Early left ventricular microvascular dysfunction in diabetic pigs: a longitudinal quantitative myocardial perfusion CMR study.

BACKGROUND: Microvascular pathology is one of the main characteristics of diabetic cardiomyopathy; however, the early longitudinal course of diabetic microvascular dysfunction remains uncertain. This study aimed to investigate the early dynamic changes in left ventricular (LV) microvascular function in diabetic pig model using the cardiac magnetic resonance (CMR)-derived quantitative perfusion technique. METHODS: Twelve pigs with streptozotocin-induced diabetes mellitus (DM) were included in this study, and longitudinal CMR scanning was performed before and 2, 6, 10, and 16 months after diabetic modeling. CMR-derived semiquantitative parameters (upslope, maximal signal intensity, perfusion index, and myocardial perfusion reserve index [MPRI]) and fully quantitative perfusion parameters (myocardial blood flow [MBF] and myocardial perfusion reserve [MPR]) were analyzed to evaluate longitudinal changes in LV myocardial microvascular function. Pearson correlation was used to analyze the relationship between LV structure and function and myocardial perfusion function. RESULTS: With the progression of DM duration, the upslope at rest showed a gradually increasing trend (P = 0.029); however, the upslope at stress and MBF did not change significantly (P > 0.05). Regarding perfusion reserve function, both MPRI and MPR showed a decreasing trend with the progression of disease duration (MPRI, P = 0.001; MPR, P = 0.042), with high consistency (r = 0.551, P < 0.001). Furthermore, LV MPR is moderately associated with LV longitudinal strain (r = - 0.353, P = 0.022), LV remodeling index (r = - 0.312, P = 0.033), fasting blood glucose (r = - 0.313, P = 0.043), and HbA1c (r = - 0.309, P = 0.046). Microscopically, pathological results showed that collagen volume fraction increased gradually, whereas no significant decrease in microvascular density was observed with the progression of DM duration. CONCLUSIONS: Myocardial microvascular reserve function decreased gradually in the early stage of DM, which is related to both structural (but not reduced microvascular density) and functional abnormalities of microvessels, and is associated with increased blood glucose, reduced LV deformation, and myocardial remodeling.

Accelerated 3D MR neurography of the brachial plexus using deep learning-constrained compressed sensing.

OBJECTIVES: To explore the use of deep learning-constrained compressed sensing (DLCS) in improving image quality and acquisition time for 3D MRI of the brachial plexus. METHODS: Fifty-four participants who underwent contrast-enhanced imaging and forty-one participants who underwent unenhanced imaging were included. Sensitivity encoding with an acceleration of 2 × 2 (SENSE4x), CS with an acceleration of 4 (CS4x), and DLCS with acceleration of 4 (DLCS4x) and 8 (DLCS8x) were used for MRI of the brachial plexus. Apparent signal-to-noise ratios (aSNRs), apparent contrast-to-noise ratios (aCNRs), and qualitative scores on a 4-point scale were evaluated and compared by ANOVA and the Friedman test. Interobserver agreement was evaluated by calculating the intraclass correlation coefficients. RESULTS: DLCS4x achieved higher aSNR and aCNR than SENSE4x, CS4x, and DLCS8x (all p < 0.05). For the root segment of the brachial plexus, no statistically significant differences in the qualitative scores were found among the four sequences. For the trunk segment, DLCS4x had higher scores than SENSE4x (p = 0.04) in the contrast-enhanced group and had higher scores than SENSE4x and DLCS8x in the unenhanced group (all p < 0.05). For the divisions, cords, and branches, DLCS4x had higher scores than SENSE4x, CS4x, and DLCS8x (all p ≤ 0.01). No overt difference was found among SENSE4x, CS4x, and DLCS8x in any segment of the brachial plexus (all p > 0.05). CONCLUSIONS: In three-dimensional MRI for the brachial plexus, DLCS4x can improve image quality compared with SENSE4x and CS4x, and DLCS8x can maintain the image quality compared to SENSE4x and CS4x. CLINICAL RELEVANCE STATEMENT: Deep learning-constrained compressed sensing can improve the image quality or accelerate acquisition of 3D MRI of the brachial plexus, which should be benefit in evaluating the brachial plexus and its branches in clinical practice. KEY POINTS: •Deep learning-constrained compressed sensing showed higher aSNR, aCNR, and qualitative scores for the brachial plexus than SENSE and CS at the same acceleration factor with similar scanning time. •Deep learning-constrained compressed sensing at acceleration factor of 8 had comparable aSNR, aCNR, and qualitative scores to SENSE4x and CS4x with approximately half the examination time. •Deep learning-constrained compressed sensing may be helpful in clinical practice for improving image quality and acquisition time in three-dimensional MRI of the brachial plexus.

Abnormal volumetric brain morphometry and cerebral blood flow in adolescents with depression.

BACKGROUND: Prior research has demonstrated that the brains of adolescents with depression exhibit distinct structural alterations. However, preliminary studies have documented the pathophysiological changes in certain brain regions, such as the cerebellum, highlighting a need for further research to support the current understanding of this disease. AIM: To study brain changes in depressed adolescents. METHODS: This study enrolled 34 adolescents with depression and 34 age-, sex-, and education-level-matched healthy control (HC) individuals. Structural and functional alterations were identified when comparing the brains of these two participant groups through voxel-based morphometry and cerebral blood flow (CBF) analysis, respectively. Associations between identified brain alterations and the severity of depressive symptoms were explored through Pearson correlation analyses. RESULTS: The cerebellum, superior frontal gyrus, cingulate gyrus, pallidum, middle frontal gyrus, angular gyrus, thalamus, precentral gyrus, inferior temporal gyrus, superior temporal gyrus, inferior frontal gyrus, and supplementary motor areas of adolescents with depression showed an increase in brain volume compared to HC individuals. These patients with depression further presented with a pronounced drop in CBF in the left pallidum (group = 98, and peak t = - 4.4324), together with increased CBF in the right percental gyrus (PerCG) (group = 90, and peak t = 4.5382). In addition, 17-item Hamilton Depression Rating Scale scores were significantly correlated with the increased volume in the opercular portion of the left inferior frontal gyrus (r = - 0.5231, P < 0.01). CONCLUSION: The right PerCG showed structural and CBF changes, indicating that research on this part of the brain could offer insight into the pathophysiological causes of impaired cognition.

MRI-based multiregional radiomics for preoperative prediction of tumor deposit and prognosis in resectable rectal cancer: a bicenter study.

OBJECTIVE: To build T2WI-based multiregional radiomics for predicting tumor deposit (TD) and prognosis in patients with resectable rectal cancer. MATERIALS AND METHODS: A total of 208 patients with pathologically confirmed rectal cancer from two hospitals were prospectively enrolled. Intra- and peritumoral features were extracted separately from T2WI images and the least absolute shrinkage and selection operator was used to screen the most valuable radiomics features. Clinical-radiomics nomogram was developed by radiomics signatures and the most predictive clinical parameters. Prognostic model for 3-year recurrence-free survival (RFS) was constructed using univariate and multivariate Cox analysis. RESULTS: For TD, the area under the receiver operating characteristic curve (AUC) for intratumoral radiomics model was 0.956, 0.823, and 0.860 in the training cohort, test cohort, and external validation cohort, respectively. AUC for the peritumoral radiomics model was 0.929, 0.906, and 0.773 in the training cohort, test cohort, and external validation cohort, respectively. The AUC for combined intra- and peritumoral radiomics model was 0.976, 0.918, and 0.874 in the training cohort, test cohort, and external validation cohort, respectively. The AUC for clinical-radiomics nomogram was 0.989, 0.777, and 0.870 in the training cohort, test cohort, and external validation cohort, respectively. The prognostic model constructed by combining intra- and peritumoral radiomics signature score (radscore)-based TD and MRI-reported lymph nodes metastasis (LNM) indicated good performance for predicting 3-year RFS, with AUC of 0.824, 0.865, and 0.738 in the training cohort, test cohort and external validation cohort, respectively. CONCLUSION: Combined intra- and peritumoral radiomics model showed good performance for predicting TD. Combining intra- and peritumoral radscore-based TD and MRI-reported LNM indicated the recurrence risk. CLINICAL RELEVANCE STATEMENT: Combined intra- and peritumoral radiomics model could help accurately predict tumor deposits. Combining this predictive model-based tumor deposits with MRI-reported lymph node metastasis was associated with relapse risk of rectal cancer after surgery. KEY POINTS: • Combined intra- and peritumoral radiomics model provided better diagnostic performance than that of intratumoral and peritumoral radiomics model alone for predicting TD in rectal cancer. • The predictive performance of the clinical-radiomics nomogram was not improved compared with the combined intra- and peritumoral radiomics model for predicting TD. • The prognostic model constructed by combining intra- and peritumoral radscore-based TD and MRI-reported LNM showed good performance for assessing 3-year RFS.

Electroconvulsive therapy-induced neuroimaging alterations measured by cerebral blood flow in adolescents with major depressive disorder.

BACKGROUND: Electroconvulsive therapy (ECT) is a novel treatment strategy for adolescents with major depressive disorder (MDD). However, its related neurobiological changes associated with ECT remain undetermined. OBJECTIVE: To elucidate the impact of ECT on the regional cerebral blood flow (CBF), and to identify alterations in the CBF associated with clinical outcomes in adolescents with MDD. METHODS: Fifty-two treatment-naive adolescents who had experienced their first episode of MDD and 36 healthy controls (HCs) were recruited. To assess baseline parameters, all subjects were scanned with arterial spin labeling resting-state functional magnetic resonance imaging (ASL-fMRI) at the beginning of the study. Subsequently, 27 MDD adolescents were re-scanned after 2 weeks after ECT. CBF imaging was used for the prediction of specific clinical outcomes. Lastly, the associations between alterations seen on brain imaging alterations after ECT and ECT clinical efficacy (ΔHAMD scores) were determined. RESULTS: Relative to HCs, adolescents with MDD exhibited reduced CBF in the left medial superior frontal gyrus (SFGmed) (cluster = 243, peak t = -3.9373, and P < 0.001) and augmented CBF in the right percental gyrus (PerCG) (cluster = 321, peak t = 4.3332, and P < 0.001) at baseline. Following ECT, MDD adolescents exhibited reduced CBF in the right fusiform gyrus (FFG) (cluster = 309, peak t = -4.346, and P < 0.001) and left hippocampus (HIP) (cluster = 290, peak t = -4.706, and P < 0.001), and enhanced CBF in the left orbital part of the inferior frontal gyrus (ORBinf) (cluster = 214, peak t = 4.073, and P < 0.001). Correlation analysis suggested an inverse association between ΔHAMD scores and CBF values in the left ORBinf (R2 = 0.196, P = 0.021). CONCLUSIONS: It was found that ECT resulted in alterations in CBF in specific brain areas, highlighting the significance of ORBinf in ECT pathophysiology in MDD adolescents.

[Using Quantitative Computed Tomography to Study the Correlation Between Physical Composition and Grip Strength in Young People].

Objective: To study with quantitative computed tomography (QCT) the correlation between grip strength and physical composition and waist and hip circumferences in young people with different body mass indexes (BMIs). Methods: A total of 1310 young people who came to West China Hospital, Sichuan University for physical checkups and underwent chest QCT at our hospital from April to July 2021 were included in the study. Their data were collected and their BMIs were calculated. The subjects were divided according to their BMIs into 4 groups, underweight group (BMI<18.5 kg/m 2), normal-weight group (18.5 kg/m 2≤BMI<24 kg/m 2), overweight group (24 kg/m 2≤BMI<28 kg/m 2), and obesity group (BMI≥28 kg/m 2). The raw data were uploaded to QCT Mindways Pro 6.1 software to be processed for measurement of the fat content (area) of the physical components of the L2 vertebral body, including total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and abdominal fat ratio, or VAT/SAT. Grip strength was measured with CAMRY EH101 digital grip dynamometer. Statistical analysis of the data was performed, and the correlations between grip strength and various physical components, waist circumference, and hip circumference in subjects of different BMIs were examined. In addition, stratified analysis of normal-weight and overweight subjects of different age groups was conducted. Results: In the normal-weight group, height, body mass, hip circumference and grip strength were positively correlated with grip strength in males aged 21-40 years, SAT was negatively correlated with grip strength in males aged 36-40 years, and VAT/SAT was positively correlated with grip strength in males aged 36-40 years. In normal-weight females aged 21-25 years, SAT was negatively correlated with grip strength, while VAT and VAT/SAT were positively correlated with grip strength. In normal-weight females aged 26-40 years, height, body mass, and hip circumference were positively correlated with grip strength. In normal-weight females aged 36-40 years, VAT/SAT was positively correlated with grip strength. In overweight males aged 21-25 years, hip circumference and body mass were positively correlated with grip strength. In overweight males aged 26-30 years, TAT, waist-to-hip ratio, and waist-to-height ratio were negatively correlated with grip strength. In overweight males aged 31-40 years, height and body mass were positively correlated with grip strength, while waist-to-hip ratio and waist-to-height ratio were negatively correlated with grip strength. In addition, hip circumference was positively correlated with grip strength in overweight males aged 31-35 years. In overweight females aged 21-25 years, waist circumference, hip circumference, and waist-to-height ratio were positively correlated with grip strength. In overweight females aged 26-30 years, height and body mass were positively correlated with grip strength. In overweight females aged 31-35 years, TAT, SAT, waist circumference, waist-to-hip ratio, and waist-to-height ratio were negatively correlated with grip strength. In overweight females aged 36-40 years, SAT and waist-to-height ratio were negatively correlated with grip strength, while VAT, VAT/SAT, height and body mass were positively correlated with grip strength. The height and body mass of males and females in the underweight group were positively correlated with grip strength, and the hip circumference of females in the underweight group was also positively correlated with grip strength. In the obesity group, TAT, VAT, and waist-to-height ratio were negatively correlated with grip strength in males, but no such correlation was observed in females. Conclusion: There is a close association between abdominal fat content and grip strength in young people with different BMIs, indicating that young people should control abdominal fat content and hip fat content in order to maintain the strength of corresponding muscles.

[Application of Diffusion-Weighted Imaging and Hepatobiliary-Specific Contrast Agent Gd-EOB-DTPA in the Diagnosis and Differential Diagnosis of Focal Liver Lesions].

There are many types of focal liver lesions (FLL) presenting different lesion signs and their diagnosis and differential diagnosis are relatively difficult. It is of great clinical significance to accurately detect, classify and characterize focal liver lesions as soon as possible. Diffusion-weighted imaging (DWI) provides information on liver cell density, microstructure, and microcirculation perfusion. Gadolinium-ethoxibenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) is a hepatobiliary-specific contrast agent. Gd-EOB-DTPA-enhanced MRI examination of liver provides information on the blood perfusion of lesions and specific information on the uptake function of normal liver cells. The combined application of the two can significantly improve the sensitivity and diagnostic accuracy in the detection of FLL. Herein, we reviewed the research findings on the application of DWI and Gd-EOB-DTPA in FLL diagnosis in order to provide reference for further clinical application. Most of the existing studies only made comparison and discussion of the DWI image quality of different b values and their fitted apparent diffusion coefficient (ADC) values before and after Gd-EOB-DTPA enhancement, and the reported findings are not only varied, but also inconsistent. Whether Gd-EOB-DTPA will affect DWI images is still been debated. Future research should focus on quantitative comparison, discussion and verification of the enhancement effect after injection of Gd-EOB-DTPA, as well as the changes in the ADC value corresponding to different b values before and after enhancement, in order to provide more objective and consistent research results for clinical application.

Prognostic value of computed tomography derived skeletal muscle mass index in lung cancer: A meta-analysis.

BACKGROUND: The prognostic role of the skeletal muscle mass index (SMI) derived from computed tomography (CT) imaging been well verified in several types of cancers. However, whether the SMI could serve as a reliable and valuable predictor of long-term survival in lung cancer patients remains unclear. AIM: To identify the prognostic value of the CT-derived SMI in lung cancer patients. METHODS: The PubMed, Web of Science, and Embase electronic databases were searched up to November 5, 2021 for relevant studies. The Reference Citation Analysis databases were used during the literature searching and selection. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to assess the association of the SMI with the overall survival (OS) of lung cancer patients. All statistical analyses were performed with STATA 12.0 software. RESULTS: A total of 12 studies involving 3002 patients were included. The pooled results demonstrated that a lower SMI was significantly related to poorer OS (HR = 1.23, 95%CI: 1.11-1.37, P < 0.001). In addition, the subgroup analyses stratified by treatment (nonsurgery vs surgery), tumor stage (advanced stage vs early stage), and tumor type (non-small cell lung cancer vs lung cancer) showed similar results. CONCLUSION: The CT-derived SMI is a novel and valuable prognostic indicator in lung cancer and might contribute to the clinical management and treatment of lung cancer patients.

Cdc42 Promotes Axonogenesis of Primary Hippocampal Neurons by Inhibiting Glycogen Synthase Kinase-3ß.

BACKGROUND: Progressive axon degeneration is a common pathological feature of neurodegenerative diseases. Cdc42 is a member of the Rho GTPase family that participates in axonogenesis. GSK-3ß is a serine/threonine kinase highly implicated in neuronal development and neurodegeneration. This study aimed to examine whether cdc42 promotes axonogenesis by regulating GSK-3ß activity. METHODS: Hippocampal neurons were isolated from neonatal Sprague-Dawley rats and transfected with designated plasmid vectors to alter the activities of cdc42 and GSK-3ß. LiCl treatment was used to inhibit the GSK-3ß activity in primary neurons. GSK-3ß activity was determined by an enzyme activity assay kit. Immunofluorescence staining was used to detect axons stained with anti-Tau-1 antibody and dendrites stained with anti-MAP2 antibody. RESULTS: Transfection with an active cdc42 mutant (cdc42F28L) decreased the activity of GSK-3ß and induced axonogenesis in primary rat hippocampal neurons, while transfection with a negative cdc42 mutant (cdc42N17) resulted an opposite effect. Moreover, transfection with plasmid vectors carrying wild-type GSK-3ß or a constitutively active GSK3ß mutant (GSK-3ß S9A) increased the activity of GSK-3ß and attenuated axonogenesis of primary hippocampal neurons with excessive cdc42 activity, whereas inhibition of GSK-3ß by LiCl abolished the inhibitory effect of the negative cdc42 mutant on axonogenesis. CONCLUSIONS: This study suggests that cdc42 induces axonogenesis of primary rat hippocampal neurons via inhibiting GSK-3ß activity. These findings support further investigation into the mechanisms of cdc42/GSK-3ß-mediated axonogenesis.

[Clinical Application of "Three-Low" Technique Combined with Artificial Intelligence Iterative Reconstruction Algorithm in Aortic CT Angiography].

Objective: To explore the application value of the "three-low" technique (low radiation dose, low contrast agent dosage and low contrast agent flow rate) combined with artificial intelligence iterative reconstruction (AIIR) in aortic CT angiography (CTA). Methods: A total of 33 patients who underwent aortic CTA were prospectively enrolled. Based on the time of their follow-up examinations, the imaging data were divided into Group A and Group B, with Group A being the control group (100 kV, 0.8 mL/kg, 5 mL/s) and Group B being the "three-low" technique group (70 kV, 0.5 mL/kg, 3 mL/s). In group A, the images were reconstructed by Karl iterative algorithm. Group B was divided into B1 and B2 subgroups, with their images being reconstructed by Karl iterative algorithm and AIIR, respectively. The CT and SD values of the ascending aorta, descending aorta, abdominal aorta, left common iliac artery and right common iliac artery were measured, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The subjective scoring of image quality was performed. The radiation dose parameters were documented. Results: Differences in the CT value, SD value, SNR and CNR of the three groups were statistically significant ( P<0.001). The CT value, SNR and CNR of group B2 were significantly higher than those of group B1, while the SD value of group B2 was significantly lower than that of group B1 ( P<0.017). There was no significant difference between the CT values of group A and those of group B2 ( P>0.017). The SD values, SNR and CNR in group B2 were better than those in group A ( P>0.017). There was significant difference in the subjective evaluation of image quality among the three groups ( P<0.05), but there was no significant difference between group A and group B2 ( P>0.017). The radiation dose and contrast medium dosage in group B decreased 84.14% and 37.08%, respectively, compared with those of group A. Conclusion: With the "three-low" technique combined with AIIR algorithm, the image quality of aortic CTA obtained is comparable to that of conventional dose scanning, while the radiation dose, contrast agent dosage and contrast agent flow rate of patients are significantly reduced.

The application of apparent diffusion coefficients derived from intratumoral and peritumoral zones for assessing pathologic prognostic factors in rectal cancer.

OBJECTIVE: To investigate the diagnostic performance of the apparent diffusion coefficient (ADC) derived from intratumoral and peritumoral zones for assessing pathologic prognostic factors in rectal cancer. MATERIALS AND METHODS: One hundred forty-six patients with rectal cancer who underwent preoperative MRI were prospectively enrolled. Two radiologists independently placed free-hand regions of interest (ROIs) in the largest tumor cross section and three small ROIs on the peritumoral zone adjacent to the tumor contour. Maximum values of tumor ADC (ADCtmax), minimum values of tumor ADC (ADCtmin), mean values of tumor ADC (ADCtmean), mean values of peritumor ADC (ADCpmean), and ADCpmean/ADCtmean (ADC ratio) were obtained on ADC maps and correlated with prognostic factors using uni- and multivariate logistic regression, and receiver operating characteristic curve (ROC) analysis. RESULTS: Interobserver agreement was excellent for ADCtmax and ADCtmean (intraclass correlation coefficient [ICC], 0.915-0.958), and were good for ADCtmin, ADCpmean, and ADC ratio (ICC, 0.774-0.878). The ADC ratio was significantly higher in the poor differentiation, T3-4 stage, lymph node metastasis (LNM)-positive, extranodal extension (ENE)-positive, tumor deposit (TD)-positive, and lymphovascular invasion (LVI)-positive groups than that in the well-moderate differentiation, T1-2 stage, LNM-negative, ENE-negative, TD-negative, and LVI-negative groups (p = 0.008, < 0.001, < 0.001, 0.001, < 0.001, and < 0.001, respectively). The area under the ROC curve (AUC) of the ADC ratio was the highest for assessing poor differentiation (0.700), T3-4 stage (0.707), LNM-positive (0.776), TD-positive (0.848), and LVI-positive (0.778). Both the ADC ratio (AUC = 0.677) and ADCpmean (AUC = 0.686) showed higher diagnostic performance for assessing ENE. CONCLUSION: The ADC ratio could provide better predictive performance for assessing preoperative prognostic factors in resectable rectal cancer. KEY POINTS: • Both the peritumor/tumor ADC ratio and ADCpmean are correlated with important prognostic factors of resectable rectal cancer. • Both peritumor ADC and peritumor/tumor ADC ratio had higher diagnostic performance than tumor ADC for assessment of prognostic factors in resectable rectal cancer. • Peritumor/tumor ADC ratio showed the most capability for the assessment of prognostic factors in resectable rectal cancer.

Distinguishing Cardiac Amyloidosis and Hypertrophic Cardiomyopathy by Thickness and Myocardial Deformation of the Right Ventricle.

OBJECTIVES: To compare right ventricular thickness (RVT) and deformation of cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) patients. METHODS: Sixty CA (mean age 58 ± 10 years; 33 males (55%)) and sixty HCM patients (mean age 55 ± 14 years; 27 males (45%)) were retrospectively enrolled. RVT, global radical peak strain (GRPS), global longitudinal peak strain (GLPS), and global circumferential peak stain (GCPS) were analyzed. To determine the cutoff values of the RVT and RV strain parameters for distinguishing CA from HCM, the areas under the receiver operating characteristic curve (AUCs) were analyzed. RESULTS: RVT of CA patients was significantly thicker than that of HCM patients (7.8 ± 2.1 vs 5.9 ± 1.3, p < 0.001). Moreover, significantly decreased RV-GRPS (12.1 ± 6.9 vs 23.5 ± 12.1, p < 0.001), RV-GCPS (-3.4 ± 2.2 vs -5.6 ± 3.5, p < 0.001), and RV-GLPS (-4.6 ± 2.3 vs -11.1 ± 4.9, p < 0.001) were observed in CA patients compared with HCM patients. RVT and RV strain demonstrate comparable diagnostic accuracy in differentiating CA from HCM. In particular, RV-GLPS combined with RVT showed the best performance for discriminating CA from HCM (AUC = 0.92, 95% CI: 0.85 to 0.96, p = 0.0001). CONCLUSIONS: Right ventricular myocardial thickness and deformation of CA patients was more severe than HCM patients. RV-GLPS combined with RVT presents an excellent diagnostic performance in distinguishing CA and HCM.

Automatic machine learning based on native T1 mapping can identify myocardial fibrosis in patients with hypertrophic cardiomyopathy.

OBJECTIVES: To investigate the feasibility of automatic machine learning (autoML) based on native T1 mapping to predict late gadolinium enhancement (LGE) status in hypertrophic cardiomyopathy (HCM). METHODS: Ninety-one HCM patients and 44 healthy controls who underwent cardiovascular MRI were enrolled. The native T1 maps of HCM patients were classified as LGE ( +) or LGE (-) based on location-matched LGE images. An autoML pipeline was implemented using the tree-based pipeline optimization tool (TPOT) for 3 binary classifications: LGE ( +) and LGE (-), LGE (-) and control, and HCM and control. TPOT modeling was repeated 10 times to obtain the optimal model for each classification. The diagnostic performance of the best models by slice and by case was evaluated using sensitivity, specificity, accuracy, and microaveraged area under the curve (AUC). RESULTS: Ten prediction models were generated by TPOT for each of the 3 binary classifications. The diagnostic accuracy obtained with the best pipeline in detecting LGE status in the testing cohort of HCM patients was 0.80 by slice and 0.79 by case. In addition, the TPOT model also showed discriminability between LGE (-) patients and control (accuracy: 0.77 by slice; 0.78 by case) and for all HCM patients and controls (accuracy: 0.88 for both). CONCLUSIONS: Native T1 map analysis based on autoML correlates with LGE ( +) or (-) status. The TPOT machine learning algorithm could be a promising method for predicting myocardial fibrosis, as reflected by the presence of LGE in HCM patients without the need for late contrast-enhanced MRI sequences. KEY POINTS: • The tree-based pipeline optimization tool (TPOT) is a machine learning algorithm that could help predict late gadolinium enhancement (LGE) status in patients with hypertrophic cardiomyopathy. • The TPOT could serve as an adjuvant method to detect LGE by using information from native T1 maps, thus avoiding the need for contrast agent. • The TPOT also detects native T1 map alterations in LGE-negative patients with hypertrophic cardiomyopathy.

Association Between Heart Failure With Preserved Left Ventricular Ejection Fraction and Impaired Left Atrial Phasic Function in Hypertrophic Cardiomyopathy: Evaluation by Cardiac MRI Feature Tracking.

BACKGROUND: The majority of heart failure (HF) in hypertrophic cardiomyopathy (HCM) manifests as a phenotype with preserved left ventricular (LV) ejection fraction; however, the exact contribution of left atrial (LA) phasic function to HF with preserved ejection fraction (HFpEF) in HCM remains unresolved. PURPOSE: To define the association between LA function and HFpEF in HCM patients using cardiac magnetic resonance imaging (MRI) feature tracking. STUDY TYPE: Retrospective. POPULATION: One hundred and fifty-four HCM patients (HFpEF vs. non-HF: 55 [34 females] vs. 99 [43 females]). FIELD STRENGTH/SEQUENCE: 3.0 T/balanced steady-state free precession. ASSESSMENT: LA reservoir function (reservoir strain [εs ], total ejection fraction [EF]), conduit function (conduit strain [εe ], passive EF), booster-pump function (booster strain [εa ] and active EF), LA volume index, and LV global longitudinal strain (LV GLS) were evaluated in HCM patients. STATISTICAL TESTS: Chi-square test, Student's t-test, Mann-Whitney U test, multivariate linear regression, logistic regression, and net reclassification analysis were used. Two-sided P < 0.05 was considered statistically significant. RESULTS: No significant difference was found in LV GLS between the non-HF and HFpEF group (-10.67 ± 3.14% vs. -10.14 ± 4.01%, P = 0.397), whereas the HFpEF group had more severely impaired LA phasic strain (εs : 27.40 [22.60, 35.80] vs. 18.15 [11.98, 25.90]; εe : 13.80 [9.20, 18.90] vs. 7.95 [4.30, 14.35]; εa : 13.50 [9.90, 17.10] vs. 7.90 [5.40, 14.15]). LA total EF (37.91 [29.54, 47.94] vs. 47.49 [39.18, 55.01]), passive EF (14.70 [7.41, 21.49] vs. 18.07 [9.32, 24.78]), and active EF (27.19 [17.79, 36.60] vs. 36.64 [26.63, 42.71]) were all significantly decreased in HFpEF patients compared with non-HF patients. LA reservoir (ß = 0.90 [0.85, 0.96]), conduit (ß = 0.93 [0.87, 0.99]), and booster (ß = 0.86 [0.78, 0.95]) strain were independently associated with HFpEF in HCM patients. The model including reservoir strain (Net Reclassification Index [NRI]: 0.260) or booster strain (NRI: 0.325) improved the reclassification of HFpEF based on LV GLS and minimum left atrial volume index (LAVImin ). DATA CONCLUSION: LA phasic function was severely impaired in HCM patients with HFpEF, whereas LV function was not further impaired compared with non-HF patients. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 3.

Value of intravoxel incoherent motion for assessment of lymph node status and tumor response after chemoradiation therapy in locally advanced rectal cancer.

OBJECTIVE: To assess the role of region of interest (ROI) selection of intravoxel incoherent motion (IVIM) for predicting lymph node metastases (LNM) and tumor response after chemoradiation therapy (CRT) in locally advanced rectal cancer. MATERIALS AND METHODS: Seventy-nine patients with biopsy-proven rectal adenocarcinoma who underwent pre- and post-CRT MRI and surgery were prospectively enrolled. The exclusion criteria included nonresectable and/or metastatic disease and loss of follow-up. Pathological stage was determined using ypTNM stage and tumor regression grade. Slow diffusion coefficient (D), fast diffusion coefficient (D*), perfusion-related diffusion fraction (f), apparent diffusion coefficient (ADC) and their percentage changes (Δ%) were evaluated by two readers using whole-volume, single-slice and small samples ROI methods. Risk factors including carcinoembryonic antigen, post-CRT T-staging, extramural venous invasion and IVIM parameters were evaluated through multivariate analyses. Areas under the receiver operating characteristic curves (AUCs) were calculated to evaluate diagnostic performance. Duration of follow-up was two-year. Recurrence-free survival of patients with LNM and tumor response was estimated using Kaplan-Meier analysis. RESULTS: Interobserver agreement were good for pre- and post-CRT three ROI methods (intraclass correlation coefficient [ICC], 0.581-0.953). Whole-volume ROI-derived Δ%D was an independent risk factor for LNM, non-pathological complete response (non-pCR) and poor response (odds ratio, 0.940, 0.952, 0.805, respectively; all p < 0.001). Whole-volume ROI-derived Δ%D showed best AUC of 0.810, 0.851 and 0.903 for LNM, non-pCR and poor response (cutoff value, 31.8%, 54.5%, 52.8%, respectively). Patients with post-CRT LNM showed reduction in 2-year recurrence-free survival (hazard ratio, 3.253). CONCLUSIONS: Whole-volume ROI-derived Δ%D provided high diagnostic performance for evaluating post-CRT LNM and tumor response. Patients with post-CRT LNM showed earlier recurrence.

MRI-based multiregional radiomics for predicting lymph nodes status and prognosis in patients with resectable rectal cancer.

Purpose: To establish and evaluate multiregional T2-weighted imaging (T2WI)-based clinical-radiomics model for predicting lymph node metastasis (LNM) and prognosis in patients with resectable rectal cancer. Methods: A total of 346 patients with pathologically confirmed rectal cancer from two hospitals between January 2019 and December 2021 were prospectively enrolled. Intra- and peritumoral features were extracted separately, and least absolute shrinkage and selection operator regression was applied for feature selection. Radiomics signatures were built using the selected features from different regions. The clinical-radiomic nomogram was developed by combining the intratumoral and peritumoral radiomics signatures score (radscore) and the most predictive clinical parameters. The diagnostic performances of the nomogram and clinical model were evaluated using the area under the receiver operating characteristic curve (AUC). The prognostic model for 3-year recurrence-free survival (RFS) was constructed using univariate and multivariate Cox analysis. Results: The intratumoral radscore (radscore 1) included four features, the peritumoral radscore (radscore 2) included five features, and the combined intratumoral and peritumoural radscore (radscore 3) included ten features. The AUCs for radscore 3 were higher than that of radscore 1 in training cohort (0.77 vs. 0.71, P=0.182) and internal validation cohort (0.76 vs. 0.64, P=0.041). The AUCs for radscore 3 were higher than that of radscore 2 in training cohort (0.77 vs. 0.74, P=0.215) and internal validation cohort (0.76 vs. 0.68, P=0.083). A clinical-radiomic nomogram showed a higher AUC compared with the clinical model in training cohort (0.84 vs. 0.67, P<0.001) and internal validation cohort (0.78 vs. 0.64, P=0.038) but not in external validation (0.72 vs. 0.76, P=0.164). Multivariate Cox analysis showed MRI-reported extramural vascular invasion (EMVI) (HR=1.099, 95%CI: 0.462-2.616; P=0.031) and clinical-radiomic nomogram-based LNM (HR=2.232, 95%CI:1.238-7.439; P=0.017) were independent risk factors for assessing 3-year RFS. Combined clinical-radiomic nomogram based LNM and MRI-reported EMVI showed good performance in training cohort (AUC=0.748), internal validation cohort (AUC=0.706) and external validation (AUC=0.688) for predicting 3-year RFS. Conclusion: A clinical-radiomics nomogram exhibits good performance for predicting preoperative LNM. Combined clinical-radiomic nomogram based LNM and MRI-reported EMVI showed clinical potential for assessing 3-year RFS.

Prognostic value of ground glass opacity on computed tomography in pathological stage I pulmonary adenocarcinoma: A meta-analysis.

BACKGROUND: The clinical role of ground glass opacity (GGO) on computed tomography (CT) in stage I pulmonary adenocarcinoma patients currently remains unclear. AIM: To explore the prognostic value of GGO on CT in lung adenocarcinoma patients who were pathologically diagnosed with tumor-node-metastasis stage I. METHODS: A comprehensive and systematic search was conducted through the PubMed, EMBASE and Web of Science databases up to April 3, 2021. The hazard ratio (HR) and corresponding 95% confidence interval (CI) were combined to assess the association between the presence of GGO and prognosis, representing overall survival and disease-free survival. Subgroup analysis based on the ratio of GGO was also conducted. STATA 12.0 software was used for statistical analysis. RESULTS: A total of 12 studies involving 4467 patients were included. The pooled results indicated that the GGO predicted favorable overall survival (HR = 0.44, 95%CI: 0.34-0.59, P < 0.001) and disease-free survival (HR = 0.35, 95%CI: 0.18-0.70, P = 0.003). Subgroup analysis based on the ratio of GGO further demonstrated that the proportion of GGO was a good prognostic indicator in pathological stage I pulmonary adenocarcinoma patients, and patients with a higher ratio of GGO showed better prognosis than patients with a lower GGO ratio did. CONCLUSION: This meta-analysis manifested that the presence of GGO on CT predicted favorable prognosis in tumor-node-metastasis stage I lung adenocarcinoma. Patients with a higher GGO ratio were more likely to have a better prognosis than patients with a lower GGO ratio.

[Feasibility Study of Ultra-High-Resolution Low-Dose Temporal Bone CT with 1 024×1 024 Reconstruction Matrix Size].

OBJECTIVE: To investigate the feasibility of low-dose CT scan of the temporal bone combined with reconstruction matrix size of 1 024×1 024 and the effect of the reconstruction matrix size on image quality. METHODS: Normal-dose and low-dose bilateral temporal bone CT scans were performed on twelve adult male cadaveric skull specimens using the 160-slice multi-detector CT scanning of United Imaging Healthcare. Normal-dose CT images were reconstructed with matrix sizes of 512×512 and 1 024×1 024, while low-dose CT images were reconstructed with the matrix size of 1 024×1 024. CT value, noise, signal-to-noise ratio, contrast-to-noise ratio, the visualization scoring of 15 anatomical structures of the temporal bone, and the result of three-dimensional reconstruction of the ossicular chain were compared among the three groups. RESULTS: The radiation dose of low-dose CT scanning was reduced by about 50% compared with that of normal-dose CT. There was no significant difference in CT values of air, soft tissues and bones among the three groups. Low-dose temporal bone CT with the matrix size of 1 024×1 024 had higher noise, but much better visualization of temporal bone structure than the normal-dose temporal bone CT with matrix size of 512×512. Both the three-dimensional reconstructions of normal-dose and low-dose 1 024×1 024 matrix images were satisfactory and showed no significant difference. The morphology, size and relative position of malleus, incus, stapes, cochlea, and labyrinth, as well as the location of the ossicular chain in the cranium were all clearly displayed. CONCLUSION: Low-dose temporal bone CT with the matrix size of 1 024×1 024 can be used to effectively reduce the radiation dose and significantly improve the spatial resolution and the visualization of the temporal bone anatomical structures compared with the normal-dose temporal bone CT with a matrix size of 512×512.

[Application of Deep Learning Reconstruction Algorithm in Low-Dose Thin-Slice Liver CT of Healthy Volunteers].

OBJECTIVE: To explore the clinical feasibility of applying deep learning (DL) reconstruction algorithm in low-dose thin-slice liver CT examination of healthy volunteers by comparing the reconstruction algorithm based on DL, filtered back projection (FBP) reconstruction algorithm and iterative reconstruction (IR) algorithm. METHODS: A standard water phantom with a diameter of 180 mm was scanned, using the 160 slice multi-detector CT scanning of United Imaging Healthcare, to compare the noise power spectrums of DL, FBP and IR algorithms. 100 healthy volunteers were prospectively enrolled, with 50 assigned to the normal dose group (ND) and 50 to the low dose group (LD). IR algorithm was used in the ND group to reconstruct images, while DL, FBP and IR algorithms were used in the LD group to reconstruct images. One-way analysis of variance was used to compare the liver CT values, the liver noise, liver signal-to-noise ratio (SNR), contrast noise ratio (CNR) and figure of merit (FOM) of the images of ND-IR, LD-FBP, LD-IR and LD-DL. The Kruskal-Wallis test was used to analyse subjective scores of anatomical structures. RESULTS: The DL algorithm had the lowest average peak value of noise power spectrum, and its shape was similar to that of medium-level IR algorithm. Liver CT values of ND-IR, LD-FBP, LD-IR and LD-DL did not show statistically significant difference. The noise of LD-DL was lower than that of LD-FBP, LD-IR and ND-IR ( P<0.05), and the SNR, CNR and FOM of LD-DL were higher than those of LD-FBP, LD-IR and ND-IR ( P<0.05). The subjective scores of anatomical structures of LD-DL did not show significant difference compared to those of ND-IR ( P >0.05), and were higher than those of LD-FBP and LD-IR. The radiation dose of the LD group was reduced by about 50.2% compared with that of the ND group. CONCLUSION: The DL algorithm with noise shape similar to the medium iterative grade IR commonly used in clinical practice showed higher noise reduction ability than IR did. Compared with FBP, the DL algorithm had smoother noise shape, but much better noise reduction ability. The application of DL algorithm in low-dose thin-slice liver CT of healthy volunteers can help achieve the standard image quality of liver CT.

[Early Assessment of Myocardial Fibrosis of Hypertrophic Cardiomyopathy with Native-T1-Mapping-Based Deep Learning: A Preliminary Study].

OBJECTIVE: To explore the diagnostic performance of deep learning (DL) model in early detection of the interstitial myocardial fibrosis using native T1 maps of hypertrophic cardiomyopathy (HCM) without late gadolinium enhancement (LGE). METHODS: Sixty HCM patients and 44 healthy volunteers who underwent cardiac magnetic resonance were enrolled in this study. Each native T1 map was labeled according to its LGE status. Then, native T1 maps of LGE (-) and those of the controls were preprocessed and entered in the SE-ResNext-50 model as the matrix for the DL model for training, validation and testing. RESULTS: A total of 241 native T1 maps were entered in the SE-ResNext-50 model. The model achieved a specificity of 0.87, sensitivity of 0.79, and area under curve ( AUC) of 0.83 ( P<0.05) in distinguishing native T1 maps of LGE (-) from those of the controls in the testing set. CONCLUSION: The DL model based on SE-ResNext-50 could be used for identifying native T1 maps of LGE (-) with relatively high accuracy. It is a promising approach for early detection of myocardial fibrosis in HCM without the use of contrast agent.