MRI in Menière’s Disease

The visualization of the morphologic substrate of Menière’s disease -the endolymphatic hydrops – can be performed using non-contrast as well as contrast-enhanced magnetic resonance imaging techniques. The non-contrast magnetic resonance imaging technique uses a heavily T2-weighted sequence; however, the reproducibility of this technique remains to be confirmed. The contrast-enhanced techniques most frequently use a 3-dimensional fluid-attenuated inversion recovery sequence or a real 3-dimensional inversion recovery sequence either after intratympanic gadolinium administration either 4 hours after intravenous gadolinium administration. The latter is the most frequently used technique and is able to detect definite Menière’s disease with a high sensitivity and specificity. It has been proven to be a reliable technique with a high diagnostic accuracy, enabling the visualization of endolymphatic hydrops

Cochlear erosion due to a facial nerve schwannoma

Facial nerve schwannomas are rare benign neoplasms. We report a case of a 60-year-old woman who initially presented with vestibular complaints. Magnetic resonance imaging (MRI) revealed a facial nerve schwannoma centered on the right geniculate ganglion extending in the labyrinthine segment. The patient consulted again after 2 months because she developed a sudden and severe right-sided sensorineural hearing loss. MRI showed no progression or pathological enhancement in the membranous labyrinth. A cone beam computed tomography (CT) of the temporal bone was performed and revealed a large erosion at the region of the geniculate ganglion in open communication with the middle turn of the cochlea. This case report demonstrates the importance of CT in facial nerve schwannomas for evaluating the impact on the surrounding structures

Imaging of radiolucent jaw lesions

Radiolucent lesions in the jaw bones comprise a whole spectrum of odontogenic and nonodontogenic lesions. Although the imaging appearance is not always specific, careful radiologic analysis may contribute to characterization of these lesions. A useful approach is to first analyze the absence or presence of a relationship of the lesion to the teeth. The relation may be either near the tooth apex or crown of the tooth. Other lesions may or may not show any specific anatomical location. After analysis of the primary location of the lesion, additional criteria that may help in further imaging characterization are lesion demarcation and morphology, involvement of the cortex and periosteum, and soft tissue changes. This article describes the most characteristic and prevalent radiolucent lesions of the jaws at each location. In routine clinical practice, cone beam computed tomography is sufficient for appropriate lesion characterization, although magnetic resonance imaging may be useful in selected cases

Staff Development Volume 6

23 cm; 234 ha

Imaging of radiolucent jaw lesions

Radiolucent lesions in the jaw bones comprise a whole spectrum of odontogenic and nonodontogenic lesions. Although the imaging appearance is not always specific, careful radiologic analysis may contribute to characterization of these lesions. A useful approach is to first analyze the absence or presence of a relationship of the lesion to the teeth. The relation may be either near the tooth apex or crown of the tooth. Other lesions may or may not show any specific anatomical location. After analysis of the primary location of the lesion, additional criteria that may help in further imaging characterization are lesion demarcation and morphology, involvement of the cortex and periosteum, and soft tissue changes. This article describes the most characteristic and prevalent radiolucent lesions of the jaws at each location. In routine clinical practice, cone beam computed tomography is sufficient for appropriate lesion characterization, although magnetic resonance imaging may be useful in selected cases

Imaging anatomy of the jaw and dentition with cone beam computed tomography

Knowledge of dental, maxillary, and mandibular anatomy and the use of correct nomenclature is critical in the evaluation of a mandibulofacial and/or maxillofacial imaging data set. The use of the correct diagnostic imaging tool tailored to the patient's needs is of equal importance. This article highlights imaging anatomy and cross-sectional imaging modalities mainly focusing on cone beam computed tomography of the mandibulofacial and maxillofacial region

A case of a temporal bone meningioma presenting as a serous otitis media

We report the imaging features of a case of a temporal bone meningioma extending into the middle ear cavity and clinically presenting as a serous otitis media. Temporal bone meningioma extending in the mastoid or the middle ear cavity, however, is very rare. In case of unexplained or therapy-resistant serous otitis media and a nasopharyngeal tumor being ruled out, a temporal bone computed tomography (CT) should be performed. If CT findings are suggestive of a temporal bone meningioma, a magnetic resonance imaging (MRI) examination with gadolinium will confirm diagnosis and show the exact extension of the lesion

Aberrant internal carotid artery presenting as a retrotympanic vascular mass

We report a case of a young woman with an aberrant right internal carotid artery (ICA) presenting as a retrotympanic reddish mass. This variant of the ICA represents the collateral pathway that is formed as a result of an embryological agenesis of the cervical segment of the ICA. The embryonic inferior tympanic artery is recruited to bypass the absent carotid segment. This hypertrophied vessel may be seen otoscopically and wrongfully considered to be a vascular middle ear tumor. Informing the otorhinolaryngologist of this important vascular variant not only obviates biopsy but also helps in careful preoperative planning of eventual middle ear procedures