ISSN:0899-3459    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The clinical course of acute otitis media is usually short, and the process terminates because of the host's immune system, the infection-resistant properties of the mucosal linings, and the susceptibility of the major organisms (beta-hemolytic streptococcus or pneumococcus) to penicillin. However, a small proportion (1% to 5%) of untreated or inadequately treated patients may experience complications. Prior to the development of an intracranial complication of otomastoiditis, warning symptoms or signs may be evident; these include severe earache, severe headache, vertigo, chills and fever, and meningeal symptoms and signs. Increasing headache, particularly temporoparietal headache near the affected ear, often indicates an impending intracranial complication. This symptom, often the only indication of an epidural abscess, demands prompt investigation and medical and surgical intervention. In our experience, computed tomography (CT) permits accurate diagnosis of acute coalescent or latent (masked) mastoiditis and its associated complications. However, magnetic resonance imaging (MRI) remains the study of choice to evaluate otogenic intracranial complications. This article demonstrates the important role of MRI in diagnosing various stages of acute otomastoiditis and its associated complications.

ISSN:0899-3459    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Magnetic resonance imaging (MRI) can be of significant benefit in characterizing expansile lesions of the petrous apex. MRI can be of particular help in distinguishing congenital cholesteatoma from cholesterol granuloma. Furthermore, with the advent of faster high-resolution scanning techniques, MRI can define precise spatial relationships of these masses with the middle and inner ear structures, internal carotid artery, jugular vein, and other structures of the skull base. MRI scanning is sensitive in detecting intracranial extension of these masses. MR angiography can provide additional information regarding the relationship of these masses with adjacent vascular structures and confirm patency of the adjacent vessels. In the postoperative period, MR scanning can help evaluate for complete removal, complication, recurrence, or formation of complicating granulation tissue.

ISSN:0899-3459    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The cerebellopontine (CP) angle is bound anterolaterally by the posterior aspect of the petrous temporal bone and posteromedially by the cerebellum and pons. It contains important vascular structures and cranial nerves and is subject to a certain gamut of lesions, notably tumors with interesting radiological manifestations. Radiological investigation of these lesions has seen significant improvement in recent decades. Magnetic resonance is the imaging modality of choice for lesions of the CP angle and internal auditory canal. Lesions of the CP angles usually are divided into those native to the angle (vestibular schwannoma, meningioma, epidermoid, arachnoid cyst, metastases, lipoma, etc.) and those extending to the angle from adjacent structures (gliomas, ependymomas, choroid plexus papillomas, vascular malformations). Vestibular schwannomas are by far the most important lesion of the CP angle.

ISSN:0899-3459    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Paragangliomas, also known as glomus tumors or chemodectomas, are tumors arising from chemoreceptor tissue (paraganglia), which are neural crest in origin and found in higher concentration along the glossopharyngeal and vagal cranial nerve. Three types of paragangliomas are related with the temporal bone: glomus tympanicum, glomus jugulare, and glomus vagale. The role of computed tomography (CT) and magnetic resonance imaging (MRI) in diagnosing these types of tumors is discussed, along with the importance of arteriography in aiding the diagnosis and treatment. This article discusses the choice between CT and MR based on clinical symptoms and tumor location, and illustrates the newest CT, MR, and angiography applications. A brief discussion on treatment options is given

ISSN:0899-3459    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

There are many vascular and neoplastic diseases as well as normal variants that produce the vestibulocochlear symptoms of pulsatile tinnitus, hearing loss, dizziness, and ataxia. Magnetic resonance imaging may be diagnostic, and magnetic resonance angiography/magnetic resonance venography have added to the ability of magnetic resonance to image vascular abnormalities. The extent of neoplasms is accurately assessed and complication of vascular lesions are clearly seen. However, detailed vascular anatomy requires high-quality selective angiography. This enables optimal treatment planning. Endovascular therapeutic intervention has a major role to play in conjunction with surgery of skull base lesions and may be curative in certain conditions, avoiding major surgical procedures. The interventionalist, however, must have an excellent knowledge of the external carotid circulation and all of its potential communications with the internal circulation to avoid serious embolic complications.

ISSN:0899-3459    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The spectrum of disease that affects the temporomandibular joint (TMJ) can be varied. To differentiate among the diseases that cause pain and dysfunction, an intimate knowledge of the anatomy, physiology, and pathology of this region is necessary. Due to the joint's complex anatomy and relationship to the skin, it has been difficult to image in the past. Magnetic resonance imaging is ideally suited for visualizing TMJ because of its superb contrast resolution when imaging soft tissues. Magnetic resonance imaging allows simultaneous bilateral visualization of both joints. The ability to noninvasively resolve anatomic detail can be performed easily and quickly using magnetic resonance imaging. The development of magnetic resonance imaging has greatly aided the diagnosis of TMJ disorders. An understanding of TMJ anatomy and pathogenesis of TMJ pain is crucial for interpretation of magnetic resonance imaging and subsequent treatment.

ISSN:0899-3459    

出版商:OVID    

年代:2000

数据来源: OVID