"Tumoral pseudoblush" identified within gliomas at high-spatial-resolution ultrahigh-field-strength gradient-echo MR imaging corresponds to microvascularity at stereotactic biopsy.

Purpose: To use directed biopsy sampling to determine whether microvascular assessment within gliomas, by means of ultrahigh-field-strength high-spatial-resolution gradient-echo (GRE) magnetic resonance (MR) imaging at 8 T, correlates with histopathologic assessment of microvascularity.

Materials And Methods: The study was institutional review board approved and HIPAA compliant. Informed consent was obtained.

Hemolytic uremic syndrome: late renal injury and changing incidence-a single centre experience in Canada.

Aims. To assess trends in the incidence of pediatric diarrhea-associated hemolytic uremic syndrome (D(+) HUS) and document long-term renal sequelae. Methods.

Serum prolactin levels in a uremic child: effects of bilateral nephrectomy and kidney transplantation.

Elevated levels of serum prolactin (PRL) are common and well described in patients with chronic renal failure. We report the case of a 4-year-old girl who also presented with premature thelarche and transient galactorrhea. Neither peritoneal dialysis nor hemodialysis reduced her extremely elevated levels of PRL, which fluctuated from time to time, probably reflecting variations in lactotroph secretion rate.

Bartter syndrome in two sisters with a novel mutation of the CLCNKB gene, one with deafness.

This article describes two sisters with type III Bartter syndrome (BS) due to a novel missense variant of the CLCNKB gene. The phenotypic expression of the disease was very different in these two siblings. In one sister, the disease followed a very severe course, especially in the neonatal period and as a toddler.

Efficacy of eculizumab in a patient with factor-H-associated atypical hemolytic uremic syndrome.

Atypical hemolytic uremic syndrome (aHUS) is a rare, chronic, life-threatening disease due to complement dysregulation. The use of early-onset plasma therapy is recommended, but optimal long-term treatment regimen is not well defined. Eculizumab, a monoclonal humanized anti-C5 antibody, has shown success in patients with aHUS.

[A specialized and integrated outpatient clinic for the care of children with chronic kidney disease: experience of CHU Sainte-Justine].

The management and optimal care for the pediatric patient with chronic kidney disease requires attention not only to medical management, but also special focus on the psychosocial and developmental factors of children which is complicated by the presence of other disease-related complications. In recent years, specialized chronic kidney disease and predialysis clinics have been set up to facilitate and improve the quality of care of these patients with a multidisciplinary organisation and coordinated management approaches of a renal team. We present our experience in establishing such a renal management clinic named "Prévoir" for children with chronic kidney disease at Sainte-Justine Hospital.

Efficacy of plasma therapy in atypical hemolytic uremic syndrome with complement factor H mutations.

Atypical hemolytic uremic syndrome (aHUS) frequently results in end-stage renal failure and can be lethal. Several studies have established an association between quantitative or qualitative abnormalities in complement factor H and aHUS. Although plasma infusion and exchange are often advocated, guidelines have yet to be established.

De novo gene conversion in the RCA gene cluster (1q32) causes mutations in complement factor H associated with atypical hemolytic uremic syndrome.

Many of the complement regulatory genes within the RCA cluster (1q32) have arisen through genomic duplication and the resulting high degree of sequence identity is likely to predispose to gene conversion events. The highest degree of identity is between the genes for factor H (CFH) and five factor H-related proteins--CFHL1, CFHL2, CFHL3, CFHL4, and CFHL5. CFH mutations are associated with atypical hemolytic uremic syndrome (aHUS).

High-resolution ultrahigh-field MRI of stroke.

Background: Ultrahigh-field MRI at 8 T offers unprecedented resolution for imaging brain structures and microvasculature.

Objective: The aim of this study is to apply high-resolution MRI for stroke imaging and to characterize findings at 1.5 and 8 T.

A large unilateral renal artery aneurysm in a young child.

The case of a 13-month-old boy with fibromuscular dysplasia (FMD) presenting with a large saccular aneurysm of the left renal artery and renovascular hypertension is reported. Renal and intrarenal arteries showed numerous small aneurysms alternating with stenoses. All arterial lesions were localized to the left kidney.

Hyperlipidemic profiles during remission in childhood idiopathic nephrotic syndrome.

Hyperlipidemia, an important characteristic of idiopathic nephrotic syndrome in children (NS), is usually observed during the active phase of the disease and disappears with the resolution of the proteinuria. However, persisting lipid anomalies during remission have been reported in a few studies and raise the question of the later development of atherosclerosis. Plasma lipid profiles in 25 children with NS at remission, with or without active prednisone treatment, were compared with those of an age-matched population.

Changes in concentrations of neuroendocrine hormones and catecholamines in dogs with myocardial failure induced by rapid ventricular pacing.

Objective: To describe neuroendocrine responses that develop in dogs subjected to prolonged periods of ventricular pacing.

Animals: 14 adult male hound-type dogs.

Procedure: Samples were obtained and neuroendocrine responses measured before (baseline) and after 3 periods of ventricular pacing.

Effect of RF coil excitation on field inhomogeneity at ultra high fields: a field optimized TEM resonator.

In this work, computational methods were utilized to optimize the field produced by the transverse electromagnetic (TEM) resonator in the presence of the human head at 8 Tesla. Optimization was achieved through the use of the classical finite difference time domain (FDTD) method and a TEM resonator loaded with an anatomically detailed human head model with a resolution of 2 mm x 2 mm x 2 mm. The head model was developed from 3D MR images.

Intracranial ossifications and microangiopathy at 8 Tesla MRI.

Unlabelled: Clinical evaluation and MR imaging of microangiopathy associated with hypertension is limited. We describe a case that illustrates sensitivity of MRI at 8 Tesla for imaging of microvasculature, iron, calcium deposits and silent white matter lesions (WML). A 60-year-old black hypertensive woman was evaluated for numbness in the face and extremities.

Plasma homocysteine concentration in children with chronic renal failure.

Hyperhomocysteinemia, a risk factor for vascular disease, is commonly found in adult patients with end-stage renal disease. Major determinants of elevated plasma homocysteine levels in these patients include deficiencies in folate and vitamin B12, methylenetetrahydrofolate reductase (MTHFR) genotype and renal function. Little information is available for children with chronic renal failure (CRF).

Dielectric resonances and B(1) field inhomogeneity in UHFMRI: computational analysis and experimental findings.

B(1) Field inhomogeneity and the relative effects of dielectric resonances are analyzed within the context of ultra high field MRI. This is accomplished by calculating the electromagnetic fields inside spherical phantoms and within a human head model in the presence and absence of an RF coil. These calculations are then compared to gradient echo and RARE images, respectively.

Ultra high field MRI at 8 Tesla of subacute hemorrhagic stroke.

Purpose: Optimal treatment strategies and neurologic outcome after stroke depend on an accurate characterization of the lesion. There is a need for high resolution noninvasive imaging for assessment of the infarct size, perfusion, and vascular territory. MRI at the ultra high field (UHF) of 8 T offers unprecedented resolution, but its utility for stroke evaluation has not been determined yet.

High resolution MRI of the brainstem at 8 T.

A recently developed ultra high field MRI system operating at 8 T (UHFMRI) was applied for brainstem imaging. UHFMRI was performed in five healthy volunteers (three men, two women; age range 34--46 years). Sagittal and axial slices were obtained with the following settings: GE, TR 750--1,000 ms, TE 7-9 ms, FOV 20 cm, matrix 1,024 x 1,024 or 512 x 512 points, slice thickness 2 mm, resolution 195 or 390 microm/pixel.

B1 field homogeneity and SAR calculations for the birdcage coil.

The finite-difference time-domain (FDTD) method is used to model a birdcage resonator. All the coil components, including the wires, lumped capacitors and the source, are geometrically modelled together. As such, the coupling effects within the birdcage, including the interactions of coil, source and human head, are accurately computed.

Computational analysis of the high pass birdcage resonator: finite difference time domain simulations for high-field MRI.

In this work, a finite difference time domain (FDTD) algorithm is validated at 1.5 tesla using the standard GE Signa quadrature head coil and a muscle phantom. The electrical characteristics of the birdcage head coil are then calculated for the linear and quadrature cases.

Application of finite difference time domain method for the design of birdcage RF head coils using multi-port excitations.

A three-dimensional finite difference time domain model was developed where the high pass birdcage coil and the imaged object are analysed as a single unit. A study was performed comparing linear, conventional quadrature, and four-port excitation at 64 MHz and 200 MHz for different coil loadings, namely muscle phantoms and an anatomically detailed human head model. A phase array concept was utilized to excite the birdcage coil in four ports.

Left ventricular myocardial adenosine triphosphate changes during reperfusion of ventricular fibrillation: the influence of flow and epinephrine.

Objective: To determine whether epinephrine in combination with high flow worsens left ventricular (LV) myocardial high-energy phosphate stores during reperfusion of ischemic ventricular fibrillation (VF).

Design: Blinded, prospective block randomized, placebo controlled study.

Setting: University medical center research laboratory.

Theoretical model for an MRI radio frequency resonator.

A theoretical model is described for a magnetic resonance imaging (MRI) radio-frequency resonator (an MRI "coil") that is useful at ultrahigh frequencies. The device is a "TEM resonator," which is based on a concept originally proposed by Röschmann (1988). The coil comprises a circular cavity-like structure containing several coaxial transmission lines operating in a transverse electromagnetic (TEM) mode.