Proton MR spectroscopy in predicting the increase of perfusion MR imaging for WHO grade II gliomas.

Purpose: To investigate the correlation between the metabolite ratios obtained from proton magnetic resonance (MR) spectroscopy and those obtained from MR perfusion parameters (relative cerebral blood volume [rCBV]) in a cohort of low-grade glioma (LGG).

Materials And Methods: Patients underwent prospectively conventional MR, proton magnetic resonance spectroscopy ((1) HMRS), and perfusion-weighted images (PWI). Statistical analyses were performed to determine the correlative and independent predictive factors of rCBVmax and the metabolite ratio thresholds with optimum sensitivity and specificity.

Mathematical modeling of energy metabolism and hemodynamics of WHO grade II gliomas using in vivo MR data.

Therapeutic management of low-grade gliomas (LGG) is a challenge because they have undergone anaplastic transformation with variable delay. Today, only progressive volume growth on successive MRI allows an in vivo monitoring of this evolution. On the other hand, multinuclear spectroscopy and perfusion available during MRI may also provide assessment of metabolic changes underlying morphological modifications.

Proton magnetic resonance spectroscopy predicts proliferative activity in diffuse low-grade gliomas.

The aim of the study was to investigate the ability of (1)HMRS to reflect proliferative activity of diffuse low-grade gliomas (WHO grade II). Between November 2002 and March 2007, a prospective study was performed on consecutive patients with suspected supratentorial hemispheric diffuse low-grade tumors. All the patients underwent MR examination using uniform procedures, and then surgical resection or biopsy within 2 weeks of the MR examination.

Brain lymphoma: usefulness of the magnetic resonance spectroscopy.

The diagnosis of primary central nervous system lymphoma (PCNSL) should always be considered as an emergency because of the therapeutic consequences it implies. In immunocompetent patients, it relies on stereotactic biopsy. Unfortunately, clinical and radiological features may be misleading and delay the diagnostic procedure.

Usefulness of magnetic resonance spectroscopy in urea cycle disorders.

Late-onset urea cycle disorders are characterized by chronic encephalopathy and a risk of hyperammonemic crises triggered by environmental stressors. Reported here is the case of a 30-year-old woman with chronic encephalopathy due to argininosuccinate lyase deficiency. Cerebral proton magnetic resonance spectroscopy showed brain creatine deficiency and its normalization during treatment.

[Cerebral tumours: which images?].

Magnetic resonance imaging became the gold standard examination of pretherapeutic planning and post-treatment follow-up of cerebral tumours, even if computed tomography remains useful. During the last years, many new modalities of magnetic resonance examination arose, thus leading to increase its specificity. Then, spectroscopy allows better understanding of tumoural metabolism, whereas perfusion weighted imaging provides informations on its neovascularisation.

Characterization and correction of distortions in stereotactic magnetic resonance imaging for bilateral subthalamic stimulation in Parkinson disease.

Object: High-frequency stimulation of the subthalamic nucleus (STN) is effective for treating refractory idiopathic Parkinson disease (PD). In stereotactic conditions magnetic resonance (MR) imaging is used by many teams to perform preoperative targeting of the STN. The goal of this study was to analyze and correct the geometrically observed MR imaging acquisitions used for targeting of the STN.

Is the subthalamic nucleus hypointense on T2-weighted images? A correlation study using MR imaging and stereotactic atlas data.

Background And Purpose: Although the subthalamic nucleus is the most frequently used target for surgical treatment of Parkinson's disease, the criteria on which it can be identified on T2-weighted images have never been clearly defined. This study was conducted to characterize the precise anatomic distribution of T2-weighted hyposignal in the subthalamic region and to correlate this hyposignal with iron content in the subthalamic nucleus.

Methods: The T2-weighted MR imaging acquisitions of 15 patients with Parkinson's disease were fused with a digitized version of the Schaltenbrand and Wahren anatomic atlas.