Distal Triceps Tendon Tears: Magnetic Resonance Imaging Patterns Using a Systematic Classification.

OBJECTIVE: This study aimed to evaluate distal triceps tendon tear patterns using a systematic classification based on the tendon's layered structure. METHODS: We retrospectively identified Magnetic resonance imaging (MRI) examinations with triceps tendon tears that underwent reconstructive surgery. Magnetic resonance images were reviewed independently by 2 musculoskeletal radiologists to determine tendon layer involvement and ancillary findings, including tear size, involvement of triceps lateral expansion, and presence of olecranon bursal fluid. Surgical reports were scrutinized for level of anatomic detail and correlation with imaging findings. RESULTS: We identified 69 triceps tendon tears in 68 subjects (61 men, 7 women; mean age, 45 ± 12 years) who underwent surgical reconstruction. On MRI, the superficial layer was always involved with either a partial or full-thickness tear. The most common tear pattern was a combination of superficial layer full-thickness tear with deep layer partial tear (25 of 69 [36%]). Mean tear length was 24 ± 12 mm. We found no cases of isolated deep layer tears. Involvement of triceps lateral expansion and presence of bursal fluid correlated positively with tear severity of superficial and deep layers (P < 0.001). Detailed surgical correlation was limited, with only 9 of 69 (13%) of surgical reports containing information specifically addressing individual tendon layers. CONCLUSIONS: Triceps tendon tears show tear patterns following its layered structure and can be assessed by MRI. Radiologists and surgeons are encouraged to describe tear patterns considering both superficial and deep tendon layers.

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.

Preliminary investigation of brown adipose tissue assessed by PET/CT and cancer activity.

OBJECTIVE: To determine the role of brown adipose tissue (BAT) in cancer activity. MATERIALS AND METHODS: The study group comprised 142 patients (121 female, 21 male; mean age, 49 ± 16 years) who underwent F18-FDG PET/CT (PET/CT) for staging or surveillance of cancer and who were BAT-positive on PET/CT. BAT volume by PET/CT, abdominal (visceral and subcutaneous) fat and paraspinous muscle cross-sectional areas (CSA) were assessed. Groups with and without active cancer on PET/CT were compared using a two-sided paired t test. Linear regression analyses between BAT and body composition parameters were performed. RESULTS: There were 62 patients (54 female, eight male) who had active cancer on PET/CT and 80 patients (67 female, 13 male) without active cancer. Groups were similar in age and BMI (p ≥ 0.4), abdominal fat and muscle CSA, fasting glucose, and outside temperature at time of scan (p ≥ 0.2). Patients who had active cancer on PET/CT had higher BAT volume compared to patients without active cancer (p = 0.009). In patients without active cancer, BAT was positively associated with BMI and abdominal fat depots (r = 0.46 to r = 0.59, p < 0.0001) while there were no such associations in patients with active cancer (p ≥ 0.1). No associations between BAT and age or muscle CSA were found (p ≥ 0.1). CONCLUSIONS: BAT activity is greater in patients with active cancer compared to age-, sex-, and BMI-matched BAT-positive patients without active cancer, suggesting a possible role of BAT in cancer activity.

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 (ß estimate: 0.6038, P = 0.01; overall model r 2 = 0.41, P = 0.0005) and FLD (OR: 1.38, P = 0.02; overall model r 2 = 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.

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.

Randomized, Placebo-Controlled Trial to Evaluate Effects of Eplerenone on Metabolic and Inflammatory Indices in HIV.

Context: HIV-infected individuals demonstrate increased renin-angiotensin-aldosterone system activation in association with visceral adiposity, insulin resistance, and inflammation. A physiologically based treatment approach targeting mineralocorticoid receptor (MR) blockade may improve metabolic and inflammatory indices in HIV. Objective: To investigate effects of eplerenone on insulin sensitivity, inflammatory indices, and other metabolic parameters in HIV. Design: Six-month, double-blind, randomized, placebo-controlled trial. Setting: Academic clinical research center. Participants: HIV-infected individuals with increased waist circumference and abnormal glucose homeostasis. Intervention: Eplerenone 50 mg or placebo daily. Outcome: The primary end point was change in insulin sensitivity measured by the euglycemic-hyperinsulinemic clamp technique. Secondary end points included change in body composition and inflammatory markers. Results: Forty-six individuals were randomized to eplerenone (n = 25) vs placebo (n = 21). Eplerenone did not improve insulin sensitivity [0.48 (-1.28 to 1.48) vs 0.43 (-1.95 to 2.55) mg/min/µIU/mL insulin; P = 0.71, eplerenone vs placebo] when measured by the gold standard euglycemic-hyperinsulinemic clamp technique. Intramyocellular lipids (P = 0.04), monocyte chemoattractant protein-1 (P = 0.04), and high-density lipoprotein (P = 0.04) improved among those randomized to eplerenone vs placebo. Trends toward decreases in interleukin-6 (P = 0.10) and high-sensitivity C-reactive protein (P = 0.10) were also seen with eplerenone vs placebo. Plasma renin activity and aldosterone levels increased in the eplerenone vs placebo-treated group, demonstrating expected physiology. MR antagonism with eplerenone was well tolerated among the HIV population, with no considerable changes in blood pressure or potassium. Conclusion: MR blockade may improve selected metabolic and inflammatory indices in HIV-infected individuals. Further studies are necessary to understand the clinical potential of MR antagonism in HIV.

MRI of pectoralis major tears: association between ancillary findings and tear severity.

OBJECTIVE: To evaluate the significance of biceps tendon (BT) displacement and peri-bicipital hematoma on MRI in subjects with pectoralis major (PM) tears. We hypothesized that these features might be associated with tear severity at surgery. MATERIALS AND METHODS: We retrospectively identified MRI cases with PM injury and reviewed clinical, imaging, and surgical records. MR images were reviewed independently by two musculoskeletal radiologists to determine anterior displacement of BT (BT-disp, in mm) and the presence of triangular-shaped peri-bicipital hematoma. Data were compared with an age- and sex-matched control group and correlated with surgical reports grouped by tear severity. RESULTS: We identified 46 subjects with PM injury (43 men, 3 women; mean age 34 ± 9 years), 26 of whom underwent surgical reconstruction, and 20 matched controls (P > 0.2). BT-disp was significantly higher in PM injury vs controls (P = 0.003), and in tendon vs myotendinous (MT) junction PM tears (P < 0.0001); however, MT junction tears vs controls were similar (P = 0.98). Higher BT-disp and presence of peri-bicipital hematoma correlated significantly with surgical reports describing full-thickness complete tears. BT-disp > 4.5 mm had 86% sensitivity and 75% specificity to detect the most severe tears on surgical reports, whereas the presence of peri-bicipital hematoma was the strongest predictor among both parameters. CONCLUSION: Anterior BT displacement and peri-bicipital hematoma are helpful indicators of full-thickness complete tears at the humeral insertion.

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.

MR imaging features of hemispherical spondylosclerosis.

OBJECTIVE: Hemispherical spondylosclerosis (HS) is a rare degenerative entity characterized by dome-shaped sclerosis of a single vertebral body that may pose a diagnostic dilemma. The goal of this study was to describe the MR imaging features of HS. MATERIALS AND METHODS: We identified spine radiographs and CT examinations of subjects with HS who also had MR imaging for correlation. Two musculoskeletal radiologists independently assessed sclerosis characteristics, presence of endplate erosions, marrow signal intensity, and disk degeneration (Pfirrmann scale). RESULTS: We identified 11 subjects (six males, five females, mean 48 ± 10 years) with radiographic/CT findings of HS. The most commonly affected vertebral body was L4 (6/11; 55%). On MR imaging, variable signal intensity was noted, being most commonly low on T1 (8/11, 73%) and high on fat-suppressed T2-weighted (8/11, 73%) images. In two subjects, diffuse post-contrast enhancement was seen in the lesion. Moderate disk degeneration and endplate bone erosions adjacent to sclerosis were present in all subjects. Erosions of the opposite endplate were present in two subjects (2/11, 18%). CT data from nine subjects showed the mean attenuation value of HS was 472 ± 96 HU. CONCLUSIONS: HS appearance on MR imaging is variable and may not correlate with the degree of sclerosis seen on radiographs or CT. Disk degenerative changes and asymmetric endplate erosions are consistent markers of HS.

El riñón en la malaria: de la patogénesis a las manifestaciones clínicas / The kidney in malaria: From pathogenesis to clinical symptoms

La malaria o paludismo, enfermedad causada por protozoos parásitos de género Plasmodium , se considera un gran problema de salud pública mundial por sus elevadas tasas de morbimortalidad. Las manifestaciones clínicas de esta infección van desde un síndrome febril agudo hasta un cuadro de malaria complicada que afecta órganos específicos, pudiendo progresar a una falla multisistémica que comprometa la vida del paciente. En la malaria, el riñón es un órgano susceptible de daño por mecanismos fisiopatológicos directos del plasmodio como el secuestro de glóbulos rojos parasitados, la obstrucción de la microcirculación y la activación del sistema inmune; además, por efectos indirectos hematológicos, hepáticos y metabólicos. La lesión renal en malaria se ha informado en Colombia hasta en el 31% de los pacientes con malaria grave; incluye la lesión renal aguda y el síndrome nefrótico, cada uno con manifestaciones clínicas, implicaciones terapéuticas y factores pronósticos propios. La lesión renal aguda es la condición más frecuente y puede llevar a una acidosis metabólica grave, daño renal crónico e incluso, cuando hace parte de una falla multiorgánica, asociarse con mortalidad que alcanza tasas de entre 40 y 50%. Un mejor entendimiento de la fisiopatología de la lesión renal en la malaria permitirá reconocer las manifestaciones clínicas para hacer un diagnóstico temprano e iniciar un tratamiento oportuno, con los beneficios que esto conlleva para la evolución y pronóstico del paciente.