The effect of hyperlipidemia and body fat distribution on subclinical left ventricular function in obesity: a cardiovascular magnetic resonance study.

BACKGROUND: Obesity is often associated with multiple comorbidities. However, whether obese subjects with hyperlipidemia in the absence of other complications have worse cardiac indices than metabolically healthy obese subjects is unclear. Therefore, we aimed to determine the effect of hyperlipidemia on subclinical left ventricular (LV) function in obesity and to evaluate the association of cardiac parameters with body fat distribution. MATERIALS AND METHODS: Ninety-two adults were recruited and divided into 3 groups: obesity with hyperlipidemia (n = 24, 14 males), obesity without hyperlipidemia (n = 25, 13 males), and c ntrols (n = 43, 25 males). LV strain parameters (peak strain (PS), peak diastolic strain rate (PDSR), peak systolic strain rate) derived from cardiovascular magnetic resonance tissue tracking were measured and compared. Dual-energy X-ray absorptiometer was used to measure body fat distribution. Correlations of hyperlipidemia and body fat distribution with LV strain were assessed by multivariable linear regression. RESULTS: Obese individuals with preserved LV ejection fraction showed lower global LV longitudinal, circumferential, and radial PS and longitudinal and circumferential PDSR than controls (all P < 0.05). Among obese patients, those with hyperlipidemia had lower longitudinal PS and PDSR and circumferential PDSR than those without hyperlipidemia (- 12.8 ± 2.9% vs. - 14.2 ± 2.7%, 0.8 ± 0.1 s-1 vs. 0.9 ± 0.3 s-1, 1.2 ± 0.2 s-1 vs. 1.4 ± 0.2 s-1; all P < 0.05). Multivariable linear regression demonstrated that hyperlipidemia was independently associated with circumferential PDSR (ß = - 0.477, P < 0.05) in obesity after controlling for growth differences, other cardiovascular risk factors, and central fat distribution. In addition, android fat had an independently negative relationship with longitudinal and radial PS (ß = - 0.486 and ß = - 0.408, respectively; all P < 0.05); and visceral fat was negatively associated with longitudinal PDSR (ß = - 0.563, P < 0.05). Differently, gynoid fat was positively correlated with circumferential PS and PDSR and radial PDSR (ß = 0.490, ß = 0.481, and ß = 0.413, respectively; all P < 0.05). CONCLUSION: Hyperlipidemia is independently associated with subclinical LV diastolic dysfunction in obesity. Central fat distribution (android and visceral fat) has a negative association, while peripheral fat distribution (gynoid fat) has a positive association on subclinical LV function. These results suggest that appropriate management of hyperlipidemia may be beneficial for obese patients, and that the differentiation of fat distribution in different regions may facilitate the precise management of obese patients. Clinical trials registration Effect of lifestyle intervention on metabolism of obese patients based on smart phone software (ChiCTR1900026476).

Unveiling the next generation of MRI contrast agents: current insights and perspectives on ferumoxytol-enhanced MRI.

Contrast-enhanced magnetic resonance imaging (CE-MRI) is a pivotal tool for global disease diagnosis and management. Since its clinical availability in 2009, the off-label use of ferumoxytol for ferumoxytol-enhanced MRI (FE-MRI) has significantly reshaped CE-MRI practices. Unlike MRI that is enhanced by gadolinium-based contrast agents, FE-MRI offers advantages such as reduced contrast agent dosage, extended imaging windows, no nephrotoxicity, higher MRI time efficiency and the capability for molecular imaging. As a leading superparamagnetic iron oxide contrast agent, ferumoxytol is heralded as the next generation of contrast agents. This review delineates the pivotal clinical applications and inherent technical superiority of FE-MRI, providing an avant-garde medical-engineering interdisciplinary lens, thus bridging the gap between clinical demands and engineering innovations. Concurrently, we spotlight the emerging imaging themes and new technical breakthroughs. Lastly, we share our own insights on the potential trajectory of FE-MRI, shedding light on its future within the medical imaging realm.

3D-DESS MRI with CAIPIRINHA two- and fourfold acceleration for quantitatively assessing knee cartilage morphology.

OBJECTIVES: This study aimed to assess the diagnostic image quality and compare the knee cartilage segmentation results using a controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA)-accelerated 3D-dual echo steady-state (DESS) research package sequence in the knee. MATERIALS AND METHODS: A total of 64 subjects underwent both two- and fourfold CAIPIRINHA-accelerated 3D-DESS and DESS without parallel acceleration technique of the knee on a 3.0 T system. Two musculoskeletal radiologists evaluated the images independently for image quality and diagnostic capability following randomization and anonymization. The consistency of automatic segmentation results between sequences was explored using an automatic knee cartilage segmentation research application. The descriptive statistics and inter-observer and inter-method concordance of various acceleration sequences were investigated. P values < .05 were considered significant. RESULTS: For image quality evaluation, the image signal-to-noise ratio and contrast-to-noise ratio decreased with the decrease in scanning time. However, it is accompanied by the reduction of artifacts. Using 3D-DESS without parallel acceleration technique as the standard for cartilage grading diagnosisand the diagnostic agreement of two- and fourfold CAIPIRINHA-accelerated 3D-DESS was good, kappa value was 0.860 (P < .001) and 0.804 (p < 0.001), respectively. Regarding cartilage defects, the sensitivity and specificity of the twofold acceleration 3D-CAIPIRINHA-DESS were 95.56% and 97.70%, and the fourfold CAIPIRINHA-accelerated 3D-DESS were 91.49% and 97.65%, respectively. The intraclass correlation coefficients of various sequences in cartilage segmentation were almost all greater than 0.9. CONCLUSION: The CAIPIRINHA-accelerated 3D-DESS sequence maintained comparable diagnostic and segmentations performance of knee cartilage after a 60% scan time reduction.

Coronary Microvascular Dysfunction and Diffuse Myocardial Fibrosis in Patients With Type 2 Diabetes Using Quantitative Perfusion MRI.

BACKGROUND: Imaging techniques that quantitatively and automatically measure changes in the myocardial microcirculation in patients with diabetes are lacking. PURPOSE: To detect diabetic myocardial microvascular complications using a novel automatic quantitative perfusion MRI technique, and to explore the relationship between myocardial microcirculation dysfunction and fibrosis. STUDY TYPE: Prospective. SUBJECTS: 101 patients with type 2 diabetes mellitus (T2DM) (53 without and 48 with complications), 20 healthy volunteers. FIELD STRENGTH/SEQUENCE: 3.0T; modified Look-Locker inversion-recovery sequence; saturation recovery sequence and dual-bolus technique; segmented fast low-angle shot sequence. ASSESSMENT: All participants underwent MRI to determine the rest myocardial blood flow (MBF), stress MBF, myocardial perfusion reserve (MPR), and extracellular volume (ECV), which represents the extent of myocardial fibrosis. STATISTICAL TESTS: Kolmogorov-Smirnov test, Shapiro-Wilk test, Kruskal-Wallis H test, Mann-Whitney U test, chi-square test, Spearman correlation coefficient, multivariable linear regression analysis. P < 0.05 was considered statistically significant. RESULTS: The rest MBF was not significantly different between the T2DM without complications group (1.1, IQR: 0.9-1.3) and the control group (1.1, 1.0-1.3) (P = 1.000), but it was significantly lower in the T2DM with complications group (0.8, 0.6-1.0) than in both other groups. The stress MBF and MPR were significantly lower in the T2DM without complications group (1.9, 1.5-2.3, and 1.7, 1.4-2.1, respectively) than in the control group (3.0, 2.6-3.5, and 2.7, 2.4-3.1, respectively), and were also significantly lower in the T2DM with complications group (1.1, 0.9-1.4, and 1.4, 1.2-1.8, respectively) than in the T2DM without complications group. A decrease in MBF and MPR were significantly associated with an increase in the ECV. DATA CONCLUSION: Quantitative perfusion MRI can evaluate myocardial microcirculation dysfunction. In T2DM, there was a significant decrease in both MBF and MPR compared to healthy controls, with the decrease being significantly different between T2DM with and without complications groups. The decrease of MBF was significantly associated with the development of myocardial fibrosis, as determined by ECV. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 3.

A comparative study of synthetic and venous hematocrit for calculating cardiovascular magnetic resonance-derived extracellular volume.

The extracellular volume (ECV) fraction derived from cardiac magnetic resonance (CMR) can reflect various pathologies. The application of ECVs was limited by the strict requirement that hematocrit (Hct0) should be obtained within 24 hours of CMR scan. The aim of this study was to obtain accurate and convenient ECV calculated from the venous Hct and synthetic Hct in CMR. A total of 839 subjects were retrospectively enrolled. The subjects were divided into derivation cohort for local sex-specific models and validation cohort for assessing the accuracy of different ECVs. In the validation cohort, venous Hcts from 7 days before the scan (Hct1 - 7), outside 7 days (Hct> 7), the closest day (Hctclosest), and Hctsyn were compared with Hct0. The agreement and correlation of the conventional ECV (ECV0) with the corresponding ECVs were analyzed. The factors affecting the accuracy of ECVsyn were assessed. ECV1-7 and ECVclosest had the best correlation and smallest bias with ECV0 (R = 0.959 and 0.951, bias = 0.02% and - 0.03%). When using an absolute 2% error as the standard, the performance of ECV1-7 was the best, with an accuracy of 81.0%, followed by ECVclosest (78.8%), ECV> 7 (77.2%) and ECVsyn (70.7%). Abnormally low and high Hcts and decreased left ventricular ejection fractions were associated with miscalculation of ECVsyn, especially patients with dilated cardiomyopathy. We recommend extending the time interval between a Hct and a CMR scan to 7 days for ECV calculation. The synthetic ECV should be used cautiously, especially for patients with extremely low or high Hcts, decreased cardiac function, and dilated cardiomyopathy.

Association of increased epicardial adipose tissue derived from cardiac magnetic resonance imaging with myocardial fibrosis in Duchenne muscular dystrophy: a clinical prediction model development and validation study in 283 participants.

Background: Epicardial adipose tissue (EAT) contributes to inflammation and fibrosis of the neighboring myocardial tissue via paracrine signaling. In this retrospective study, we investigated the abnormal changes in the amount of EAT in male children with Duchenne muscular dystrophy (DMD) using cardiac magnetic resonance (CMR) imaging. Furthermore, we constructed and validated a nomogram including EAT-related CMR imaging parameter for predicting the occurrence of myocardial fibrosis in patients with DMD. Methods: This study enrolled 283 patients with DMD and 57 healthy participants who underwent CMR acquisitions to measure the quantitative parameters of EAT, pericardial adipose tissue (PAT), paracardial adipose tissue, and subcutaneous adipose tissue. Late gadolinium enhancement (LGE) was performed to confirm myocardial fibrosis in patients with DMD. The DMD group consisted of 200 patients from institution 1 (the ratio of the training set and the internal validation set was 7:3) and 83 patients from four other institutions (the external validation set). Logistic and least absolute shrinkage and selection operator (LASSO) regression was used to select the optimal predictors and to develop and validate the nomogram model predicting LGE risk in the training set, internal validation set, and external validation set. Results: Compared with those in healthy controls, some regional EAT thicknesses, areas, and global volumes were significantly higher in patients with DMD, and 41.7% of patients with DMD showed positive LGE. These LGE-positive patients with DMD showed significantly higher EAT volume (median 23.9 mL/m3; P<0.001) and PAT volume (median 31.8 mL/m3; P<0.001) compared with the LGE-negative patients with DMD. Age [odds ratio (OR) 2.0; P<0.001], body fat percentage (OR 1.3; P<0.001), and EAT volume (OR 1.4; P<0.001) were independently associated with positive LGE in the training set. The interactive dynamic nomogram showed superior prediction performance, with a high degree of the calibration, discrimination, and clinical net benefit in the training and validation of the DMD datasets. The area under the curve (AUC) values of the nomogram in the training set, internal validation set, and external validation set were 0.95 [95% confidence interval (CI): 0.91-0.98], 0.97 (95% CI: 0.92-0.99), and 0.95 (95% CI: 0.91-0.99), respectively. Conclusions: The onset of LGE-based myocardial fibrosis was associated with EAT volume in patients with DMD. Additionally, the nomogram with EAT volumes showed superior performance in patients with DMD for predicting the occurrence of myocardial fibrosis.

Cardiac magnetic resonance imaging detection of intramyocardial hemorrhage in patients with ST-elevated myocardial infarction: comparison between susceptibility-weighted imaging and T1/T2 mapping techniques.

Background: Susceptibility-weighted imaging (SWI) and T1/T2 mapping can be used to detect reperfusion intramyocardial hemorrhage (IMH) in ST-segment elevation myocardial infarction (STEMI) patients. However, the sensitivity and accuracy of the SWI and T1/T2 mapping sequences were not systematically compared. The study aimed to evaluate image quality and diagnostic performance of SWI in patients with IMH, compared with T1/T2 mapping. Methods: A prospective study was conducted on consecutive acute STEMI patients who were recruited from January to July 2022. Within 2-6 days after reperfusion treatment, all patients underwent a 3T cardiac magnetic resonance (CMR) examination, including T2-weighted short-tau inversion recovery (T2W-STIR), T1/T2 mapping, and SWI. A total of 36 patients [age, 56.50±17.25 years; males, 83.33% (30/36)] were enrolled. The relative infarct-remote myocardium signal intensity ratio (SIinfarct-remote) and contrast-to-noise ratio (CNR) were calculated for each patient on T1/T2 mapping and SWI, and the difference between relative signal intensity-to-noise ratio (rSNR) in the IMH (rSNRIMH) was measured for IMH patients on T1/T2 mapping and SWI. SIinfarct-remote, CNR, and rSNRIMH were compared among the three sequences. Receiver operating characteristic (ROC) analyses were used to evaluate the diagnostic performance of three sequences by SIinfarct-remote and visual assessment. Results: A total of 26 (72.22%) patients had IMH. Quantitatively, the SIinfarct-remote of three sequences had excellent diagnostic performance for detecting IMH [SWI area under the curve (AUC) =1.000, 95% confidence interval (CI): 1.000-1.000 vs. T1 mapping AUC =0.954, 95% CI: 0.885-1.000 vs. T2 mapping AUC =0.985, 95% CI: 0.955-1.000; SWI vs. T1 mapping, P=0.300; SWI vs. T2 mapping, P=0.188; T1 mapping vs. T2 mapping, P=0.302). Qualitatively, three sequences had similar performance on detecting IMH (SWI AUC =0.895, 95% CI: 0.784-1.000; T1 mapping AUC =0.835, 95% CI: 0.711-0.958; and T2 mapping AUC =0.855, 95% CI: 0.735-0.974; SWI vs. T1 mapping, P=0.172; SWI vs. T2 mapping, P=0.317; T1 mapping vs. T2 mapping, P=0.710). The rSNRIMH was highest in T1 mapping, followed by T2 mapping and SWI, but SWI had the highest CNR. Conclusions: SWI, as well as T1/T2 mapping, is a feasible and accurate approach for clinical diagnosis of IMH with excellent performance.

Comparison between diaphragmatic-navigated and self-navigated coronary magnetic resonance angiography at 3T in pediatric patients with congenital coronary artery anomalies.

Background: Coronary magnetic resonance angiography (CMRA) is being increasingly used in pediatric patients with congenital coronary artery anomalies (CAAs). However, the data on the free-breathing self-navigation technique, which has the potential to simplify the acquisition plan with a high success rate at 3T, remain scarce. This study investigated the clinical application value of self-navigated (sNAV) CMRA at 3T in pediatric patients with suspected CAAs and compared it to conventional diaphragmatic-navigated (dNAV) CMRA. Methods: From April 2019 to March 2022, we enrolled 65 pediatric patients (38 males and 27 females; mean age 8.5±4.4 years) with suspected CAAs in this prospective study. All patients underwent both dNAV and sNAV sequences in random order with gradient recalled echo (GRE) sequence during free breathing, with 39 (20 males and 19 females; mean age 10.2±3.6 years) of them additionally undergoing coronary computed tomography angiography (CCTA) or invasive coronary angiography (ICA). We measured and compared the success rate, scan time, visual score of the 9 main coronary artery segments, vessel sharpness, and vessel length between the two sequences. The diagnostic accuracy was compared using CCTA or ICA as a reference. Results: The success rate of sNAV-CMRA (65/65, 100%) was higher than that of dNAV-CMRA (61/65, 93.8%) (P<0.001), and the scan time of sNAV-CMRA (7.3±2.5 min) was significantly shorter than that of dNAV-CMRA (9.1±3.6 min) (P=0.002). The acquisition efficiency of dNAV-CMRA was 40.5%±12.9%, while for sNAV-CMRA, 100% acquisition efficiency was achieved. There was no significant difference in vessel length of any of the coronary arteries, visual score, or vessel sharpness of the left circumflex coronary artery (LCX) between the two sequences (all P values >0.050). The visual score and vessel sharpness of the right coronary artery and left anterior descending coronary artery (LAD) were significantly improved in dNAV-CMRA compared with sNAV-CMRA (all P values <0.050). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the detection of CAAs were not significantly different between the two sequences (all P values >0.050). Conclusions: Our findings demonstrated that both sNAV and dNAV in CMRA provide clinical application value in pediatric patients with CAAs and have similar diagnostic performance. Although the image quality of sNAV-CMRA is slightly inferior compared to that of dNAV-CMRA, sNAV-CMRA allows for a simpler scanning procedure.

The Global Leadership Initiative on Malnutrition criteria for diagnosis of malnutrition and outcomes prediction in emergency abdominal surgery.

OBJECTIVES: Malnutrition has adverse postoperative outcomes, especially in emergency surgery. Among the numerous tools for nutritional assessment, this study aims to investigate malnutrition diagnosed by Global Leadership Initiative on Malnutrition criteria and the Global Leadership Initiative on Malnutrition predictive value for outcomes after emergency abdominal surgery. METHODS: This was a prospective observational study. Among the 468 patients undergoing emergency abdominal surgery admitted to a department of emergency surgery from June 2020 to December 2021, 53 patients were not eligible for enrollment, and 19 patients had missing data. Thus, the final number of participants was 396. Muscle mass was evaluated by skeletal muscle index at the third lumbar vertebra on computed tomography scans, and the lower quartile was defined as the threshold of muscle mass reduction. The associations of Global Leadership Initiative on Malnutrition, Global Leadership Initiative on Malnutrition (muscle mass reduction excluded), and skeletal muscle index with in-hospital mortality, postoperative complications, and postoperative stay were evaluated using χ2. In addition, confounding factors were screened, regression models were established, and the Global Leadership Initiative on Malnutrition predictive value was analyzed for clinical outcome. Ethical approval was obtained from the appropriate department. RESULTS: Malnutrition was observed in 19.9% of the total 396 patients based on the Global Leadership Initiative on Malnutrition and in 12.4% on the Global Leadership Initiative on Malnutrition (muscle mass reduction excluded). Sarcopenia by skeletal muscle index was found in 24.7% of patients. Univariate analysis indicated that in-hospital mortality, postoperative complications, infective complication rate, and postoperative hospital stay were significantly higher in malnourished and sarcopenic patients. Multivariate analysis found that malnutrition diagnosed by the Global Leadership Initiative on Malnutrition was predictive for complications, infective complications, and postoperative stay (total postoperative complications: odds ratio = 3.620; 95% CI, 1.635-8.015; P = 0.002; infective complications: odds ratio = 3.127; 95% CI, 1.194-8.192; P = 0.020; and postoperative stay: regression coefficient = 2.622; P = 0.022). The Global Leadership Initiative on Malnutrition (muscle mass reduction excluded) identified postoperative complications and postoperative stay (total postoperative complications: odds ratio = 3.364; 95% CI, 1.247-9.075; P = 0.017 and postoperative stay: regression coefficient = 3.547; P = 0.009). Sarcopenia by skeletal muscle index was a risk factor for postoperative complications (odds ratio = 3.366; 95% CI, 1.587-7.140; P = 0.002). CONCLUSION: The Global Leadership Initiative on Malnutrition and Global Leadership Initiative on Malnutritison (muscle mass reduction excluded) had predictive value for adverse clinical outcomes due to malnutrition in patients undergoing emergency abdominal surgery.

A double-tuned 1 H/31 P coil for rabbit heart metabolism detection at 3 T.

Magnetic resonance imaging (MRI)/magnetic resonance spectroscopy (MRS) employing proton nuclear resonance has emerged as a pivotal modality in clinical diagnostics and fundamental research. Nonetheless, the scope of MRI/MRS extends beyond protons, encompassing nonproton nuclei that offer enhanced metabolic insights. A notable example is phosphorus-31 (31 P) MRS, which provides valuable information on energy metabolites within the skeletal muscle and cardiac tissues of individuals affected by diabetes. This study introduces a novel double-tuned coil tailored for 1 H and 31 P frequencies, specifically designed for investigating cardiac metabolism in rabbits. The proposed coil design incorporates a butterfly-like coil for 31 P transmission, a four-channel array for 31 P reception, and an eight-channel array for 1 H reception, all strategically arranged on a body-conformal elliptic cylinder. To assess the performance of the double-tuned coil, a comprehensive evaluation encompassing simulations and experimental investigations was conducted. The simulation results demonstrated that the proposed 31 P transmit design achieved acceptable homogeneity and exhibited comparable transmit efficiency on par with a band-pass birdcage coil. In vivo experiments further substantiated the coil's efficacy, revealing that the rabbit with experimentally induced diabetes exhibited a lower phosphocreatine/adenosine triphosphate ratio compared with its normal counterpart. These findings emphasize the potential of the proposed coil design as a promising tool for investigating the therapeutic effects of novel diabetes drugs within the context of animal experimentation. Its capability to provide detailed metabolic information establishes it as an indispensable asset within this realm of research.

A reproducibility study of knee cartilage volume and thickness values derived by fully automatic segmentation based on three-dimensional dual-echo in steady state data from 1.5 T and 3 T magnetic resonance imaging.

OBJECTIVE: To evaluate the repeatability of cartilage volume and thickness values at 1.5 T MRI using a fully automatic cartilage segmentation method and reproducibility of the method between 1.5 T and 3 T data. METHODS: The study included 20 knee joints from 10 healthy subjects with each subject having undergone double-knee MRI. All knees were scanned at 1.5 T and 3 T MR scanners using a three-dimensional (3D) high-resolution dual-echo in steady state (DESS) sequence. Cartilage volume and thickness of 21 subregions were quantified using a fully automatic cartilage segmentation research application (MR Chondral Health, version 3.0, Siemens Healthcare, Erlangen, Germany). The volume and thickness values derived from fully automatically computed segmentation masks were analyzed for the scan-rescan data from the same volunteers. The accuracy of the automatic segmentation of the cartilage in 1.5 T images was evaluated by the dice similarity coefficient (DSC) and Hausdorff distance (HD) using the manually corrected segmentation as a reference. The volume and thickness values calculated from 1.5 T and 3 T were also compared. RESULTS: No statistically significant differences were found for cartilage thickness or volume across all subregions between the scan-rescanned data at 1.5 T (P > 0.05). The mean DSC between the fully automatic and manually corrected knee cartilage segmentation contours at 1.5 T was 0.9946. The average value of HD was 2.41 mm. Overall, there was no statistically significant difference in the cartilage volume or thickness in most-subregions between the two field strengths (P > 0.05) except for the medial region of femur and tibia. Bland-Altman plot and intraclass correlation coefficient (ICC) showed high consistency between results obtained based on same and different scanning sequences. CONCLUSION: The cartilage segmentation software had high repeatability for DESS images obtained from the same device. In addition, the overall reproducibility of the images obtained from equipment of two different field strengths was satisfactory.

Assessment of Myocardial Viability and Risk Stratification in Coronary Chronic Total Occlusion: A Qualitative and Quantitative Stress Cardiac MRI Study.

BACKGROUND: Indicators for assessing myocardial viability and risk stratification in patients with coronary chronic total occlusion (CTO) are still in the research stage. PURPOSE: To use stress-MRI to assess myocardial function, blood perfusion, and viability and to explore their relationship with collateral circulation. STUDY TYPE: Prospective. SUBJECTS: Fifty-one patients with CTO in at least one major artery confirmed by X-ray coronary angiography (male: 46; age 55.2 ± 10.8 years). FIELD STRENGTH/SEQUENCE: 3.0T; TurboFlash, balanced steady-state free precession cine, and phase-sensitive inversion recovery sequences. ASSESSMENT: Stress-MRI was used to obtain qualitative and quantitative parameters of segmental myocardium. Myocardial segments supplied by CTO target vessels were grouped according to the degree of collateral circulation assessed by radiographic coronary angiography (no/mild, moderate, or good). Depending on qualitative stress perfusion assessment and late gadolinium enhancement (LGE) extent, segments were also categorized as negative, viable, or trans-infarcted. STATISTICAL TESTS: Independent sample Student's t-test, one-way analysis of variance (ANOVA) test, Mann-Whitney U test, Kruskal-Wallis test, Spearman correlation coefficient (r). P < 0.05 was considered statistically significant. RESULTS: A total of 334 segments were supplied by CTO target vessels. The radial strain (RS), circumferential strain (CS), longitudinal strain (LS) of the negative, viable, and trans-infarcted regions showed a significant and stepwise impairment. Myocardial blood flow at rest was positively correlated with RS, CS, and LS (r = 0.42, 0.43, 0.38, respectively). Among the different collateral circulation, there were no significant differences in RS, CS, LS, and LGE volume (P = 0.788, 0.562, 0.122, 0.170, respectively), and there were also no statistically significant differences in the proportions of negative, viable, and trans-infarcted regions (P = 0.372). DATA CONCLUSION: Myocardial perfusion obtained by stress-MRI combined with strain and LGE may comprehensively evaluate myocardial function and viability, and has potential to facilitate risk stratification of CTO. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.

Quantitative multi-parameter assessment of age- and gender-related variation of back extensor muscles in healthy adults using Dixon MR imaging.

OBJECTIVES: Investigate sex differences in age-related back extensor muscle degeneration using Dixon MRI and analyze the relationship between quantitative muscle parameters and back muscle strength in healthy adults. METHODS: 105 healthy subjects underwent lumbar Dixon MRI. Fat fraction (FF), cross-sectional area (CSA), functional CSA (FCSA), and relative FCSA (RFCSA) of multifidus muscle (MF) and erector spinae (ES) were quantified. Back extension muscle strength was measured using an external fixation dynamometer. ANOVA with post hoc Tukey correction was used for age group comparisons. Partial and Spearman's correlation analyzed relationships between age, muscle parameters, and muscle strength. RESULTS: MF and ES FF significantly increased with age in both genders (r = 0.55-0.85; p < 0.001). Muscle FF increased prominently for females (40-49 years, MF and 50-59 years, ES) and males (60-73 years, MF and ES). In females, total ES FCSA and RFCSA (r = - 0.42, - 0.37; p < 0.01) correlated with age. While in males, all MF and ES muscle size parameters, except total MF CSA, correlated with age (r = - 0.30 to - 0.58; p < 0.05). Back extension muscle strength correlated with mean FF, total CSA, and total FCAS for MF and ES individually (p < 0.001). The combined MF + ES FCSA correlation coefficient (r = 0.63) was higher than FF (r = - 0.51) and CSA (r = 0.59) (p < 0.001). CONCLUSIONS: Age-related back extensor muscle degeneration varies by muscle type and sex. FCSA has the highest association with back muscle strength compared to FF and CSA. CLINICAL RELEVANCE STATEMENT: The investigation of sex differences in age-related back extensor muscle degeneration utilizing Dixon imaging may hold significant implications for evaluating spine health and enabling earlier intervention. Muscles' FCSA could contribute to acquiring additional evidence for reflecting muscle function change. KEY POINTS: • The multifidus muscle (MF) and erector spinae (ES) fat fraction (FF) increased with age at all lumbar disc levels in females and males. • Age-related changes in muscle morphological quantitative parameters of healthy adults were specific by muscle type and gender. • The muscle functional cross-sectional area (FCSA) measured by Dixon imaging may better monitor back extensor muscle strength changes than muscle FF and cross-sectional area (CSA).

Reference Ranges of Ventricular Morphology and Function in Healthy Chinese Adults: A Multicenter 3 T MRI Study.

BACKGROUND: Magnetic resonance imaging (MRI) reference ranges for ventricular morphology and function in the Chinese population are lacking. PURPOSE: To establish the MRI reference ranges of left and right ventricular (LV and RV) morphology and function based on a large multicenter cohort. STUDY TYPE: Prospective. POPULATION: One thousand and twelve healthy Chinese Han adults. FIELD STRENGTH/SEQUENCE: Balanced steady-state free procession cine sequence at 3.0 T. ASSESSMENT: Biventricular end-diastolic, end-systolic, stroke volume, and ejection fraction (EDV, ESV, SV, and EF), LV mass (LVM), end-diastolic and end-systolic dimension (LVEDD and LVESD), anteroseptal wall thickness (AS), and posterolateral wall thickness (PL) were measured. Body surface area (BSA) and height were used to index biventricular parameters. Parameters were compared between age groups and sex. STATISTICAL TESTS: Independent-samples t-tests or Mann-Whitney U test to compare mean values between sexes; ANOVA or Kruskal-Wallis test to compare mean values among age groups; linear regression to assess the relationships between cardiac parameters and age (correlation coefficient, r). A P value <0.05 was considered statistically significant. RESULTS: The biventricular volumes, LVM, LVEDD, RVEDV/LVEDV ratio, LVESD, AS, and PL were significantly greater in males than in females, even after indexing to BSA or height, while LVEF and RVEF were significantly lower in males than in females. For both sexes, age was significantly negatively correlated with biventricular volumes (male and female: LVEDV [r = -0.491; r = -0.373], LVESV [r = -0.194; r = -0.184], RVEDV [r = -0.639; r = -0.506], RVESV [r = -0.270; r = -0.223]), with similar correlations after BSA normalization. LVEF (r = 0.043) and RVEF (r = 0.033) showed a significant correlation with age in females, but not in males (P = 0.889; P = 0.282). DATA CONCLUSION: MRI reference ranges for biventricular morphology and function in Chinese adults are presented and show significant associations with age and sex. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

Myocardial tissue remodeling in early adult obesity and its association with regional adipose tissue distribution and ectopic fat deposits: a prospective study.

OBJECTIVES: To evaluate the left ventricular (LV) myocardial tissue characteristics in early adult obesity and its association with regional adipose tissue and ectopic fat deposition. METHODS: Forty-nine obese adults (mean body mass index: 29.9 ± 2.0 kg/m2) and 44 healthy controls were prospectively studied. LV native and post-contrast T1 values, extracellular volume fraction (ECV), regional adipose tissue (epicardial, visceral, and subcutaneous adipose tissue (EAT, VAT, and SAT)), and ectopic fat deposition (hepatic and pancreatic proton density fat fractions (H-PDFF and P-PDFF)) based on magnetic resonance imaging were compared. The association was assessed by multivariable linear regression. RESULTS: The obese participants showed reduced global ECV compared to the healthy controls (p < 0.05), but there was no significant difference in global native or post-contrast T1 values between the two groups. Additionally, the obese individuals exhibited higher EAT, VAT, SAT, H-PDFF, and P-PDFF than the controls (p < 0.05). ECV was associated with insulin resistance, dyslipidemia, and systolic blood pressure (SBP) (p < 0.05). Multiple linear regression demonstrated that H-PDFF and SAT were independently associated with ECV in entire population (ß = - 0.123 and - 0.012; p < 0.05). CONCLUSIONS: Reduced myocardial ECV in patients with mild-to-moderate obesity and its relationship to SBP may indicate that cardiomyocyte hypertrophy, rather than extracellular matrix expansion, is primarily responsible for myocardial tissue remodeling in early adult obesity. Our findings further imply that H-PDFF and SAT are linked with LV myocardial tissue remodeling in this cohort beyond the growth difference and cardiovascular risk factors. CLINICAL TRIALS REGISTRATION: Effect of lifestyle intervention on metabolism of obese patients based on smart phone software (ChiCTR1900026476). CLINICAL RELEVANCE STATEMENT: Myocardial fibrosis in severe obesity predicts poor prognosis. We showed that cardiomyocyte hypertrophy, not myocardial fibrosis, is the main myocardial tissue characteristic of early obesity. This finding raises the possibility that medical interventions, like weight loss, may prevent cardiac fibrosis. KEY POINTS: • Myocardial tissue characteristics in early adult obesity are unclear. • Myocardial extracellular volume fraction (ECV) can be quantitatively evaluated using T1 mapping based on cardiac magnetic resonance imaging (MRI). • Cardiac MRI-derived ECV may noninvasively evaluate myocardial tissue remodeling in early adult obesity.

Free-Breathing Compressed Sensing Cine Cardiac MRI for Assessment of Left Ventricular Strain by Feature Tracking in Children.

BACKGROUND: Cardiac MRI feature-tracking (FT) with breath-holding (BH) cine balanced steady state free precession (bSSFP) imaging is well established. It is unclear whether FT-strain measurements can be reliably derived from free-breathing (FB) compressed sensing (CS) bSSFP imaging. PURPOSE: To compare left ventricular (LV) strain analysis and image quality of an FB CS bSSFP cine sequence with that of a conventional BH bSSFP sequence in children. STUDY TYPE: Prospective. SUBJECTS: 40 children able to perform BHs (cohort 1 [12.1 ± 2.2 years]) and 17 children unable to perform BHs (cohort 2 [5.2 ± 1.8 years]). FIELD STRENGTH/SEQUENCE: 3T, bSSFP sequence with and without CS. ASSESSMENT: Acquisition times and image quality were assessed. LV myocardial deformation parameters were compared between BH cine and FB CS cine studies in cohort 1. Strain indices and image quality of FB CS cine studies were also assessed in cohort 2. Intraobserver and interobserver variability of strain parameters was determined. STATISTICAL TESTS: Paired t-test, Wilcoxon signed-rank test, intraclass correlation coefficient (ICC), and Bland-Altman analysis. A P-value <0.05 was considered statistically significant. RESULTS: In cohort 1, the mean acquisition time of the FB CS cine study was significantly lower than for conventional BH cine study (15.6 s vs. 209.4 s). No significant difference were found in global circumferential strain rate (P = 0.089), global longitudinal strain rate (P = 0.366) and EuroCMR image quality scores (P = 0.128) between BH and FB sequences in cohort 1. The overall image quality score of FB CS cine in cohort 2 was 3.5 ± 0.5 with acquisition time of 14.7 ± 2.1 s. Interobserver and intraobserver variabilities were good to excellent (ICC = 0.810 to 0.943). DATA CONCLUSION: FB CS cine imaging may be a promising alternative technique for strain assessment in pediatric patients with poor BH ability. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 1.

The value of cardiac magnetic resonance post-contrast T1 mapping in improving the evaluation of myocardial infarction.

Objective: To explore the additional value of cardiac magnetic resonance (CMR) post-contrast T1 mapping in the detection of myocardial infarction, compared with late gadolinium enhancement (LGE). Materials and methods: A CMR database of consecutive patients with myocardial infarction was retrospectively analyzed. All patients were scanned at 3 T magnetic resonance; they underwent conventional CMR (including LGE) and post-contrast T1 mapping imaging. Two radiologists interpreted the CMR images using a 16-segment model. The first interpretation included only LGE images. After 30 days, the same radiologists performed a second analysis of random LGE images, with the addition of post-contrast T1 mapping images. Images were analyzed to diagnose myocardial scars, and the transmural extent of each scar was visually evaluated. Diagnoses retained after LGE were compared with diagnoses retained after the addition of post-contrast T1 mapping. Results: In total, 80 patients (1,280 myocardial segments) were included in the final analysis. After the addition of post-contrast T1 mapping, eight previously unidentified subendocardial scars were detected. Compared with LGE images, the percentage of infarcted segments was higher after the addition of post-contrast T1 mapping images (21.7% vs. 22.3%, P = 0.008), the percentage of uncertain segments was lower after the addition of post-contrast T1 mapping (0.8% vs. 0.1%, P = 0.004), and the percentage of uncertain transmural extent of scarring was lower after the addition of post-contrast T1 mapping (0.9% vs. 0.1%, P = 0.001). Conclusion: The addition of post-contrast T1 mapping after LGE helps to improve the detection of myocardial infarction, as well as the assessment of the transmural extent of scarring.

Early reverse remodeling of left heart morphology and function evaluated by cardiac magnetic resonance in hypertrophic obstructive cardiomyopathy after transapical beating-heart septal myectomy.

PURPOSE: This study aimed to evaluate the early morphology and function of the left heart in hypertrophic obstructive cardiomyopathy (HOCM) after transapical beating-heart septal myectomy (TA-BSM) using cardiovascular magnetic resonance (CMR). MATERIALS AND METHODS: Between April 2022 and January 2023, HOCM patients who underwent CMR before and 3 months after TA-BSM were prospectively and consecutively enrolled in the study. Preoperative and postoperative cardiac morphological and functional parameters, including those for the left atrium (LA) and left ventricle (LV), were compared. The left ventricular remodeling index (LVRI) was defined as the ratio between left ventricular mass (LVM) and left ventricular end-diastolic volume (LVEDV). Healthy participants with a similar age and sex distribution were enrolled for comparison. Pearson or Spearman correlation analysis was used to investigate the relationships between the parameters and LVRI. Last, univariate and multivariate linear regression identified variables associated with the LVM index (LVMI) and LVRI. RESULTS: Forty-one patients (mean age ± standard deviation, 46 ± 2 years; 27 males) and 41 healthy control participants were evaluated. Eighteen (44%) HOCM patients were classified as having a sigmoid septum, and 23 patients had a reverse septal curvature. LA volume, diameter and function were significantly improved postoperatively, but still worse than healthy controls (all p < 0.001). Compared to before the operation, left ventricular wall thickness, left ventricular ejection fraction (LVEF), LVMI, and LVRI decreased after TA-BSM (all p < 0.001). The left ventricular end-diastolic volume index (LVEDVI) and left ventricular end-diastolic diameter (LVEDD) decreased in patients with a sigmoid septum. However, LVEDVI and LVEDD increased in those with a reverse septal curvature (both p < 0.001). In addition, both preoperative and postoperative LVRI was positively correlated with LVMI (r = 0.734 and 0.853, both p < 0.001) and maximum wall thickness (r = 0.679 and 0.676, both p < 0.001), respectively. In the multivariable analysis, the weight of the resected myocardium (adjusted ß = 0.476, p = 0.005) and △mitral regurgitation degree (adjusted ß = - 0.245, p = 0.040) were associated with △LVRI. Last, the △LVOTG (adjusted ß = 0.436, p = 0.018) and baseline LVMI (adjusted ß = 0.323, p = 0.040) were independently associated with greater left ventricular mass regression after TA-BSM. CONCLUSION: CMR confirmed early reverse remodeling of left heart morphology and function in HOCM patients following TA-BSM.

Staphylococcus warneri strain XSB102 exacerbates psoriasis and promotes keratinocyte proliferation in imiquimod-induced psoriasis-like dermatitis mice.

Psoriasis is one of the common chronic inflammatory skin diseases worldwide. The skin microbiota plays a role in psoriasis through regulating skin homeostasis. However, the studies on the interactions between symbiotic microbial strains and psoriasis are limited. In this study, Staphylococcus strain XSB102 was isolated from the skin of human, which was identified as Staphylococcus warneri using VITEK2 Compact. To reveal the roles of Staphylococcus warneri on psoriasis, XSB102 were applied on the back of imiquimod-induced psoriasis-like dermatitis mice. The results indicated that it exacerbated the psoriasis and significantly increased the thickening of the epidermis. Furthermore, in vitro experiments confirmed that inactivated strain XSB102 could promote the proliferation of human epidermal keratinocytes (HaCaT) cell. However, real-time quantitative PCR and immunofluorescence results suggested that the expression of inflammatory factors such as IL-17a, IL-6, and so on were not significantly increased, while extracellular matrix related factors such as Col6a3 and TGIF2 were significantly increased after XSB102 administration. This study indicates that Staphylococcus warneri XSB102 can exacerbate psoriasis and promote keratinocyte proliferation independently of inflammatory factors, which paves the way for further exploration of the relationship between skin microbiota and psoriasis.