ABSTRACT
Detecting a new area of contrast-enhancement at MRI after irradiation of malignant brain tumor arises the problem of differential diagnosis between tumor recurrence and radiation necrosis induced by the treatment. The challenge for imaging is to distinguish the two diagnoses given: the prognostic and therapeutic issues. Various criteria have been proposed in the literature based on morphological, functional or metabolic MRI. The purpose of this study was to perform an analysis of these tools to identify MRI best criteria to differentiate radiation necrosis lesions from malignant gliomas and brain metastases recurrence. For gliomas, the morphology of the contrast-enhancement cannot guide the diagnosis and the use of perfusion techniques and spectroscopy (multivoxels if possible) are necessary. In the follow-up of metastasis, a transient increase and moderate lesion volume is possible with a good prognosis. Morphological characteristics (volume ratio T2/T1Gd) and perfusion analysis provide valuable tools for approaching the diagnosis of radionecrosis.
Subject(s)
Brain Neoplasms/pathology , Brain Neoplasms/radiotherapy , Glioma/pathology , Glioma/radiotherapy , Magnetic Resonance Imaging/methods , HumansABSTRACT
Early-onset dementias are defined by onset of first symptoms before the age of 65. They have specific diagnostic features which differ from those of elderly patients in terms of their many causes and atypical clinical presentations. MRI is an essential procedure for identifying the underlying cause of the dementia (degenerative, vascular, infectious, inflammatory, metabolic or toxic). Clinical clues and MRI signs are described, and their defining features are related to the young age of the patients concerned. Diagnostic algorithms are proposed from signs which can be seen on the different MRI sequences (T1-weighted volume acquisition, T2-weighted FLAIR sequences, T2-weighted gradient-echo, diffusion-weighted imaging). Once obvious causes have been excluded, MRI can point towards the rarer causes of dementia which are characteristic in young people (particularly metabolic and autoimmune) and which require specific management and genetic counseling.
Subject(s)
Dementia/diagnosis , Dementia/etiology , Magnetic Resonance Imaging , Age of Onset , Algorithms , Central Nervous System Infections/complications , Dementia, Vascular/complications , Humans , Metabolic Diseases/complications , Neurodegenerative Diseases/complicationsSubject(s)
Antibodies, Anticardiolipin/analysis , Cytomegalovirus Infections/immunology , Stroke/immunology , Adult , Antibodies, Antiphospholipid/analysis , Brain Ischemia/etiology , Cytomegalovirus Infections/complications , Humans , Infarction, Middle Cerebral Artery/pathology , Infectious Mononucleosis/immunology , Infectious Mononucleosis/pathology , Magnetic Resonance Imaging , Male , Stroke/complicationsSubject(s)
Brain Diseases, Metabolic, Inborn/diagnosis , Cystinosis/diagnosis , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Brain/drug effects , Brain/pathology , Brain Diseases, Metabolic, Inborn/drug therapy , Cerebral Arteries/pathology , Child , Cysteamine/therapeutic use , Cystinosis/drug therapy , Follow-Up Studies , Humans , Immunosuppressive Agents/therapeutic use , Kidney Transplantation , Male , Medication Adherence , Neurologic ExaminationABSTRACT
Autism is a pervasive disorder of childhood development. Polymorphous clinical profiles combining various degrees of communication and social interaction with restricted and stereotyped behaviour are grouped under the heading of 'autism spectrum disorders' (ASD). Many teams are trying to pick out the underlying cerebral abnormalities in order to understand the neuronal networks involved in relationships with others. Here we review the morphological, spectroscopic and functional abnormalities in the amygdala-hippocampal circuit, the caudate nuclei, the cerebellum, and the frontotemporal regions, which have been described in subjects with ASD. White matter abnormalities have also been described in diffusion tensor imaging, leading to suspected damage to the subjacent neural networks, such as mirror neurones or the social brain.
Subject(s)
Brain/pathology , Brain/physiopathology , Child Development Disorders, Pervasive/diagnosis , Child Development Disorders, Pervasive/physiopathology , Diffusion Magnetic Resonance Imaging , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Magnetic Resonance Imaging , Tomography, Emission-Computed, Single-Photon , Brain/abnormalities , Brain Mapping , Child , Child Development Disorders, Pervasive/pathology , Child, Preschool , Dominance, Cerebral/physiology , Facial Expression , Humans , Interdisciplinary Communication , Mirror Neurons/pathology , Mirror Neurons/physiology , Neural Pathways/pathology , Neural Pathways/physiopathology , Patient Care Team , Pattern Recognition, Visual/physiologyABSTRACT
OBJECTIVE: To report the clinical and radiological features of temporal bone metastases and their association with primary lung cancer. CASE REPORTS: Both patients complained of headache, cochlear signs or cranial nerve palsy. Computed tomography of the petrous temporal bones and magnetic resonance imaging showed an osteolytic lesion of the temporal bone. The preoperative work-up was completed by chest, abdomen and pelvis computed tomography and positron emission tomography. Bronchoscopic biopsies confirmed the diagnosis of lung cancer. DISCUSSION/CONCLUSION: The discovery of an osteolytic lesion of the temporal bone requires an aetiological work-up, including the search for a lung tumour based on the hypothesis of temporal bone metastasis. Positron emission tomography should now be performed in the context of such lesions. Management consists of palliative chemotherapy and analgesic radiotherapy.
