Comparing 1.5 T and 3.0 T MR data for 3D visualization of neurovascular relationships in the posterior fossa.

BACKGROUND: Neurovascular relationships in the posterior fossa are more frequently investigated due to the increasing availability of 3.0 Tesla MRI. For an assessment with 3D visualization, no systematic analyzes are available so far and the question arises as to whether 3.0 Tesla MRI should be given preference over 1.5 Tesla MRI. METHODS: In a prospective study, a series of 25 patients each underwent MRI investigations with 3D-CISS and 3D-TOF at 1.5 and 3.0 Tesla. For both field strengths separately, blood vessel information from the TOF data was fused into the CISS data after segmentation and registration. Four visualizations were created for each field strength, with and without optimization before and after fusion, which were evaluated with a rating system and verified with the intraoperative situation. RESULTS: When only CISS data was used, nerves and vessels were better visualized at 1.5 Tesla. After fusion, flow and pulsation artifacts were reduced in both cases, missing vessel sections were supplemented at 3.0 Tesla and 3D visualization at 1.5 and 3.0 Tesla led to anatomically comparable results. By subsequent manual correction, the remaining artifacts were further eliminated, with the 3D visualization being significantly better at 3.0 Tesla, since the higher field strength led to sharper contours of small vessel and nerve structures. CONCLUSION: 3D visualizations at 1.5 Tesla are sufficiently detailed for planning microvascular decompression and can be used without restriction. Fusion further improves the quality of 3D visualization at 3.0 Tesla and enables an even more accurate delineation of cranial nerves and vessels.

Matrix metalloproteinase -2, -9 and arterial stiffness in children and adolescents: The role of chronic kidney disease, diabetes, and hypertension.

BACKGROUND AND AIMS: Matrix metalloproteinases (MMPs) may contribute to the pathogenesis of arterial stiffness inducing extracellular matrix remodeling. We aimed to compare MMP-2 and -9 levels in children with chronic kidney disease (CKD), type 1 diabetes (without chronic kidney disease) and healthy control and to investigate associations of MMPs levels with cardiovascular risk factors and markers of arterial stiffness. METHODS: The study population included 33 CKD, 18 type 1 diabetes patients, and 24 healthy controls. MMP-2, MMP-9, office blood pressure, pulse wave analysis, and carotid-femoral pulse wave velocity (cfPWV) measurements were performed. RESULTS: MMP-2 levels were higher in the CKD compared to the diabetes and control groups (p < 0.05). MMP-9 levels did not differ among groups. In hypertensive individuals logMMP-2 independently associated with PWV z score (ß = 0.744, 95%CI 0.105 to 2.921, p < 0.05) after adjustment for age, sex, GRF, and phosphate levels. Creatinine levels correlated positively with MMP-2 in the CKD (r = 0.39, p < 0.05) and negatively in the diabetes group (r = -0.72, p < 0.05). Cholesterol levels correlated with MMP-2 in the diabetes group (r = 0.70, p < 0.05). Phosphate levels correlated with MMP-2 level in the control group (r = 0.67, p < 0.05). In multivariate regression model adjusted for age and sex, including phosphate and GRF as covariates, only phosphate predicted logMMP-2 levels (ß = 0.333, 95%CI 0.060 to 0.671, p < 0.05). CONCLUSIONS: MMP-2 associated with arterial stiffness in the presence of hypertension, while the role of MMP-9 is less clear in children with CKD or type 1 diabetes. Whether up-regulation of MMPs could predict poor outcomes in young high-risk patient groups need to be confirmed by future studies.

Cortisol Levels in Glucagon Stimulation Test in Children Assessed for Short Stature: Clinical and Laboratorial Correlations.

To assess total cortisol levels in children being evaluating for short stature with normal cortisol reserve and to correlate this response to clinical and laboratory data. Children assessed with glucagon test in our department were recruited in this study retrospectively. Inclusion criteria were: i) age>1 year, ii) absence of chronic illness or medication interfering with ACTH-cortisol axis, iii) GH stimulation levels>3ng/mL at least in one provocation test (glucagon or clonidine), iv) absence of multiple pituitary growth hormone deficiencies, v) normal short Synacthen test in cases of low cortisol response in glucagon test.Two hundred and thirty-seven subjects (160 males, 67.5%) with a mean age of 9.02±3.19 years, were finally included in the analysis. Cortisol peak levels but not cortisol AUC were significantly increased in females compared to males (26.83±7.31 µg/dl vs. 24.04±7.20 µg/dl). When linear correlations were studied, both cortisol peak levels and cortisol AUC were linearly but inversely correlated to age (r=-0.234, p<0.001 and r=-0.315, p<0.001, respectively). Finally, cortisol AUC was inversely correlated to weight Z-scores (r=-0.160, p=0.014). When our analysis was limited only to subjects with intact GH response (GH peak> 7 ng/mL), age was still inversely correlated to cortisol AUC (r=-0.312, p<0.001), and cortisol AUC was linearly correlated to GH AUC assessed with clonidine test (r=0.223, p=0.013). Girls, younger and thinner children exhibit higher cortisol response to glucagon test.

Arterial Stiffness in a Toddler with Neurofibromatosis Type 1 and Refractory Hypertension.

Arterial hypertension is a common finding in patients with neurofibromatosis (NF) type 1. Renovascular hypertension due to renal artery stenosis or midaortic syndrome could be the underlying cause. We report the case of a 4-year-old girl with NF type 1 and midaortic syndrome whose changes in blood pressure and pulse wave velocity suggested the evolution of vasculopathy, diagnosis of renovascular hypertension, and provided insights of response to treatment. Hypertension persisted after percutaneous transluminal angioplasty in the abdominal aorta, requiring escalation of antihypertensive treatment, while arterial stiffness demonstrated a mild decrease. Regular assessment of blood pressure using ambulatory blood pressure monitoring and noninvasive assessment of arterial stiffness may enhance the medical care of patients with NF type 1.

Familial Hypercholesterolemia in Children and Adolescents: Diagnosis and Treatment.

Familial hypercholesterolemia is a hereditary genetic disorder predisposing in premature atherosclerosis and cardiovascular complications. Early diagnosis as well as effective treatment strategies in affected children are challenges among experts. Universal screening and cascade screening among families with familial hypercholesterolemia are being controversially discussed. Diagnosis of familial hypercholesterolemia in children and adolescents is usually based on clinical phenotype upon LDL-C levels and family history of premature cardiovascular and/or elevated LDL-C. Treatment approaches for familial hypercholesterolemia in the pediatric population are multidisciplinary and aim to reduce total cardiovascular risk. The most widely recommended and effective pharmacotherapy in the pediatric age group is currently statins. Ezetimibe and bile acid sequestrants are usually used as second-line agents. New therapeutic approaches, such as mipomersen and PCSK9 inhibitors seem promising. The main gap of evidence remains the lack of longitudinal follow up studies investigating cardiovascular outcomes, side effects, and effectiveness of treatment starting from childhood. Evidence would be expected in the near future by cohort and registry studies.