Opportunistic CT for Prediction of Adverse Postoperative Events in Patients with Spinal Metastases

The purpose of this study was to assess the value of body composition measures obtained from opportunistic abdominal computed tomography (CT) in order to predict hospital length of stay (LOS), 30-day postoperative complications, and reoperations in patients undergoing surgery for spinal metastases. 196 patients underwent CT of the abdomen within three months of surgery for spinal metastases. Automated body composition segmentation and quantifications of the cross-sectional areas (CSA) of abdominal visceral and subcutaneous adipose tissue and abdominal skeletal muscle was performed. From this, 31% (61) of patients had postoperative complications within 30 days, and 16% (31) of patients underwent reoperation. Lower muscle CSA was associated with increased postoperative complications within 30 days (OR [95% CI] = 0.99 [0.98-0.99], p = 0.03). Through multivariate analysis, it was found that lower muscle CSA was also associated with an increased postoperative complication rate after controlling for the albumin, ASIA score, previous systemic therapy, and thoracic metastases (OR [95% CI] = 0.99 [0.98-0.99], p = 0.047). LOS and reoperations were not associated with any body composition measures. Low muscle mass may serve as a biomarker for the prediction of complications in patients with spinal metastases. The routine assessment of muscle mass on opportunistic CTs may help to predict outcomes in these patients.

Decreased rotator cuff muscle cross-sectional areas in subjects with adhesive capsulitis: a study comparing male and female subjects

OBJECTIVE

To compare rotator cuff (RC) muscle cross-sectional areas (CSA) in subjects with adhesive capsulitis (AC) to age- and sex-matched controls.

MATERIALS AND METHODS

We retrospectively analyzed 97 shoulder MRIs or MR arthrography studies, of which 42 were clinically diagnosed with AC (27 female, 15 male) and 55 were age- and sex-matched controls (38 female, 17 male). All AC subjects underwent imaging ≥ 6 months after symptom onset. All imaging was examined to exclude RC full-thickness tears and prior surgery. A standardized T1 sagittal MR image was segmented in each subject to obtain the CSA of subscapularis (SSC), supraspinatus (SSP), and infraspinatus (ISP) muscles. Differences in CSAs between AC and control subjects were analyzed by sex (females and males separately) and all subjects combined.

RESULTS

AC females had significantly decreased SSC (P = 0.002) and total (P = 0.006) CSAs compared to controls. Male AC subjects showed decreased SSC (P = 0.044), SSP (P = 0.001), and total (P = 0.005) CSAs. Across all subjects, male and female, the AC cohort had significantly decreased SSC (P = 0.019) and total (P = 0.029) CSAs compared to controls.

CONCLUSION

Decreased RC muscle CSAs were present in AC subjects with ≥ 6 months of symptom duration, with decreased SSC and total CSAs in male and female subjects, and decreased SSP CSA in males.

Cross-sectional areas of rotator cuff muscles in males without tears on shoulder MRI

OBJECTIVE

To establish reference values of rotator cuff (RC) cross sectional area (CSA) in males.

MATERIALS AND METHODS

We retrospectively analyzed shoulder MRIs from 500 patients aged 13-78 years, grouped as follows (N=100 in each): <20, 20-30, 30-40, 40-50, >50 years. All examinations were reviewed to exclude prior surgery, tears, or significant RC pathology. We segmented a standardized T1 sagittal MR image in each case to obtain CSA of supraspinatus (SUP), infraspinatus/teres minor (INF), and subscapularis (SUB) muscles. Across age groups, we recorded individual and total muscle CSA. We also performed ratios between individual muscle CSA and total CSA to examine total muscle mass contribution over age groups. We tested for differences between age groups controlled for BMI.

RESULTS

CSAs for SUP, INF, SUB, and total RC CSA were lower in subjects >50 years compared to all other groups (P<0.003 for all comparisons), persisting after controlling for BMI (P<0.03). Relative contribution of SUP CSA to total RC CSA was stable across age groups (P>0.32). INF CSA relative to total RC CSA increased with age, whereas SUB decreased (P<0.005). Subjects >50 years showed lower SUP (-15%), INF (-6%), and SUB (-21%) CSA, when compared to mean CSAs of all subjects <50 years. Total RC CSA significantly correlated with age (r=-0.34, P<0.001), persisting after controlling for BMI (r=-0.42, P<0.001).

CONCLUSION

RC muscles in male subjects with no tears on MRI show decreasing CSA with age, independent of BMI.

Breast adipose tissue attenuation as a novel imaging biomarker for cardiometabolic risk

BACKGROUND

Certain adipose tissue depots infer higher cardiometabolic risk than body mass index (BMI).

PURPOSE

To assess breast adipose tissue (BrAT) attenuation as a novel imaging biomarker for cardiometabolic risk.

MATERIAL AND METHODS

We studied 151 women (mean age = 56 ± 1 years) across the weight spectrum. BrAT attenuation, abdominal adipose tissue cross-sectional areas (CSA), and attenuation were quantified using non-contrast computed tomography (CT) scans. Cardiometabolic risk factors were assessed from medical records.

RESULTS

BrAT attenuation was lower in obese women compared to lean women. BrAT attenuation was inversely associated with BMI, waist circumference, abdominal fat CSA, fasting glucose, and triglycerides (P ≤ 0.02), and positively associated with abdominal adipose tissue attenuation (P < 0.001). BrAT attenuation had a sensitivity of 90% but a specificity of only 35% in detecting the metabolic syndrome (area under the curve = 0.63).

CONCLUSION

BrAT attenuation is associated with cardiometabolic risk markers and could serve as an imaging biomarker for opportunistic risk assessment in patients undergoing CT examination of the chest.

MRI 3D simulation of hip motion in female patients with and without ischiofemoral impingement

OBJECTIVE

To utilize hip MRI 3D models for demonstration of location and frequency of impingement during simulated range-of-motion in ischiofemoral impingement (IFI) compared to non-IFI hips.

MATERIALS AND METHODS

Sixteen hips (N = 7 IFI, 9 non-IFI) from 8 females were examined with high-resolution MRI. We performed image segmentation and generated 3D bone models and simulated hip range-of-motion and impingement. We examined the frequency and location of bone contact in early external rotation and early extension (0-20°), isolated maximum external rotation, and isolated maximum extension. Frequency and location of impingement at varied combinations of external rotation and extension and areas of simulated bone impingement at early external rotation and extension were compared between IFI and non-IFI.

RESULTS

Higher frequency of bony impingement occurred more often in IFI hips at each simulated range-of-motion combination (P < 0.05). Impingement involved the lesser trochanter more often in IFI hips (P < 0.001) and occurred at early degrees of external rotation and extension. In isolated maximum external rotation, only the greater trochanter, intertrochanteric area, or both combined were involved, in 14%, 57%, and 29% in IFI hips. In isolated maximum extension, the lesser trochanter, intertrochanteric area, or both combined were involved in 71%, 14%, and 14% in IFI hips. The simulated area of bone impingement was significantly higher in IFI hips (P = 0.02).

CONCLUSION

Hip MRI 3D models are feasible for simulated range-of-motion and show a higher frequency of extra-articular impingement at early stages of external rotation and extension in IFI compared to non-IFI hips.

Posterior capsule edema in adhesive capsulitis: comparison with established non-contrast MRI findings and multivariable analysis

OBJECTIVES

To evaluate posterior glenohumeral capsule edema compared to other MRI findings in adhesive capsulitis (AC).

METHODS

This study was approved by the local Institutional Review Board and it is HIPAA compliant. A retrospective search identified subjects who received fluoroscopically guided intra-articular corticosteroid injections for AC and had an MRI within 6 months prior to injection. The study group was compared with an age-, sex-, and side-matched control group who underwent the same procedures but did not have AC. MRIs were evaluated for edema of posterior capsule, anterior capsule, axillary pouch, coracohumeral ligament (CHL) and rotator interval (RI), thickness of axillary pouch and CHL, thickness of anterior capsule, RI and subcoracoid fat replacement, and teres minor atrophy and edema. Multivariable analysis was performed.

RESULTS

A total of 57 subjects with AC and 57 matched controls were studied: mean age 52 ± 7 (range 31-71) years, 37 female and 20 male, 22 right and 35 left. Posterior capsule edema was more common in the AC group vs. control group (66.7 vs 17.5%, p < 0.001). Multivariable analysis showed posterior capsule edema, CHL edema, and axillary pouch (glenoid) thickness (optimum cutoff = 4 mm) were significant independent predictors of AC. Simplified analysis using these three variables had an area under the curve of 0.860 (95%CI: 0.792-0.928). With all three variables present, the sensitivity and specificity for AC were 32% and 98%, respectively.

CONCLUSIONS

Posterior joint capsule edema may be helpful to confirm AC. Posterior capsule edema, CHL edema, and axillary pouch (glenoid) thickness produce a strong model for distinguishing AC from controls.

CLINICAL RELEVANCE STATEMENT

Edema involving the posterior shoulder joint capsule is an imaging marker of capsulitis and is useful in differentiating patients with adhesive capsulitis from those without in conjunction with other proven MRI findings.

KEY POINTS

• Posterior capsule edema has a sensitivity of 66.7% and a specificity of 82.5% for the detection of adhesive capsulitis. • Posterior capsule edema, coracohumeral ligament (CHL) edema, and axillary pouch (glenoid) thickness were significant independent predictors of adhesive capsulitis, and combining these variables together produces a very strong model for distinguishing cases from controls (AUC = 0.860). • Optimal cutoff values for CHL, axillary pouch (humeral), axillary pouch (glenoid), and axillary pouch (total) thickness were 2.5, 2.6, 4, and 6.3 mm, respectively.

Randomized Placebo-Controlled Trial to Evaluate Effects of Eplerenone on Myocardial Perfusion and Function Among Persons With Human Immunodeficiency Virus (HIV)-Results From the MIRACLE HIV Study

BACKGROUND

Increased renin angiotensin aldosterone system (RAAS) activity may contribute to excess cardiovascular disease in people with HIV (PWH). We investigated how RAAS blockade may improve myocardial perfusion, injury, and function among well-treated PWH.

METHODS

Forty PWH, on stable ART, without known heart disease were randomized to eplerenone 50 mg PO BID (n = 20) or identical placebo (n = 20) for 12 months. The primary endpoints were (1) myocardial perfusion assessed by coronary flow reserve (CFR) on cardiac PET or stress myocardial blood flow (sMBF) on cardiac MRI or (2) myocardial inflammation by extracellular mass index (ECMi) on cardiac MRI.

RESULTS

Beneficial effects on myocardial perfusion were seen for sMBF by cardiac MRI (mean [SD]: 0.09 [0.56] vs -0.53 [0.68] mL/min/g; P = .03) but not CFR by cardiac PET (0.01 [0.64] vs -0.07 [0.48]; P = .72, eplerenone vs placebo). Eplerenone improved parameters of myocardial function on cardiac MRI including left ventricular end diastolic volume (-13 [28] vs 10 [26] mL; P = .03) and global circumferential strain (GCS; median [interquartile range 25th-75th]: -1.3% [-2.9%-1.0%] vs 2.3% [-0.4%-4.1%]; P = .03), eplerenone versus placebo respectively. On cardiac MRI, improvement in sMBF related to improvement in global circumferential strain (ρ = -0.65, P = .057) among those treated with eplerenone. Selecting for those with impaired myocardial perfusion (CFR <2.5 and/or sMBF <1.8), there was a treatment effect of eplerenone versus placebo to improve CFR (0.28 [0.27] vs -0.05 [0.36]; P = .04). Eplerenone prevented a small increase in troponin (0.00 [-0.13-0.00] vs 0.00 [0.00-0.74] ng/L; P = .03) without effects on ECMi (0.9 [-2.3-4.3] vs -0.7 [-2.2--0.1] g/m2; P = .38). CD4+ T-cell count (127 [-38-286] vs -6 [-168-53] cells/μL; P = .02) increased in the eplerenone- versus placebo-treated groups.

CONCLUSIONS

RAAS blockade with eplerenone benefitted key indices and prevented worsening of myocardial perfusion, injury, and function among PWH with subclinical cardiac disease when compared with placebo.

CLINICAL TRIALS REGISTRATION

NCT02740179 (https://clinicaltrials.gov/ct2/show/NCT02740179?term=NCT02740179&draw=2&rank=1).

Visceral Adiposity Index as a Measure of Cardiovascular Disease in Persons With Human Immunodeficiency Virus

Background

Persons with well-treated human immunodeficiency virus (HIV) demonstrate a 2-fold higher risk of cardiovascular disease (CVD), which may be related to excess visceral adipose tissue (VAT). The visceral adiposity index (VAI) is a score to approximate VAT by combining biochemical measures with anthropometrics without quantification by imaging. We evaluated VAI in association with cardiometabolic factors among persons with HIV (PWH).

Methods

Forty-five PWH on antiretroviral therapy and virologically controlled with increased abdominal VAT (VAT area >110 cm2 on CT) and no known CVD were included. VAI was calculated using standard sex-specific formulas. Coronary plaque was assessed using coronary CT angiography.

Results

Participants were predominantly male (73%), white (53%), and non-Hispanic (84%), with a mean age of 55 (standard deviation, 7) years. Among PWH, median VAI was calculated to be 4.9 (interquartile range [IQR], 2.8-7.3). Log VAI correlated with log VAT (r = 0.59, P < .0001) and anthropometric measures (body mass index: r = 0.36, P = .02; waist circumference: r = 0.43, P = .004; waist-to-hip ratio: r = 0.33, P = .03). Participants with coronary plaque had a higher VAI compared to those without coronary plaque (median, 5.3 [IQR, 3.4-10.5] vs 2.8 [IQR, 1.8-5.0]; P = .004). VAI (area under the curve = 0.760, P = .008) performed better than the atherosclerotic CVD risk score to predict the presence of plaque in receiver operating characteristic analyses.

Conclusions

VAI may be a useful biomarker of metabolic dysfunction and increased CVD risk that may occur with VAT accumulation in PWH.

Clinical Trials Registration

NCT02740179.

Proteomic Analysis of Hepatic Fibrosis in Human Immunodeficiency Virus-Associated Nonalcoholic Fatty Liver Disease Demonstrates Up-regulation of Immune Response and Tissue Repair Pathways

BACKGROUND

Human immunodeficiency virus (HIV)-associated nonalcoholic fatty liver disease (NAFLD) is characterized by a high prevalence of hepatic fibrosis as a strong clinical predictor of all-cause and liver-specific mortality risk.

METHODS

We leveraged data from an earlier clinical trial to define the circulating proteomic signature of hepatic fibrosis in HIV-associated NAFLD. A total of 183 plasma proteins within 2 high-multiplex panels were quantified at baseline and at 12 months (Olink Cardiovascular III; Immuno-Oncology).

RESULTS

Twenty proteins were up-regulated at baseline among participants with fibrosis stages 2-3 versus 0-1. Proteins most differentially expressed included matrix metalloproteinase 2 (P < .001), insulin-like growth factor-binding protein 7 (P = .001), and collagen α1(I) chain (P = .001). Proteins were enriched within pathways including response to tumor necrosis factor and aminopeptidase activity. Key proteins correlated directly with visceral adiposity and glucose intolerance and inversely with CD4+ T-cell count. Within the placebo-treated arm, 11 proteins differentially increased among individuals with hepatic fibrosis progression over a 12-month period (P < .05).

CONCLUSIONS

Among individuals with HIV-associated NAFLD, hepatic fibrosis was associated with a distinct proteomic signature involving up-regulation of tissue repair and immune response pathways. These findings enhance our understanding of potential mechanisms and biomarkers of hepatic fibrosis in HIV.

Original research: utilization of a convolutional neural network for automated detection of lytic spinal lesions on body CTs

OBJECTIVE

To develop, train, and test a convolutional neural network (CNN) for detection of spinal lytic lesions in chest, abdomen, and pelvis CT scans.

MATERIALS AND METHODS

Cases of malignant spinal lytic lesions in CT scans were identified. Images were manually segmented for the following classes: (i) lesion, (ii) normal bone, (iii) background. If more than one lesion was on a single slice, all lesions were segmented. Images were stored as 128×128 pixel grayscale, with 10% segregated for testing. The training pipeline of the dataset included histogram equalization and data augmentation. A model was trained on Keras/Tensorflow using an 80/20 training/validation split, based on U-Net architecture. Additional testing of the model was performed on 1106 images of healthy controls. Global sensitivity measured detection of any lesion on a single image. Local sensitivity and positive predictive value (PPV) measured detection of all lesions on an image. Global specificity measured false positive rate in non-pathologic bone.

RESULTS

Six hundred images were obtained for model creation. The training set consisted of 540 images, which was augmented to 20,000. The test set consisted of 60 images. Model training was performed in triplicate. Mean Dice scores were 0.61 for lytic lesion, 0.95 for normal bone, and 0.99 for background. Mean global sensitivity was 90.6%, local sensitivity was 74.0%, local PPV was 78.3%, and global specificity was 63.3%. At least one false positive lesion was noted in 28.8-44.9% of control images.

CONCLUSION

A task-trained CNN showed good sensitivity in detecting spinal lytic lesions in axial CT images.

Role of renin-angiotensin-aldosterone system activation and other metabolic variables in relation to arterial inflammation in HIV

BACKGROUND

Arterial inflammation remains increased among persons with HIV (PWH) compared with persons without HIV (PWOH) even when controlling for traditional risk factors. We sought to understand whether increased renin-angiotensin-aldosterone system (RAAS) activation may be related to arterial inflammation in PWH and when compared with PWOH.

DESIGN

Twenty PWH and 9 PWOH followed a controlled, standardized low and liberal sodium diet to simulate a RAAS-activated and RAAS-suppressed state, respectively. We measured serum lipoprotein-associated phospholipase A2 (LpPLA2) concentrations following both conditions to assess the physiologic dynamics of aldosterone in relation to arterial inflammation.

RESULTS

LpPLA2 levels were significantly higher among PWH versus PWOH during both the RAAS-activated state[5.3(4.2, 6.1) versus 4.0(3.0, 4.8)nmol/L, median(interquartile range),p = .01]) and RAAS-suppressed state[4.4(3.9, 5.3) versus 3.8(3.4, 4.1)nmol/L,p = .01]. Among PWH, but not PWOH, LpPLA2 increased significantly with RAAS activation(p = .03). LpPLA2 levels measured during the RAAS-suppressed state among PWH remained relatively higher than LpPLA2 levels under both conditions among PWOH. Log LpPLA2 was related to log aldosterone during the RAAS-activated state(r = .39,p = .04) among all participants. Log LpPLA2 was correlated with visceral fat(r = .46,p = .04) and log systolic blood pressure(r = .57,p = .009) during a RAAS-activated state when an increase in aldosterone was stimulated in HIV.

CONCLUSION

LpPLA2 is increased during a RAAS-activated state among PWH, but not among PWOH. Further, LpPLA2 was increased in both RAAS-activated and suppressed states in PWH compared with PWOH. These data suggest a biological link between increased aldosterone and arterial inflammation in this population. Future studies should test RAAS blockade on arterial inflammation as a targeted treatment approach in HIV.

A randomized, double-blind, placebo-controlled clinical trial of 8-week intranasal oxytocin administration in adults with obesity: Rationale, study design, and methods

BACKGROUND

Obesity affects more than one-third of adults in the U.S., and effective treatment options are urgently needed. Oxytocin administration induces weight loss in animal models of obesity via effects on caloric intake, energy expenditure, and fat metabolism. We study intranasal oxytocin, an investigational drug shown to reduce caloric intake in humans, as a potential novel treatment for obesity.

METHODS

We report the rationale, design, methods, and biostatistical analysis plan of a randomized, double-blind, placebo-controlled clinical trial of intranasal oxytocin for weight loss (primary endpoint) in adults with obesity. Participants (aged 18-45 years) were randomly allocated (1:1) to oxytocin (four times daily over eight weeks) versus placebo. Randomization was stratified by biological sex and BMI (30 to <35, 35 to <40, ≥40 kg/m2). We investigate the efficacy, safety, and mechanisms of oxytocin administration in reducing body weight. Secondary endpoints include changes in resting energy expenditure, body composition, caloric intake, metabolic profile, and brain activation via functional magnetic resonance imaging in response to food images and during an impulse control task. Safety and tolerability (e.g., review of adverse events, vital signs, electrocardiogram, comprehensive metabolic panel) are assessed throughout the study and six weeks after treatment completion.

RESULTS

Sixty-one male and female participants aged 18-45 years were randomized (mean age 34 years, mean BMI 37 kg/m2). The study sample is diverse with 38% identifying as non-White and 20% Hispanic.

CONCLUSION

Investigating intranasal oxytocin's efficacy, safety, and mechanisms as an anti-obesity medication will advance the search for optimal treatment strategies for obesity and its associated severe sequelae.

Body composition predictors of mortality on computed tomography in patients with spinal metastases undergoing surgical treatment

BACKGROUND CONTEXT

Although survival of patients with spinal metastases has improved over the last decades due to advances in multi-modal therapy, there are currently no reliable predictors of mortality. Body composition measurements obtained using computed tomography (CT) have been recently proposed as biomarkers for survival in patients with and without cancer. Patients with cancer routinely undergo CT for staging or surveillance of therapy. Body composition assessed using opportunistic CTs might be used to determine survival in patients with spinal metastases.

PURPOSE

The purpose of this study was to determine the value of body composition measures obtained on opportunistic abdomen CTs to predict 90-day and 1-year mortality in patients with spinal metastases undergoing surgery. We hypothesized that low muscle and abdominal fat mass were positive predictors of mortality.

STUDY DESIGN

Retrospective study at a single tertiary care center in the United States.

PATIENT SAMPLE

This retrospective study included 196 patients between 2001 and 2016 that were 18 years of age or older, underwent surgical treatment for spinal metastases, and had a preoperative CT of the abdomen within three months prior to surgery.

OUTCOME MEASURES

Ninety-day and 1-year mortality by any cause.

METHODS

Quantification of cross-sectional areas (CSA) and CT attenuation of abdominal subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and paraspinous and abdominal skeletal muscle were performed on CT images at the level of L4 using an in-house automated algorithm. Sarcopenia was determined by total muscle CSA (cm²) divided by height squared (m²) with cutoff values of <52.4 cm²/m² for men and <38.5 cm²/m² for women. Bivariate and multivariate Cox proportional-hazard analyses were used to determine the associations between body compositions and 90-day and 1-year mortality.

RESULTS

The median age was 62 years (interquartile range=53-70). The mortality rate for 90-day was 24% and 1-year 54%. The presence of sarcopenia was associated with an increased 1-year mortality rate of 66% compared with a 1-year mortality rate of 41% in patients without sarcopenia (hazard ratio, 1.68; 95% confidence interval, 1.08-2.61; p=.02) after adjusting for various clinical factors including primary tumor type, ECOG performance status, additional metastases, neurology status, and systemic therapy. Additional analysis showed an association between sarcopenia and increased 1-year mortality when controlling for the prognostic modified Bauer score (HR, 1.58; 95%CI, 1.04-2.40; p=.03). Abdominal fat CSAs or muscle attenuation were not independently associated with mortality.

CONCLUSIONS

The presence of sarcopenia is associated with an increased risk of 1-year mortality for patients surgically treated for spinal metastases. Sarcopenia retained an independent association with mortality when controlling for the prognostic modified Bauer score. This implies that body composition measurements such as sarcopenia could serve as novel biomarkers for prediction of mortality and may supplement other existing prognostic tools to improve shared decision making for patients with spinal metastases that are contemplating surgical treatment.

Automated detection and segmentation of sclerotic spinal lesions on body CTs using a deep convolutional neural network

PURPOSE

To develop a deep convolutional neural network capable of detecting spinal sclerotic metastases on body CTs.

MATERIALS AND METHODS

Our study was IRB-approved and HIPAA-compliant. Cases of confirmed sclerotic bone metastases in chest, abdomen, and pelvis CTs were identified. Images were manually segmented for 3 classes: background, normal bone, and sclerotic lesion(s). If multiple lesions were present on a slice, all lesions were segmented. A total of 600 images were obtained, with a 90/10 training/testing split. Images were stored as 128 × 128 pixel grayscale and the training dataset underwent a processing pipeline of histogram equalization and data augmentation. We trained our model from scratch on Keras/TensorFlow using an 80/20 training/validation split and a U-Net architecture (64 batch size, 100 epochs, dropout 0.25, initial learning rate 0.0001, sigmoid activation). We also tested our model's true negative and false positive rate with 1104 non-pathologic images. Global sensitivity measured model detection of any lesion on a single image, local sensitivity and positive predictive value (PPV) measured model detection of each lesion on a given image, and local specificity measured the false positive rate in non-pathologic bone.

RESULTS

Dice scores were 0.83 for lesion, 0.96 for non-pathologic bone, and 0.99 for background. Global sensitivity was 95% (57/60), local sensitivity was 92% (89/97), local PPV was 97% (89/92), and local specificity was 87% (958/1104).

CONCLUSION

A deep convolutional neural network has the potential to assist in detecting sclerotic spinal metastases.

Body composition predictors of mortality in patients undergoing surgery for long bone metastases

Background and Objectives

Body composition measurements using computed tomography (CT) may serve as imaging biomarkers of survival in patients with and without cancer. This study assesses whether body composition measurements obtained on abdominal CTs are independently associated with 90‐day and 1‐year mortality in patients with long‐bone metastases undergoing surgery.

Methods

This single institutional retrospective study included 212 patients who had undergone surgery for long‐bone metastases and had a CT of the abdomen within 90 days before surgery. Quantification of cross‐sectional areas (CSA) and CT attenuation of abdominal subcutaneous adipose tissue, visceral adipose tissue, and paraspinous and abdominal muscles were performed at L4. Multivariate Cox proportional‐hazards analyses were performed.

Results

Sarcopenia was independently associated with 90‐day mortality (hazard ratio [HR] = 1.87; 95% confidence interval [CI] = 1.11–3.16; p = 0.019) and 1‐year mortality (HR = 1.50; 95% CI = 1.02–2.19; p = 0.038) in multivariate analysis while controlling for clinical variables such as primary tumors, comorbidities, and chemotherapy. Abdominal fat CSAs and muscle attenuation were not associated with mortality.

Conclusions

The presence of sarcopenia assessed by CT is predictive of 90‐day and 1‐year mortality in patients undergoing surgery for long‐bone metastases. This body composition measurement can be used as novel imaging biomarker supplementing existing prognostic tools to optimize patient selection for surgery and improve shared decision making.

Bone marrow adipose tissue composition following high-caloric feeding and fasting

BACKGROUND

Bone marrow adipose tissue (BMAT) plays a role in systemic energy metabolism and responds to nutritional changes. Chronic starvation as well as visceral adiposity are associated with BMAT accumulation. Two types of BMAT have been described which differ in anatomic location (proximal-regulated-rBMAT vs distal-constitutive-cBMAT) and composition (higher unsaturated lipids of cBMAT compared to rBMAT).

OBJECTIVE

To determine the response of BMAT composition to short-term high-caloric feeding and fasting. We hypothesized that high-feeding and caloric restriction would be associated with differences in BMAT composition according to the skeletal site.

MATERIALS AND METHODS

We examined 23 healthy subjects (13 m, 10 f, mean age 33 ± 7 years, BMI 26 ± 1.5 kg/m²) who were admitted for a 10-day high-caloric stay (caloric intake with goal to achieve 7% weight gain) followed by discharge home for 13-18 days to resume normal diet (stabilization period), followed by a 10-day fasting stay (no caloric intake). Subjects underwent single voxel proton MR spectroscopy (1H-MRS) at 3T of the lumbar spine (L4) (rBMAT), the femoral diaphysis and distal tibial metaphysis (cBMAT) to determine BMAT composition (unsaturation index, UI and saturation index, SI). Within group comparisons were performed by the Wilcoxon signed rank test.

RESULTS

After the high-calorie visit, SI of L4 increased compared to baseline (0.62 ± 0.27 to 0.70 ± 0.28, p = 0.02), and there was a trend of an increase in femoral SI and UI (p ≥ 0.07), while there was no significant change in tibial BMAT (p ≥ 0.13). During the stabilization period, SI of L4 decreased (0.70 ± 0.28 to 0.57 ± 0.21, p < 0.0001) and SI of the femoral diaphysis decreased (5.37 ± 2.27 to 5.09 ± 2.43, p = 0.03), while there was no significant change in UI or tibial BMAT (p ≥ 0.14). During the fasting period, SI of L4 increased (0.57 ± 0.21 to 0.63 ± 0.30, p = 0.03), while there was no change in UI (p = 0.7). SI and UI of femoral diaphysis decreased (5.09 ± 2.43 to 4.68 ± 2.15, p = 0.03, and 0.62 ± 0.42 to 0.47 ± 0.37, p = 0.02, respectively) and UI of the tibial metaphysis decreased (1.48 ± 0.49 to 1.24 ± 0.57, p = 0.04).

CONCLUSION

1H-MRS is able to quantify BMAT composition during short-term nutritional challenges, showing a significant increase in SI of rBMAT during high caloric feeding and a differential response to fasting with an increase in SI of rBMAT and a decrease in SI and UI of femoral cBMAT and decrease in UI of tibial cBMAT.

Synthesizing Quantitative T2 Maps in Right Lateral Knee Femoral Condyles from Multicontrast Anatomic Data with a Conditional Generative Adversarial Network

PURPOSE

To develop a proof-of-concept convolutional neural network (CNN) to synthesize T2 maps in right lateral femoral condyle articular cartilage from anatomic MR images by using a conditional generative adversarial network (cGAN).

MATERIALS AND METHODS

In this retrospective study, anatomic images (from turbo spin-echo and double-echo in steady-state scans) of the right knee of 4621 patients included in the 2004-2006 Osteoarthritis Initiative were used as input to a cGAN-based CNN, and a predicted CNN T2 was generated as output. These patients included men and women of all ethnicities, aged 45-79 years, with or at high risk for knee osteoarthritis incidence or progression who were recruited at four separate centers in the United States. These data were split into 3703 (80%) for training, 462 (10%) for validation, and 456 (10%) for testing. Linear regression analysis was performed between the multiecho spin-echo (MESE) and CNN T2 in the test dataset. A more detailed analysis was performed in 30 randomly selected patients by means of evaluation by two musculoskeletal radiologists and quantification of cartilage subregions. Radiologist assessments were compared by using two-sided t tests.

RESULTS

The readers were moderately accurate in distinguishing CNN T2 from MESE T2, with one reader having random-chance categorization. CNN T2 values were correlated to the MESE values in the subregions of 30 patients and in the bulk analysis of all patients, with best-fit line slopes between 0.55 and 0.83.

CONCLUSION

With use of a neural network-based cGAN approach, it is feasible to synthesize T2 maps in femoral cartilage from anatomic MRI sequences, giving good agreement with MESE scans.See also commentary by Yi and Fritz in this issue.Keywords: Cartilage Imaging, Knee, Experimental Investigations, Quantification, Vision, Application Domain, Convolutional Neural Network (CNN), Deep Learning Algorithms, Machine Learning Algorithms© RSNA, 2021.

Altered pattern of circulating miRNAs in HIV lipodystrophy perturb key adipose differentiation and inflammation pathways

We identified a microRNA (miRNA) profile characterizing HIV lipodystrophy and explored the downstream mechanistic implications with respect to adipocyte biology and the associated clinical phenotype. miRNA profiles were extracted from small extracellular vesicles (sEVs) of HIV-infected individuals with and without lipodystrophic changes and individuals without HIV, among whom we previously showed significant reductions in adipose Dicer expression related to HIV. miR-20a-3p was increased and miR-324-5p and miR-186 were reduced in sEVs from HIV lipodystrophic individuals. Changes in these miRNAs correlated with adipose Dicer expression and clinical markers of lipodystrophy, including fat redistribution, insulin resistance, and hypertriglyceridemia. Human preadipocytes transfected with mimic miR-20a-3p, anti–miR-324-5p, or anti–miR-186 induced consistent changes in latent transforming growth factor beta binding protein 2 (Ltbp2), Wisp2, and Nebl expression. Knockdown of Ltbp2 downregulated markers of adipocyte differentiation (Fabp4, Pparγ, C/ebpa, Fasn, adiponectin, Glut4, CD36), and Lamin C, and increased expression of genes involved in inflammation (IL1β, IL6, and Ccl20). Our studies suggest a likely unique sEV miRNA signature related to dysregulation of Dicer in adipose tissue in HIV. Enhanced miR-20a-3p or depletion of miR-186 and miR-324-5p may downregulate Ltbp2 in HIV, leading to dysregulation in adipose differentiation and inflammation, which could contribute to acquired HIV lipodystrophy and associated metabolic and inflammatory perturbations.

A measuring technique for intra-osseous pressure

OBJECTIVE

Pulsatile intra-osseous pressures result in bone remodeling, and therefore may affect lesion growth and response to treatment. However, there is no known method used to measure intra-osseous pressures. The purpose of this study is to describe a novel image-guided technique for measuring intra-osseous pressures.

MATERIALS AND METHODS

This study was IRB-approved and HIPAA compliant. Written informed consent was obtained. Intra-osseous pressure measurements were performed during a CT-guided bone marrow biopsy in eight patients (6 male, 2 female) with mean age 66 ± 13 years (median 72, range 45-87) and suspected or known bone marrow disease. Bone marrow pressure measurements were obtained connecting the biopsy needle to a dedicated monitor using a standard arterial line setup. Monitor data was collected at 5-s intervals in order to record continuous pressure measurements for 2 min.

RESULTS

Pressure measurements were successfully performed in all 8 patients. The mean bone marrow pressures were 36.8 ± 7.2 mmHg (median 37.7, range 24.7-47.4). The peak and trough pressures varied by 11%, and the standard deviation of mean pressure measurement varied by 18%. Our findings for marrow pressure measures most closely approximate the pressure profile of the venous system.

CONCLUSION

We describe a novel and minimally invasive technique able to provide functional data of bone marrow. This technique has the potential to provide insights into normal and diseased bone marrow and may be helpful to evaluate features of cystic and vascular tumors that may be amenable to percutaneous treatments.

Clinical Predictors of Liver Fibrosis Presence and Progression in Human Immunodeficiency Virus-Associated Nonalcoholic Fatty Liver Disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) affects more than one-third of people living with human immunodeficiency virus (HIV). Nonetheless, its natural history is poorly understood, including which patients are most likely to have a progressive disease course.

METHODS

We leveraged a randomized trial of the growth hormone-releasing hormone analogue tesamorelin to treat NAFLD in HIV. Sixty-one participants with HIV-associated NAFLD were randomized to tesamorelin or placebo for 12 months with serial biopsies.

RESULTS

In all participants with baseline biopsies (n = 58), 43% had hepatic fibrosis. Individuals with fibrosis had higher NAFLD Activity Score (NAS) (mean ± standard deviation [SD], 3.6 ± 2.0 vs 2.0 ± 0.8; P < .0001) and visceral fat content (mean ± SD, 284 ± 91 cm2 vs 212 ± 95 cm2; P = .005), but no difference in hepatic fat or body mass index. Among placebo-treated participants with paired biopsies (n = 24), 38% had hepatic fibrosis progression over 12 months. For each 25 cm2 higher visceral fat at baseline, odds of fibrosis progression increased by 37% (odds ratio, 1.37 [95% confidence interval, 1.03-2.07]). There was no difference in baseline NAS between fibrosis progressors and nonprogressors, though NAS rose over time in the progressor group (mean ± SD, 1.1 ± 0.8 vs -0.5 ± 0.6; P < .0001).

CONCLUSIONS

In this longitudinal study of HIV-associated NAFLD, high rates of hepatic fibrosis and progression were observed. Visceral adiposity was identified as a novel predictor of worsening fibrosis. In contrast, baseline histologic characteristics did not relate to fibrosis progression.

Growth Hormone Releasing Hormone Reduces Plasma Markers of Immune Activation and Hepatic Immune Pathways in Nonalcoholic Fatty Liver Disease

Introduction: The GH/IGF-1 axis affects multiple metabolic pathways, and animal models demonstrate that it also modulates immune function. Little is known, however, regarding effects of augmenting GH secretion on immune function in humans. This study used proteomics and gene set enrichment analysis to assess effects of a GH releasing hormone (GHRH) analog, tesamorelin, on circulating immune markers and immune-related gene pathways in the liver in people with HIV (PWH) and NAFLD. We hypothesized that tesamorelin would decrease circulating markers of immune activation in conjunction with previously reported reductions in visceral fat and hepatic triglyceride. Methods: 92 biomarkers associated with immune function (Olink Immuno-Oncology panel) were measured in plasma samples from 61 PWH with NAFLD who participated in a double-blind, randomized, 12-month trial of tesamorelin versus identical placebo. Proteins differentially altered by tesamorelin at a false discovery rate < 0.1 were considered significantly changed. Gene set enrichment analysis targeted to immune pathways was subsequently performed on liver tissue from serial biopsies. Results: Compared to placebo, tesamorelin decreased circulating concentrations of 13 proteins, including four chemokines (C-C Motif Chemokine Ligands 3 [CCL3, effect size -0.38 Log₂ fold change], 4 [CCL4, -0.36 Log₂ fold change], and 13 [CCL13 or MCP4, -0.42 Log₂ fold change] and interleukin-8 [-0.50 Log₂ fold change]), two cytokines (interleukin-10 [-0.32 Log₂ fold change] and cytokine stimulating factor 1 [-0.22 Log₂ fold change]), and four T-cell associated molecules (CD8A [-0.37 Log₂ fold change], Cytotoxic And Regulatory T Cell Molecule [CRTAM, -0.47 Log₂ fold change], granzyme A [-0.53 Log₂ fold change], and adhesion G protein-coupled receptor G1 [ADGRG1, -0.54 Log₂ fold change]), as well as arginase-1 [-0.95 Log₂ fold change], galectin-9 [-0.26 Log₂ fold change], and hepatocyte growth factor [-0.30 Log₂ fold change]. No proteins in the panel were significantly increased by tesamorelin. Network analysis indicated close interaction among the gene pathways responsible for the reduced proteins, with imputational analyses suggesting down regulation of a closely related cluster of immune pathways. Targeted transcriptomics using tissue from liver biopsy confirmed an end-organ signal of down-regulated immune pathways, including pathways involved in antigen presentation, complement activation, toll like receptor and inflammatory signaling, and T-cell activation. Conclusions: Long-term treatment with tesamorelin decreased circulating markers of T-cell and monocyte/macrophage activity, with corresponding downregulation of immune pathways in the liver. These findings suggest that augmenting pulsatile GH may ameliorate immune activation in a population with metabolic dysregulation and systemic inflammation.

Growth Hormone Releasing Hormone Reduces Circulating Markers of Immune Activation in Parallel with Effects on Hepatic Immune Pathways in Individuals with HIV-Infection and Nonalcoholic Fatty Liver Disease

BACKGROUND

The growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis modulates critical metabolic pathways; however, little is known regarding effects of augmenting pulsatile GH secretion on immune function in humans. This study used proteomics and gene set enrichment analysis to assess effects of a GH releasing hormone (GHRH) analog, tesamorelin, on circulating immune markers and liver tissue in people with HIV (PWH) and NAFLD.

METHODS

92 biomarkers associated with immunity, chemotaxis, and metabolism were measured in plasma samples from 61 PWH with NAFLD who participated in a double-blind, randomized trial of tesamorelin versus placebo for 12 months. Gene set enrichment analysis was performed on serial liver biopsies targeted to immune pathways.

RESULTS

Tesamorelin, compared to placebo, decreased interconnected proteins related to cytotoxic T-cell and monocyte activation. Circulating concentrations of 13 proteins were significantly decreased, and no proteins increased, by tesamorelin. These included four chemokines (CCL3, CCL4, CCL13 [MCP4], IL8 [CXCL8]), two cytokines (IL-10 and CSF-1), and four T-cell associated molecules (CD8A, CRTAM, GZMA, ADGRG1), as well as ARG1, Gal-9, and HGF. Network analysis indicated close interaction among the gene pathways responsible for these proteins, with imputational analyses suggesting down regulation of a closely related cluster of immune pathways. Targeted transcriptomics using liver tissue confirmed a significant end-organ signal of down-regulated immune activation pathways.

CONCLUSIONS

Long-term treatment with a GHRH analog reduced markers of T-cell and monocyte/macrophage activity, suggesting that augmentation of the GH axis may ameliorate immune activation in an HIV population with metabolic dysregulation, systemic and end organ inflammation.

Imaging Assessment of Thoracic Outlet Syndrome

Imaging studies play a significant role in assessment of thoracic outlet syndrome. In this article, we discuss the etiology and definition of thoracic outlet syndrome and review the spectrum of imaging findings seen in patients with thoracic outlet syndrome. We then discuss an optimized technique for computed tomography and MRI of patients with thoracic outlet syndrome, based on the experience at our institution and present some representative examples. Based on our experience, a combination of computed tomography angiography and MRI (with postural maneuvers) effectively demonstrate thoracic outlet syndrome abnormalities.

Effect of recombinant human growth hormone on liver fat content in young adults with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent in young adults with obesity. Obesity is associated with relative growth hormone (GH) deficiency, and data from animal studies and from humans with pituitary GH deficiency suggest a role for GH deficiency in the pathogenesis of NAFLD. The effects of GH on NAFLD in those with obesity are unknown, however, prompting this pilot study to assess effects of GH administration on measures of NAFLD in young adults.

METHODS

Twenty-four men and women aged 18-29 years with BMI ≥ 30 kg/m² , hepatic fat fraction (HFF) ≥ 5% on proton magnetic resonance spectroscopy (¹ H-MRS) and insulin-like growth factor 1 (IGF-1) z-score ≤ 0 were randomized to treatment with recombinant human GH (rhGH) versus no treatment for 24 weeks. The primary endpoint was change in HFF.

RESULTS

Compared to no treatment, the effect size of rhGH on absolute HFF over 24 weeks was -3.3% (95% confidence interval: -7.8%, 1.2%; p = .14). At 24 weeks, HFF < 5% was achieved in 5 of 9 individuals receiving rhGH versus 1 of 9 individuals receiving no treatment (p = .04). rhGH did not significantly reduce ALT, AST or GGT. Serum IGF-1 increased as expected with rhGH treatment, and there were no changes in fasting lipids, C-reactive protein, fasting glucose or 2-h glucose following an oral glucose tolerance test.

CONCLUSION

Data from this pilot study suggest that rhGH treatment in young adults with obesity and NAFLD may have benefits to reduce liver fat content, although larger studies are needed to confirm this effect.

Relationship of IGF-1 and IGF-Binding Proteins to Disease Severity and Glycemia in Nonalcoholic Fatty Liver Disease

CONTEXT

Growth hormone (GH) and IGF-1 help regulate hepatic glucose and lipid metabolism, and reductions in these hormones may contribute to development of nonalcoholic fatty liver disease (NAFLD).

OBJECTIVE

To assess relationships between hepatic expression of IGF1 and IGF-binding proteins (IGFBPs) and measures of glycemia and liver disease in adults with NAFLD. Secondarily to assess effects of GH-releasing hormone (GHRH) on circulating IGFBPs.

DESIGN

Analysis of data from a randomized clinical trial of GHRH.

SETTING

Two US academic medical centers.

PARTICIPANTS

Participants were 61 men and women 18 to 70 years of age with HIV-infection, ≥5% hepatic fat fraction, including 39 with RNA-Seq data from liver biopsy.

MAIN OUTCOME MEASURES

Hepatic steatosis, inflammation, and fibrosis by histopathology and measures of glucose homeostasis.

RESULTS

Hepatic IGF1 mRNA was significantly lower in individuals with higher steatosis and NAFLD Activity Score (NAS) and was inversely related to glucose parameters, independent of circulating IGF-1. Among the IGFBPs, IGFBP2 and IGFBP4 were lower and IGFBP6 and IGFBP7 (also known as IGFBP-related protein 1) were higher with increasing steatosis. Hepatic IGFBP6 and IGFBP7 mRNA levels were positively associated with NAS. IGFBP7 mRNA increased with increasing fibrosis. Hepatic IGFBP1 mRNA was inversely associated with glycemia and insulin resistance, with opposite relationships present for IGFBP3 and IGFBP7. GHRH increased circulating IGFBP-1 and IGFBP-3, but decreased IGFBP-2 and IGFBP-6.

CONCLUSIONS

These data demonstrate novel relationships of IGF-1 and IGFBPs with NAFLD severity and glucose control, with divergent roles seen for different IGFBPs. Moreover, the data provide new information on the complex effects of GHRH on IGFBPs.

Kinematic MRI of ischiofemoral impingement

OBJECTIVE

To examine the effect of external hip rotation on ischiofemoral (IF) and quadratus femoris (QF) spaces using real-time kinematic MRI, with the hypothesis that hips with IF and QF space narrowing have distinct motion patterns compared with control hips.

MATERIALS AND METHODS

This prospective study was IRB-approved and complied with HIPAA guidelines. We recruited women (≥ 18 years) with and without ischiofemoral impingement to undergo kinematic MRI of the hips. A kinematic imaging protocol using T2-HASTE was performed beginning at maximal internal rotation followed by active external hip rotation. The duration of each acquisition was 30 s, providing 8 images/3 s. IF and QF spaces, and femoral metaphyseal and lesser trochanter centroid coordinates were measured on sequential images. Hips were classified as controls or narrowed based on IF and QF space thresholds and compared statistically throughout motion stages.

RESULTS

The cohort comprised 12 women (24 hips; 10 control and 14 narrowed hips) aged 58 ± 10 years. External rotation caused IF space reduction of 59% in narrowed hips versus 41% in control hips. QF space decreased 71% in narrowed hips versus 50% in control hips. IF and QF spaces differed significantly between groups only when external rotation exceeded the neutral position (P < 0.02 for both). The lesser trochanter terminated more posteriorly in narrowed hips compared with controls (P = 0.03).

CONCLUSIONS

Kinematic MRI during external hip rotation in women with narrowed and control hips reveals dynamic differences in IF and QF spaces and lesser trochanter terminal position.

Hip abductor tears in ischiofemoral impingement

PURPOSE

Ischiofemoral impingement (IFI) is associated with abnormalities of the quadratus femoris muscle and narrowing of the ischiofemoral (IF) and quadratus femoris (QF) spaces. The hip abductors play an important role in pelvic stability and abductor tears might play a role in the pathophysiology of IFI. The purpose of our study was to assess the association between hip abductor tears and IFI on MRI.

MATERIALS AND METHODS

The study was IRB approved and HIPAA compliant. Inclusion criteria were MRI findings of IFI (narrowing of the IF space ≤ 15 mm or QF space ≤ 10 mm with associated ipsilateral quadratus femoris edema or fatty infiltration/atrophy). Two MSK radiologists assessed hip/pelvic MRIs and integrity of the tensor fascia lata, gluteus medius, and minimus tendons. IFI and control groups were compared with a two-tailed Student t test or chi-squared test.

RESULTS

We identified 140 patients with MRI findings of IFI (mean age 56 ± 13 years, 130 f, 10 m) and 140 controls of similar age and sex. Patients with IFI had a higher prevalence of gluteus medius/minimus partial tears (37 vs 21, p = 0.02) and full-thickness tears (24 vs 21, p = 0.03). Patients with IFI had a higher prevalence and higher grade of gluteal muscle atrophy compared with controls (p < 0.03). There were no tears of the tensor fascia lata in either group.

CONCLUSION

Patients with IFI had a higher prevalence of abductor tears and abductor muscle atrophy compared with matched controls. This suggests that abductor tears might play a role in the pathophysiology of IFI.

Relationship of Telomere Length to Fat Redistribution in HIV

Persons with HIV demonstrate increased risk for aging-associated complications and have reduced telomere length (TL) compared with age-matched persons without HIV. Our data show that greater visceral fat is related to reduced TL in HIV, independent of age and smoking. Fat redistribution may be a relevant mediator of TL attrition in HIV.

Quantitative Imaging of Body Composition

Body composition refers to the amount and distribution of lean tissue, adipose tissue, and bone in the human body. Lean tissue primarily consists of skeletal muscle; adipose tissue comprises mostly abdominal visceral adipose tissue and abdominal and nonabdominal subcutaneous adipose tissue. Hepatocellular and myocellular lipids are also fat pools with important metabolic implications. Importantly, body composition reflects generalized processes such as increased adiposity in obesity and age-related loss of muscle mass known as sarcopenia.In recent years, body composition has been extensively studied quantitatively to predict overall health. Multiple imaging methods have allowed precise estimates of tissue types and provided insights showing the relationship of body composition to varied pathologic conditions. In this review article, we discuss different imaging methods used to quantify body composition and describe important anatomical locations where target tissues can be measured.

Effects of tesamorelin on hepatic transcriptomic signatures in HIV-associated NAFLD

Nonalcoholic fatty liver disease (NAFLD) is a common comorbidity among people living with HIV that has a more aggressive course than NAFLD among the general population. In a recent randomized placebo-controlled trial, we demonstrated that the growth hormone-releasing hormone analog tesamorelin reduced liver fat and prevented fibrosis progression in HIV-associated NAFLD over 1 year. As such, tesamorelin is the first strategy that has shown to be effective against NAFLD among the population with HIV. The current study leveraged paired liver biopsy specimens from this trial to identify hepatic gene pathways that are differentially modulated by tesamorelin versus placebo. Using gene set enrichment analysis, we found that tesamorelin increased hepatic expression of hallmark gene sets involved in oxidative phosphorylation and decreased hepatic expression of gene sets contributing to inflammation, tissue repair, and cell division. Tesamorelin also reciprocally up- and downregulated curated gene sets associated with favorable and poor hepatocellular carcinoma prognosis, respectively. Notably, among tesamorelin-treated participants, these changes in hepatic expression correlated with improved fibrosis-related gene score. Our findings inform our knowledge of the biology of pulsatile growth hormone action and provide a mechanistic basis for the observed clinical effects of tesamorelin on the liver.

Does MR arthrography cause intracranial gadolinium deposition?

PURPOSE

To determine (i) whether intra-articular gadolinium from MR arthrography (MRA) results in gadolinium deposition in the brain and (ii) whether there is a correlation between intra-articular gadolinium dose and intracranial gadolinium deposition.

MATERIALS AND METHODS

This retrospective study was institutional review board (IRB) approved and HIPAA compliant. The study group included consecutive adult patients who had undergone MRA of the hip or shoulder and subsequent MRI of the brain. None of the patients had a history of intravenous gadolinium exposure. A control group of patients of similar age and sex who were never exposed to gadolinium and had brain MRIs available was included. Signal intensities (SI) of four brain regions: pons, dentate nuclei (DN), globus pallidi (GP), and thalamus (Thal) normalized to cerebrospinal fluid (CSF) and expressed in SI ratios were measured on T1-weighted non-contrast MR images. Groups were compared using the student's t test. Linear correlation analysis of gadolinium dose and brain SI ratios was performed, and Pearson correlation coefficients (r) are reported.

RESULTS

We identified 109 patients (mean age 44 ± 14 years, 54% men) who had undergone MRA and 149 controls of similar age and sex distribution. There was no significant difference in mean SI ratios of the brain regions between patients and controls: pons/CSF (p = 0.7), DN/CSF (p = 0.4), GP/CSF (p > 0.99), Thal/CSF (p = 0.3). Within the MRA group, gadolinium dose was not associated with SI ratios (p > 0.2).

CONCLUSION

Our study found no MR evidence of intracranial gadolinium deposition following MRA. In addition, there was no association between intra-articular gadolinium dose and SI ratios in commonly affected regions of the brain.

MRI texture analysis in acromegaly and its role in predicting response to somatostatin receptor ligands

PURPOSE

Given the paucity of reliable predictors of tumor recurrence, progression, or response to somatostatin receptor ligand (SRL) therapy in acromegaly, we attempted to determine whether preoperative MR image texture was predictive of these clinical outcomes. We also determined whether image texture could differentiate somatotroph adenomas from non-functioning pituitary adenomas (NFPAs).

METHODS

We performed a retrospective study of patients with acromegaly due to a macroadenoma who underwent transsphenoidal surgery at our institution between 2007 and 2015. Clinical data were extracted from electronic medical records. MRI texture analysis was performed on preoperative non-enhanced T1-weighted images using ImageJ (NIH). Logistic and Cox models were used to determine if image texture parameters predicted outcomes.

RESULTS

Eighty-nine patients had texture parameters measured, which were compared to that of NFPAs, while 64 of these patients had follow-up and were included in the remainder of analyses. Minimum pixel intensity, skewness, and kurtosis were significantly different in somatotroph adenomas versus NFPAs (area under the receiver operating characteristic curve, 0.7771, for kurtosis). Furthermore, those with a maximum pixel intensity above the median had an increased odds of IGF-I normalization on SRL therapy (OR 5.96, 95% CI 1.33-26.66), which persisted after adjusting for several potential predictors of response. Image texture did not predict tumor recurrence or progression.

CONCLUSION

Our data suggest that MRI texture analysis can distinguish NFPAs from somatotroph macroadenomas with good diagnostic accuracy and can predict normalization of IGF-I with SRL therapy.

Effects of intra-articular corticosteroid injections on lumbar trabecular density

PURPOSE

To determine the effect of intra-articular corticosteroid injections on lumbar spine trabecular density.

MATERIALS AND METHODS

This retrospective study was IRB-approved and HIPAA-compliant. We identified 50 patients (26 F, 24 M, mean age 69 ± 14 years) who had undergone at least three medium or large joint corticosteroid injections using insoluble corticosteroids and a subsequent non-contrast abdominal CT within 5 years of the first injection. About 126 age- and sex-matched controls without history of prior corticosteroid use who had undergone non-contrast abdominal CT were identified. Cumulative corticosteroid dose was calculated. Density measurements (HU) of trabecular bone of L1 to L4 were performed, and measurements of L1 were compared to established normative data. Groups were compared using a two-sided paired t-test or a chi-squared test. Linear regression analysis between cumulative corticosteroid dose and trabecular density was performed.

RESULTS

Patients underwent a mean of 4 corticosteroid injections (range 3 to 11) with a mean cumulative corticosteroid dose of 232 ± 100 mg triamcinolone equivalent (range 120 mg to 480 mg). There was no significant difference in trabecular density of L1 to L4 between cases and controls, and there was no significant difference in trabecular density at L1 compared to normative data (p > 0.2). There was no association between cumulative intra-articular corticosteroid dose and mean lumbar trabecular density (p > 0.3).

CONCLUSION

Patients who underwent repetitive intra-articular insoluble corticosteroid injections showed no increased risk of bone loss compared to controls. Cumulative intra-articular corticosteroid dose was not associated with lumbar trabecular density.

Measures of Adipose Tissue Redistribution and Atherosclerotic Coronary Plaque in HIV

OBJECTIVE

People with HIV (PWH) who are well treated on antiretroviral therapy remain at increased risk for body composition changes, including increased visceral adipose tissue (VAT) and reduced subcutaneous adipose tissue (SAT), as well as increased cardiovascular disease (CVD). The relationship between adipose compartments and coronary disease is not well understood among PWH.

METHODS

A total of 148 PWH and 68 uninfected individuals without CVD were well phenotyped for VAT and SAT via single-section abdominal computed tomography (CT) at L4. Coronary artery calcium (CAC) score was assessed by noncontrast cardiac CT and coronary plaque composition by coronary CT angiography.

RESULTS

Increased VAT was significantly related to increased presence of plaque (OR, 1.55 per 100 cm2 ; P = 0.008) and CAC > 0 (OR, 1.56 per 100 cm2 ; P = 0.006) in the HIV group. In contrast, increased SAT was related to reduced presence of plaque (OR, 0.79 per 100 cm2 ; P = 0.057) and reduced CAC > 0 (OR, 0.69 per 100 cm2 , P = 0.007) among PWH. The VAT to SAT ratio showed a strong relationship to overall presence of calcified plaque (OR, 3.30; P = 0.03) and CAC > 0 (OR, 3.57; P < 0.001) in the HIV group. VAT and waist to hip ratio, but not SAT, were strong predictors of plaque in the uninfected group. BMI did not relate in either group.

CONCLUSIONS

Fat redistribution phenotyping by simultaneous quantification of VAT and SAT as independent measures could help identify those PWH at higher risk for CVD.

Deep learning for automated segmentation of pelvic muscles, fat, and bone from CT studies for body composition assessment

OBJECTIVE

To develop a deep convolutional neural network (CNN) to automatically segment an axial CT image of the pelvis for body composition measures. We hypothesized that a deep CNN approach would achieve high accuracy when compared to manual segmentations as the reference standard.

MATERIALS AND METHODS

We manually segmented 200 axial CT images at the supra-acetabular level in 200 subjects, labeling background, subcutaneous adipose tissue (SAT), muscle, inter-muscular adipose tissue (IMAT), bone, and miscellaneous intra-pelvic content. The dataset was randomly divided into training (180/200) and test (20/200) datasets. Data augmentation was utilized to enlarge the training dataset and all images underwent preprocessing with histogram equalization. Our model was trained for 50 epochs using the U-Net architecture with batch size of 8, learning rate of 0.0001, Adadelta optimizer and a dropout of 0.20. The Dice (F1) score was used to assess similarity between the manual segmentations and the CNN predicted segmentations.

RESULTS

The CNN model with data augmentation of N = 3000 achieved accurate segmentation of body composition for all classes. The Dice scores were as follows: background (1.00), miscellaneous intra-pelvic content (0.98), SAT (0.97), muscle (0.95), IMAT (0.91), and bone (0.92). Mean time to automatically segment one CT image was 0.07 s (GPU) and 2.51 s (CPU).

CONCLUSIONS

Our CNN-based model enables accurate automated segmentation of multiple tissues on pelvic CT images, with promising implications for body composition studies.

The effect of music on pain and subjective experience in image-guided musculoskeletal corticosteroid injections: a randomized controlled trial

PURPOSE

To investigate the role of music on subjects undergoing routine image-guided musculoskeletal corticosteroid injections and its effect on post-procedure pain and subjective overall experience.

MATERIALS AND METHODS

This prospective study was IRB-approved and HIPAA-compliant. A total of 126 subjects referred for outpatient image-guided musculoskeletal corticosteroid injections were enrolled in the study and randomized into a music offered group ((+)MO) and a no music offered group ((-)MO). (+)MO subjects were given the opportunity to listen to music during their corticosteroid injection. All subjects were then given an anonymous survey on which they recorded their pre-procedural and post-procedural pain on a scale from 0 to 9 and rated their overall experience and how likely they were to recommend our department for musculoskeletal procedures on scales from 1 to 5.

RESULTS

(+)MO subjects had significantly lower post-procedural pain (p = 0.013) and significantly greater decrease in pain (p = 0.031) compared to (-)MO subjects. Among the (+)MO subjects, there was no statistically significant difference in post-procedure pain (p = 0.34) or change in pain (p = 0.62) if music was accepted or declined. However, subjects who listened to music did have lower post-procedural pain compared to those who did not listen to music (p = 0.012), although the differences in the decrease of pain between the two groups did not quite reach statistical significance (p = 0.062).

CONCLUSIONS

Playing music during image-guided musculoskeletal corticosteroid injections may reduce patients' post-procedure pain. Offering patients some measure of control over their procedure may be a factor that contributes to decreased post-procedure pain as well.

Artificial Intelligence in the Evaluation of Body Composition

Body composition entails the measurement of muscle and fat mass in the body and has been shown to impact clinical outcomes in various aspects of human health. As a result, the need is growing for reliable and efficient noninvasive tools to measure body composition. Traditional methods of estimating body composition, anthropomorphic measurements, dual-energy X-ray absorptiometry, and bioelectrical impedance, are limited in their application. Cross-sectional imaging remains the reference standard for body composition analysis and is accomplished through segmentation of computed tomography and magnetic resonance imaging studies. However, manual segmentation of images by an expert reader is labor intensive and time consuming, limiting its implementation in large-scale studies and in routine clinical practice. In this review, novel methods to automate the process of body composition measurement are discussed including the application of artificial intelligence and deep learning to tissue segmentation.

Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a substantial cause of comorbidity in people with HIV and there are no proven pharmacological treatments for the disease in this population. We assessed the effects of tesamorelin on liver fat and histology in people with HIV and NAFLD.

METHODS

This randomised, double-blind, multicentre study with identical placebo as a comparator was done in a hospital and a medical research centre in the USA. People with HIV infection and a hepatic fat fraction (HFF) of 5% or more by proton magnetic resonance spectroscopy were eligible. Participants were randomly assigned (1:1) to receive either tesamorelin 2 mg once daily or placebo once daily for 12 months, followed by a 6-month open-label phase during which all participants received tesamorelin 2 mg daily. The randomisation list was prepared by the study statistician using a permuted block algorithm within each stratum with randomly varying block sizes. The primary endpoint was change in HFF between baseline and 12 months. The primary safety endpoint was glucose. Analysis was by intention to treat using all available data. This trial is registered with ClinicalTrials.gov, number NCT02196831.

FINDINGS

61 patients were enrolled between Aug 20, 2015, and Jan 16, 2019, of whom 30 received tesamorelin and 30 received placebo. Patients receiving tesamorelin had a greater reduction of HFF than did patients receiving placebo, with an absolute effect size of -4·1% (95% CI -7·6 to -0·7, p=0·018), corresponding to a -37% (95% CI -67 to -7, p=0·016) relative reduction from baseline. After 12 months, 35% of individuals receiving tesamorelin and 4% receiving placebo had a HFF of less than 5% (p=0·0069). Changes in fasting glucose and glycated haemoglobin were not different between groups at 12 months. Individuals in the tesamorelin group experienced more localised injection site complaints than those in the placebo group, though none were judged to be serious.

INTERPRETATION

Tesamorelin might be beneficial in people with HIV and NAFLD. Further studies are needed to determine the long-term effects of tesamorelin on liver histology.

FUNDING

National Institutes of Health and National Institute of Allergy and Infectious Diseases.

Value of low-dose whole-body CT in the management of patients with multiple myeloma and precursor states

OBJECTIVE

To determine the value of low-dose whole-body CT (WBCT) in the management of patients with multiple myeloma (MM) and precursor states.

MATERIALS AND METHODS

The study group comprised 116 patients (mean age: 68 ± 11 years, 48% women) who underwent WBCT for the work-up or surveillance of MM or MM precursor disease. WBCTs were reviewed for the presence of MM-related bone disease and incidental findings requiring therapy. The medical records, results from bone marrow aspirations and biopsies and follow-up imaging studies were reviewed to assess the influence of WBCT on patient management.

RESULTS

Whole-body CT led to a change in management in 32 patients (28%). Of those, 17 patients with MM precursor disease were found to have MM-related bone disease, 13 patients had progression of MM, requiring a change in treatment, in one patient hepatocellular carcinoma was diagnosed, requiring a change in therapy, and one patient had a rib lesion requiring intervention. In 65 patients (56%), WBCT was performed for surveillance of MM precursor disease or stable treated MM, and did not detect new lesions, thereby providing reassurance to the hematologist on disease status and management. In 15 patients (13%) WBCT was performed as a new baseline before a change or new therapy. In 4 patients (3%), WBCT was performed for a change in symptoms, but did not detect lesions that would lead to a change in management.

CONCLUSION

Whole-body CT provides important information for disease monitoring and detection of incidental findings, thereby improving the management of patients with MM.

MON-100 Unique miRNA Signature in HIV Lipodystrophy with Reduced Adipose Dicer Expression

Suppression of Dicer, an endoribonuclease that regulates microRNAs(miRNA), has evolved as a viral mechanism to enhance host HIV infectivity and may have unintended metabolic consequences. Animal knockout models of adipose-specific dicer(ADicer) acquire lipodystrophy accompanied by severe metabolic abnormalities. Data show adipose is a source of exosomal miRNAs, functioning as adipokines influencing metabolic homeostasis. We hypothesized a unique miRNA profile among individuals well-phenotyped for HIV lipodystrophy and reduced ADicer expression. We evaluated >1000 miRNAs from exosomes derived from sera among the 27 male individuals [9 HIV lipodystrophy(HIV/lipo), 9 HIV without lipodystrophy(HIV/non-lipo), 9 non-HIV] whom we previously showed variations in ADicer: most suppressed among HIV lipo, followed by HIV non-lipo and non-HIV (2.49[0.02,4.88] vs. 11.20[4.83,21.45] vs. 17.69[10.72,47.91],P=.002). To estimate miRNA abundance, data was normalized using the geomean of expressed Ct values. A false discovery rate analysis(FDR) was applied. We investigated whether significant exosomal miRNAs demonstrated a similar pattern in corresponding subcutaneous adipose tissue(SAT) samples. Using target prediction databases (TargetScan, miRDB, Diana), we identified genes related to fat biology (target score ≥85%) with clinical relevance to lipodystrophic phenotypes and further evaluated these in the adipose depot. HIV/lipo individuals(age 56±3years, BMI 30±1kg/m², duration HIV 24±2years, duration ART 20±2years, CD4+ count 482±90cells/μl, undetectable VL 67%) were similar to HIV/non-lipo(age 52±3 years, BMI 30±1 kg/m²) and non-HIV(age 55±3years, BMI 30±1kg/m²) individuals. Reduced ADicer expression was significantly related to reduced CD4⁺ count(r=0.55,P=.02), duration ART use(r=-0.70,P=.001) and tended to be related to duration HIV(r=-0.44,P=.07) and reduced CD8⁺ count(r=0.42,P=.08). Applying FDR, we detected exosomal miRNA-20a-3p(P=.0026), 324-5p(P=.0059), and 186-5p(P=.0977) were expressed differentially in HIV/lipo vs. non-HIV and 324-5p(P=.0348) in HIV/lipo vs. HIV/non-lipo. We further confirmed that miRNA-20a-3p was significantly and differentially expressed in the SAT, expressed highest in HIV lipo followed by HIV non-lipo and non-HIV [9.73±12.38 vs. 2.24±1.84 vs. 1.02±0.19, P<0.05] in a pattern similar to the exosomal profiles. Relevant miRNA and their target genes which tended to be differentially expressed in the SAT of HIV lipo vs. HIV non-lipo include: 20a-3p (TDG, P=0.07) and 186-5p (PDE10A, PID1; P<0.05). Altered ADicer expression and specific exosomal miRNAs may affect gene expression of regulators important to fat biology and metabolic homeostasis in HIV. In particular, miRNA-20a-3p may function as an adipokine demonstrating similar expression profiles in exosomes and adipose tissue of individuals with HIV lipodystrophy.

Measurement of Glenoid Bone Loss With 3-Dimensional Magnetic Resonance Imaging: A Matched Computed Tomography Analysis

PURPOSE

To compare the measurement of glenoid bone surface area (GBSA) and glenoid bone loss (GBL) between 3-dimensional computed tomography (3D CT) and an autosegmentation approach for 3D magnetic resonance imaging (MRI) of patients with recurrent shoulder instability.

METHODS

Eight subjects (2 women and 6 men; age range, 15-72 years [mean, 44 ± 19 years]) were consecutively enrolled who had both CT and MRI of the shoulder for clinical shoulder instability. Inclusion criteria were patients with shoulder instability or other shoulder injury who had both a CT scan and MRI performed of the same shoulder. All patients underwent a 3D CT scan and a 3-Tesla 3D MRI with additional volumetric and autosegmented sequences. En face views of the glenoid for both CT and MRI were auto- and manually measured for overall GBSA and GBL using best-fit circle technique; the amount of GBL was compared with loss of GBSA and was expressed as a percentage of bone loss.

RESULTS

There were no differences in GBL measured by 3D CT (41 mm², 6.6%) vs 3D MRI (40 mm², 6.5%, P = .852). The mean GBSA was not different among the manual- and autocalculated 3D CT (644 mm² vs 640 mm², P = .482). In addition, the manual MRI scan glenoid area was similar to the autocalculated 3D MRI (622 mm² vs 618 mm², respectively; P = .482). Overall regression analysis demonstrated excellent correlation between CT and MRI for both GBSA and GBL calculations (R² = 0.84-0.90).

CONCLUSIONS

3D MRI of the glenoid is nearly identical to 3D CT scans for measurement of GBSA and GBL, making 3D MRI a reliable alternative to a CT scan for a preoperative shoulder evaluation of the glenoid pathology. This study shows that a 3D MRI could be a radiation-free and reliable alternative to a preoperative CT shoulder scan.

LEVEL OF EVIDENCE

Level III, case-control study.

I-FABP Is Higher in People With Chronic HIV Than Elite Controllers, Related to Sugar and Fatty Acid Intake and Inversely Related to Body Fat in People With HIV

Background

Intestinal fatty acid binding protein (I-FABP) has been shown to be a marker of intestinal damage among people living with HIV. We hypothesized that I-FABP would be increased in chronically HIV-infected patents more than elite controllers and would relate to specific nutrient intake and body composition.

Methods

In an observational study, serum I-FABP was measured by enzyme-linked immunosorbent assay. Anthropometric measurements, dual-energy x-ray absorptiometry, and single-slice abdominal computed tomography were obtained to assess body composition, as well as visceral and subcutaneous adipose tissue areas (VAT and SAT). Dietary intake was assessed using 4-day food records.

Results

One hundred forty-nine people with chronic HIV (65% male, 47 ± 7 years of age, 54.7% white, and 14 ± 6 years of known HIV), 10 elite controllers (60% male, 53 ± 8 years, 60% white, and 20 ± 7 years of known HIV), and 69 HIV-negative controls (59.4% male, 46 ± 7 years, and 52.2% white) were included in the analysis. I-FABP was significantly higher in HIV progressors relative to HIV-negative controls and elite controllers. In the chronic HIV group, I-FABP was positively associated with dietary intake of added sugar and with saturated fatty acids. I-FABP was inversely associated with body mass index, VAT, and SAT. I-FABP also correlated with MCP-1, CXCL10, sCD163, and lipopolysaccharide (LPS) among all participants.

Conclusions

I-FABP was increased among chronically HIV-infected patients to a greater degree than in elite controllers and was related to nutrient intake and body composition in HIV progressors. Future studies to investigate the role of intestinal damage on nutrient absorption are needed to elucidate the mechanisms of these relationships.

Trial Registration Identifier

NCT00455793.

Effects of Pitavastatin on Insulin Sensitivity and Liver Fat: A Randomized Clinical Trial

Context

3-Hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors (statins) are widely prescribed. Statins may have important metabolic effects on insulin sensitivity and liver fat, but limited studies have assessed these effects by using euglycemic hyperinsulinemic clamp, stable isotopes, and 1H magnetic resonance spectroscopy (MRS) for liver fat quantification.

Objective

To study the effects of pitavastatin on hepatic fat and insulin sensitivity.

Design

Six-month, double-blind, randomized, placebo-controlled trial.

Setting

Academic clinical research center in Boston, Massachusetts.

Participants

Overweight, insulin-resistant men aged 40 to 65 years who had not received statin therapy for ≥1 year.

Interventions

Pitavastatin 4 mg or placebo daily.

Outcome

The primary endpoints were changes in insulin sensitivity measured by euglycemic hyperinsulinemic clamp and liver fat measured by 1H MRS.

Results

Pitavastatin showed no effect on endogenous glucose production (ΔRa glucose 0.07 ± 0.07 vs 0.04 ± 0.07 mg/kg/min, pitavastatin vs placebo, P = 0.76) or insulin-stimulated glucose uptake during "low dose" (ΔM 0.1 ± 0.1 vs -0.3 ± 0.2 mg/kg/min, P = 0.11) and "high dose" (ΔM -0.5 ± 0.3 vs -0.7 ± 0.4 mg/kg/min, P = 0.70) euglycemic hyperinsulinemic clamps. There was also no effect of pitavastatin on fasting glucose, HbA1c, and 2-hour glucose after 75-g glucose challenge. There was also no change in liver fat fraction (-1 ± 1 vs -0 ± 1%, P = 0.56).

Conclusion

Compared with placebo, pitavastatin did not affect hepatic or whole-body insulin sensitivity, and it did not reduce liver fat.

Sex differences in pericardial adipose tissue assessed by PET/CT and association with cardiometabolic risk

Background Recent studies suggest that pericardial adipose tissue (PAT) is associated with whole body adiposity and insulin resistance. Moreover, the incidence of cardiovascular disease (CVD) differs between men and women. Although CVD is more prevalent in men, women suffering from CVD have a higher mortality compared to men. Differences in PAT may account for some of the observed sex differences in manifestations of CVD. Purpose To assess pericardial adipose tissue (PAT) as a biomarker for cardiometabolic risk and to assess potential sex differences. Material and Methods We studied 303 individuals (151 women, 152 men; mean age = 57 ± 17 years) across the weight spectrum. PAT and abdominal adipose tissue were quantified using clinical computed tomography (CT) scans obtained as part of a positron emission tomography (PET)/CT. Cardiometabolic risk factors were assessed from medical records. Linear regression and receiver operating characteristic (ROC) curve analyses were performed to evaluate associations between PAT and cardiometabolic risk. Results PAT was higher in overweight and obese individuals compared to lean individuals and higher in men compared to women. PAT was positively associated with body mass index, abdominal fat ( P < 0.0001), fasting glucose, and serum lipids ( P < 0.05) with stronger associations in women than in men. PAT was accurate in detecting the prevalence of the metabolic syndrome with 74% sensitivity and 76% specificity (AUC = 0.80). Conclusion PAT is associated with measures of cardiometabolic risk and these associations are stronger in women compared to men. PAT could serve as a biomarker for opportunistic screening for cardiometabolic risk in patients undergoing chest CT.

Significant Association of Aldosterone and Liver Fat Among HIV-Infected Individuals With Metabolic Dysregulation

Objective

Fatty liver disease is increased among individuals with HIV. We sought to explore how aldosterone, a key hormone linked to insulin resistance and inflammation, relates to liver fat in the large population of individuals with HIV and metabolic abnormalities.

Methods

Forty-six individuals with HIV and increased waist circumference and dysglycemia were assessed for liver fat using proton magnetic resonance spectroscopy. Serum aldosterone level was obtained following strictly controlled posture conditions and a standardized sodium diet and was related to liver fat.

Results

Among the entire group [median (interquartile range) liver fat: 5% (3%, 12%) and homeostatic model assessment of insulin resistance: 1.74 (1.21, 2.83)], serum aldosterone significantly correlated with liver fat (r = 0.31; P = 0.049). Liver fat level was significantly higher in those with aldosterone above vs below the median [8% (3%, 20%) vs 4% (2%, 10%); P = 0.02]. In the presence of metabolic syndrome, individuals with aldosterone levels above vs below the median had markedly elevated liver fat values [14% (9%, 23%) vs 5% (3%, 12%); P = 0.005] and increased presence of fatty liver disease (FLD; 92% vs 50%; P = 0.02). Controlling for metabolic syndrome, hepatitis C virus, and alcohol use, aldosterone was a significant and independent predictor of liver fat (β estimate: 0.6038, P = 0.01; overall model r² = 0.41, P = 0.0005) and FLD (OR: 1.38, P = 0.02; overall model r² = 0.28, P = 0.002).

Conclusion

These data highlight a robust association between aldosterone and liver fat among individuals with HIV and metabolic dysregulation. Increased aldosterone may be a risk factor for liver fat accumulation among the population with HIV.

MRI texture analysis as a predictor of tumor recurrence or progression in patients with clinically non-functioning pituitary adenomas

BACKGROUND

There are limited predictors of prognosis in patients with clinically non-functioning pituitary adenomas (NFPAs). We hypothesized that MRI texture analysis may predict tumor recurrence or progression in patients with NFPAs undergoing transsphenoidal pituitary surgery (TSS).

OBJECTIVE

To characterize texture parameters on preoperative MRI examinations in patients with NFPAs in relation to prognosis.

METHODS

Retrospective study of patients with NFPAs who underwent TSS at our institution between 2009 and 2010. Clinical, radiological and histopathological data were extracted from electronic medical records. MRI texture analysis was performed on coronal T1-weighted non-enhanced MR images using ImageJ (NIH). MRI texture parameters were used to predict tumor recurrence or progression. Both logistic regression and Cox proportional hazard analyses were conducted to adjust for potential confounders.

RESULTS

Data on 78 patients were analyzed. On both crude and multivariable-adjusted analyses, mean, median, mode, minimum and maximum pixel intensity were associated with the risk of pituitary tumor recurrence or progression after TSS. Patients whose tumor mean pixel intensity was above the median for the population had a hazard ratio of 0.44 (95% CI: 0.21-0.94, P = 0.034) for recurrence or progression in comparison with tumors below the median.

CONCLUSIONS

Our data suggest that MRI texture analysis can predict the risk of tumor recurrence or progression in patients with NFPAs.