Estimation of the Impact of Abdominal Adipose Tissue (Subcutaneous and Visceral) on the Occurrence of Carbohydrate and Lipid Metabolism Disorders in Patients with Obesity-A Pilot Study.

Obesity represents a significant global public health concern. The excessive accumulation of abdominal adipose tissue is often implicated in the development of metabolic complications associated with obesity. Our study aimed to investigate the impact of particular deposits of abdominal adipose tissue on the occurrence of carbohydrate and lipid metabolism complications. We established cut-off points for visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and the VAT/SAT ratio at which selected metabolic complications of obesity-related diseases (disorders of carbohydrate and/or lipid metabolism) occur. We conducted an observational study involving 91 subjects with first- and second-degree obesity, accounting for gender differences. Anthropometric measurements were taken, body composition analysis (BIA) was conducted, and biochemical determinations were made. Our findings suggest that commonly used parameters for assessing early metabolic risk, such as BMI or waist circumference, may overlook the significant factor of body fat distribution, as well as gender differences. Both visceral and subcutaneous adipose tissue were found to be important in estimating metabolic risk. We identified the cut-off points in women in terms of their elevated fasting glucose levels and the presence of insulin resistance (HOMA-IR: homeostasis model assessment of insulin resistance) based on SAT, VAT, and the VAT/SAT ratio. In men, cut-off points were determined for the presence of insulin resistance (HOMA-IR) based on VAT and the VAT/SAT ratio. However, the results regarding lipid disorders were inconclusive, necessitating further investigation of a larger population.

Application of 18F-PSMA-1007 PET/MR Imaging in Early Biochemical Recurrence of Prostate Cancer: Results of a Prospective Study of 60 Patients with Very Low PSA Levels ≤ 0.5 ng/mL.

The use of 18F-PSMA-1007 and the role of PET/MR in the diagnosis of prostate cancer are not conclusively confirmed. There are reports indicating the potential pros and cons of using 18F-PSMA-1007 as well as the PET/MR technique in prostate cancer recurrence, but they are not yet included in the EAU guidelines. The aim of the study was to assess the effectiveness of 18F-PSMA-1007 PET/MR in detecting BCR lesions at very low PSA levels <0.5 ng/mL. METHODS: Sixty patients with BCR after radical prostatectomy (RP) with PSA ranged 0.1-0.5 ng/mL were enrolled in a prospective study. All patients underwent simultaneous whole-body and pelvic 18F-PSMA-1007 PET/MR. The obtained results were verified by 12-month follow-up. RESULTS: Fifty-three lesions were detected in 45 patients with 75% detection rate. The mean PSA value was 0.31 ng/mL. Of all PSMA-positive foci, 91% were localized in the pelvis, and only 9% of lesions were located in the extrapelvic region. Local recurrences were detected in 29%, PSMA-positive lymph nodes were detected in 64% of patients and bone metastases lesions were detected in 7% of patients. CONCLUSIONS: 18F-PSMA-1007 PET/MR seems to be an excellent diagnostic tool in patients with early BCR with very low PSA levels, especially with dt PSA < 6 months. The synergistic effect of combining 18F-PSMA-1007 and whole-body PET/MR with precise multiparametric assessment of pelvic lesions is of particular benefit in early BCR.

The impact of specific pulmonary arterial hypertension therapy on cardiac fluorodeoxyglucose distribution in PET/MRI hybrid imaging-follow-up study.

BACKGROUND: PET/MRI hybrid imaging in pulmonary arterial hypertension (PAH) provides important prognostic information identifying patients who might benefit from early therapy escalation, as right ventricle (RV) metabolic alterations are linked with hemodynamics and might precede clinical deterioration. Now, we hypothesize that adequate PAH therapy escalation may result in reversal of unfavourable increased glucose uptake of RV, which is associated with improved prognosis. METHODS: Out of twenty-six initially clinically stable PAH patients who had baseline PET/MRI scans, twenty (49.9 ± 14.9 years) had second PET/MRI after 24 months. SUVRV/SUVLV ratio was used to estimate and compare cardiac glucose uptake. Occurrences of clinical endpoints (CEP), defined as death or clinical deterioration, were assessed during 48-month follow-up from baseline. RESULTS: In first 24 months of observation, sixteen patients had CEP and needed PAH therapy escalation. At follow-up visits, we observed significant improvement of RV ejection fraction (45.1 ± 9.6% to 52.4 ± 12.9%, p = 0.01), mean pulmonary artery pressure (50.5 ± 18.3 to 42.8 ± 18.6 mmHg, p = 0.03), and SUVRV/SUVLV, which tended to decrease (mean change -0.20 ± 0.74). Patients with baseline SUVRV/SUVLV value higher than 0.54 had worse prognosis in 48 months observation (log-rank test, p = 0.0007); follow up SUVRV/SUVLV > 1 predicted CEP in the following 24 months, regardless of previously escalated treatment. CONCLUSIONS: PAH therapy escalation may influence RV glucose metabolism, what seems to be related with patients' prognosis. PET/MRI assessment may predict clinical deterioration regardless of previous clinical course, however its clinical significance in PAH requires further studies. Importantly, even mild alterations of RV glucose metabolism predict clinical deterioration in long follow-up. Clinical Trial Registration ClinicalTrials.gov, NCT03688698, 05/01/2016, https://clinicaltrials.gov/ct2/show/study/NCT03688698?term=NCT03688698&draw=2&rank=1.

Visualization of human optic nerve by diffusion tensor mapping and degree of neuropathy.

Diffusion-weighted magnetic resonance imaging of the human optic nerve and tract is technically difficult because of its small size, the inherent strong signal generated by the surrounding fat and the cerebrospinal fluid, and due to eddy current-induced distortions and subject movement artifacts. The effects of the bone canal through which the optic nerve passes, and the proximity of blood vessels, muscles and tendons are generally unknown. Also, the limited technical capabilities of the scanners and the minimization of acquisition times result in poor quality diffusion-weighted images. It is challenging for current tractography methods to accurately track optic pathway fibers that correspond to known anatomy. Despite these technical limitations and low image resolution, here we show how to visualize the optic nerve and tract and quantify nerve atrophy. Our visualization method based on the analysis of the diffusion tensor shows marked differences between a healthy male subject and a male subject with progressive optic nerve neuropathy. These differences coincide with diffusion scalar metrics and are not visible on standard morphological images. A quantification of the degree of optic nerve atrophy in a systematic way is provided and it is tested on 9 subjects from the Human Connectome Project.

Platelet sTWEAK and plasma IL-6 are associated with 18F-fluorodeoxyglucose uptake in right ventricles of patients with pulmonary arterial hypertension: A pilot study.

BACKGROUND: Cytokines soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) and interleukin 6 (IL-6) are involved in immune response, proliferation, apoptosis, and cardiovascular pathologies. We have previously confirmed that changes of their platelet or plasma contents are associated with pulmonary arterial hypertension (PAH). The positron emission tomography/magnetic resonance imaging (PET/MRI) hybrid imaging provides detailed insight into right ventricle (RV) hemodynamic and metabolic function. OBJECTIVES: To evaluate the relationship between RV parameters obtained using PET/MRI and concentrations of plasma and platelet sTWEAK and IL-6 in stable PAH patients. MATERIAL AND METHODS: Eighteen stable PAH patients (48.44 ±16.7 years) had simultaneous PET/MRI scans with 18F-fluorodeoxyglucose (18F-FDG) performed. Its uptake was presented as a standardized uptake value (SUV) for RV and left ventricle (LV). Cytokines concentrations were measured in platelet-poor plasma and platelet lysate. Follow-up time of this study was 58 months; the combined endpoint (CEP) was defined as death or clinical deterioration. RESULTS: We observed significant correlations between platelet sTWEAK levels, plasma IL-6 and PET parameter SUVRV/LV (r = -0.57, p = 0.011; r = 0.50, p = 0.032, respectively). In logistic regression, platelet sTWEAK and IL-6 were both prognostic factors for unfavorable ratio of SUVRV/LV higher than 1 (hazard ratio (HR) = 0.44, 95% confidence interval (95% CI): [0.23; 0.84], p = 0.017; and HR = 3.62, 95% CI: [1.21; 10.17], p = 0.011, respectively). Furthermore, their concentrations were related with prognostically important higher late gadolinium enhancement mass index (LGEMI) and RV global longitudinal strain/systolic pulmonary artery pressure (RV GLS/sPAP) values. Patients who had CEP in follow-up (n = 13) had significantly lower platelet sTWEAK content and higher plasma IL-6 at baseline than stable patients. Lower platelet sTWEAK was related to a worse prognosis in log-rank test (p = 0.006). Platelet sTWEAK and plasma IL-6 together with RV GLS/sPAP, RV ejection fraction (RVEF), mean pulmonary arterial pressure (mPAP), and SUVRV/LV were significantly associated with time to CEP in univariate Cox analysis. CONCLUSIONS: The sTWEAK and IL-6 concentrations in PAH patients are linked with metabolic and functional changes of RV visualized in PET/MRI, and both sTWEAK and IL-6 predict clinical deterioration.

Multimodal assessment of right ventricle overload-metabolic and clinical consequences in pulmonary arterial hypertension.

BACKGROUND: In pulmonary arterial hypertension (PAH) increased afterload leads to adaptive processes of the right ventricle (RV) that help to maintain arterio-ventricular coupling of RV and preserve cardiac output, but with time the adaptive mechanisms fail. In this study, we propose a multimodal approach which allows to estimate prognostic value of RV coupling parameters in PAH patients. METHODS: Twenty-seven stable PAH patients (49.5 ± 15.5 years) and 12 controls underwent cardiovascular magnetic resonance (CMR). CMR feature tracking analysis was performed for RV global longitudinal strain assessment (RV GLS). RV-arterial coupling was evaluated by combination of RV GLS and three proposed surrogates of RV afterload-pulmonary artery systolic pressure (PASP), pulmonary vascular resistance (PVR) and pulmonary artery compliance (PAC). 18-FDG positron emission tomography (PET) analysis was used to assess RV glucose uptake presented as SUVRV/LV. Follow-up time of this study was 25 months and the clinical end-point was defined as death or clinical deterioration. RESULTS: Coupling parameters (RV GLS/PASP, RV GLS/PVR and RV GLS*PAC) significantly correlated with RV function and standardized uptake value (SUVRV/LV). Patients who experienced a clinical end-point (n = 18) had a significantly worse coupling parameters at the baseline visit. RV GLS/PASP had the highest area under curve in predicting a clinical end-point and patients with a value higher than (-)0.29%/mmHg had significantly worse prognosis. It was also a statistically significant predictor of clinical end-point in multivariate analysis (adjusted R2 = 0.68; p < 0.001). CONCLUSIONS: Coupling parameters are linked with RV hemodynamics and glucose metabolism in PAH. Combining CMR and hemodynamic measurements offers more comprehensive assessment of RV function required for prognostication of PAH patients. TRIAL REGISTRATION: NCT03688698, 09/26/2018, retrospectively registered; Protocol ID: 2017/25/N/NZ5/02689.

Prognostic role of PET/MRI hybrid imaging in patients with pulmonary arterial hypertension.

OBJECTIVE: Right ventricular (RV) function is a major determinant of survival in patients with pulmonary arterial hypertension (PAH). Metabolic alterations may precede haemodynamic and clinical deterioration. Increased RV fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) was recently associated with progressive RV dysfunction in MRI, but the prognostic value of their combination has not been established. METHODS: Twenty-six clinically stable patients with PAH (49.9±15.2 years) and 12 healthy subjects (control group, 44.7±13.5 years) had simultaneous PET/MRI scans. FDG uptake was quantified as mean standardised uptake value (SUV) for both left ventricle (LV) and RV. Mean follow-up time of this study was 14.2±7.3 months and the clinical end point was defined as death or clinical deterioration. RESULTS: Median SUVRV/SUVLV ratio was 1.02 (IQR 0.42-1.21) in PAH group and 0.16 (0.13-0.25) in controls, p<0.001. In PAH group, SUVRV/SUVLV significantly correlated with RV haemodynamic deterioration. In comparison to the stable ones, 12 patients who experienced clinical end point had significantly higher baseline SUVRV/SUVLV ratio (1.21 (IQR 0.87-1.95) vs 0.53 (0.24-1.08), p=0.01) and lower RV ejection fraction (RVEF) (37.9±5.2 vs 46.8±5.7, p=0.03). Cox regression revealed that SUVRV/SUVLV ratio was significantly associated with the time to clinical end point. Kaplan-Meier analysis showed that combination of RVEF from MRI and SUVRV/SUVLV assessment may help to predict prognosis. CONCLUSIONS: Increased RV glucose uptake in PET and decreased RVEF identify patients with PAH with worse prognosis. Combining parameters from PET and MRI may help to identify patients at higher risk who potentially benefit from therapy escalation, but this hypothesis requires prospective validation.

Prognostic value of late gadolinium enhancement mass index in patients with pulmonary arterial hypertension.

PURPOSE: Dysfunction of the right ventricle (RV) is an important determinant of survival in patients with pulmonary arterial hypertension (PAH). The presence of late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) at RV insertion points (RVIPs) has been found in majority of PAH patients and was associated with parameters of RV dysfunction. We hypothesize, that more detailed quantification of LGE may provide additional prognostic information. MATERIAL AND METHODS: Twenty-eight stable PAH patients (mean age 49.9 â€‹± â€‹15.9 years) and 12 healthy subjects (control group, 44.8 â€‹± â€‹13.5 years) were enrolled into the study. Septal LGE mass was quantified at the RVIPs and subsequently indexed by subject's body surface area. Mean follow-up time of this study was 16.6 â€‹± â€‹7.5 months and the clinical end-point (CEP) was defined as death or clinical deterioration. RESULTS: Median LGE mass index (LGEMI) at the RVIPs was 2.75 â€‹g/m2 [1.41-4.85]. We observed statistically significant correlations between LGEMI and hemodynamic parameters obtained from right heart catheterization - mPAP (r â€‹= â€‹0.61, p â€‹= â€‹0.001); PVR (r â€‹= â€‹0.52, p â€‹= â€‹0.007) and from CMR - RVEF (r â€‹= â€‹-0.54, p â€‹= â€‹0.005); RV global longitudinal strain (r â€‹= â€‹0.42, p â€‹= â€‹0.03). Patients who had CEP (n â€‹= â€‹16) had a significantly higher LGEMI (4.49 [2.75-6.17] vs 1.67 [0.74-2.7], p â€‹= â€‹0.01); univariate Cox analysis confirmed prognostic value of LGEMI. Furthermore, PAH patients with LGEMI higher than median had worse prognosis in Kaplan-Meier analysis (log-rank test, p â€‹= â€‹0.0006). CONCLUSIONS: The body surface indexed mass of LGE at RV septal insertion points are suggestive of RV hemodynamic dysfunction and could be a useful non-invasive marker of PAH prognosis.

Neuronal loss or dysfunction in patients with early Lyme neuroborreliosis: a proton magnetic resonance spectroscopy study of the brain.

BACKGROUND: We hypothesized that since Borrelia burgdorferi causes systemic inflammation and infects the brain, it may lead to alterations in cerebral metabolism, as measured by 1H-magnetic resonance spectroscopy (1H-MRS). The purpose of our study was to determine whether 1H-MRS could detect brain metabolite alterations in patients with early Lyme neuroborreliosis (LNB) in normal-appearing brain tissue on the conventional magnetic resonance imaging (MRI). METHODS: Twenty-six patients diagnosed with early LNB and twenty-six healthy volunteers as a control group have been involved in the study. All of them underwent routine MRI protocol using 3.0-T MRI scanner. 1H-MRS examinations were performed with repetition time (TR) = 2000 ms, and echo time (TE) = 135 ms. Single voxels were positioned in the anterior and posterior parts of the right and left frontal lobes. RESULTS: We found a statistically significant decrease of the N-acetylaspartate/creatine ratio within the anterior part of the right and left frontal lobes (p ≤ 0.001 and p = 0.001 respectively) and in the posterior part of the right and left frontal lobes (p ≤ 0.001 and 0.031) in the patients with LNB. CONCLUSION: A significant reduction in NAA/Cr ratio in comparison with the controls suggests the presence of diffuse neuronal loss in patients with early LNB.

Proton magnetic resonance spectroscopy (1H-MRS) of the brain in patients with tick-borne encephalitis.

Tick-borne encephalitis (TBE) is a disease caused by a tick-borne encephalitis virus (TBEV) belonging to the Flaviviridae family. The aforementioned virus is transmitted by the bite of infected ticks. In the recent years, TBEV has become a serious public health problem with a steady increase in its incidence, mainly due to the climate changes and spreading the infected ticks into new territories. The standard protocol of TBE diagnosis involves the serological laboratory test with a minor role of imaging techniques such as magnetic resonance imaging. Long-term complications affecting patients daily activities are reported in about 40-50% of the cases. However, no changes are revealed in the laboratory tests or the imaging examination. The development of new imaging techniques such as proton magnetic resonance spectroscopy (1H-MRS) can broaden the knowledge about TBE, contributing to its prevention. The aim of this study was to assess the usefulness of 1H-MRS of the brain in patients with TBE. Compared to controls, a statistically significant decrease in the N-acetylaspartate /creatine ratio was found bilaterally in the right and left thalamus as well as a statistically significant increase in the choline/creatine ratio in the right and left thalamus.

Cerebrovascular Manifestations of Lyme Neuroborreliosis-A Systematic Review of Published Cases.

BACKGROUND: Lyme neuroborreliosis (LNB) is a disease caused by spirochete Borrelia burgdorferi, involving the nervous system. It usually manifests as lymphocytic meningoradiculitis, but in rare cases, it can also lead to cerebrovascular complications. We aimed to perform a systematic review of all reported cases of LNB complicated by central nervous system vasculitis and stroke or transient ischemic attack (TIA). MATERIALS AND METHODS: We conducted a systematic review of literature between May 1987 and December 2016 with patients who presented with cerebrovascular course of LNB. RESULTS: This study included 88 patients with a median age of 46 years. The median interval from onset of symptoms suggesting Lyme disease to first symptoms of cerebrovascular manifestations of LNB was 3.5 months. The most common cerebrovascular manifestation of LNB was ischemic stroke (76.1%), followed by TIA (11.4%). The posterior circulation was affected alone in 37.8% of patients, the anterior circulation in 24.4% of patients, and in 37.8% of cases, posterior and anterior circulations were affected simultaneously. The most common affected vessels were middle cerebral artery-in 19 cases, basilar artery-in 17 cases, and anterior cerebral artery-in 16 cases. A good response to antibiotic treatment was achieved in the vast number of patients (75.3%). The overall mortality rate was 4.7%. CONCLUSION: Cerebral vasculitis and stroke due to LNB should be considered, especially in patients who live in or have come from areas with high prevalence of tick-borne diseases, as well as in those without cardiovascular risk factors, but with stroke-like symptoms of unknown cause.

Evaluation of Imaging Methods in Tick-Borne Encephalitis.

Tick-borne encephalitis (TBE) is caused by a virus that belongs to the Flaviviridae family and is transmitted by tick bites. The disease has a biphasic course. Diagnosis is based on laboratory examinations because of non-specific clinical features, which usually entails the detection of specific IgM antibodies in either blood or cerebrospinal fluid that appear in the second phase of the disease. Neurological symptoms, time course of the disease, and imaging findings are multifaceted. During the second phase of the disease, after the onset of neurological symptoms, magnetic resonance imaging (MRI) abnormalities are observed in a limited number of cases. However, imaging features may aid in predicting the prognosis of the disease.