Whole tissue and single cell mechanics are correlated in human brain tumors.

Biomechanical changes are critical for cancer progression. However, the relationship between the rheology of single cells measured ex-vivo and the living tumor is not yet understood. Here, we combined single-cell rheology of cells isolated from primary tumors with bulk tumor rheology in patients with brain tumors.

How tissue fluidity influences brain tumor progression.

Mechanical properties of biological tissues and, above all, their solid or fluid behavior influence the spread of malignant tumors. While it is known that solid tumors tend to have higher mechanical rigidity, allowing them to aggressively invade and spread in solid surrounding healthy tissue, it is unknown how softer tumors can grow within a more rigid environment such as the brain. Here, we use in vivo magnetic resonance elastography (MRE) to elucidate the role of anomalous fluidity for the invasive growth of soft brain tumors, showing that aggressive glioblastomas (GBMs) have higher water content while behaving like solids.

Impact of the use of an endorectal coil for 3 T prostate MRI on image quality and cancer detection rate.

This work aims to assess the impact of an additional endorectal coil on image quality and cancer detection rate within the same patients. At a single academic medical center, this transversal study included 41 men who underwent T2- and diffusion-weighted imaging at 3 T using surface coils only or in combination with an endorectal coil in the same session. Two blinded readers (A and B) randomly evaluated all image data in separate sessions.

Idiopathic normal pressure hydrocephalus: diagnostic and predictive value of clinical testing, lumbar drainage, and CSF dynamics.

OBJECTIVE The aim of the study was to analyze the diagnostic and predictive values of clinical tests, CSF dynamics, and intracranial pulsatility tests, compared with external lumbar drainage (ELD), for shunt response in patients with idiopathic normal pressure hydrocephalus (iNPH). METHODS Sixty-eight consecutive patients with suspected iNPH were prospectively evaluated. Preoperative assessment included clinical tests, overnight intracranial pressure (ICP) monitoring, lumbar infusion test (LIFT), and ELD for 24-72 hours.

MRI assessment of the effects of acetazolamide and external lumbar drainage in idiopathic normal pressure hydrocephalus.

Background: The objective was to identify changes in quantitative MRI measures in patients with idiopathic normal pressure hydrocephalus (iNPH) occurring in common after oral acetazolamide (ACZ) and external lumbar drainage (ELD) interventions.

Methods: A total of 25 iNPH patients from two clinical sites underwent serial MRIs and clinical assessments. Eight received ACZ (125-375 mg/day) over 3 months and 12 underwent ELD for up to 72 hours.

High-resolution mechanical imaging of glioblastoma by multifrequency magnetic resonance elastography.

Objective: To generate high-resolution maps of the viscoelastic properties of human brain parenchyma for presurgical quantitative assessment in glioblastoma (GB).

Methods: Twenty-two GB patients underwent routine presurgical work-up supplemented by additional multifrequency magnetic resonance elastography. Two three-dimensional viscoelastic parameter maps, magnitude |G*|, and phase angle φ of the complex shear modulus were reconstructed by inversion of full wave field data in 2-mm isotropic resolution at seven harmonic drive frequencies ranging from 30 to 60 Hz.

Multisite longitudinal reliability of tract-based spatial statistics in diffusion tensor imaging of healthy elderly subjects.

Large-scale longitudinal neuroimaging studies with diffusion imaging techniques are necessary to test and validate models of white matter neurophysiological processes that change in time, both in healthy and diseased brains. The predictive power of such longitudinal models will always be limited by the reproducibility of repeated measures acquired during different sessions. At present, there is limited quantitative knowledge about the across-session reproducibility of standard diffusion metrics in 3T multi-centric studies on subjects in stable conditions, in particular when using tract based spatial statistics and with elderly people.

Seven-tesla magnetic resonance imaging in Wilson disease using quantitative susceptibility mapping for measurement of copper accumulation.

Objectives: In Wilson disease (WD), the copper content of cerebral tissue is increased, particularly in the basal ganglia. This study investigated whether a change in magnetic susceptibility can be detected using quantitative susceptibility mapping of the brain in patients with WD compared with healthy controls.

Materials And Methods: Eleven patients with WD (6 with the neurological form, 5 with the hepatic form) and 10 age-matched healthy controls who gave informed consent were examined at 7 T in a whole-body scanner (MAGNETOM; Siemens Medical Solutions, Erlangen, Germany) using a 24-channel phased array coil (Nova Medical).

The influence of lumbar spinal drainage on diffusion parameters in patients with suspected normal pressure hydrocephalus using 3T MRI.

Background: Normal pressure hydrocephalus (NPH) has been an ongoing and challenging field of research for the past decades because two main issues are still not fully understood: the pathophysiologic mechanisms underlying ventricular enlargement and prediction of outcome after surgery.

Purpose: To evaluate changes in diffusion tensor imaging (DTI) derived parameters in patients with suspected normal pressure hydrocephalus before and after withdrawal of cerebrospinal fluid (CSF).

Material And Methods: Twenty-four consecutive patients with clinical and radiological suspicion of NPH and 14 age-matched control subjects were examined with DTI on a clinical 3T scanner.

Improvement of SNR and acquisition acceleration using a 32-channel head coil compared to a 12-channel head coil at 3T.

Background: Magnetic resonance imaging (MRI) techniques continue to improve in manifold ways. Besides field strength and sequence optimization, technical advances in coil design and sensitivity yield to increase the signal detection and therefore improve image quality.

Purpose: To evaluate the performance of signal-to-noise ratio (SNR) and parallel acquisition technique (PAT) acceleration of a dedicated 32-channel head coil compared with a standard 12-channel head coil.

Novel technique for MR elastography of the prostate using a modified standard endorectal coil as actuator.

Purpose: To present a novel method for MR elastography (MRE) of the prostate at 3 Tesla using a modified endorectal imaging coil.

Materials And Methods: A commercial endorectal coil was modified to dynamically generate mechanical stress (contraction and dilation) in a prostate phantom with embedded phantom "lesions" (6 mm diameter) and in a porcine model. Resulting tissue displacements were measured with a motion-sensitive EPI sequence at actuation frequencies of 50-200 Hz.

Diagnostic value of ADC in patients with prostate cancer: influence of the choice of b values.

Objectives: To evaluate the influence of the choice of b values on the diagnostic value of the apparent diffusion coefficient (ADC) for detection and grading of prostate cancer (PCa).

Methods: Forty-one patients with biopsy-proven PCa underwent endorectal 3-T MRI before prostatectomy. Different combinations of b values (0-800 s/mm(2)) were used to calculate four representative ADC maps.

Pyogenic osteomyelitis of the vertebral arch in children.

Vertebral infection represents 2% to 4% of all cases of osteomyelitis in children. Extension of vertebral osteomyelitis into the vertebral arch is rare; and exclusive pyogenic involvement is exceedingly rare, especially in children. A review of the literature revealed less than 25 combined cases, most of them reported in the beginning of the 20th century without cross-sectional imaging.

Yersinia enterocolitica-associated generalized microinfarctions of bone and spleen in a child.

We report a case of unusual extraintestinal yersiniosis in a 16-year-old girl with generalized microinfarctions of the bone and spleen. For the past 2 years she had been repeatedly admitted to our hospital with reactive arthritis, erythema nodosum and iridocyclitis of unknown aetiology. Ultrasound showed multiple round hypoechoic lesions in the spleen that were shown to have low T2 signal on MRI.

Correction for partial volume errors in MR heart perfusion imaging.

Myocardial MR first-pass perfusion time courses are contaminated by signals from the ventricles (spillover) as a consequence of partial volume effects and motion. An early increase in the signal intensity from the myocardium is an indicator of contamination. This contamination leads to under- or overestimation of perfusion, depending on the amount of contamination.