The Lateral Corticospinal Tract Sign: An MRI Marker for Amyotrophic Lateral Sclerosis.

Background Radially sampled averaged magnetization inversion-recovery acquisition (rAMIRA) imaging shows hyperintensity in the lateral corticospinal tract (CST) in patients with motor neuron diseases. Purpose To systematically determine the accuracy of the lateral corticospinal tract sign for detecting patients with amyotrophic lateral sclerosis (ALS) at rAMIRA MRI. Materials and Methods This study included prospectively acquired data from participants in ALS and other motor neuron disease imaging studies at the University Hospital Basel, Switzerland.

Cervical and thoracic spinal cord gray matter atrophy is associated with disability in patients with amyotrophic lateral sclerosis.

Background And Purpose: In amyotrophic lateral sclerosis (ALS), there is an unmet need for more precise patient characterization through quantitative, ideally operator-independent, assessments of disease extent and severity. Radially sampled averaged magnetization inversion recovery acquisitions (rAMIRA) magnetic resonance imaging enables gray matter (GM) and white matter (WM) area quantitation in the cervical and thoracic spinal cord (SC) with optimized contrast. We aimed to investigate rAMIRA-derived SC GM and SC WM areas and their association with clinical phenotype and disability in ALS.

Robust T estimation with balanced steady state free precession.

Purpose: To develop a novel signal representation for balanced steady state free precession (bSSFP) displaying its T independence on B and on magnetization transfer (MT) effects.

Methods: A signal model for bSSFP is developed that shows only an explicit dependence (up to a scaling factor) on E (and, therefore, T) and a novel parameter c (with implicit dependence on the flip angle and E). Moreover, it is shown that MT effects, entering the bSSFP signal via a binary spin bath model, can be captured by a redefinition of T and, therefore, leading to modification of E, resulting in the same signal model.

The Non-Affected Muscle Volume Compensates for the Partial Loss of Strength after Injection of Botulinum Toxin A.

Local botulinum toxin (BTX-A, Botox) injection in overactive muscles is a standard treatment in patients with cerebral palsy. The effect is markedly reduced in children above the age of 6 to 7. One possible reason for this is the muscle volume affected by the drug.

The functional role of hip muscles during gait in patients with increased femoral anteversion.

Background: Femoral anteversion affects the lever arm and moment-generating capacity of the hip abductors, while an increased hip internal rotation during walking was proposed to be a compensatory mechanism to restore the abductive lever arm. Children with isolated increased femoral anteversion, however, do not always present a deficit in the net hip abduction moment during gait, suggesting that a more comprehensive understanding of the effect of morphology and motion on muscle forces and moments is needed to aid clinical decision making.

Research Question: Are muscle contributions to hip joint moments and muscle forces altered in patients with increased femoral anteversion and internally rotated gait pattern compared to a control group of typically developing children? And how would the functional role of the muscle be altered if the patients walked straight?

Methods: This follow-up study compared patients with increased femoral anteversion (n = 42, 12.

Quantification and Monitoring of the Effect of Botulinum Toxin A on Paretic Calf Muscles of Children With Cerebral Palsy With MRI: A Preliminary Study.

Muscles from patients with cerebral palsy (CP) are often spastic and form contractures that limit the range of motion. Injections of botulinum toxin A (BTX) into the calf muscles are an important treatment for functional equinus; however, improvement in gait function is not always achieved. BTX is also used to test muscle weakening for risk evaluation of muscle lengthening surgery.

Normalization of Spinal Cord Total Cross-Sectional and Gray Matter Areas as Quantified With Radially Sampled Averaged Magnetization Inversion Recovery Acquisitions.

MR imaging of the spinal cord (SC) gray matter (GM) at the cervical and lumbar enlargements' level may be particularly informative in lower motor neuron disorders, e. g., spinal muscular atrophy, but also in other neurodegenerative or autoimmune diseases affecting the SC.

Combination of Quantitative MRI Fat Fraction and Texture Analysis to Evaluate Spastic Muscles of Children With Cerebral Palsy.

Cerebral palsy (CP) is the most common cause of physical disability in childhood. Muscle pathologies occur due to spasticity and contractures; therefore, diagnostic imaging to detect pathologies is often required. Imaging has been used to assess torsion or estimate muscle volume, but additional methods for characterizing muscle composition have not thoroughly been investigated.

The nitric oxide donor JS-K sensitizes U87 glioma cells to repetitive irradiation.

As a potent radiosensitizer nitric oxide (NO) may be a putative adjuvant in the treatment of malignant gliomas which are known for their radio- and chemoresistance. The NO donor prodrug JS-K (O2-(2.4-dinitrophenyl) 1-[(4-ethoxycarbonyl) piperazin-1-yl] diazen-1-ium-1,2-diolate) allows cell-type specific intracellular NO release via enzymatic activation by glutathione-S-transferases overexpressed in glioblastoma multiforme.

Imaging and Selective Elimination of Glioblastoma Stem Cells with Theranostic Near-Infrared-Labeled CD133-Specific Antibodies.

Near-infrared photoimmunotherapy (NIR-PIT), which employs monoclonal antibody (mAb)-phototoxic phthalocyanine dye IR700 conjugates, permits the specific, image-guided and spatiotemporally controlled elimination of tumor cells. Here, we report the highly efficient NIR-PIT of human tumor xenografts initiated from patient-derived cancer stem cells (CSCs). Using glioblastoma stem cells (GBM-SCs) expressing the prototypic CSC marker AC133/CD133, we also demonstrate here for the first time that NIR-PIT is highly effective against brain tumors.

Tumour T1 changes in vivo are highly predictive of response to chemotherapy and reflect the number of viable tumour cells--a preclinical MR study in mice.

Background: Effective chemotherapy rapidly reduces the spin-lattice relaxation of water protons (T1) in solid tumours and this change (ΔT1) often precedes and strongly correlates with the eventual change in tumour volume (TVol). To understand the biological nature of ΔT1, we have performed studies in vivo and ex vivo with the allosteric mTOR inhibitor, everolimus.

Methods: Mice bearing RIF-1 tumours were studied by magnetic resonance imaging (MRI) to determine TVol and T1, and MR spectroscopy (MRS) to determine levels of the proliferation marker choline and levels of lipid apoptosis markers, prior to and 5 days (endpoint) after daily treatment with vehicle or everolimus (10 mg/kg).

Simultaneous assessment of vessel size index, relative blood volume, and vessel permeability in a mouse brain tumor model using a combined spin echo gradient echo echo-planar imaging sequence and viable tumor analysis.

Purpose: Combining multiple imaging biomarkers in one magnetic resonance imaging (MRI) session would be beneficial to gain more data pertaining to tumor vasculature under therapy. Therefore, simultaneous measurement of perfusion, permeability, and vessel size imaging (VSI) using a gradient echo spin echo (GE-SE) sequence with injection of a clinically approved gadolinium (Gd)-based contrast agent was assessed in an orthotopic glioma model.

Materials And Methods: A combined spin echo gradient echo echo-planar imaging sequence was implemented using a single contrast agent Gd diethylenetriaminepentaacetic acid (Gd-DTPA).

Effects of the nitric oxide donor JS-K on the blood-tumor barrier and on orthotopic U87 rat gliomas assessed by MRI.

Nitric oxide (NO) released from NO donors can be cytotoxic in tumor cells and can enhance the transport of drugs into brain tumors by altering blood-tumor barrier permeability. The NO donor JS-K [O(2)-(2,4-dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate] releases NO upon enzymatic activation selectively in cells overexpressing glutathione-S-transferases (GSTs) such as gliomas. Thus, JS-K-dependent NO effects - especially on cell viability and vascular permeability - were investigated in U87 glioma cells in vitro and in an orthotopic U87 xenograft model in vivo by magnetic resonance imaging (MRI).

Quantified tumor t1 is a generic early-response imaging biomarker for chemotherapy reflecting cell viability.

Purpose: Identification of a generic response biomarker by comparison of chemotherapeutics with different action mechanisms on several noninvasive biomarkers in experimental tumor models.

Experimental Design: The spin-lattice relaxation time of water protons (T(1)) was quantified using an inversion recovery-TrueFISP magnetic resonance imaging method in eight different experimental tumor models before and after treatment at several different time points with five different chemotherapeutics. Effects on T(1) were compared with other minimally invasive biomarkers including vascular parameters, apparent diffusion coefficient, and interstitial fluid pressure, and were correlated with efficacy at the endpoint and histologic parameters.

Phosphorylation of Tau at S422 is enhanced by Abeta in TauPS2APP triple transgenic mice.

Amyloid beta peptides and microtubule-associated protein Tau are misfolded and form aggregates in brains of Alzheimer's disease patients. To examine their specific roles in the pathogenesis of Alzheimer's disease and their relevance in neurodegenerative processes, we have created TauPS2APP triple transgenic mice that express human mutated Amyloid Precursor Protein, presenilin 2 and Tau. We present a cross-sectional analysis of these mice at 4, 8, 12 and 16 months of age.

Cortical hypoperfusion in the B6.PS2APP mouse model for Alzheimer's disease: comprehensive phenotyping of vascular and tissular parameters by MRI.

Function and morphology of the cerebral vasculature were studied in the amyloid (Abeta) plaque-containing double-transgenic (TG) B6.PS2APP Alzheimer's disease (AD) mouse model with MRI at an age range of 10 to 17 months. Perfusion, blood volume, and average vessel geometry were assessed in the brain and compared to age-matched controls (wild-type [WT] C57Bl/6).

Physicochemical and MRI characterization of Gd3+-loaded polyamidoamine and hyperbranched dendrimers.

Generation 4 polyamidoamine (PAMAM) and, for the first time, hyperbranched poly(ethylene imine) or polyglycerol dendrimers have been loaded with Gd3+ chelates, and the macromolecular adducts have been studied in vitro and in vivo with regard to MRI contrast agent applications. The Gd3+ chelator was either a tetraazatetracarboxylate DOTA-pBn4- or a tetraazatricarboxylate monoamide DO3A-MA3- unit. The water exchange rate was determined from a 17O NMR and 1H Nuclear Magnetic Relaxation Dispersion study for the corresponding monomer analogues [Gd(DO3A-AEM)(H2O)] and [Gd(DOTA-pBn-NH2)(H2O)]- (kex298=3.

Quantitative dynamic contrast-enhanced MRI in tumor-bearing rats and mice with inversion recovery TrueFISP and two contrast agents at 4.7 T.

Purpose: To characterize tumor vascularization by dynamic-contrast enhanced (DCE) MRI using low and medium molecular weight paramagnetic contrast agents (CA) and inversion recovery (IR) true fast imaging with steady state precession (TrueFISP) in tumor-bearing rats and mice.

Materials And Methods: T(1) mapping was performed using IR True FISP in phantoms and in vivo at 4.7 T and validated with a segmented IR gradient-echo (IR GE) method.

Stability of real-time MR temperature mapping in healthy and diseased human liver.

Purpose: To determine the stability and quality of MR temperature mapping using the proton resonance frequency (PRF) method in the liver of hepatic tumor patients.

Materials And Methods: The standard deviation (SD) of a series of temperature maps was determined in 30 patients (21 patients with cirrhotic livers with carcinoma, and nine patients with noncirrhotic livers with metastasis or angioma) and in five volunteers at normal body temperature under free breathing. A respiratory-gated segmented echo-planar imaging (EPI) sequence (three slices in one expiration phase) was performed with sensitivity encoding (SENSE) acceleration on a 1.

Real-time MR temperature mapping of rabbit liver in vivo during thermal ablation.

It has been shown that quantitative MRI thermometry using the proton resonance frequency (PRF) method can be used to noninvasively monitor the evolution of tissue temperature, and to guide minimally-invasive tumor ablation based on local hyperthermia. Although hepatic tumors are among the main targets for thermal ablation, PRF-based temperature MRI of the liver is difficult to perform because of motion artifacts, fat content, and low T(*) (2). In this study the stability of real-time thermometry was tested on a clinical 1.

Imaging of intracellular sodium with shift reagent aided (23)Na CSI in isolated rat hearts.

23Na chemical shift imaging (CSI) in conjunction with shift reagents was used to obtain images of intracellular (Na(i)) and extracellular sodium (Na(e)) in isolated rat hearts. It was demonstrated that the increase of Na(i) concentration in ischemic myocardium can be detected with this technique. 3D acquisition-weighted (23)Na CSI datasets with a nominal spatial resolution of 1.