM8). The rs-fMRI data were processed using Statistical Parametric Mapping (SPM8) and Data Processing Assistant for Resting-State fMRI (DPARSF) software. Within-group analysis was performed with a one-sample Student's t-test to identify brain regions with ALFF value larger than the mean. Intergroup analysis was performed with a two-sample Student's t-test to identify ALFF differences of whole brain between SIVD and control subjects. Partial correlations between ALFF values and Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) scores were analyzed in the SIVD group across the parameters of age, gender, years of education, and GM volume. RESULTS: Within-group analysis showed that the bilateral anterior cingulate cortex (ACC), posterior cingulate cortex, medial prefrontal cortex (MPFC), inferior parietal lobe (IPL), occipital lobe, and adjacent precuneus had significantly higher standardized ALFF values than the global mean ALFF value in both groups. Compared to the controls, patients with SIVD presented lower ALFF values in the bilateral precuneus and higher ALFF values in the bilateral ACC, left insula and hippocampus. Including GM volume as an extra covariate, the ALFF inter-group difference exhibited highly similar spatial patterns to those without GM volume correcting. Close negative correlations were found between the ALFF values of left insula and the MoCA and MMSE scores of SIVD patients. CONCLUSION: SIVD is associated with a unique spontaneous aberrant activity of rs-fMRI signals, and measurement of ALFF in the precuneus, ACC, insula, and hippocampus may aid in the detection of SIVD.

Comparison of medial temporal measures between Binswanger's disease and Alzheimer's disease.

Binswanger's disease (BD) is a common cause of vascular dementia in elderly patients; however, few studies have investigated the medial temporal lobe (MTL) atrophy in BD, and the differences in the atrophic patterns between BD and Alzheimer's disease (AD) remain largely unknown. Such knowledge is essential for understanding the pathologic basis of dementia. In this study, we collected structural magnetic resonance imaging (MRI) data from 16 normal controls, 14 patients with AD and 14 patients with BD. The volumes of the hippocampus and amygdala, and morphologic parameters (volume, surface area, cortical thickness and mean curvature) of the entorhinal cortex (ERC) and perirhinal cortex (PRC) were calculated using an automated approach. Volume reduction of the hippocampus, amygdala and ERC, and disturbance of the PRC curvature was found in both AD and BD patients compared with the controls (p<0.05, uncorrected). There were no significant differences among all the structural measures between the AD and BD patients. Finally, partial correlation analyses revealed that cognitive decline could be attributed to ERC thinning in AD and volume reduction of PRC in BD. We conclude that AD and BD exhibit similar atrophy patterns in the medial temporal cortices and deep gray matter but have distinct pathologic bases for cognitive impairments. Although atrophy of the MTL structures is a sensitive biomarker for AD, it is not superior for discrimination between AD and BD.

Analysis of cerebrospinal fluid flow dynamics and morphology in Chiari I malformation with cine phase-contrast magnetic resonance imaging.

BACKGROUND: To determine cerebrospinal fluid (CSF) dynamics and morphology in Chiari I malformation (CMI) and assess the response to surgery of the posterior cranial fossa, we examined midsagittal imaging along with anterior cervical 2-3 (AC2-3), posterior cervical 2-3 (PC2-3), and aqueduct CSF flow hydrodynamics in axial imaging by using cine phase-contrast magnetic resonance imaging (PCMR). METHOD: We examined 52 patients with CMI, both with and without syringomyelia (SM), pre-/post-surgery, and compared them to 17 healthy volunteers. Statistical analyses included paired t-tests, independent-samples t-tests, binary logistic regression, and crosstab with MedCalc software. RESULTS: Patients with CMI had significantly shorter clivus length and larger tentorial angle than the healthy controls (P = 0.004, P = 0.019, respectively). The AC2-3 cranial/caudal peak velocity (PV), PC2-3 cranial/caudal PV and aqueduct cranial peak PV of patients with CMI were significantly lower than healthy volunteers pre-surgery (P = 0.034 AC2-3 cranial PV, P = 0.000002 AC2-3 caudal PV; P = 0.046 PC2-3 cranial PV, P = 0.015 PC2-3 caudal PV; P = 0.022 aqueduct cranial PV) and increased after surgery (P = 0.024 AC2-3 cranial PV, P = 0.002 AC2-3 caudal PV; P = 0.001 PC2-3 cranial PV, P = 0.032 PC2-3 caudal PV; P = 0.003 aqueduct cranial PV). The aqueduct caudal PV of patients with CMI was higher than that of healthy controls (P = 0.004) and decreased post-surgery (P = 0.012). Patients with pre-surgery PC2-3 cranial PV >2.63 cm/s and aqueduct cranial PV >2.13 cm/s, respectively, experienced primary symptom improvement after surgery. CONCLUSIONS: The innate bony dysontogenesis in patients with CMI contributes to tonsilar ectopia and exacerbates CSF flow obstruction. A pressure gradient that existed between SM and SAS supports the perivascular space theory that is used to explain SM formation. Our findings demonstrate that PCMR maybe a useful tool for predicting patient prognosis.

Grey matter abnormalities in untreated hyperthyroidism: a voxel-based morphometry study using the DARTEL approach.

OBJECTIVE: Hyperthyroidism is frequently associated with pronounced neuropsychiatric symptoms such as impulsiveness, irritability, poor concentration, and memory impairments. Functional neuroimaging has revealed changes in cerebral metabolism in hyperthyroidism, but regional changes in cortical morphology associated with specific neurological deficits have not been studied so far. To investigate the pathophysiology underlying hyperthyroid-associated neural dysfunction, we compared grey matter volume (GMV) between adult hyperthyroid patients and matched healthy controls using voxel-based morphometry (VBM). MATERIALS AND METHODS: High resolution 3D T1-weighted images were acquired by 3T MRI from 51 hyperthyroid patients and 51 controls. VBM analysis was performed using SPM8. Correlations between regional GMV and both serum free thyroid hormone (TH) concentrations and disease duration were assessed by multiple regression analysis. RESULTS: Compared to controls, GM volumes in the bilateral hippocampus, parahippocampal gyrus, calcarine, lingual gyrus, and left temporal pole were lower and bilateral supplementary motor area GMV higher in hyperthyroid patients. Serum free triiodothyronine (FT3) concentration was negatively correlated with the normalized regional volume (NRV) of the left parahippocampal gyrus and serum free thyroxine (FT4) concentration negatively correlated with the NRV of the left hippocampus and right parahippocampal gyrus. Disease duration was negatively correlated with the NRV of the left hippocampus, bilateral parahippocampal gyrus, and left temporal pole. CONCLUSION: Hyperthyroid patients exhibited reduced GMV in regions associated with memory, attention, emotion, vision, and motor planning. Negative correlations between GMV and both free TH and disease duration suggest that chronic TH elevation induces abnormalities in the adult cortex.

Morphologic and functional connectivity alterations of corticostriatal and default mode network in treatment-naïve patients with obsessive-compulsive disorder.

BACKGROUND: Previous studies have demonstrated that structural deficits and functional connectivity imbalances might underlie the pathophysiology of obsessive-compulsive disorder (OCD). The purpose of the present study was to investigate gray matter deficits and abnormal resting-state networks in patients with OCD and further investigate the association between the anatomic and functional alterations and clinical symptoms. METHODS: Participants were 33 treatment-naïve OCD patients and 33 matched healthy controls. Voxel-based morphometry was used to investigate the regions with gray matter abnormalities and resting-state functional connectivity analysis was further conducted between each gray matter abnormal region and the remaining voxels in the brain. RESULTS: Compared with healthy controls, patients with OCD showed significantly increased gray matter volume in the left caudate, left thalamus, and posterior cingulate cortex, as well as decreased gray matter volume in the bilateral medial orbitofrontal cortex, left anterior cingulate cortex, and left inferior frontal gyrus. By using the above morphologic deficits areas as seed regions, functional connectivity analysis found abnormal functional integration in the cortical-striatum-thalamic-cortical (CSTC) circuits and default mode network. Subsequent correlation analyses revealed that morphologic deficits in the left thalamus and increased functional connectivity within the CSTC circuits positively correlated with the total Y-BOCS score. CONCLUSION: This study provides evidence that morphologic and functional alterations are seen in CSTC circuits and default mode network in treatment-naïve OCD patients. The association between symptom severity and the CSTC circuits suggests that anatomic and functional alterations in CSTC circuits are especially important in the pathophysiology of OCD.

Abnormalities of frontal-parietal resting-state functional connectivity are related to disease activity in patients with systemic lupus erythematosus.

Cerebral involvement is common in patients with systemic Lupus erythematosus (SLE) and is characterized by multiple clinical presentations, including cognitive disorders, headaches, and syncope. Several neuroimaging studies have demonstrated cerebral dysfunction during different tasks among SLE patients; however, there have been few studies designed to characterize network alterations or to identify clinical markers capable of reflecting the cerebral involvement in SLE patients. This study was designed to characterize the profile of the cerebral activation area and the functional connectivity of cognitive function in SLE patients by using a task-based and a resting state functional magnetic resonance imaging (fMRI) technique, and to determine whether or not any clinical biomarkers could serve as an indicator of cerebral involvement in this disease. The well-established cognitive function test (Paced Visual Serial Adding Test [PVSAT]) was used. Thirty SLE patients without neuropsychiatric symptoms and 25 age- and gender-matched healthy controls were examined using PVSAT task-based and resting state fMRI. Outside the scanner, the performance of patients and the healthy controls was similar. In the PVSAT task-based fMRI, patients presented significantly expanded areas of activation, and the activated areas exhibited significantly higher functional connectivity strength in patients in the resting state. A positive correlation existed between individual connectivity strength and disease activity scoring. No correlation with cerebral involvement existed for serum markers, such as C3, C4, and anti-dsDNA. Thus, our findings may shed new light on the pathologic mechanism underlying neuropsychiatric SLE, and suggests that disease activity may be a potential effective biomarker reflecting cerebral involvement in SLE.

Direct portal vein thrombosis visualization with t2*--weighted magnetic resonance imaging.

BACKGROUND AND PURPOSE: To investigate the feasibility of direct magnetic resonance portal vein thrombosis (PVT) visualization with T2*-weighted imaging (T2*WI) without contrast agent. METHODS: Thirty patients with PVT were included in this study. All of them were imaged with contrast-enhanced CT (CE-CT) as well as non-contrast MRI T1, T2 and T2*WI. Imaging data was independently analyzed by two experienced radiologists. T2*WI of all PVT was compared slice-by-slice with each of the comparison sequences (T1WI, T2WI and CE-CT) on the following categories: the location, size, boundary, and conspicuity of thrombus and portal veins. RESULTS: The average score of PVT visualization in T2*WI was higher than T1WI and T2WI in location, size, boundary and conspicuity (t = 7.54 - 84.16, P<0.05), and higher than CE-CT in boundary and conspicuity (t = 3.03- 6.98, P<0.05). For portal vein visualization, there was no significant score difference in left, middle and right portal veins between CE-CT and T2*WI (t = -1.76- 1.35, P>0.05). CONCLUSIONS: Our results suggest T2*WI can characterize PVT accurately with high quality without the use of intravenous contrast agents.

Magnetic resonance susceptibility-weighted imaging versus other imaging modalities in detecting splenic siderotic lesions.

BACKGROUND: Susceptibility-weighted imaging (SWI) has been proven to be superior to T2*-weighted imaging and also other existing magnetic resonance imaging (MRI) techniques for the detection of iron content and hemorrhage in the brain. The purpose of this study was to compare SWI with T1WI, T2WI and T2*WI in detecting splenic siderotic lesions. METHODOLOGY/PRINCIPAL FINDINGS: Twenty-two patients with splenic siderotic nodule were imaged with non-contrast MRI T1WI, T2WI, T2*WI and SWI at 3.0 Tesla. Imaging data were independently analyzed by two experienced radiologists. The number of splenic siderotic nodules was counted, and the size (largest diameter) was measured. The conspicuity was calculated as the nodule to background parenchyma intensity ratio. We found that SWI detected a larger average number of splenic siderotic nodules than T1WI, T2WI, or T2*WI (all P<0.05). The average size of the nodules detected by SWI was larger than that of those detected by T1WI, T2WI or T2*WI (all P<0.05). SWI provided superior contrast and visibility for splenic siderotic nodules compared to any other sequence (all P<0.001). CONCLUSIONS: SWI may be a better detection scheme for splenic siderotic nodules than T1WI, T2WI and T2*WI.