[Microfocussed vs. macrofocussed ultrasound for body contouring]

Focussed ultrasound is capable of heating tissue in small microscopic areas up to 65-70 °C and is a technique that can be used not only for destruction of superficial tissue but also for fat reduction. The focussing of sound waves according to the principle of a bundling of rays is carried out without injury to the skin. The penetration depth of the coagulation depends on the wavelength. Wavelengths that reach penetration depths of 6mm, 9mm and even 13mm and therefore deeper layers of the dermis and fat tissue are new. These enable fat cells to be eliminated and ultimately lead to girth reduction and also additionally to tightening. The effectiveness has been confirmed by several studies.

Development of a nomogram based on pericoronary adipose tissue histogram parameters to differentially diagnose acute coronary syndrome

PURPOSE

To develop a nomogram based on pericoronary adipose tissue (PCAT) histogram parameters to identify patients with acute coronary syndrome (ACS).

MATERIALS AND METHODS

This study retrospectively enrolled 114 and 383 eligible patients with ACS and stable coronary artery disease (CAD), respectively, and divided them into training and testing cohorts in a 7:3 ratio. A blinded radiologist obtained PCAT histogram parameters from the right coronary artery's proximal segment using fully automated software and compared clinical characteristics and PCAT histogram parameters between the two patient groups. The binary logistic regression included significant parameters (P < 0.05), and a nomogram was constructed.

RESULTS

In both the training and testing cohorts, the mean, 10th percentile, 90th percentile, median, and minimum values of PCAT were higher, and the interquartile range, skewness, and variance values of PCAT were lower in patients with ACS than in those with stable CAD (P ≤ 0.001). The mean (OR = 4.007), median (OR = 0.576), minimum (OR = 0.893), skewness (OR = 85,158.806) and variance (OR = 1.013) values of PCAT were independent risk factors for ACS and stable CAD in the training cohort. The nomogram was constructed using the five variables mentioned above with area under the curve values of 0.903 and 0.897, respectively, while the calibration and decision curves showed the nomogram's good clinical efficacy for the training and testing cohorts.

CONCLUSIONS

The constructed nomogram had good discrimination and accuracy and can be a noninvasive tool to intuitively and individually distinguish between ACS and stable CAD.

Impact of pericoronary adipose tissue attenuation on recurrence after radiofrequency catheter ablation for atrial fibrillation

BACKGROUND

Inflammation plays a vital role in the occurrence and progression of atrial fibrillation (AF). The association between pericoronary adipose tissue attenuation (PCATA) and AF recurrence following ablation has not been fully clarified.

HYPOTHESIS

We aimed to evaluate the association between PCATA and AF recurrence after radiofrequency catheter ablation (RFCA).

METHODS

Patients who underwent the first RFCA for AF and performed coronary computed tomography angiography before ablation between 2018 and 2021 were enrolled. The predictive values of PCATA for AF recurrence after ablation were investigated. The area under curve (AUC), relative integrated discrimination improvement (IDI), and categorical free net reclassification improvement (NRI) were used to assess the discrimination ability of different models for AF recurrence.

RESULTS

During 1-year follow-up, 34.1% patients experienced AF recurrence. The multivariable analysis model revealed that PCATA of the right coronary artery (RCA) was an independent risk factor for AF recurrence. Patients with a high level of RCA-PCATA had a high risk of recurrence, after adjusting for other risk factors by restricted cubic splines. The performance in predicting AF recurrence was significantly improved by adding the marker of RCA-PCATA to the clinical model (AUC: 0.724 vs. 0.686, p = .024), with a relative IDI of 0.043 (p = .006) and continuous NRI of 0.521 (p < .001).

CONCLUSIONS

PCATA of RCA was independently associated with AF recurrence after ablation. PCATA may be helpful for risk classification for AF ablation patients.

High-Speed T2 -Corrected Multiecho Magnetic Resonance Spectroscopy for Quantitatively Detecting Skeletal Muscle Fatty Infiltration and Predicting the Loss of Ambulation in Patients With Duchenne Muscular Dystrophy

BACKGROUND

High-speed T2 -corrected multiecho MRS (HISTO-MRS) is emerging as a quantitative modality for detecting muscle fat infiltration (MFF). However, the predictive value of HISTO-MRS for the loss of ambulation (LoA) in Duchenne muscular dystrophy (DMD) is unknown.

PURPOSE

To determine the feasibility of HISTO-MRS for assessing MFF in DMD and further identify the predictive value of HISTO-MRS for the LoA.

STUDY TYPE

Prospective.

SUBJECTS

A total of 134 DMD boys (9.20 ± 2.43 years old) and 21 healthy boys (9.25 ± 2.10 years old).

FIELD STRENGTH/SEQUENCE

A 3 T, fast spin echo T1 -weighted imaging (T1 WI), two-point-Dixon gradient echo sequence (2-pt-Dixon) and HISTO-MRS.

ASSESSMENT

Subjective T1 WI fat grades by three radiologists, ROI analysis for MFF on 2 pt-Dixon (Dixon MFF) and MFF on HISTO-MRS (HISTO MFF) by two radiologists. Clinical motor function: North Star Ambulatory Assessment, 10-m run/walk time, Gowers maneuver, and time to four-stairs climb and descend.

STATISTICAL TESTS

Spearman rank correlation was used to assess the relation of fat filtration assessments and motor ability. Bland-Altman plots was performed to determine the agreement of HISTO MFF and Dixon MFF. Receiver operating characteristic (ROC) curves were analyzed to determine the discriminating ability of above MRI modalities for ambulatory and nonambulatory DMD. Logistic regression was used to identify the predictor of LoA. Variables with P < 0.05 in univariate logistic regression analysis were entered into the multivariate logistic regression model.

RESULTS

HISTO MFF was significantly correlated with Dixon MFF. Bland-Altman plots show good agreement of HISTO MFF and Dixon MFF. ROC curves indicated that HISTO MFF show similar discrimination of LoA for DMD with Dixon MFF but better value than T1WI fat grades. Logistic regression showed that HISTO MFF was an independent predictor for LoA.

DATA CONCLUSION

HISTO-MRS is a potential quantitative method for assessing fat infiltration and shows predictive value for LoA in DMD patients.

LEVEL OF EVIDENCE: 1

TECHNICAL EFFICACY

Stage 5.

High intramuscular adipose tissue content was a favorable prognostic factor in patients with advanced gastric cancer treated with nivolumab monotherapy

BACKGROUND

Nivolumab extends the overall survival (OS) of patients with advanced gastric cancer (AGC). Intramuscular adipose tissue (IMAT) is associated with the prognosis of patients with various cancers. We investigated the effect of IMAT on OS in patients with AGC treated with nivolumab.

METHODS

We enrolled patients with AGC treated with nivolumab (n = 58, 67 years old, men/women 40/18). The subjects were classified into long-term or short-term survival groups according to the median value. The IMAT was evaluated using computed tomography scans at the umbilical level. The decision tree algorithm was employed to reveal the profile associated with prognosis.

RESULTS

In decision tree analysis, immune-related adverse events (irAEs) were the first divergence variable, and prolonged survival was observed in 100% of patients with irAEs (profile 1). However, long survival was observed in 38% of patients with no irAEs. Among these patients, IMAT was identified as the second divergence variable, and long survival was observed in 63% of patients with high IMAT (profile 2). In patients with low IMAT, only 21% showed prolonged survival (profile 3). Median OS was 717 days (95% confidence interval [CI], 223 to not reached) in profile 1, 245 days (95% CI, 126 to 252) in profile 2, and 132 days (95% CI, 69 to 163) in profile 3.

CONCLUSION

Immune-related adverse events and high IMAT were favorable factors for OS in patients with AGC treated with nivolumab. Thus, along with irAEs, skeletal muscle quality is important in managing patients with AGC treated with nivolumab.

Ultrasound-Guided Gluteal Fat Grafting: A to Z

Low-cost, high-resolution ultrasound systems allow surgeons to visualize and manipulate the subcutaneous space and inject fat graft with millimeter accuracy.

Call for standardization in assessment and reporting of muscle and adipose change using computed tomography analysis in oncology: A scoping review

Investigators are increasingly measuring skeletal muscle (SM) and adipose tissue (AT) change during cancer treatment to understand impact on patient outcomes. Recent meta-analyses have reported high heterogeneity in this literature, representing uncertainty in the resulting estimates. Using the setting of palliative-intent chemotherapy as an exemplar, we aimed to systematically summarize the sources of variability among studies evaluating SM and AT change during cancer treatment and propose standards for future studies to enable reliable meta-analysis. Studies that measured computed tomography-defined SM and/or AT change in adult patients during palliative-intent chemotherapy for solid tumours were included, with no date or geographical limiters. Of 2496 publications screened by abstract/title, 83 were reviewed in full text and 38 included for extraction, representing 34 unique cohorts across 8 tumour sites. The timing of baseline measurement was frequently defined as prior to treatment, while endpoint timing ranged from 6 weeks after treatment start to time of progression. Fewer than 50% specified the actual time interval between measurements. Measurement error was infrequently discussed (8/34). A single metric (cm2 /m2 , cm2 or %) was used to describe SM change in 18/34 cohorts, while multiple metrics were presented for 10/34 and no descriptive metrics for 6/34. AT change metrics and sex-specific reporting were available for 10/34 cohorts. Associations between SM loss and overall survival were evaluated in 24 publications, with classification of SM loss ranging from any loss to >14% loss over variable time intervals. Age and sex were the most common covariates, with disease response in 50% of models. Despite a wealth of data and effort, heterogeneity in study design, reporting and statistical analysis hinders evidence synthesis regarding the severity and outcomes of SM and AT change during cancer treatment. Proposed standards for study design include selection of homogenous cohorts, clear definition of baseline/endpoint timing and attention to measurement error. Standard reporting should include baseline SM and AT by sex, actual scan interval, SM and AT change using multiple metrics and visualization of the range of change observed. Reporting by sex would advance understanding of sexual dimorphism in SM and AT change. Evaluating the impact of tissue change on outcomes requires adjustment for relevant covariates and concurrent disease response. Adoption of these standards by researchers and publishers would alter the current paradigm to enable meta-analysis of future studies and move the field towards meaningful application of SM and AT change to clinical care.

Diagnostic Ability of Perivascular Fat Attenuation Index in Predicting Atherosclerotic Plaque Formation Proximal to Myocardial Bridging of the Left Anterior Descending Artery within 3 Years

RATIONALE AND OBJECTIVES

This study was designed to investigate the association between the perivascular fat attenuation index (FAI) and atherosclerotic plaque formation proximal to myocardial bridging (MB) of the left anterior descending artery (LAD) within 3 years.

MATERIALS AND METHODS

LAD-MB patients who underwent coronary computed tomography angiography at least twice between January 2016 and December 2022 were retrospectively included in this study. In total, 99 LAD-MB patients were included in the study. Based on the formation of atherosclerotic plaques proximal to LAD-MB during follow-up, the patients were classified into two groups: LAD-MB with plaque formation and LAD-MB without plaque formation within 3 years. The anatomical features, clinical factors, and proximal perivascular FAI of LAD-MB were measured and recorded. The association of the previously mentioned factors with the presence of atherosclerotic plaque proximal to LAD-MB was determined.

RESULTS

The results showed that MB length, MB stenosis, and the perivascular FAI were significant predictors of the formation of atherosclerotic plaques proximal to LAD-MB. The area under the curve of the combined predictive model incorporating MB length, MB stenosis, and the perivascular FAI was 0.901(95% confidence interval: 0.824-0.952), with higher diagnostic performance than any other single parameter (all P < 0.05). Moreover, dynamic changes in the perivascular FAI of the vascular segments proximal to LAD-MB were higher in high-risk plaques than in non-high-risk plaques (P = 0.003).

CONCLUSION

The combined use of the perivascular FAI, MB length, and MB stenosis may enable prediction of the probability of atherosclerotic plaque formation proximal to LAD-MB within 3 years. Dynamic changes in perivascular FAI were associated with the vulnerability of plaques proximal to LAD-MB.

Pericoronary adipose tissue attenuation on coronary computed tomography angiography associates with male sex and Indigenous Australian status

To evaluate if Indigenous Australians have higher coronary inflammation demonstrated non-invasively using pericoronary adipose tissue attenuation on coronary computed tomography angiography (CCTA). We retrospectively obtained a cohort 54 Indigenous patients age- and sex-matched to 54 non-Indigenous controls (age: 46.5 ± 13.1 years; male: n = 66) undergoing CCTA at the Royal Darwin Hospital and Monash Medical Centre. Patient groups were defined to investigate the interaction of ethnicity and sex: Indigenous + male, Indigenous + female, control + male, control + female. Semi-automated software was used to assess pericoronary adipose tissue attenuation (PCAT-a) and volume (PCAT-v). Males had significantly higher PCAT-a (- 86.7 ± 7.8 HU vs. - 91.3 ± 7.1 HU, p = 0.003) than females. Indigenous patients had significantly higher PCAT-v (1.5 ± 0.5cm3 vs. 1.3 ± 0.4cm3, p = 0.032), but only numerically higher PCAT-a (p = 0.133) than controls. There was a significant difference in PCAT-a and PCAT-v across groups defined by Indigenous status and sex (p = 0.010 and p = 0.030, respectively). Among patients with matching CCTA contrast density, multivariable linear regression analysis showed an independent association between Indigenous status and PCAT-a. Indigenous men have increased PCAT-a in an age- and sex-matched cohort. Male sex is strongly associated with increased PCAT-a. Coronary inflammation may contribute to adverse cardiovascular outcomes in Indigenous Australians, but larger studies are required to validate these findings.

Association Between Alcohol Consumption and Ectopic Fat in the Multi-Ethnic Study of Atherosclerosis

Background The relationship between alcohol consumption and ectopic fat distribution, both known factors for cardiovascular disease, remains understudied. Therefore, we aimed to examine the association between alcohol consumption and ectopic adiposity in adults at risk for cardiovascular disease. Methods and Results In this cross-sectional analysis, we categorized alcohol intake among participants in MESA (Multi-Ethnic Study of Atherosclerosis) as follows (drinks/day): <1 (light drinking), 1 to 2 (moderate drinking), >2 (heavy drinking), former drinking, and lifetime abstention. Binge drinking was defined as consuming ≥5 drinks on 1 occasion in the past month. Visceral, subcutaneous, and intermuscular fat area, pericardial fat volume, and hepatic fat attenuation were measured using noncontrast computed tomography. Using multivariable linear regression, we examined the associations between categories of alcohol consumption and natural log-transformed fat in ectopic depots. We included 6756 MESA participants (62.1±10.2 years; 47.2% women), of whom 6734 and 1934 had chest computed tomography (pericardial and hepatic fat) and abdominal computed tomography (subcutaneous, intermuscular, and visceral fat), respectively. In adjusted analysis, heavy drinking, relative to lifetime abstention, was associated with a higher (relative percent difference) pericardial 15.1 [95% CI, 7.1-27.7], hepatic 3.4 [95% CI, 0.1-6.8], visceral 2.5 [95% CI, -10.4 to 17.2], and intermuscular 5.2 [95% CI, -6.6 to 18.4] fat but lower subcutaneous fat -3.5 [95% CI, -15.5 to 10.2]). The associations between alcohol consumption and ectopic adiposity exhibited a J-shaped pattern. Binge drinking, relative to light-to-moderate drinking, was also associated with higher ectopic fat. Conclusions Alcohol consumption had a J-shaped association with ectopic adiposity. Both heavy alcohol intake and binge alcohol drinking were associated with higher ectopic fat.

Ultrasound Calculation of Fat Volume for Liposuction: A Clinical Software Validation

BACKGROUND

Fat manipulation procedures such as liposuction contain a degree of subjectivity primarily guided by the surgeon's visual or tactile perception of the underlying fat. Currently, there is no cost-effective, direct method to objectively measure fat depth and volume in real time.

OBJECTIVES

Utilizing innovative ultrasound-based software, the authors aimed to validate fat tissue volume and distribution measurements in the preoperative setting.

METHODS

Eighteen participants were recruited to evaluate the accuracy of the new software. Recruited participants underwent ultrasound scans within the preoperative markings of the study area before surgery. Ultrasound-estimated fat profiles were generated with the in-house software and compared directly with the intraoperative aspirated fat recorded after gravity separation.

RESULTS

Participants' mean age and BMI were 47.6 (11.3) years and 25.6 (2.3) kg/m2, respectively. Evaluation of trial data showed promising results following the use of a Bland Altman agreement analysis. For the 18 patients and 44 volumes estimated, 43 of 44 measurements fell within a confidence interval of 95% when compared with the clinical lipoaspirate (dry) volumes collected postsurgery. The bias was estimated at 9.15 mL with a standard deviation of 17.08 mL and 95% confidence interval between -24.34 mL and 42.63 mL.

CONCLUSIONS

Preoperative fat assessment measurements agreed significantly with intraoperative lipoaspirate volumes. The pilot study demonstrates, for the first time, a novel companion tool with the prospect of supporting surgeons in surgical planning, measuring, and executing the transfer of adipose tissues.

LEVEL OF EVIDENCE: 4

Assessment of correlation between conventional anthropometric and imaging-derived measures of body fat composition: a systematic literature review and meta-analysis of observational studies

BACKGROUND

In studies of the association of adiposity with disease risk, widely used anthropometric measures of adiposity (e.g. body-mass-index [BMI], waist circumference [WC], waist-hip ratio [WHR]) are simple and inexpensive to implement at scale. In contrast, imaging-based techniques (e.g. magnetic resonance imaging [MRI] and dual x-ray absorptiometry [DXA]) are expensive and labour intensive, but can provide more accurate quantification of body fat composition. There is, however, limited evidence about the relationship between conventional and imaging-derived measures of adiposity.

METHODS

We searched Scopus and Web of Science for published reports in English of conventional versus imaging-derived measurements of adiposity. We identified 42 articles (MRI = 22; DXA = 20) that met selection criteria, involving 42,556 (MRI = 15,130; DXA = 27,426) individuals recruited from community or hospital settings. Study-specific correlation coefficients (r) were transformed using Fisher's Z transformation, and meta-analysed to yield weighted average correlations, both overall and by ancestry, sex and age, where feasible. Publication bias was investigated using funnel plots and Egger's test.

RESULTS

Overall, 98% of participants were 18 + years old, 85% male and 95% White. BMI and WC were most strongly correlated with imaging-derived total abdominal (MRI-derived: r = 0.88-; DXA-derived: 0.50-0.86) and subcutaneous abdominal fat (MRI-derived: 0.83-0.85), but were less strongly correlated with visceral abdominal fat (MRI-derived: 0.76-0.79; DXA-derived: 0.80) and with DXA-derived %body fat (0.76). WHR was, at best, strongly correlated with imaging-derived total abdominal (MRI-derived: 0.60; DXA-derived: 0.13), and visceral abdominal fat (MRI-derived: 0.67; DXA-derived: 0.65), and moderately with subcutaneous abdominal (MRI-derived: 0.54), and with DXA-derived %body fat (0.58). All conventional adiposity measures were at best moderately correlated with hepatic fat (MRI-derived: 0.36-0.43). In general, correlations were stronger in women than in men, in Whites than in non-Whites, and in those aged 18 + years.

CONCLUSIONS

In this meta-analysis, BMI and WC, but not WHR, were very strongly correlated with imaging-derived total and subcutaneous abdominal fat. By comparison, all three measures were moderately or strongly correlated with imaging-based visceral abdominal fat, with WC showing the greatest correlation. No anthropometric measure was substantially correlated with hepatic fat. Further larger studies are needed to compare these measures within the same study population, and to assess their relevance for disease risks in diverse populations.

Pericoronary adipose tissue density is increased in patients with recent spontaneous coronary dissection

OBJECTIVE

Inflammatory activity is one of the potential mechanisms of spontaneous coronary artery dissection (SCAD). Recently, the pericoronary adipose tissue attenuation (PCAT) derived from CT angiography (CTA) has been established as a method for measuring vascular inflammation. We aimed to characterise the pancoronary and vessel-specific PCAT in patients with and without recent SCAD.

METHODS

The study comprised patients with SCAD referred to a tertiary centre between 2017 and 2022 who underwent CTA and were compared with individuals with no prior SCAD. PCAT was analysed on end-diastolic CTA reconstructions along proximal 40 mm of all major coronary vessels as well as the SCAD-related vessel. We analysed 48 patients with recent SCAD (median 6.1 (IQR 3.5-14.9) months since SCAD, 95.8% female) and 48 patients in the group without SCAD.

RESULTS

Pancoronary PCAT was higher in patients with SCAD compared with those without SCAD (-80.6±7.9 vs -85.3 HU±6.1, p=0.002). Vessel-specific PCAT in patients with SCAD compared with patients without SCAD was higher for both the RCA (-80.9±9.5 vs -87.1±6.9 HU, p=0.001) and the LCA (-80.3±7.8 vs -83.4±7.2 HU, p=0.04). In patients with SCAD, PCAT of the SCAD-related vessel was not significantly different from averaged PCAT of unaffected vessels (-81.2±9.2 vs -80.6±7.6, p=0.74). There was no association between PCAT and the interval from SCAD to CTA.

CONCLUSIONS

Patients with recent SCAD have higher PCAT compared with patients without SCAD, suggesting an increased perivascular inflammatory activity. This association is not restricted to the dissected vessel.

Association of Regional Muscle Thickness and Echo Intensity with Muscle Volume, Intramuscular Adipose Tissue, and Strength of the Quadriceps Femoris

Purpose

This study aimed to investigate the association of muscle thickness (MT) and echo intensity (EI) obtained at different regions along the muscle length with muscle volume (MV), intramuscular adipose tissue (IntraMAT), and muscle strength of the quadriceps femoris (QF).

Patients and Methods

A total of 135 community-dwelling adults (64 men and 71 women) participated in the study. Ultrasound scanning of the rectus femoris (RF) and vastus intermedius (VI) was performed at three locations (from mid- to distal thigh). The MT of the RF and VI and EI of the RF were measured. MRI-derived MV, IntraMAT, and muscle strength of the QF were measured.

Results

The correlation between RF-MT and RF-MV weakened as scanning approached the distal thigh, and the difference between the coefficients for the scanning locations was significant for women. However, the correlation of VI-MT with VI-MV and that of the combined MT of RF and VI with the MV of the whole QF and muscle strength were comparable among the scanning locations for both sexes. The correlation of RF-EI with the IntraMAT of the RF and the whole QF and muscle strength was also comparable among the scanning locations for both sexes.

Conclusion

The results of this study suggest that ultrasound measurements at the distal thigh can predict MV, IntraMAT, and muscle strength of the QF to the same degree as those at the mid-thigh.

Association between epicardial adipose tissue and myocardial work by non-invasive left ventricular pressure-strain loop in people with suspected metabolic syndrome

Given the inconsistent results on the prognostic significance of epicardial adipose tissue (EAT), the purpose of the present study was to investigate the association of EAT thickness and myocardial work by non-invasive left ventricular pressure-strain loop in people with suspected metabolic syndrome (MS). A total of 194 participants imaged with echocardiography were evaluated. In accordance with the median EAT thickness, MS patients fell into thin EAT group and thick EAT group. Conventional echocardiographic parameters, global longitudinal strain (GLS) and the global myocardial work parameters obtained by pressure-strain loop analysis, comprising the global work index (GWI), global work efficiency (GWE), global constructive work (GCW) and global wasted work (GWW) were compared between the two groups. In comparison with the thin EAT group, thick EAT group achieved significantly higher values in interventricular septal thickness, end-diastolic left ventricular posterior wall thickness, left ventricular mass index and GWW (p < 0.05). while the absolute value of GLS, GWI, GCW, and GWE were notably lower in the thick EAT group (p < 0.001). EAT thickness showed a significant correlation with GWI and GCW (r = - 0.328, p = 0.001; r = - 0.253, p = 0.012), and also independently correlated with GWI and GCW in the multivariate regression analysis (β = - 0.310, p = 0.001; β = - 0.199, p = 0.049). EAT thickness is associated with left ventricular myocardial function in subjects with suspected metabolic syndrome, independently of other risk factors. Further studies are supposed to ensure the causal associations and related mechanisms.

Automatic prediction of acute coronary syndrome based on pericoronary adipose tissue and atherosclerotic plaques

Cardiovascular disease is the leading cause of human death worldwide, and acute coronary syndrome (ACS) is a common first manifestation of this. Studies have shown that pericoronary adipose tissue (PCAT) computed tomography (CT) attenuation and atherosclerotic plaque characteristics can be used to predict future adverse ACS events. However, radiomics-based methods have limitations in extracting features of PCAT and atherosclerotic plaques. Therefore, we propose a hybrid deep learning framework capable of extracting coronary CT angiography (CCTA) imaging features of both PCAT and atherosclerotic plaques for ACS prediction. The framework designs a two-stream CNN feature extraction (TSCFE) module to extract the features of PCAT and atherosclerotic plaques, respectively, and a channel feature fusion (CFF) to explore feature correlations between their features. Specifically, a trilinear-based fully-connected (FC) prediction module stepwise maps high-dimensional representations to low-dimensional label spaces. The framework was validated in retrospectively collected suspected coronary artery disease cases examined by CCTA. The prediction accuracy, sensitivity, specificity, and area under curve (AUC) are all higher than the classical image classification networks and state-of-the-art medical image classification methods. The experimental results show that the proposed method can effectively and accurately extract CCTA imaging features of PCAT and atherosclerotic plaques and explore the feature correlations to produce impressive performance. Thus, it has the potential value to be applied in clinical applications for accurate ACS prediction.

Association of pericoronary adipose tissue with atrial fibrillation recurrence after ablation based on computed tomographic angiography

PURPOSE

Quantitative measurement of pericoronary adipose tissue volume (PCATV) and fat attenuation index (FAI) has mostly been used in the study of coronary artery related diseases but rarely in the relationship with atrial fibrillation (AF). This study was conducted to investigate the correlation of PCATV and FAI with the AF recurrence after ablation and the clinical significance.

MATERIALS AND METHODS

Patients with continuous AF who underwent radiofrequency ablation and computed tomographic angiography (CTA) were retrospectively enrolled. The PCATV, FAI, epicardial adipose tissue volume (EATV) and EAT density (EATD) arround the three main branches of the coronary arteries (LAD, LCX, and RCA) were measured quantitatively with cardiac function software and analyzed.

RESULTS

189 patients with continuous AF who underwent radiofrequency ablation for the first time were enrolled. After 12-month follow-up with a mean follow-up time of 10.93 ± 0.16 months, 47 (24.9%) patients were confirmed to have AF recurrence. The 3 V-FAI (- 81.17 ± 4.27 vs. - 83.31 ± 4.59 HU, P = 0.005), LCX-FAI (median - 77 vs. median - 81HU, P < 0.001), EATV (median 141.14vs. median 125.39 ml, P = 0.010), and EATVI (median 70.77 vs. 66.73 ml/m2, P = 0.008) were significantly increased in the recurrence group. EATVI (OR 1.043, 95% CI 1.020-1.066) and LCX-FAI (OR 1.254, 95% CI 1.145-1.374) were two significant independent risk factors for AF recurrence. In the comparison of ROC, the predictive value of LCX-FAI (cut-off value of >- 81.5 HU, area under the curve (AUC) of 0.722) was higher than that of EATVI (cut-off value > 81.07 ml/m2, AUC of 0.630).

CONCLUSION

EATVI and LCX-FAI were related to recurrence of AF after ablation and have important clinical value in predicting the AF recurrence.

Increase in skeletal muscular adiposity and cognitive decline in a biracial cohort of older men and women

BACKGROUND

Obesity and loss of muscle mass are emerging as risk factors for dementia, but the role of adiposity infiltrating skeletal muscles is less clear. Skeletal muscle adiposity increases with older age and especially among Black women, a segment of the US population who is also at higher risk for dementia.

METHODS

In 1634 adults (69-79 years, 48% women, 35% Black), we obtained thigh intermuscular adipose tissue (IMAT) via computerized tomography at Years 1 and 6, and mini-mental state exam (3MS) at Years 1, 3, 5, 8 and 10. Linear mixed effects models tested the hypothesis that increased IMAT (Year 1-6) would be associated with 3MS decline (Year 5-10). Models were adjusted for traditional dementia risk factors at Year 1 (3MS, education, APOe4 allele, diabetes, hypertension, and physical activity), with interactions between IMAT change by race or sex. To assess the influence of other muscle and adiposity characteristics, models accounted for change in muscle strength, muscle area, body weight, abdominal subcutaneous and visceral adiposity, and total body fat mass (all measured in Years 1 and 6). Models were also adjusted for cytokines related to adiposity: leptin, adiponectin, and interleukin-6.

RESULTS

Thigh IMAT increased by 4.85 cm2 (Year 1-6) and 3MS declined by 3.20 points (Year 6-10). The association of IMAT increase with 3MS decline was statistically significant: an IMAT increase of 4.85 cm2 corresponded to a 3MS decline of an additional 3.60 points (p < 0.0001), indicating a clinically important change. Interactions by race and sex were not significant.

CONCLUSIONS

Clinicians should be aware that regional adiposity accumulating in the skeletal muscle may be an important, novel risk factor for cognitive decline in Black and White participants independent of changes to muscle strength, body composition and traditional dementia risk factors.

Anterior Tibiotalar Fat Pad Involvement in Ankle Osteoarthritis: MRI Features in Patients 1 Year After a Lateral Ankle Sprain

OBJECTIVE

To investigate the characteristics of the anterior tibiotalar fat pad (ATFP) in the ankle joint in a population of patients 1 year after an ankle sprain and its correlation with systemic factors and local articular pathology.

DESIGN

The study is a secondary analysis of an observational case-control study. We included 206 patients who were followed 6-12 months after ankle sprain. T1 MRI scans were assessed for signal intensity and area of ATFP by mapping the fat pad using dedicated imaging software (Mimics 18.0). Quantitative values of intensity and area were generated. Linear regression analysis was used to examine the association between both local and systemic factors and the ATFP. Variables with a P value <0.2 were entered in 5 stepwise multivariate models: (1) age-sex-body mass index (BMI); (2) anamnesis; (3) physical examination; (4) radiographic findings; and (5) MRI findings. Predictors in these separate models were entered in the final model.

RESULTS

The final multivariate model showed a significant positive association between age (P = 0.04; 95% confidence interval [CI] = 1.13 ± 1.06), BMI (P = 0.05; 95% CI = 3.61 ± 3.53), and sex (P < 0.01; 95% CI = -49.26 ± 30.04) with T1 intensity. The final model also showed a significant negative association between age (P < 0.01; 95% CI = -0.57 ± 0.34), diffuse cartilage loss in the lateral talus (P = 0.03; 95% CI = -0.71 ± 0.63), and Kellgren and Lawrence score in the tibiotalar joint (P < 0.01; 95%CI = -21.61 ± 7.24) and ATFP area. A positive association was found between BMI (P < 0.01; 95% CI = 2.25 ± 1.15) and ATFP area.

CONCLUSION

This study demonstrates a correlation between ATFP and both systemic factors and local pathology in the ankle joint.

Diagnostic Performance Comparison Between Ultrasound Attenuation Measurements From Right and Left Hepatic Lobes for Steatosis Detection in Non-alcoholic Fatty Liver Disease

RATIONALE AND OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is currently diagnosed by liver biopsy or MRI proton density fat fraction (MRI-PDFF) from left hepatic lobe (LTHL) and/or right hepatic lobe (RTHL). The objective of this study was to compare the diagnostic value of ultrasound attenuation coefficients (ACs) from RTHL and LTHL in detecting hepatic steatosis using biopsy or MRI-PDFF as a reference standard.

MATERIALS AND METHODS

Sixty-six patients with suspected NAFLD were imaged with an Aplio i800 ultrasound scanner (Canon Medical Systems, Tustin, CA). Five AC measurements from RTHL and LTHL were averaged separately and together to be compared with the reference standard.

RESULTS

Forty-seven patients (71%) were diagnosed with NAFLD. Mean ACs were significantly higher in fatty livers than non-fatty livers (RTHL: 0.73 ± 0.10 vs. 0.63 ± 0.07 dB/cm/MHZ; p < 0.0001, LTHL: 0.78 ± 0.11 vs. 0.63 ± 0.06 dB/cm/MHz; p < 0.0001, RTHL & LTHL: 0.76 ± 0.09 vs. 0.63 ± 0.05 dB/cm/MHz; p < 0.0001). Biopsy steatosis grades (n =31) were better correlated with the mean ACs of RTHL & LTHL (r = 0.72) compared to LTHL (r = 0.67) or RTHL (r = 0.61). Correlation between MRI-PDFF (n = 35) and mean ACs was better for LTHL (r = 0.69) compared to the RTHL & LTHL (r = 0.66) or RTHL (r = 0.45). Higher diagnostic accuracy was shown for the mean ACs of RTHL & LTHL (AUC 0.89, specificity 94%, sensitivity 78%) compared to LTHL (AUC 0.89, specificity 88%, sensitivity 82%) or RTHL (AUC 0.81, specificity 89%, sensitivity 68%).

CONCLUSION

Ultrasound ACs from RTHL and LTHL showed comparable diagnostic values in detection of hepatic steatosis with the highest diagnostic accuracy when they were averaged together.

The quantity and quality of cardiovascular fat at mid-life and future cognitive performance among women: The SWAN cardiovascular fat ancillary study

INTRODUCTION

Cardiovascular fat is a novel risk factor that may link to dementia. Fat volume and radiodensity are measurements of fat quantity and quality, respectively. Importantly, high fat radiodensity could indicate healthy or adverse metabolic processes.

METHODS

The associations of cardiovascular fat (including epicardial, paracardial, and thoracic perivascular adipose tissue [PVAT]) quantity and quality assessed at mean age of 51 with subsequent cognitive performance measured repeatedly over 16 years of follow-up were examined using mixed models among 531 women.

RESULTS

Higher thoracic PVAT volume was associated with a higher future episodic memory (β[standard error (SE)] = 0.08 [0.04], P = 0.033), while higher thoracic PVAT radiodensity with lower future episodic (β[SE] = -0.06 [0.03], P = 0.045) and working (β[SE] = -0.24 [0.08], P = 0.003) memories. The latter association is prominent at higher volume of thoracic PVAT.

DISCUSSION

Mid-life thoracic PVAT may have a distinct contribution to future cognition possibly due to its distinct adipose tissue type (brown fat) and anatomical proximity to the brain circulation.

HIGHLIGHTS

Higher mid-life thoracic perivascular adipose tissue (thoracic PVAT) volume is related to a better future episodic memory in women. Higher mid-life thoracic PVAT radiodensity is related to worse future working and episodic memories. Negative association of high thoracic PVAT radiodensity with working memory is prominent at higher thoracic PVAT volume. Mid-life thoracic PVAT is linked to future memory loss, an early sign of Alzheimer's disease. Mid-life women's epicardial and paracardial fat are not related to future cognition.

Can lung semi-quantitative measurements and mediastinal adipose tissue volume predict prognosis in patients with idiopathic pulmonary fibrosis (IPF)? A CT-based preliminary study

Introduction

The aim of this study was to assess the potential of subcutaneous adipose tissue volume, mediastinal adipose tissue volume, lung density, and lung volume (as measured on high-resolution computed tomography) to predict disease progression in patients with idiopathic pulmonary fibrosis (IPF). Additionally, the study aimed to evaluate the changes in these semiquantitative measures over time.

Materials and Methods

The HRCT images of 57 patients diagnosed with IPF were retrospectively screened. Subcutaneous adipose tissue volume, mediastinal adipose tissue volume, and mean lung density and volume were measured at the time of diagnosis and at the 12th month. The ability of these parameters to predict progression was evaluated using the univariate and multivariate Cox regression analyses.

Results

Low mediastinal adipose tissue volume at diagnosis had a 0.991-fold effect [odds ratio (OR)= 0.991, 95% confidence interval (CI)= 0.984-0.997, p< 0.001] on progression. Low mediastinal adipose tissue volume at diagnosis had a 0.993-fold effect [odds ratio (OR)= 0.993, 95% confidence interval (CI)= 0.975-1.011, p< 0.001] and progression development at the 12th month had a 6.5-fold effect [odds ratio (OR)= 6.516, 95% confidence interval (CI)= 1.594-26.639, p< 0.009] on mortality.

Conclusion

This study indicate that the prognosis was better in those with a large mediastinal adipose tissue volume among the patients with IPF.

Evaluation of perivascular fat attenuation with coronary CT angiography in cardiac transplantation patients: an imaging biomarker candidate for prediction of cardiac mortality and re-transplantation

OBJECTIVES

In cardiac transplant recipients, non-invasive allograft surveillance for identifying patients at risk for graft failure remains challenging. The fat attenuation index (FAI) of the perivascular adipose tissue in coronary computed tomography angiography (CCTA) predicts outcomes in coronary artery disease in non-transplanted hearts; however, it has not been evaluated in cardiac transplant patients.

METHODS

We followed 39 cardiac transplant patients with two or more CCTAs obtained between 2010 and 2021. We performed FAI measurements around the proximal 4 cm segments of the left anterior descending (LAD), right coronary artery (RCA), and left circumflex artery (LCx) using a previously validated methodology. The FAI was analyzed at a threshold of - 30 to - 190 Hounsfield units.

RESULTS

FAI measurements were completed in 113 CCTAs, obtained on two same-vendor CT models. Within each CCTA, the FAI values between coronary vessels were strongly correlated (RCA and LAD R = 0.67 (p < 0.0001), RCA and LCx R = 0.58 (p < 0.0001), LAD and LCx R = 0.67 (p < 0.0001)). The FAIs of each coronary vessel between the patient's first and last CCTA completed at 120 kV were also correlated (RCA R = 0.73 (p < 0.0001), LAD R = 0.81 (p < 0.0001), LCx R = 0.55 (p = 0.0069). Finally, a high mean FAI value of all three coronary vessels at baseline (mean ≥  - 71 HU) was predictive of cardiac mortality or re-transplantation, however, not predictive of all cause-mortality.

CONCLUSION

High baseline FAI values may identify a higher-risk cardiac transplant population; thus, FAI may support the implementation of CCTA in post-transplant surveillance.

KEY POINT

• Perivascular fat attenuation measured with coronary CT is feasible in cardiac transplant patients and may predict cardiac mortality or need for re-transplantation.

Relationship between trunk intramuscular adipose tissue content and prevalence of metabolic syndrome in middle-aged Japanese men

OBJECTIVES

The aim of the present study was to examine the dose-response relationship between trunk tissue composition and prevalence of metabolic syndrome (MetS) in middle-aged Japanese men.

METHODS

The 1026 men (between 35 and 59 y of age) who participated in the present study were divided into two groups: those with metabolic syndrome (MetS) and those without (non-MetS). Intramuscular adipose tissue (IntraMAT) content and the cross-sectional areas (CSAs) of visceral adipose tissue and skeletal muscle tissue were calculated using low-dose computed tomography images acquired at the level of the third lumbar vertebra. Height, body mass, body fat, waist circumference, the presence of MetS, and lifestyle habits were also assessed.

RESULTS

IntraMAT content was significantly higher in MetS than in non-MetS men. A 10% increase in IntraMAT content correlated with the prevalence of MetS (odds ratio, 4.197; 95% confidence interval, 3.108-7.088; P < 0.001), even after adjustments for age, height, adjusted skeletal muscle CSA, sleeping time, alcohol consumption, exercise habit, and cigarette smoking. Skeletal muscle CSA did not correlate with the prevalence of MetS after adjustments for IntraMAT content and other cofactors.

CONCLUSIONS

Increase in IntraMAT content, not in skeletal muscle CSA, significantly correlated with the prevalence of MetS. These results suggest that countermeasures against the accumulation of trunk IntraMAT effectively prevent MetS in middle-aged Japanese men.

Prognostic Impact of Quantifying Sarcopenia and Adipopenia by Chest CT in Severe Aplastic Anemia Patients Treated With Allogeneic Hematopoietic Stem Cell Transplantation

RATIONALE AND OBJECTIVES

To investigate the prognostic role of chest CT-defined sarcopenia and adipopenia in severe aplastic anemia (SAA) patients treated with hematopoietic stem cell transplantation (HSCT).

MATERIALS AND METHODS

This was a retrospective study of 123 consecutive SAA patients treated with HSCT. CT imaging was performed to quantify the pectoralis muscle (including major and minor) index (PMI) and the corresponding subcutaneous adipose tissue index (SAI). Sarcopenia and adipopenia were defined as PMI and SAI lower than the respective sex-specific medians. Correlations of the PMI and SAI with anthropometric indexes were calculated. Transplant-related outcomes were compared between the sarcopenia and adipopenia groups. Prognostic factors for overall survival (OS) and fail-free survival (FFS) were identified by Cox regression and were used to create a nomogram. The accuracy of the nomogram was evaluated by ROC curves.

RESULTS

PMI showed good correlation with BMI and fat-free mass index (p < 0.001). SAI correlated with BMI and fat mass index (p < 0.001). The sarcopenia group (47.2%) had a significantly worse 3-year OS (90.8% vs. 77.6%, p = 0.045) and 3-year FFS (89.2% vs. 74.1%, p = 0.035) than the nonsarcopenia group. Sarcopenia status and diagnostic category were used to construct the nomogram of OS, as these were independent prognostic factors in the multivariate analysis for OS and FFS (p < 0.05). The area under the curve of the nomogram at one year and three years was 0.801 and 0.721, respectively.

CONCLUSION

Sarcopenia indicates a poor prognosis in SAA patients undergoing HSCT. Intensive supportive care is suggested for SAA patients with sarcopenia before transplantation.

Epicardial Fat Volume as a Good Predictor for Multivessel Coronary Artery Disease

INTRODUCTION

Epicardial adipose tissue may have an important role in the pathogenesis of coronary artery disease (CAD).

AIM

We aimed to study the association between epicardial fat volume (EFV) and presence of obstructive as well as multivessel CAD.

METHODS

A total of 87 adult subjects with suspected CAD who underwent both quantified by multidetector computerized tomography (MDCT) and Invasive Coronary Angiography (ICA) were enrolled in this observational study. EVF was measured by MDCT by calculating the sum of cross- sectional areas of fat multiplied by slice thickness. EFV measurement and its association with the presence of obstructive CAD (defined as coronary artery stenosis > 70%) was evaluated.

RESULTS

Overall, 89.6% patients had obstructive CAD with higher EFV as compared to 10.3% patients with non-obstructive CAD (57 ± 20.14 cm3 vs. 44 ± 7.4 cm3; P < 0.001). Furthermore, EFV was significantly increased in group II as compared with group I (74 ± 24.3 ml vs. 53 ± 16.2 ml; P < 0.003). On the hand, the coronary calcium score (CAC) was insignificantly increased in group II as compared with group I (486.1 vs. 211.2; P = 0.10). Multivariate analysis revealed that, EFV might be an independent risk factor for not only the presence of obstructive CAD (odds ratio [OR], 1.062; 95% CI 1.018- 1.108; P < 0.005) but also in predicting multivessel disease affection.

CONCLUSIONS

Our results demonstrated that, EFV was significantly increased not only with obstructive CAD, independent of other traditional risk factors and CAC score, but also it can be considered a good predictor of multivessel disease occurrence.

Quantification of epicardial adipose tissue by computed tomographic scanning as a prognostic criterion of atrial fibrillation recurrence after catheter ablation

Aim    This study focused on a systematic review and meta-analysis on the predictive role of quantifying the epicardial adipose tissue (EAT) volume using data of computed tomography (CT) in patients after catheter ablation for atrial fibrillation (AF).Material and methods    We performed a search in PubMed and Google Scholar for studies that examined the predictive value of EAT volume measured by CT for AF recurrence in patients after undergoing pulmonary venous isolation. Risk ratio (RR) values from studies, where similar scoring criteria were available, were pooled for the meta-analysis.Results    Eighteen studies were selected from 901 publications for these systematic review and meta-analysis. In total, 4087 patients were included in this analysis (mean age, 59.0 years; mean follow-up duration, 14.9 mos). Patients with recurrent AF after ablation had higher left atrial EAT volume compared to patients without relapse (weighted mean difference, 5.99 ml; 95% CI: -10.04 to -1.94; p = 0.004). An increase in left atrial EAT volume per ml was significantly associated with the development of AF recurrence after ablation (RR 1.08; 95% CI: 1.01 to 1.16; p=0.03). Patients with recurrent AF after ablation also had higher total EAT values than patients without relapse (difference in weighted values, 11.67 ml; 95% CI: -19.81 to -3.54; p = 0.005). However, no significant association was found between the total EAT volume and the risk of AF relapse (RR 1.00; 95% CI: 1.00 to 1.01; p=0.06).Conclusions    The volume of left atrial EAT measured by CT has a significant predictive value in AF patients after catheter ablation and can be used for stratification of the risk for recurrent AF.

Association among peripatellar fat pad edema and related patellofemoral maltracking parameters: a case-control magnetic resonance imaging study

BACKGROUND

The peripatellar fat pads are critical for protective cushioning during movement, and their endocrine function has been shown to affect osteoarthritis. Magnetic resonance imaging (MRI) is frequently used to visualize edema of the peripatellar fat pads due to injury. In this study, we aimed to assess the relationship between peripatellar fat pad edema and patellofemoral maltracking MRI parameters and investigate the association among cases of peripatellar fat pad edema.

METHODS

Age- and sex-matched peripatellar fat pad edema cases were identified and divided into superolateral Hoffa, quadriceps, and prefemoral groups. Images were assessed according to tibial tuberosity lateralization, trochlear dysplasia, patellar alta, patellar tilt, and bisect offset. McNemar's test or paired t-tests and Spearman's correlation were used for statistical analysis. Interobserver agreement was assessed with the intraclass correlation coefficient.

RESULTS

Of 1210 MRI scans, 50, 68, and 42 cases were in the superolateral Hoffa, quadriceps, and prefemoral groups, respectively. Subjects with superolateral Hoffa fat pad edema had a lower lateral trochlear inclination (p = 0.028), higher Insall-Salvati (p < 0.001) and modified Insall-Salvati (p = 0.021) ratios, and lower patellotrochlear index (p < 0.001) than controls. The prefemoral group had a lower lateral trochlear inclination (p = 0.014) and higher Insall-Salvati (p < 0.001) and modified Insall-Salvati (p = 0.004) ratios compared with the control group. In contrast, the patellotrochlear index (p = 0.001) was lower. Mean patellar tilt angle (p = 0.019) and mean bisect offset (p = 0.005) were significantly different between cases and controls. The quadriceps group showed no association. Superolateral Hoffa was positively correlated with prefemoral (p < 0.001, r = 0.408) and negatively correlated with quadriceps (p < 0.001, r = -0.500) fat pad edema.

CONCLUSIONS

Superolateral Hoffa and prefemoral fat pad edemas were associated with patellar maltracking parameters. Quadriceps fat pad edema and maltracking parameters were not associated. Superolateral Hoffa fat pad edema was positively correlated with prefemoral and negatively correlated with quadriceps fat pad edema.

Bone Marrow Adipose Tissue Is Increased in Postmenopausal Women With Postsurgical Hypoparathyroidism

CONTEXT

Suppression of bone turnover, greater trabecular volume, and normal-high normal all-site bone mineral density (BMD) are hallmarks of postsurgical hypoparathyroidism (HypoPT). Impairment in the trabecular microarchitecture with possible higher risk of vertebral fractures (VF) in women with postmenopausal HypoPT has also been described. Currently, no data on bone marrow adipose tissue (BMAT) are available in HypoPT.

OBJECTIVE

To assess BMAT by magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H-MRS) in postmenopausal women with chronic postsurgical HypoPT.

METHODS

This cross-sectional pilot study, conducted at an ambulatory referral center, included 29 postmenopausal women (mean age 66 ± 8.4 years) with postsurgical HypoPT and 31 healthy postmenopausal women (mean age 63 ± 8.5). Lumbar spine MRI was performed and BMAT was measured by applying PRESS sequences on the L3 body. Lumbar spine, femoral neck, and total hip BMD were measured by dual x-ray absorptiometry (DXA); site-matched spine trabecular bone score (TBS) was calculated by TBS iNsight (Medimaps, Switzerland); VF assessment was performed with lateral thoracic and lumbar spine DXA.

RESULTS

Fat content (FC) and saturation level (SL%) were higher (P <.0001 and P <.001), while water content (W) was lower in HypoPT compared to controls (P <.0001). FC significantly correlated with years since menopause and body weight (P <.05) in HypoPT, while TBS negatively correlated with FC and SL% (P <.05) and positively with residual lipids (RL) and W (P <.05).

CONCLUSION

We demonstrate for the first time that BMAT is increased in postmenopausal women with postsurgical hypoparathyroidism and negatively associated with trabecular microarchitecture.

Relationship between impaired myocardial blood flow by positron emission tomography and low-attenuation plaque burden and pericoronary adipose tissue attenuation from coronary computed tomography: From the prospective PACIFIC trial

BACKGROUND

Positron emission tomography (PET) is the clinical gold standard for quantifying myocardial blood flow (MBF). Pericoronary adipose tissue (PCAT) attenuation may detect vascular inflammation indirectly. We examined the relationship between MBF by PET and plaque burden and PCAT on coronary CT angiography (CCTA).

METHODS

This post hoc analysis of the PACIFIC trial included 208 patients with suspected coronary artery disease (CAD) who underwent [15O]H2O PET and CCTA. Low-attenuation plaque (LAP, < 30HU), non-calcified plaque (NCP), and PCAT attenuation were measured by CCTA.

RESULTS

In 582 vessels, 211 (36.3%) had impaired per-vessel hyperemic MBF (≤ 2.30 mL/min/g). In multivariable analysis, LAP burden was independently and consistently associated with impaired hyperemic MBF (P = 0.016); over NCP burden (P = 0.997). Addition of LAP burden improved predictive performance for impaired hyperemic MBF from a model with CAD severity and calcified plaque burden (P < 0.001). There was no correlation between PCAT attenuation and hyperemic MBF (r = - 0.11), and PCAT attenuation was not associated with impaired hyperemic MBF in univariable or multivariable analysis of all vessels (P > 0.1).

CONCLUSION

In patients with stable CAD, LAP burden was independently associated with impaired hyperemic MBF and a stronger predictor of impaired hyperemic MBF than NCP burden. There was no association between PCAT attenuation and hyperemic MBF.

CT Scan-Derived Muscle, But Not Fat, Area Independently Predicts Mortality in COVID-19

BACKGROUND

COVID-19 has demonstrated a highly variable disease course, from asymptomatic to severe illness and eventually death. Clinical parameters, as included in the 4C Mortality Score, can predict mortality accurately in COVID-19. Additionally, CT scan-derived low muscle and high adipose tissue cross-sectional areas (CSAs) have been associated with adverse outcomes in COVID-19.

RESEARCH QUESTION

Are CT scan-derived muscle and adipose tissue CSAs associated with 30-day in-hospital mortality in COVID-19, independent of 4C Mortality Score?

STUDY DESIGN AND METHODS

This was a retrospective cohort analysis of patients with COVID-19 seeking treatment at the ED of two participating hospitals during the first wave of the pandemic. Skeletal muscle and adipose tissue CSAs were collected from routine chest CT-scans at admission. Pectoralis muscle CSA was demarcated manually at the fourth thoracic vertebra, and skeletal muscle and adipose tissue CSA was demarcated at the first lumbar vertebra level. Outcome measures and 4C Mortality Score items were retrieved from medical records.

RESULTS

Data from 578 patients were analyzed (64.6% men; mean age, 67.7 ± 13.5 years; 18.2% 30-day in-hospital mortality). Patients who died within 30 days demonstrated lower pectoralis CSA (median, 32.6 [interquartile range (IQR), 24.3-38.8] vs 35.4 [IQR, 27.2-44.2]; P = .002) than survivors, whereas visceral adipose tissue CSA was higher (median, 151.1 [IQR, 93.6-219.7] vs 112.9 [IQR, 63.7-174.1]; P = .013). In multivariate analyses, low pectoralis muscle CSA remained associated with 30-day in-hospital mortality when adjusted for 4C Mortality Score (hazard ratio, 0.98; 95% CI, 0.96-1.00; P = .038).

INTERPRETATION

CT scan-derived low pectoralis muscle CSA is associated significantly with higher 30-day in-hospital mortality in patients with COVID-19 independently of the 4C Mortality Score.

Relationship between epicardial adipose tissue, systemic inflammatory diseases, and subclinical atheromatosis: A systematic review

BACKGROUND AND AIMS

Systemic inflammatory diseases could act as an unfavorable condition in which epicardial adipose tissue (EAT) becomes harmful to cardiovascular health. The objectives were: (a) to quantitatively compare the presence of EAT between patients with systemic inflammatory diseases and controls; (b) to analyze the association between EAT and subclinical atheromatosis in individuals with systemic inflammatory diseases.

METHODS

Studies that have quantified EAT in a population with systemic inflammatory diseases compared to a control group, or that describe the association between EAT and the presence of subclinical atheromatosis in patients with systemic inflammatory diseases were included. A quantitative analysis was performed for the first objective. This systematic review was performed according to PRISMA guidelines.

RESULTS

Twenty-one studies including 1448 patients with systemic inflammatory diseases, were considered eligible for this study. Patients with systemic inflammatory disease have a higher volume (MD: 10.4cm3 [1.8-19.1]; p<0.01), higher thickness (MD: 1.0mm [0.8-1.2]; p<0.01), and a statistically non-significant higher area (MD: 3.1cm2 [1.0-5.2]; p=0.46) of EAT compared to the control group. Most studies reported a significant association between EAT and subclinical atheromatosis in patients with different systemic inflammatory diseases.

CONCLUSION

This study demonstrated that EAT is increased in patients with systemic inflammatory diseases compared with healthy controls, and that EAT measurement is closely correlated with subclinical atherosclerosis in these patients. The causality of this association should be tested in prospective studies.

Peri-Coronary Adipose Tissue Is a Predictor of Stent Failure in Patients Undergoing Percutaneous Coronary Intervention

PURPOSE

Coronary inflammation is postulated as a driver of atherosclerosis and dysfunctional arterial healing which may trigger stent failure. Pericoronary adipose tissue (PCAT) attenuation, detected on computer tomography coronary angiography (CTCA), is an emerging non-invasive marker of coronary inflammation. This propensity matched study assessed the utility of both lesion specific (PCATLesion) and standardized PCAT attenuation as assessed in the proximal RCA (PCATRCA) as a predictor of stent failure in patients undergoing elective percutaneous coronary intervention. This is the first study to our knowledge that assesses the association of PCAT with stent failure.

METHODS

Patients undergoing CTCA assessment for coronary artery disease with subsequent stent insertion within 60 days and repeat coronary angiography for any clinical reason within 5 years were included in the study. Stent failure was defined as binary restenosis of >50 % on quantitative coronary angiography analysis or stent thrombosis. Both PCATLesion and PCATRCA was assessed utilizing semi-automated proprietary software on baseline CTCA. Patients with stent failure were propensity matched utilizing age, sex, cardiovascular risk factors and procedural characteristics.

RESULTS

One hundred and fifty-one patients met inclusion criteria. Of these, 26 (17.2 %) had study-defined failure. A significant difference in PCATLesion attenuation between patients with and without failure was observed (-79.0 ± 12.6 vs. -85.9 ± 10.3HU, p = 0.035). There was no significant difference in PCATRCA attenuation between the two groups (-79.5 ± 10.1 vs -81.0 ± 12.3HU, p = 0.50). Univariate regression analysis showed PCATLesion attenuation was independently associated with stent failure (OR 1.06, 95 % CI 1.01-1.12, P = 0.035).

CONCLUSIONS

Patients with stent failure exhibit significantly increased PCATLesion attenuation at baseline. These data suggest that baseline plaque inflammation may be an important driver for coronary stent failure.

Automatic segmentation of human supraclavicular adipose tissue using high-resolution T2-weighted magnetic resonance imaging

OBJECTIVE

To achieve efficient segmentation of human supraclavicular adipose tissue (sclavAT) using high-resolution T2-weighted magnetic resonance images.

METHODS

High-resolution 1.0 mm isotropic 3D T2-weighted images covering human supraclavicular area were acquired in transverse or coronary plane from 29 volunteers using a 3.0 T MRI scanner. There were typically 144/288 slices for the transverse/coronary scans for each subject, which amounts to a total of 6816 images in 29 volunteers. A U-NET network was trained to segment the supraclavicular adipose tissue (sclavAT). The performance of the automatic segmentation method was evaluated by comparing the output results with the manual labels using the quantitative indices of dice similarity coefficient (DSC), precision rate (PR), and recall rate (RR). The auto-segmented images were used to calculate the sclavAT volumes and registered to the MR fat fraction (FF) images to quantify the fat component of the sclavAT area. The relationship between body mass index (BMI), the volume and FF of sclavAT area was evaluated for all subjects.

RESULTS

The DSC, PR and RR of the automatic sclavAT segmentation method on the testing datasets were 0.920 ± 0.048, 0.915 ± 0.070 and 0.930 ± 0.058. The volume and the mean FF of sclavAT were both found to be strongly correlated to BMI, with the correlation coefficient of 0.703 and 0.625 (p < 0.05), respectively. The averaged computation time of the automatic segmentation method was approximately 0.06 s per slice, compared to more than 5 min for manual labeling.

CONCLUSION

The present study demonstrates that the proposed automatic segmentation method using U-Net network is able to identify human sclavAT efficiently and accurately.

Athletes with different habitual fluid intakes differ in hydration status but not in body water compartments

Physiological differences have been reported between individuals who have habitual low (LOW) and high (HIGH) water intake (WI). The aims of this study were to explore body water compartments, hydration status, and fat-free mass (FFM) hydration of elite athletes exposed to different habitual WI. A total of 68 athletes (20.6 ± 5.3 years, 23 females) participated in this observational cross-sectional study. Total WI was assessed by seven-day food diaries and through WI, athletes were categorized as HIGH (n = 28, WI≥40.0 mL/kg/d) and LOW (n = 40, WI≤35.0 mL/kg/d). Total body water (TBW) and extracellular water (ECW) were determined by dilution techniques and intracellular water (ICW) as TBW-ECW. Hydration status was assessed by urine-specific gravity (USG) using a refractometer. Fat (FM) and FFM were assessed by dual-energy X-ray absorptiometry (DXA). The FFM hydration was calculated by TBW/FFM. The USG was statistically different between groups for females (LOW: 1.024 ± 0.003; HIGH: 1.015 ± 0.006; p = 0.005) and males (LOW: 1.024 ± 0.002; HIGH: 1.018 ± 0.005; p < 0.001). No differences between groups were detected in body water compartments and FFM hydration in both sexes (p > 0.05). Multiple regression showed that WI remains a predictor of USG regardless of FFM, age, and sex (β = -0.0004, p < 0.01). We concluded that LOW athletes were classified as dehydrated through USG although their water compartments were not different from HIGH athletes. These results suggest that LOW athletes may expectedly maintain the body water compartments' homeostasis through endocrine mechanisms. Interventions should be taken to encourage athletes to have sufficient WI to maintain optimal hydration.

Strain-dependent shear properties of human adipose tissue in vivo

INTRODUCTION

Human adipose tissue (fat) deforms substantially under normal physiological loading and during impact. Thus, accurate data on strain-dependent stiffness of fat is essential for the creation of accurate biomechanical models. Previous studies on ex vivo samples reported human fat to be nonlinear and viscoelastic. When static compression is combined with magnetic resonance (MR) elastography (an imaging technique used to measure viscoelasticity in vivo), the large deformation properties of tissues can be determined. Here, we use magnetic resonance elastography to quantify fat shear modulus in vivo under increasing compressive strain and compare it to the underlying passive gluteal muscle.

METHODS

The right buttocks of ten female participants were incrementally compressed at four levels while MR elastography (50 Hz) and mDixon images were acquired. Maps of tissue shear modulus (G*) were reconstructed from the MR elastography phase images. Tissue strain was estimated from registration of deformed and undeformed mDixon images. Linear mixed models were fit to the natural logarithm of the compressive strain and shear modulus data for each tissue.

RESULTS

Shear modulus increased in an exponential relationship with compressive strain in fat: Gfat*=748.5*Cyy-1.18Pa, and to a lesser extent in muscle: Gmuscle*=956.4*Cyy-0.36Pa. The baseline (undeformed) stiffness of fat was significantly lower than that of muscle (mean G*fat = 752 Pa, mean G*muscle = 1000 Pa, paired samples t-test, t = -4.24, p = 0.001). However, fat exhibited a significantly higher degree of strain dependence (characterised by the exponent of the curve, t = -6.47, p = 0.0001).

CONCLUSION

Static compression of human adipose tissue results in an increase in apparent viscoelastic shear modulus (stiffness), in an exponentially increasing relationship. The relationships defined here can be used in the development of physiologically realistic computational models for impact, injury and biomechanical modelling.

Intravoxel Incoherent Motion Diffusion-Weighted MR Imaging Findings of Infrapatellar Fat Pad Signal Abnormalities: Comparison Between Symptomatic and Asymptomatic Knee Osteoarthritis

RATIONALE AND OBJECTIVES

Infrapatellar fat pad (IPFP) proton density-weighted images (PdWI) hyperintense regions on MRI are an important imaging feature of knee osteoarthritis (KOA) and are thought to represent inflammation which may induce knee pain. The aim of the study was to compare the intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) findings of PdWI hyperintense regions of IPFP between symptomatic and asymptomatic KOA and to determine whether IVIM-DWI parameters can be used as an objective biomarker for symptomatic KOA.

MATERIALS AND METHODS

In total, 84 patients with symptomatic KOA, 43 asymptomatic KOA persons, and 30 healthy controls with MRI were retrospectively reviewed. Demographic, IPFP-synovitis, Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain sub-score, IPFP volume and depth and quantitative parameters of IVIM-DWI were collected. The chi-square test, Binary logistic regression and receiver operating characteristic curve (ROC) analysis were used for diagnostic performance comparison.

RESULTS

The IPFP volume and depth were statistically significant differences between the non-KOA and sKOA groups (p<0.05). The IPFP PdWI hyperintense regions demonstrated significantly higher values of D and D* in the symptomatic KOA compared to those in the asymptomatic KOA (1.51±0.47 vs. 1.73±0.40 for D and 19.24±6.44 vs. 27.09±9.75 for D*) (both p<0.05). Multivariate logistic regression analyses showed that Higher D and D* values of IPFP hyperintense region were significantly associated with higher risks of knee pain (OR: 1.97; 95% CI: 1.21-3.19; p=0.006 for D and OR: 1.24; 95% CI: 1.09-1.41; p=0.001 for D*). Sensitivity and specificity of D value for symptomatic KOA were 80.28% and 83.33%, with an AUC of 0.78 (0.68-0.86). D* value had the sensitivity with 92.96% and a specificity of 58.33%, with an AUC of 0.82 (0.73-0.89) for symptomatic KOA.

CONCLUSION

IVIM-DWI can be used as an additional functional imaging technique to study IPFP with signal abnormalities on PdWI, and the D and D* values may have potential value to predict the symptom in mild-to-moderate KOA patients.

Deep-Learning for Epicardial Adipose Tissue Assessment With Computed Tomography: Implications for Cardiovascular Risk Prediction

BACKGROUND

Epicardial adipose tissue (EAT) volume is a marker of visceral obesity that can be measured in coronary computed tomography angiograms (CCTA). The clinical value of integrating this measurement in routine CCTA interpretation has not been documented.

OBJECTIVES

This study sought to develop a deep-learning network for automated quantification of EAT volume from CCTA, test it in patients who are technically challenging, and validate its prognostic value in routine clinical care.

METHODS

The deep-learning network was trained and validated to autosegment EAT volume in 3,720 CCTA scans from the ORFAN (Oxford Risk Factors and Noninvasive Imaging Study) cohort. The model was tested in patients with challenging anatomy and scan artifacts and applied to a longitudinal cohort of 253 patients post-cardiac surgery and 1,558 patients from the SCOT-HEART (Scottish Computed Tomography of the Heart) Trial, to investigate its prognostic value.

RESULTS

External validation of the deep-learning network yielded a concordance correlation coefficient of 0.970 for machine vs human. EAT volume was associated with coronary artery disease (odds ratio [OR] per SD increase in EAT volume: 1.13 [95% CI: 1.04-1.30]; P = 0.01), and atrial fibrillation (OR: 1.25 [95% CI: 1.08-1.40]; P = 0.03), after correction for risk factors (including body mass index). EAT volume predicted all-cause mortality (HR per SD: 1.28 [95% CI: 1.10-1.37]; P = 0.02), myocardial infarction (HR: 1.26 [95% CI:1.09-1.38]; P = 0.001), and stroke (HR: 1.20 [95% CI: 1.09-1.38]; P = 0.02) independently of risk factors in SCOT-HEART (5-year follow-up). It also predicted in-hospital (HR: 2.67 [95% CI: 1.26-3.73]; P ≤ 0.01) and long-term post-cardiac surgery atrial fibrillation (7-year follow-up; HR: 2.14 [95% CI: 1.19-2.97]; P ≤ 0.01).

CONCLUSIONS

Automated assessment of EAT volume is possible in CCTA, including in patients who are technically challenging; it forms a powerful marker of metabolically unhealthy visceral obesity, which could be used for cardiovascular risk stratification.

Accumulation in Visceral Adipose Tissue Over 6 Years Is Associated With Lower Paraspinal Muscle Density

CONTEXT

Visceral adipose tissue (VAT) has been recognized to be a metabolically active fat depot that may have paracrine effects on surrounding tissues, including muscle. Since many adults accumulate VAT as they age, the effect of changes in VAT on muscle is of interest.

OBJECTIVE

We determined the association between 6-year changes in VAT and paraspinal muscle density, an indicator of fatty infiltration.

METHODS

This study included 1145 participants from the Framingham Study third-generation cohort who had both quantitative computed tomography scans of the spine at baseline and 6-year's follow-up, on whom muscle density was measured along with VAT. We implemented multiple regression to determine the association of muscle density at follow-up as primary outcome measure with changes in VAT (follow-up minus baseline divided by 100), adjusting for VAT at baseline, age, sex, height, menopausal status, presence of diabetes, and physical activity. Analyses were performed in men and women separately.

RESULTS

After adjustment for covariates, individuals with the greatest accumulation of VAT over 6 years had significantly lower paraspinal density at the follow-up with an estimated 0.302 (95% CI, -0.380 to -0.224) and 0.476 (95% CI: -0.598 to -0.354) lower muscle density (HU) per 100-cm3 increase in VAT (both P values < .001) in men and women, respectively.

CONCLUSION

These results highlight that age-related accumulation of VAT in men and women is associated with lower muscle density. VAT may represent a modifiable risk factor for poor musculoskeletal outcomes with aging.

Radiofrequency coil design for improving human liver fat quantification in a portable single-side magnetic resonance system

Earlier diagnosis of nonalcoholic fatty liver disease (NAFLD) is important to prevent progression of the disease. Recently, a low-cost portable magnetic resonance (MR) system was developed as a point-of-care screening tool for in vivo liver fat quantification. However, subcutaneous fat may confound the liver fat quantification, particularly in the NAFLD population. In this work, we propose a novel radiofrequency (RF) coil design composed of a set of "saturation" coils sandwiching a main coil to improve human liver fat quantification. By comparison with conventional MR imaging, we demonstrate the capability and effectiveness of the novel RF coil design in phantom experiments as well as in vivo liver scans. In the phantom experiment, the saturation coil reduced the error in the measured proton density fat fraction (PDFF) results from 28.9% to 4.0%, and in the in vivo experiment, it reduced the discrepancy in the PDFF results from 13.2% to 4.0%. The novel coil design, together with the adapted Carr-Purcell-Meiboom-Gill-based sequence, improves the practicability and robustness of the portable single-side MR system.

The association between leptin and subclinical cardiovascular disease explained by body fat: Observational and Mendelian randomization analyses

BACKGROUND AND AIMS

Leptin has been associated with adverse effects on cardiovascular disease, but the effect of confounding by body fat in these associations remains unclear. To investigate associations between leptin and heart function and subclinical cardiovascular disease adjusted for total body fat, and to investigate the causal relation between leptin and cardiovascular disease using Mendelian randomisation.

METHODS AND RESULTS

Leptin concentrations, total body fat and diverse measures of subclinical cardiovascular disease were determined in participants of the Netherlands Epidemiology of Obesity study. Linear regression between leptin concentration and measures of heart function, ECG measures, and carotid intima media thickness as a measure of subclinical atherosclerosis was adjusted for potential confounding factors, and additionally including total body fat. We analysed the combined effects of genetic variants from a GWAS on leptin concentrations in publicly-available summary statistics of coronary heart disease GWAS (CARDIoGRAMplusC4D, n = 184,305). As many as 6107 men and women, mean (SD) age 56 (6) years, BMI 26 (4) kg/m², and median leptin concentration 12.1 μg (IQR: 6.7-22.6) were included. In observational analyses, leptin was weakly associated with heart function and subclinical cardiovascular disease, but these associations attenuated when adjusting for total body fat. A doubling of genetically-determined leptin concentration was associated with an odds ratio of cardiovascular disease of 0.69 (0.37, 1.27).

CONCLUSION

Observational associations between leptin and subclinical measures of cardiovascular disease were largely explained by differences in total body fat. Results of analyses of genetically-determined leptin and coronary heart disease risk were inconclusive due to a large confidence interval.