Left ventricular function assessment in Kawasaki disease by two-dimensional global longitudinal systolic strain with automated function imaging.

BACKGROUND: Kawasaki disease is an acute febrile vasculitis of childhood mainly affecting children under 4 years of age. In the acute stage of the disease, heart function decreases and gradually returns to normal after treatment. However, subendocardial involvement may persist, which cannot be assessed by M-mode echocardiography. Strain echocardiography is a recently developed technique to assess subendocardial involvement of myocardial deformation. We aimed to study the stratified strain of left ventricular function in a Kawasaki patient at least 6 months after the acute stage of the disease with special conditions for entering the study using two-dimensional speckle-tracking imaging. Between September 2020 and October 2022, 27 healthy children and 27 children with a history of Kawasaki disease more than 6 months ago were evaluated using two-dimensional global longitudinal peak systolic strain with automated function imaging technology. RESULTS: The mean age of patients was 5.6 years. With M-mode echocardiography, ejection fraction of each group was in the normal range. Mean (± standard deviation) global longitudinal peak strain in four-chamber view of girls with Kawasaki disease was - 23.74 ± 2.77, and that in boys with Kawasaki disease was - 20.93 ± 2.06 (P value = 0.008). GLPS (global longitudinal peak strain) was compared as an overall average and as in a separate segment, which showed significant difference in two comparisons. In our study, a decrease in the function of some cardiac segments is reported. Global longitudinal peak strain in four-chamber view was significantly lower in boys. Comparing different segments, a difference in global left ventricular long-axis strain was found between the two groups. On the other hand, there was a major difference between the two groups in the basal inferolateral, basal anterolateral, and mid-inferolateral, which receives blood from Left Circumflex artery. CONCLUSION: Using stain echocardiography to detect continued subendocardial involvement in asymptomatic children with a history of Kawasaki disease for a better understanding of the condition, effective management and follow-up is recommended.

Application of MRI-based image navigation and target selection in transcranial magnetic stimulation treatment / 中国组织工程研究

BACKGROUND:In clinical application,the therapeutic effect of transcranial magnetic stimulation depends on the ability to accurately target the areas of the brain that need to be stimulated.In recent years,with the development of neuronavigation systems,mobile augmented reality technology,and the new methods of processing magnetic resonance imaging(MRI)data,the accuracy of stimulus target localization and the optimization of target selection are expected to improve further. OBJECTIVE:To review the principle of MRI-based image navigation and its application in transcranial magnetic stimulation and summarize the roles of different modal MRI data analyses in guiding the selection of target areas for transcranial magnetic stimulation. METHODS:An online computer search for relevant literature was performed in PubMed,CNKI database and WanFang database,with the keywords"transcranial magnetic stimulation,coil positioning,neuronavigation,augmented reality,magnetic resonance,theory."Finally,63 documents were included for review. RESULTS AND CONCLUSION:Among the traditional methods of positioning transcranial magnetic stimulation coils,the"5 cm rule"and the international electroencephalogram 10-20 positioning method are the most commonly used.These methods have the advantages of simplicity and economy,but they rely too much on the operator's experience and there were technical differences between operators.The neuronavigation system,which is based on stereotactic technology,is the guiding method for positioning transcranial magnetic stimulation coils with the highest visual degree and accuracy.It achieves visual positioning through MRI data acquisition,3D brain reconstruction,head model registration and stereogeometric positioning.It has high application value in clinical treatment and scientific research,but it cannot be promoted in medical institutions due to its high cost.For various medical institutions,mobile augmented reality is a cost-effective and efficient alternative to the neuronavigation system,which achieves visual positioning of brain tissue under the scalp through MRI data acquisition,2D/3D image construction,virtual image and real brain image superposition.It has the advantages of directly visualization and low cost,and is expected to be popularized and applied in primary medical units.Although the superiority of clinical efficacy of visual coil positioning over the electroencephalogram 10-20 localization strategy has not yet been fully demonstrated,with the progress of brain MRI data analysis,visual positioning is expected to further optimize the target selection strategy of transcranial magnetic stimulation therapy and to improve the response rate and individuation degree of transcranial magnetic stimulation treatment.This is a promising and challenging research direction in the future.

Assessment of Pulmonary Ventilation Using 3D Ventilation Flow-Weighted and Ventilation-Weighted Maps From 3D Ultrashort Echo Time (UTE) MRI.

BACKGROUND: Three-dimensional (3D) ventilation flow-weighted (VFW) maps together with 3D ventilation-weighted (VW) maps may help to better assess pulmonary function. PURPOSE: To investigate the use of 3D VFW and VW maps for evaluating pulmonary ventilation function. STUDY TYPE: Prospective. POPULATION: Two patients (one male, 85 years old; one female, 64 years old) with chronic obstructive pulmonary disease (COPD) and nine healthy subjects (all male; 23-27 years). FIELD STRENGTH/SEQUENCE: 3-T, 3D radial UTE imaging. ASSESSMENT: 3D VFW and VW maps were calculated from 3D UTE MRI by voxel-wise subtraction of respiratory phase images. Their validation was tested in nine healthy volunteers using slow/deep and fast/shallow breathing conditions. Additional validation was performed by comparison with single photon emission computed tomography (SPECT) ventilation maps of one healthy participant. For comparison, gravity dependence of anterior-posterior regional ventilation was assessed by one-dimensional plot of the mean signal intensity for each coronal slice. Structural similarity index measure was also calculated. Finally, VW maps and VFW maps of two COPD patients were evaluated for emphysema lesions with reference to CT images. STATISTICAL TESTS: Wilcoxon sign-rank tests for regional Ventilation and Ventilation flow, analysis of variance, post-hoc t-tests and Bonferroni correction, coefficient of variation, Kullback-Liebler divergence. A P-value <0.05 was considered statistically significant. RESULTS: The validation of 3D VFW and VW maps was shown by statistically significant differences in ventilation flow and ventilation between the breathing conditions. Additionally, UTE-MRI and SPECT-based ventilation maps showed gravitational dependence in the anteroposterior direction. When applied to patients with COPD, the use of 3D VFW and VW maps was able to differentiate between two patients with different phenotypes. DATA CONCLUSION: The use of 3D VFW and VW maps can provide regional information on ventilation function and potentially contribute to assessment of COPD subtypes and disease progression. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.

An adaptive acoustoelectric signal decoding algorithm based on Fourier fitting for brain function imaging.

Acousticelectric brain imaging (ABI), which is based on the acoustoelectric (AE) effect, is a potential brain function imaging method for mapping brain electrical activity with high temporal and spatial resolution. To further enhance the quality of the decoded signal and the resolution of the ABI, the decoding accuracy of the AE signal is essential. An adaptive decoding algorithm based on Fourier fitting (aDAF) is suggested to increase the AE signal decoding precision. The envelope of the AE signal is first split into a number of harmonics by Fourier fitting in the suggested aDAF. The least square method is then utilized to adaptively select the greatest harmonic component. Several phantom experiments are implemented to assess the performance of the aDAF, including 1-source with various frequencies, multiple-source with various frequencies and amplitudes, and multiple-source with various distributions. Imaging resolution and decoded signal quality are quantitatively evaluated. According to the results of the decoding experiments, the decoded signal amplitude accuracy has risen by 11.39% when compared to the decoding algorithm with envelope (DAE). The correlation coefficient between the source signal and the decoded timing signal of aDAF is, on average, 34.76% better than it was for DAE. Finally, the results of the imaging experiment show that aDAF has superior imaging quality than DAE, with signal-to noise ratio (SNR) improved by 23.32% and spatial resolution increased by 50%. According to the experiments, the proposed aDAF increased AE signal decoding accuracy, which is vital for future research and applications related to ABI.

Corrigendum: Investigation of a novel deep learning-based computed tomography perfusion mapping framework for functional lung avoidance radiotherapy.

[This corrects the article DOI: 10.3389/fonc.2021.644703.].

Fast assessment of left ventricular systolic function in obstructive sleep apnea patients with automated function imaging: Comparison with mitral annular plane systolic excursion.

BACKGROUND: Early detection of left ventricular (LV) subclinical dysfunction is clinically relevant before developing irreversible impairment in obstructive sleep apnea (OSA) patients. Mitral annulus plane systolic excursion (MAPSE) is a fast tool for OSA due to high prevalent obesity; another quick but more comprehensive tool is LV global longitudinal stain (GLS) based on automated function imaging (AFI). We therefore aimed to compare the feasibility and reproducibility of AFI to MAPSE in OSA patients, as a good model in whom obesity is common. METHODS: A comprehensive echocardiographic examination was done in 186 consecutive patients having polysomnography for suspected OSA. MAPSE was measured by using M-mode to calculate excursion of mitral annulus. GLS was derived by offline analysis of three long-axis views that semi-automatically detects LV endocardial boundary, which is adjusted manually as necessary with AFI measurement. Variability of AFI and MAPSE were compared among the different subgroups. RESULTS: Despite a relatively high obesity rate (42.9%), the feasibility of AFI was 94% (175/186) and that of 100% in MAPSE. AFI showed excellent correlation (r = .882) superior to MAPSE (r = .819) between the Expert and Beginner. Intra- and inter- observer variability of AFI and MAPSE in Bland-Altman analysis were 5.5% and 6.5%; 6.2% and 8.8%, respectively. In repeated measurements, AFI showed higher intra-class correlation (ICC = .95) than MAPSE (ICC = .87) (p < 0.05). Furthermore, analysis showed that AFI was feasible even in more obese patients (BMI≥28 kg/m2 ). CONCLUSIONS: Even in obese patients with OSA, AFI-GLS is feasible and more reliable for less expert operators than MAPSE in detecting LV longitudinal dysfunction.

Reliability and feasibility of automated function imaging for quantification in patients with left ventricular dilation: comparison with cardiac magnetic resonance.

Automated function imaging (AFI, GE Healthcare) is a novel promising algorithm of speckle-tracking echocardiography that combines two-dimensional strain and AI technology. It shortens the analysis time, saves the cost associated with streamlining of image acquisition, rapid analysis, and reporting, and has greater accuracy and reproducibility of measurements. This study aimed to evaluate the reliability and feasibility of AFI for the quantification of left ventricular (LV) volumes and function in patients with LV dilation by comparison with CMR. We retrospectively studied 50 patients with LV dilation on echocardiography whom both underwent CMR and coronary angiography within three days. LV volumes, ejection fraction (EF), and global longitudinal strain (GLS) were measured from 3 long-axis cine-views via the AFI technique in two modes: without editing (auto-AFI) and with partial border editing (semi-auto-AFI). The LV volumes and EF were also measured with 2D Simpson's biplane method, and CMR, as the standard method, was used for comparison. The AFI method still had significantly underestimated the LV volumes compared with CMR (P<0.01), but there were no significant differences between the AFI method and the conventional Simpson's biplane method. There were no significant differences in EF between CMR and the AFI method with good correlations (auto-AFI: r = 0.81, semi-auto-AFI: r = 0.86). The auto-AFI method provided the most rapid analysis and excellent reproducibility, while the semi-auto-AFI method further improved measurement accuracy. However, there were no significant differences in LV volumes and EF between these two AFI methods. The accuracy of AFI seems to be more affected by the image quality than the left ventricular morphology.  AFI enables accurate, efficient, and rapid evaluation of LV volumes and EF in patients with dilated LV, with good reproducibility and correlations with CMR.

Comparison between Nondedicated and Novel Dedicated Tracking Tool for Right Ventricular and Left Atrial Strain.

BACKGROUND: Recently, dedicated speckle-tracking solutions for right ventricular (RV) and left atrial (LA) strain assessment have become commercially available. The purpose of this study was to assess the level of agreement between nondedicated (left ventricular [LV] tracking software) and novel dedicated tracking software for RV and LA strain. METHODS: In 200 patients with various cardiovascular pathologies, we measured global longitudinal strain (GLS), free wall strain (FWS), and segmental values, as well as LA strain during reservoir, conduit, and contraction phases, by using the (1) LV-tracking software and (2) the novel dedicated tracking software for RV or LA strain analysis. Agreement between corresponding measurements obtained with the LV and dedicated RV or LA software was determined by using mean absolute difference (MAD) and Bland-Altman test. The intra- and interobserver reproducibility related to the nondedicated and novel dedicated tracking software was tested in 30 randomly selected subjects. RESULTS: The dedicated RV-tracking software provided slightly lower strain values without reaching statistical significance. The agreement between software was best for RV GLS (MAD, 2.4 ± 1.8) and significantly poorer for segmental values (MAD ranging from 4.5 ± 3.8 to 5.1 ± 4.0; analysis of variance, P < .05). The intra- and interobserver reproducibility for RV measurements was similar with both software (P > .05 for all parameters). Left atrial mean values showed no statistical difference when obtained with the two tracking tools. The use of LA dedicated tracking software increased significantly the intra- and interobserver reproducibility for LA strain during reservoir and atrial contraction (P < .01 for both). CONCLUSIONS: Our results suggest that the choice of tracking software does not significantly impact RV strain measurements. Nonetheless, the use of the same tracking software is recommended when performing serial measurements. The use of the dedicated software for LA strain analysis significantly improved the intra- and interobserver reproducibility.

Investigation of a Novel Deep Learning-Based Computed Tomography Perfusion Mapping Framework for Functional Lung Avoidance Radiotherapy.

Functional lung avoidance radiation therapy aims to minimize dose delivery to the normal lung tissue while favoring dose deposition in the defective lung tissue based on the regional function information. However, the clinical acquisition of pulmonary functional images is resource-demanding, inconvenient, and technically challenging. This study aims to investigate the deep learning-based lung functional image synthesis from the CT domain. Forty-two pulmonary macro-aggregated albumin SPECT/CT perfusion scans were retrospectively collected from the hospital. A deep learning-based framework (including image preparation, image processing, and proposed convolutional neural network) was adopted to extract features from 3D CT images and synthesize perfusion as estimations of regional lung function. Ablation experiments were performed to assess the effects of each framework component by removing each element of the framework and analyzing the testing performances. Major results showed that the removal of the CT contrast enhancement component in the image processing resulted in the largest drop in framework performance, compared to the optimal performance (~12%). In the CNN part, all the three components (residual module, ROI attention, and skip attention) were approximately equally important to the framework performance; removing one of them resulted in a 3-5% decline in performance. The proposed CNN improved ~4% overall performance and ~350% computational efficiency, compared to the U-Net model. The deep convolutional neural network, in conjunction with image processing for feature enhancement, is capable of feature extraction from CT images for pulmonary perfusion synthesis. In the proposed framework, image processing, especially CT contrast enhancement, plays a crucial role in the perfusion synthesis. This CTPM framework provides insights for relevant research studies in the future and enables other researchers to leverage for the development of optimized CNN models for functional lung avoidance radiation therapy.

Subclinical left ventricular systolic dysfunction detected in obstructive sleep apnea with automated function imaging and its association with nocturnal hypoxia.

BACKGROUND: Early detection of left ventricular (LV) dysfunction is crucial in obstructive sleep apnea (OSA) due to its close relationship with cardiovascular diseases. Global longitudinal strain (GLS) derived from automated function imaging (AFI) can precisely assess global longitudinal function. The aim of this study was to determine if LV GLS was reduced in patients with OSA and a normal LV ejection fraction (LVEF) and to assess any associated determinants. METHODS: Polysomnography (PSG) and echocardiography were done in consecutive patients with suspected OSA and normal LVEF in this prospective study. Patients were divided into two groups according to apnea-hypopnea index (AHI) (Group 1, normal or mild OSA: AHI < 15/h; Group 2, moderate-to-severe OSA: AHI ≥ 15/h). Clinical, PSG, and echocardiographic parameters were compared between the two groups and the associated factors were investigated. RESULTS: Of 425 consecutive patients, 244 were analyzed after exclusions. Patients in Group 2 had significantly worse GLS than those in Group 1 (p < 0.001). The prevalence of GLS reduction (defined as < - 19.7%) was 25% and 76%, respectively (χ2 = 34.19, p < 0.001). Nocturnal lowest pulse oxygen saturation (SpO2), AHI, body mass index (BMI), and gender were associated with GLS reduction (all p < 0.05). Further multivariate analysis showed that the lowest SpO2 (OR: 2.15), gender (OR: 2.45), and BMI (OR: 2.66) remained independent (all p < 0.05), and the lowest SpO2 was the most powerful determinant (χ2 = 33.0, p < 0.001) in forward regression analysis. The intra- and inter-operator variability for AFI and coefficient of repeatability was low even in those with relatively poor images. CONCLUSIONS: In patients with normal LVEF, more severe OSA was associated with a worse GLS. The major determinants were lowest nocturnal SpO2, gender, and obesity, but not AHI. GLS can be rapidly and reliably assessed using AFI.

Comparative study of microvascular function: Forearm blood flow versus dynamic retinal vessel analysis.

OBJECTIVE: Recently, dynamic retinal vessel analysis (DVA) has gained interest for investigation of microvascular function but comparative measurements with standard methods like the forearm blood flow technique (FBF) are uncommon till now. METHODS: We recruited 23 high-risk cardiovascular patients (Risk) and 17 healthy persons (Ctrl). During the FBF experiment, postocclusive reactive hyperaemia (RH) as well as endothelium-dependent and independent vasodilation was measured by infusion of acetylcholine (ACh) and sodium nitroprusside (SNP) into the brachial artery. The dynamic vessel analyzer was applied for measurement of the retinal arterial and venous response to flickering light during DVA and for determination of the central retinal arterial (CRAE) and venous equivalent (CRVE). RESULTS: Forearm blood flow technique was significantly attenuated in the patient group during postocclusive RH (p < .005). The increase of FBF in response to SNP did not differ significantly between the two groups (p = .09). In contrast, the FBF response to ACh was significantly blunted in the patient group (p < .05), indicating endothelial dysfunction. DVA did not detect any difference of retinal arterial (p = .68) or retinal venous (p = .93) vasodilation between both groups. The CRAE (p = .55) and CRVE (p = .83) did not differ significantly in either group. CONCLUSIONS: Forearm blood flow and DVA cannot be regarded as equivalent methods for testing of microvascular function. Possible explanations include differences in the vascular beds and vessel diameters examined as well as differences in the trigger mechanisms applied. Further studies are needed to define the role of DVA in this context.

Radiosynthesis and biological evaluation of an fluorine-18 labeled galactose derivative [18F]FPGal for imaging the hepatic asialoglycoprotein receptor.

The asialoglycoprotein receptor (ASGPR) is abundantly expressed on the surface of hepatocytes where it recognizes and endocytoses glycoproteins with galactosyl and N-acetylgalactosamine groups. Given its hepatic distribution, the asialoglycoprotein receptor can be targeted by positron imaging agents to study liver function using PET imaging. In this study, the positron imaging agent [18F]FPGal was designed to specifically target hepatic asialoglycoprotein receptor and its effectiveness was assessed in in vitro and in vivo models. The radiosynthesis of [18F]FPGal required 50 min with total radiochemical yields of [18F]FPGal from [18F]fluoride as 10% (corrected radiochemical yield). The Kd of [18F]FPGal to ASGPR in HepG2 cells was 1.99 ± 0.05 mM. Uptake values of 0.55% were observed within 30 min of incubation with HepG2 cells, which could be blocked by 200 mM d(+)-galactose (<0.1%). In vivo biodistribution analysis showed that the liver accumulation of [18F]FPGal at 30 min was 4.47 ± 0.96% ID/g in normal mice compared to 1.33 ± 0.07% ID/g in hepatic fibrotic mice (P < 0.01). Reduced uptake in the hepatic fibrosis mouse models was confirmed through PET/CT images at 30 min. Compared to normal mice, the standard uptake value (SUV) in the hepatic fibrosis mice was significantly lower when assessed through dynamic data collection for 1 h. Therefore, [18F]FPGal is a feasible PET probe that provide insight into ASGPR related liver disease.

Brain pathways of pain empathy activated by pained facial expressions: a meta-analysis of fMRI using the activation likelihood estimation method.

OBJECTIVE: The objective of this study is to summarize and analyze the brain signal patterns of empathy for pain caused by facial expressions of pain utilizing activation likelihood estimation, a meta-analysis method. DATA SOURCES: Studies concerning the brain mechanism were searched from the Science Citation Index, Science Direct, PubMed, DeepDyve, Cochrane Library, SinoMed, Wanfang, VIP, China National Knowledge Infrastructure, and other databases, such as SpringerLink, AMA, Science Online, Wiley Online, were collected. A time limitation of up to 13 December 2016 was applied to this study. DATA SELECTION: Studies presenting with all of the following criteria were considered for study inclusion: Use of functional magnetic resonance imaging, neutral and pained facial expression stimuli, involvement of adult healthy human participants over 18 years of age, whose empathy ability showed no difference from the healthy adult, a painless basic state, results presented in Talairach or Montreal Neurological Institute coordinates, multiple studies by the same team as long as they used different raw data. OUTCOME MEASURES: Activation likelihood estimation was used to calculate the combined main activated brain regions under the stimulation of pained facial expression. RESULTS: Eight studies were included, containing 178 subjects. Meta-analysis results suggested that the anterior cingulate cortex (BA32), anterior central gyrus (BA44), fusiform gyrus, and insula (BA13) were activated positively as major brain areas under the stimulation of pained facial expression. CONCLUSION: Our study shows that pained facial expression alone, without viewing of painful stimuli, activated brain regions related to pain empathy, further contributing to revealing the brain's mechanisms of pain empathy.

Using 4DCT-ventilation to characterize lung function changes for pediatric patients getting thoracic radiotherapy.

PURPOSE: A form of lung functional imaging has been developed that uses 4DCT data to calculate ventilation (4DCT-ventilation). Because 4DCTs are acquired as standard-of-care to manage breathing motion during radiotherapy, 4DCT-ventilation provides functional information at no extra dosimetric or monetary cost. 4DCT-ventilation has yet to be described in children. 4DCT-ventilation can be used as a tool to help assess post-treatment lung function and predict for future clinical thoracic toxicities for pediatric patients receiving radiotherapy to the chest. The purpose of this work was to perform a preliminary evaluation of 4DCT-ventilation-based lung function changes for pediatric patients receiving radiotherapy to the lungs. METHODS: The study used four patients with pre and postradiotherapy 4DCTs. The 4DCTs, deformable image registration, and a density-change-based algorithm were used to compute pre and post-treatment 4DCT-ventilation images. The post-treatment 4DCT-ventilation images were compared to the pretreatment 4DCT-ventilation images for a global lung response and for an intrapatient dose-response (providing an assessment for dose-dependent regional dose-response). RESULTS: For three of the four patients, a global ventilation decline of 7-37% was observed, while one patient did not demonstrate a global functional decline. Dose-response analysis did not reveal an intrapatient dose-response from 0 to 20 Gy for three patients while one patient demonstrated increased 4DCT-ventilation decline as a function of increasing lung doses up to 50 Gy. CONCLUSIONS: Compared to adults, pediatric patients have unique lung function, dosimetric, and toxicity profiles. The presented work is the first to evaluate spatial lung function changes in pediatric patients using 4DCT-ventilation and showed lung function changes for three of the four patients. The early changes demonstrated with lung function imaging warrant further longitudinal work to determine whether the imaging-based early changes can be predicted for long-term clinical toxicity.

[68Ga]NOTA-Galactosyl Human Serum Albumin: a Tracer for Liver Function Imaging with Improved Stability.

PURPOSE: Non-invasive techniques allowing quantitative determination of the functional liver mass are of great interest for patient management in a variety of clinical settings. Recently, we presented [68Ga]DTPA-GSA to target the hepatic asialoglycoprotein receptor for this purpose. Here, we introduce [68Ga]NOTA-GSA to improve metabolic stability of the radiopharmaceutical and compare the imaging properties with [68Ga]DTPA-GSA. PROCEDURES: Labeling of the compounds was carried out at room temperature using 1.9 M sodium acetate as buffer. For quality control, thin-layer, high-performance liquid, and size exclusion chromatographies were used. Metabolic stability was studied in rat and human serums. For in vivo evaluation, Fischer rats were scanned by positron emission tomography and magnetic resonance imaging and subsequently sacrificed for biodistribution studies. Time activity curves (TACs) for heart and liver were generated and corresponding parameters (T50, T90, LHL15, HH15) were calculated. RESULTS: [68Ga]NOTA-GSA can be produced in high radiochemical yield and purity (>95 %) within 15 min. Stability studies revealed almost no metabolite formation over the 2-h observation period. Analysis of the TACs showed comparable results for most of the investigated parameters. The only significant difference was found in the T90 value, where [68Ga]NOTA-GSA showed slower uptake in comparison with 68Ga-DTPA-GSA (123 ± 10 vs. 89 ± 3 s, p < 0.01). CONCLUSIONS: [68Ga]NOTA-GSA showed a significant increase of the metabolic stability and in most organs lower background activity. However, comparison of LHL15 and HH15 indicates that the increased stability did not further improve the diagnostic value. Thus, [68Ga]NOTA-GSA and [68Ga]DTPA-GSA can be used equivalent for imaging hepatic function with positron emission tomography.

Automated function imaging for predicting severe stenosis of left anterior descending coronary artery / 中国医学影像技术

Objective To explore the value of automated function imaging (AFI) based on two-dimensional speckle tracking imaging (2D-STI) technique longitudinal strain for predicting severe stenosis of left anterior descending (LAD) coronary artery in patients with suspected coronary heart disease (CHD).Methods Ninety-two patients with suspected CHD were divided into two groups according to the coronary angiography (CAG) results.There were 49 cases in group A (LAD stenosis rate ＜70％) and 43 cases in group B (LAD stenosis rate ≥70％).The two dimensional gray scale dynamic images were obtained in apical four-chamber view,apical two-chamber view and long axis of left ventricle (LV) view.Eighteen segments of LV longitudinal peak systolic strain,global longitudinal strain (GLS) and territorial longitudinal strain (TLS) supplied with LAD were measured with AFI software.The conventional ultrasonic parameters and the two-dimensional longitudinal strain parameters were compared between the two groups and ROC curve analysis of these parameters was used to predict LAD severe stenosis.Results There was no significant difference in the conventional ultrasonic parameters between the two groups (all P＞0.05).The group B had lower GLS,TLS than group A (both P＜0.001).GLS and TLS showed the highest area under ROC curve (0.715 and 0.705) for predicting LAD severe stenosis.The cut-off value,sensitivity and specificity for predicting LAD severe stenosis were-19.58 ％,63.3 ％,67.4 ％ in TLS,and-20.85 ％,74.4 ％,61.2 ％ in GLS respectively.Conclusion The longitudinal strain parameters measured with AFI based on 2D-STI technique can be used to predict LAD severe stenosis in patients with CHD,and GLS is more sensitive than TLS.

Automated function imaging for predicting severe stenosis of left anterior descending coronary artery / 中国医学影像技术

Objective To explore the value of automated function imaging (AFI) based on two-dimensional speckle tracking imaging (2D-STI) technique longitudinal strain for predicting severe stenosis of left anterior descending (LAD) coronary artery in patients with suspected coronary heart disease (CHD).Methods Ninety-two patients with suspected CHD were divided into two groups according to the coronary angiography (CAG) results.There were 49 cases in group A (LAD stenosis rate ＜70％) and 43 cases in group B (LAD stenosis rate ≥70％).The two dimensional gray scale dynamic images were obtained in apical four-chamber view,apical two-chamber view and long axis of left ventricle (LV) view.Eighteen segments of LV longitudinal peak systolic strain,global longitudinal strain (GLS) and territorial longitudinal strain (TLS) supplied with LAD were measured with AFI software.The conventional ultrasonic parameters and the two-dimensional longitudinal strain parameters were compared between the two groups and ROC curve analysis of these parameters was used to predict LAD severe stenosis.Results There was no significant difference in the conventional ultrasonic parameters between the two groups (all P＞0.05).The group B had lower GLS,TLS than group A (both P＜0.001).GLS and TLS showed the highest area under ROC curve (0.715 and 0.705) for predicting LAD severe stenosis.The cut-off value,sensitivity and specificity for predicting LAD severe stenosis were-19.58 ％,63.3 ％,67.4 ％ in TLS,and-20.85 ％,74.4 ％,61.2 ％ in GLS respectively.Conclusion The longitudinal strain parameters measured with AFI based on 2D-STI technique can be used to predict LAD severe stenosis in patients with CHD,and GLS is more sensitive than TLS.

fMRI adaptation revisited.

Adaptation has been widely used in functional magnetic imaging (fMRI) studies to infer neuronal response properties in human cortex. fMRI adaptation has been criticized because of the complex relationship between fMRI adaptation effects and the multiple neuronal effects that could underlie them. Many of the longstanding concerns about fMRI adaptation have received empirical support from neurophysiological studies over the last decade. We review these studies here, and also consider neuroimaging studies that have investigated how fMRI adaptation effects are influenced by high-level perceptual processes. The results of these studies further emphasize the need to interpret fMRI adaptation results with caution, but they also provide helpful guidance for more accurate interpretation and better experimental design. In addition, we argue that rather than being used as a proxy for measurements of neuronal stimulus selectivity, fMRI adaptation may be most useful for studying population-level adaptation effects across cortical processing hierarchies.

Broken heart as work-related accident: Occupational stress as a cause of takotsubo cardiomyopathy in 55-year-old female teacher - Role of automated function imaging in diagnostic workflow.

Takotsubo cardiomiopathy (TTC) (known also as "ampulla cardiomyopathy," "apical ballooning" or "broken heart syndrome") is connected with a temporary systolic left ventricular dysfunction without the culprit coronary lesion. Takotsubo cardiomyopathy was first described in 1990 in Japan after octopus trapping pot with a round bottom and narrow neck similar in shape to left ventriculogram in TTC patients. The occurrence of TTC is usually precipitated by a stressful event with a clinical presentation mimicking myocardial infarction: chest pain, ST-T segment elevation or T-wave inversion, a rise in cardiac troponin, and contractility abnormalities in echocardiography. A left ventricular dysfunction is transient and improves within a few weeks. Takotsubo cardiomyopathy typically occurs in postmenopausal women and the postulated mechanism is catecholamine overstimulation. Moreover, the distribution of contractility impairments usually does not correspond with typical region supplied by a single coronary artery. Therefore, the assessment of regional pattern of systolic dysfunction with speckle-tracking echocardiography and automated function imaging (AFI) technique may be important in diagnosis of TTC and may improve our insight into its patophysiology. We described a 55-year-old female teacher with TTC diagnosed after acute psychological stress in workplace. The provoking factor related with occupational stress and pattern of contraction abnormalities documented with AFI technique including basal segments of left ventricle make this case atypical.

One-Dimensional Nature of InAs/InP Quantum Dashes Revealed by Scanning Tunneling Spectroscopy.

We report on low-temperature cross-sectional scanning tunneling microscopy and spectroscopy on InAs(P)/InGaAsP/InP(001) quantum dashes, embedded in a diode-laser structure. The laser active region consists of nine InAs(P) quantum dash layers separated by the InGaAsP quaternary alloy barriers. The effect of the p-i-n junction built-in potential on the band structure has been evidenced and quantified on large-scale tunneling spectroscopic measurements across the whole active region. By comparing the tunneling current onset channels, a consistent energy shift has been measured in successive quantum dash or barrier layers, either for the ground state energy of similar-sized quantum dashes or for the conduction band edge of the barriers, corresponding to the band-bending slope. The extracted values are in good quantitative agreement with the theoretical band structure calculations, demonstrating the high sensitivity of this spectroscopic measurement to probe the electronic structure of individual nanostructures, relative to local potential variations. Furthermore, by taking advantage of the potential gradient, we compared the local density of states over successive quantum dash layers. We observed that it does not vanish while increasing energy, for any of the investigated quantum dashes, in contrast to what would be expected for discrete level zero-dimensional (0D) structures. In order to acquire further proof and fully address the open question concerning the quantum dash dimensionality nature, we focused on individual quantum dashes obtaining high-energy-resolution measurements. The study of the local density of states clearly indicates a 1D quantum-wirelike nature for these nanostructures whose electronic squared wave functions were subsequently imaged by differential conductivity mapping.