Posterior Fossa Tumors.

Pediatric brain tumors are the leading cause of death from solid tumors in childhood. The most common posterior fossa tumors in children are medulloblastoma, atypical teratoid/rhabdoid tumor, cerebellar pilocytic astrocytoma, ependymoma, and brainstem glioma. Location, and imaging findings on computed tomography (CT) and conventional MR (cMR) imaging may provide important clues to the most likely diagnosis. Moreover, information obtained from advanced MR imaging techniques increase diagnostic confidence and help distinguish between different histologic tumor types. Here we discuss the most common posterior fossa tumors in children, including typical imaging findings on CT, cMR imaging, and advanced MR imaging studies.

Lymphomas-Part 1.

Primary central nervous system lymphomas are aggressive, high-cell-density tumors. There is recent increase in their incidence in immunocompetent patients. Knowledge of imaging findings on computed tomography and conventional MR imaging is important to suggest the diagnosis. Moreover, information obtained from advanced MR imaging techniques, such as diffusion-weighted imaging, diffusion tensor imaging, MR spectroscopy, perfusion-weighted imaging, and dynamic contrast-enhanced studies, increases diagnostic confidence and helps distinguish them from other aggressive intracranial tumors. This article discusses typical imaging findings of primary and secondary central nervous system lymphomas on computed tomography and conventional MR imaging, advanced MR imaging techniques, and changes related to steroid therapy.

Lymphomas-Part 2.

There are 2 types of central nervous system lymphoma: primary and secondary. Both have variable imaging features making them diagnostic challenges. Furthermore, a patient's immune status significantly alters the imaging findings. Familiarity with typical appearances, variations, and common mimics aids radiologists in appropriately considering lymphoma in the differential diagnosis. Moreover, special types of lymphoma, such as lymphomatosis cerebri, intravascular lymphoma, and lymphomatoid granulomatosis, also are found. This article discusses uncommon types of lymphoma and the differential diagnosis for focal, multifocal, meningeal, and infiltrative lymphomas.

Adult Brain Tumors: Clinical Applications of Magnetic Resonance Spectroscopy.

Proton magnetic resonance spectroscopy (H-MRS) may be helpful in suggesting tumor histology and tumor grade and may better define tumor extension and the ideal site for biopsy compared with conventional magnetic resonance (MR) imaging. A multifunctional approach with diffusion-weighted imaging, perfusion-weighted imaging, and permeability maps, along with H-MRS, may enhance the accuracy of the diagnosis and characterization of brain tumors and estimation of therapeutic response. Integration of advanced imaging techniques with conventional MR imaging and the clinical history help to improve the accuracy, sensitivity, and specificity in differentiating tumors and nonneoplastic lesions.

Hypoxic-ischemic injuries: the role of magnetic resonance spectroscopy.

Hypoxic ischemic injuries are a very common clinical situation in the pediatric population. This article focuses on the metabolic signature of hypoxic ischemic injuries and metabolic indicators of prognosis.

Pediatric brain tumors.

Pediatric brain tumors are the most common solid tumor of childhood. This article focuses on the metabolic signature of common pediatric brain tumors using MR spectroscopic analyses.

Adult brain tumors: clinical applications of magnetic resonance spectroscopy.

Proton magnetic resonance spectroscopy (H-MRS) may be helpful in suggesting tumor histology and tumor grade and may better define tumor extension and the ideal site for biopsy compared with conventional magnetic resonance (MR) imaging. A multifunctional approach with diffusion-weighted imaging, perfusion-weighted imaging, and permeability maps, along with H-MRS, may enhance the accuracy of the diagnosis and characterization of brain tumors and estimation of therapeutic response. Integration of advanced imaging techniques with conventional MR imaging and the clinical history help to improve the accuracy, sensitivity, and specificity in differentiating tumors and nonneoplastic lesions.

Brain tumors: a multimodality approach with diffusion-weighted imaging, diffusion tensor imaging, magnetic resonance spectroscopy, dynamic susceptibility contrast and dynamic contrast-enhanced magnetic resonance imaging.

This article focuses on advanced magnetic resonance (MR) imaging techniques and how they can be used to help diagnose a specific tumor, suggest tumor grade and prognosis, follow tumor progression, evaluate tumor extension, suggest the ideal site for biopsy, and assess therapeutic response. Advanced MR imaging techniques may also help to distinguish between lesions that simulate brain tumors on conventional MR imaging studies.

Demências rapidamente progressivas. Importância da neuroimagem nas etapas diagnósticas. / Rapidly progressive dementias. Importance of neuroimage in the diagnostic steps.

As demências rapidamente progressivas constituem um grupo heterogêneo de condições clínicas (neurodegenerativas, vasculares, infecciosas, imunomediadas, tóxicas, metabólicas, tumorais, psicogênicas) e cirúrgicas. Avaliação detalhada é imprescindível, devendo ser seguido protocolo extenso constituído por diversas etapas diagnósticas, que compreendem anamnese detalhada, exames clínico e neurológico, e avaliação complementar. É ressaltada a importância da neuroimagem (RM estrutural do cérebro), sendo apresentadas imagens ilustrativas características das principais condições.

Rapidly progressive dementias constitute a heterogeneous group of clinical (neurodegenerative, vascular, infectious, immunomediated, toxic, metabolic, tumoral, psychogenic) and surgical conditions. Detailed evaluation is essential, and an extensive protocol constituted by several diagnostic steps must be followed, which include detailed anamnesis, clinical and neurological examination, and complementary assessment. The importance of neuroimage (structural MRI of the brain) is highlighted, and illustrative images characteristic of the main conditions are presented.

Neuroma de Morton: diagnóstico pela ressonância magnética / Morton's neuroma: diagnosis by magnetic resonance

Os autores apresentam quatro casos de pacientes com quadro clínico de neuroma interdigital plantar (neuroma de Morton), cujos diagnósticos foram confirmados pela ressonância magnética.

Ossículo meniscal: relato de um caso e diagnóstico pela ressonância magnética / Meniscus ossiculum: report of a case and doagnosis by MRI

Os autores apresentam um caso de ossículo intrameniscal, enfatizando ser patologia rara, mas que deve ser pensada no diagnóstico diferencial de calcificaçäo intrameniscal e corpo livre intra-articular em funçäo do tratamento diferenciado. Enfatizam a contribuiçäo da ressonância magnética para diagnosticar ou confirmar a patologia.

Síndrome de Hughes-Stovin: relato de um caso / Hughes-Stovin syndrome: a case report

Relata caso de paciente que desenvolveu hipertensäo intracraniana por trombose do seio digital. Evolui, meses depois, com embolia pulmonar e trombose venosa profunda do membro inferior direito. Ocorreu óbito por hemoptise maciça. Na avaliaçäo radiológica do tórax, realizada por meio de telerradiografias, tomografia linear, tomografia computadorizada e arteriografia pulmonar, ficou caracterizada a presença de aneurismas das artérias pulmonares, bilateralmente