Thyroid ophthalmopathy is an autoimmune orbital disorder closely associated with Graves' disease, although both conditions may also occur isolatedly. Thyroid ophthalmopathy may precede, coincide or follow the thyroid dysfunction onset and may rarely occur in euthyroid and hypothyroid patients. The extraocular muscles are most frequently involved and become enlarged resulting in ophthalmoplegia and proptosis. Other relevant signs include palpebral retraction, conjuctival hyperemia and periorbitary edema. Visual loss may occur in association with compressive optic neuropathy at the orbital apex. Thyroid ophthalmopathy is characterized by inflammation, congestion, hypertrophy and fibrosis involving fat and the orbital muscles. The disease activity is divided into two phases: an acute or inflammatory phase and a second one corresponding to an inactive phase associated with fibrotic changes and fat infiltration of the retrobulbar tissues. The diagnosis is based on clinical findings and imaging methods are indicated in case of doubt or suspicion of optic neuropathy. Computed tomography and magnetic resonance imaging can confirm the diagnosis, allowing the evaluation of the critical region of the orbital apex. Magnetic resonance imaging is the method of choice considering the superior tissue contrast resolution, besides the capacity of evaluating the disease activity by means of long TR sequences and detecting inflammatory changes, with a relevant role in a timely therapeutic planning, which may improve the prognosis.

Keywords: Thyroid ophthalmopathy, Extraocular muscles, Magnetic resonance imaging, Computed tomography

Vocal cord paralysis is a common cause of hoarseness. It may be secondary to many types of lesions along the cranial nerve X pathway and its branches, particularly the laryngeal recurrent nerves. Despite the idiopathic nature of a great number of cases, imaging methods play a very significant role in the investigation of etiologic factors, such as thyroid and esophagus neoplasias with secondary invasion of the laryngeal recurrent nerves. Other conditions such as aortic and right subclavian artery aneurysms also may be found. The knowledge of local anatomy and related diseases is of great importance for the radiologist, so that he can tailor the examination properly to allow an appropriate diagnosis and therapy planning. Additionally, considering that up to 35% of patients with vocal cord paralysis are asymptomatic, the recognition of radiological findings indicative of this condition is essential for the radiologist who must warn the referring physician on the imaging findings. In the present study, the authors review the anatomy and main diseases related to vocal cord paralysis, demonstrating them through typical cases evaluated by computed tomography and magnetic resonance imaging, besides describing radiological findings of laryngeal abnormalities indicative of this condition.

Keywords: Vocal cord, Paralysis, Imaging

Several diseases should be considered in the differential diagnosis of disorders affecting the temporomandibular joints. Internal derangement is the main condition responsible for pain related to this joint. Clinical signs may, though, be quite non-specific, and many other conditions present with similar and not infrequently indistinguishable signs and symptoms. In the present study, the authors describe several non-dysfunctional conditions affecting the temporomandibular joints through computed tomography and magnetic resonance imaging, emphasizing the importance of these imaging methods in the diagnosis of inflammatory, neoplastic and traumatic diseases of this region. Considering that clinical presentations are frequently non-specific, radiologists play a critical role in the differential diagnosis.

Keywords: Temporomandibular joint, Computed tomography, Magnetic resonance imaging

The aim of this study is to review the anatomy and main pathologic conditions affecting cranial nerve III using imaging studies, particularly magnetic resonance imaging. Imaging methods are essential in the evaluation of patients with suspected lesions of the oculomotor nerve once signs and symptoms are unspecific and a large number of diseases can affect cranial nerve III. A brief review of the literature is also presented.

Keywords: Isolated disfunction of oculomotor nerve, Computed tomography, Magnetic resonance imaging

Cholesteatomas are cystic lesions which may be either congenital or acquired, affecting the ears and presenting typical imaging patterns at computed tomography because of its expansile nature and tendency to erode bone. However, particularly in cases of lesion residue or recurrence after surgery, the distinction between cholesteatoma and inflammatory tissue based solely on computed tomography findings may be quite difficult, if not impossible. Magnetic resonance imaging might be very useful, particularly in such a context, since delayed postcontrast and diffusion-weighted images can demonstrate different imaging patterns in these two situations. Artifacts related to air-bone interface in the mastoid region may represent a relevant limitation to the utilization of echo-planar diffusion-weighted imaging. Non-echo-planar diffusion-weighted imaging represents an alternative to resolve this problem, once this method is less subject to this type of artifact, besides offering images with higher spatial resolution and thinner slice thickness, allowing the detection of small-sized cholesteatomas.

Keywords: Cholesteatomas; Magnetic resonance imaging; Diffusion-weighted imaging.