Showing papers by "Alex Rovira published in 2012"

MR Imaging of Neoplastic Central Nervous System Lesions: Review and Recommendations for Current Practice

Abstract: MR imaging is the preferred technique for the diagnosis, treatment planning, and monitoring of patients with neoplastic CNS lesions. Conventional MR imaging, with gadolinium-based contrast enhancement, is increasingly combined with advanced, functional MR imaging techniques to offer morphologic, metabolic, and physiologic information. This article provides updated recommendations to neuroradiologists, neuro-oncologists, neurosurgeons, and radiation oncologists on the practical applications of MR imaging of neoplastic CNS lesions in adults, with particular focus on gliomas, based on a review of the clinical trial evidence and personal experiences shared at a recent international meeting of experts in neuroradiology, neuro-oncology, neurosurgery, and radio-oncology.

Automated detection of multiple sclerosis lesions in serial brain MRI

Abstract: Multiple sclerosis (MS) is a serious disease typically occurring in the brain whose diagnosis and efficacy of treatment monitoring are vital. Magnetic resonance imaging (MRI) is frequently used in serial brain imaging due to the rich and detailed information provided. Time-series analysis of images is widely used for MS diagnosis and patient follow-up. However, conventional manual methods are time-consuming, subjective, and error-prone. Thus, the development of automated techniques for the detection and quantification of MS lesions is a major challenge. This paper presents an up-to-date review of the approaches which deal with the time-series analysis of brain MRI for detecting active MS lesions and quantifying lesion load change. We provide a comprehensive reference source for researchers in which several approaches to change detection and quantification of MS lesions are investigated and classified. We also analyze the results provided by the approaches, discuss open problems, and point out possible future trends. Lesion detection approaches are required for the detection of static lesions and for diagnostic purposes, while either quantification of detected lesions or change detection algorithms are needed to follow up MS patients. However, there is not yet a single approach that can emerge as a standard for the clinical practice, automatically providing an accurate MS lesion evolution quantification. Future trends will focus on combining the lesion detection in single studies with the analysis of the change detection in serial MRI.

MMP-2/MMP-9 plasma level and brain expression in cerebral amyloid angiopathy-associated hemorrhagic stroke.

Abstract: Cerebral amyloid angiopathy (CAA) is one of the main causes of intracerebral hemorrhage (ICH) in the elderly. Matrix metalloproteinases (MMPs) have been implicated in blood-brain barrier disruption and ICH pathogenesis. In this study, we determined the levels MMP-2 and MMP-9 in plasma and their brain expression in CAA-associated hemorrhagic stroke. Although MMP-2 and MMP-9 plasma levels did not differ among patients and controls, their brain expression was increased in perihematoma areas of CAA-related hemorrhagic strokes compared with contralateral areas and nonhemorrhagic brains. In addition, MMP-2 reactivity was found in β-amyloid (Aβ)-damaged vessels located far from the acute ICH and in chronic microbleeds. MMP-2 expression was associated to endothelial cells, histiocytes and reactive astrocytes, whereas MMP-9 expression was restricted to inflammatory cells. In summary, MMP-2 expression within and around Aβ-compromised vessels might contribute to the vasculature fatal fate, triggering an eventual bleeding.

Plasma β-Amyloid Levels in Cerebral Amyloid Angiopathy-Associated Hemorrhagic Stroke

Abstract: Background: Cerebral amyloid angiopathy (CAA) is one of the main causes of intracerebral hemorrhage (ICH) in the elderly. Objective: To analyze β-amyloid (Aβ) species in plasma in order to uncover biological markers that may contribute to improve the diagnosis of CAA in life. Methods: We determined the level of Aβ(1–40), Aβ(N–40), Aβ(1–42) and Aβ(N–42) in plasma of CAA-related ICH patients (n = 29) and healthy controls (n = 21) using xMAP® technology. Hemorrhages were identified and classified using a CT scan and brain MRI. Patients were clinically classified as probable or possible CAA according to the Boston criteria. Results: We found that plasma full-length Aβ(1–42) and truncated fragments Aβ(N–42) were higher in probable CAA patients than in controls (p Conclusion: Our results suggest that specific Aβ fragments in plasma might be considered as potential biomarkers for the diagnosis of CAA.

Nigrostriatal pathway dysfunction in a methanol-induced delayed dystonia-parkinsonism.

Abstract: Images correspond to an 18-year-old woman with delayed-onset parkinsonism-dystonia and hypophonia 3 months after methanol intoxication (see video). MRI of the brain showed bilateral necrohemorrhagic lesions in the putamen (Fig. 1A), and dopamine transporter 123-I-Ioflupane single-photon emission computed tomography (SPECT) revealed bilateral nigroestriatal denervation (Fig. 1C). Bilateral necrosis of the putamen is the most characteristic finding, but presynaptic dopaminergic denervation has not been previously reported in methanol poisoning. FIG. 1. (A) Turbo spin echo T2-weighted MRI: increased signal in both putamen resulting from necrosis and signal abnormality in corona radiata and internal capsule resulting from edema. (B) Arterial spin-labeled MRI: lack of perfusion in both putamen preserving caudate nuclei. (C) [123-I]FP-CIT SPECT: severe bilateral putaminal low uptaking. (D) T1-weighted MRI images fused with [123-I]-FP-CIT SPECT: dopamine transporter loss corresponding to both putamen.