[Pathology of the cerebellopontine angle].

The pathology of the cistern of the cerebellopontine angle is primarily that of the nervous and vascular structures that it contains and of the meninges that line it. Knowledge of its anatomy makes it possible to understand and search for a rare pathology, the hemifacial spasm, due to a conflict between the facial nerve and the vertebral artery and the posterior inferior cerbellerar artery. However, the pathology of the cerebellopontine angle remains especially tumoral.

T1 signal hyperintensity in the sellar region: spectrum of findings.

T1 signal hyperintensity is a common finding at magnetic resonance imaging of the sellar region. However, this signal intensity pattern has different sources, and its significance depends on the clinical context. Normal variations in sellar T1 signal hyperintensity are related to vasopressin storage in the neurohypophysis, the presence of bone marrow in normal and variant anatomic structures, hyperactive hormone secretion in the anterior pituitary lobe (eg, in newborns and pregnant or lactating women), and flow artifacts and magnetic susceptibility effects.

[Von Hippel-Lindau disease: recent advances in genetics and clinical management].

Von Hippel-Lindau (VHL) disease is a hereditary cancer syndrome that predisposes to the development of a panel of highly vascularized tumors including CNS and retinal hemangioblastomas, endolymphatic sac tumors, clear-cell renal cell carcinomas (RCC), pheochromocytomas and pancreatic neuroendocrine tumors. CNS hemangioblastomas and RCC are the two main life-threatening manifestations. The disease is caused by germline mutations in the VHL tumor-suppressor gene that plays a major role in regulating the oxygen-sensing pathway by targeting the hypoxia-inducible factor HIF for degradation in proteasome.

Brain MR diffusion tensor imaging and fibre tracking to differentiate between two diffuse axonal injuries.

We report here two cases of diffuse axonal injury (DAI) studied by MR diffusion tensor imaging (DTI) and fibre tracking (FT) focused on the corpus callosum. In one case, DTI and FT pattern matched the diagnosis of broken white matter tracts. In the other case there was a discrepancy between DTI and FT data that showed unaltered white matter tracts with the presence of intra-cellular oedema.

Bilateral dystrophic ossification of the thyroid cartilage appearing as symmetrical laryngeal masses.

Primary cartilaginous lesions of the larynx are relatively uncommon. We present a case of bilaterally pseudocystic lesion of the thyroid cartilage that demonstrated progressive calcification. Pathologic analysis showed features suggesting a dystrophic lesion with no evidence of malignancy.

Foramen tympanicum, or foramen of Huschke: pathologic cases and anatomic CT study.

Background And Purpose: A persistent foramen tympanicum, or foramen of Huschke, is an anatomic variation of the tympanic portion of the temporal bone due to a defect in normal ossification in the first 5 years of life. The foramen is located at the anteroinferior aspect of the external auditory canal (EAC), posteromedial to the temporomandibular joint (TMJ). We sought to define its prevalence, location, and size on high-resolution spiral CT (HRCT).

"Duplicated" or "multiple" cervical internal carotid and vertebral arteries from fenestration, duplication and vasa vasorum to segmental rete.

The appearance of multiple cervical arteries may be due to a variety of anatomic situations. Arterial fenestrations and duplications have different anatomic origins, with distinct appearances on angiography. They are associated with incomplete segmental development.

Massive calcium pyrophosphate dihydrate crystal deposition disease: a cause of pain of the temporomandibular joint.

Calcium pyrophosphate dihydrate deposition (CPDD) disease is a disorder that occasionally affects the temporomandibular joint (TMJ) and temporal bone, causing pain (66.6% of cases), swelling (50%), trismus (36.8%), and hearing loss (22.

A rare expression of neural crest disorders: an intrasphenoidal development of the anterior pituitary gland.

Congenital abnormalities of the pituitary gland are rare and may be associated with midline cranial, orbital, and facial anomalies and with hormonal insufficiency. Here we report a case of asymptomatic, abnormal migration of the adenohypophysis. The normally developed adenohypophysis was located in the sphenoid bone and developed on the intersphenoidal septum, extending from the superior pharyngeal wall to the floor of the sella turcica (craniopharyngeal canal).

Head and neck lesions in the immunocompromised host.

Head and neck lesions are encountered in more than 40-50% in patients with immunosuppression (HIV-infected individuals, diabetes mellitus, transplant recipients, patients treated with immunosuppressive drugs or post-radiotherapy). The organs affected are the salivary glands, the lymph nodes, the sinonasal tract, the orbits, the temporal bones, and the pharyngo-laryngeal mucosa. They are mainly involved by granulation tissue, perivascular and perineural inflammation, and neoplasms.

Acute epiglottitis: MRI.

We report the MRI findings in an adult with epiglottitis. There was thickening of the epiglottis and left aryepiglottic fold. Management of this life-threatening condition requires imaging only when the diagnosis is uncertain or when an abscess or other complication is suspected.

[Anatomic variants of paranasal sinuses].

During the last 15 years period, the development of functional endoscopic sinus surgery underlines the needs of a better knowledge of sinonasal anatomy and consequently, of sinonasal anatomic variations. These anatomic variations are widely spread into the population and commonly encountered in daily CT practice. The difference of anatomic landmarks during endoscopic surgery can result in bony transgression and increase the difficulties of the surgery.

[Lyrical and musical auditive mental imagery in functional MRI].

Purpose: to explore with functional MRI cerebral areas involved in musical and lyrical sounds signal processing with the mental imagery method.

Material: and

Methods: nine volunteers (mean age: 27 years old) underwent functional MRI with BOLD contrast at 1.5 T.

Sinonasal Wegener's granulomatosis: CT characteristics.

Wegener's granulomatosis (WG) is a severe and potentially lethal granulomatosis. Even though no specific radiological criteria exist, CT may suggest the correct diagnosis at an early stage. Recent improvement in the prognosis is related to earlier diagnosis, allowing the initiation of efficient and specific treatment before any severe complications occur.

Functional MRI in symptomatic proliferative angiopathies.

Seizures, the main expression of cerebral arteriovenous malformations (AVMs) can be difficult to control medically. We studied fMRI in correlation with clinical findings cerebral activation clusters patterns in relation with singular AVMs (proliferative angiopathy). We carried out blood oxygen-level dependent functional MRI (fMRI) in seven patients with language problems due to capillary ectasia with verbal fluency and repetition language tasks in box-car paradigms.

[A palate tumor revealed by pain].

A 41-year-old female presented in April 1996 with a tumor of the hard palate revealed by increasing left palate pain. Adenoid cystic carcinoma was suspected on clinical and imaging data. Two limited surgical procedures showed a tumor histologically made of small lobules of granular cells, PAS positive and expressing S100 protein, infiltrating some medullary spaces of the palatine bone, consistent with a granular-cell tumour.

MR perfusion imaging in a case of cerebral proliferative angiopathy.

Proliferative angiopathy is an uncommon type of cerebral arteriovenous shunt characterized by an extensive capillary network with normal brain intermingled and few clinical symptoms (mostly seizures and headaches). This case report depicts an extensive proliferative angiopathy located in the right hemisphere. Its hemodynamic disturbances were studied with MR perfusion imaging (local or remote areas of increased time to peak, decrease ratio of signal, and relative regional cerebral blood volume values).

Lemierre syndrome: usefulness of CT in detection of extensive occult thrombophlebitis.

We report a case of Lemierre syndrome with extensive suppurative thrombophlebitis involving concomitantly the internal jugular, facial and anterior jugular veins. This case illustrates two unusual clinical and imaging features: the lack of characteristic neck symptoms at admission and a negative initial neck US exam. The value of postcontrast CT of the neck and chest for diagnosis of this potentially life-threatening syndrome is illustrated.

Granular cell tumor of the palate: a case report.

Granular cell tumor (GCT) is an infrequent benign neoplasm, which Abrikosoff accurately described in 1926. GCT probably has a neural crest cell origin. We present the clinical and imaging findings in a 45-year-old woman with a GCT involving the palate.

Diffusion-weighted imaging in a case of wernicke encephalopathy.

In a chronic alcoholic patient with progressive confusion, which was consistent with the clinical diagnosis of Wernicke encephalopathy, T2-weighted, FLAIR and diffusion weighted (DWI) MR imaging depicted brain abnormalities located in both medial thalamic nuclei. Apparent Diffusion Coefficient (ADC) measurements in these regions shown unexpected normal values, referring to Wernicke pathological findings and DWI data. DWI may be helpful to diagnose early basal nuclei abnormalities, but may fail to compute ADC values in these locations.

Wegener granulomatosis involving the pterygopalatine fossa: an unusual case of trigeminal neuropathy.

We report on a case of Wegener granulomatosis in the pterygopalatine fossa that was associated with trigeminal neuropathy. MR and CT examinations were useful in depicting the extent of the lesion and suggesting a perineural spread. Diagnosis was confirmed with positive serum assay findings for the presence of cytoplasmic antineutrophil cytoplasm antibody.

Hemangioma of the porus acusticus. Impact of imaging studies: case reports.

Hemangiomas are tumors. Hemangiomas near the geniculate ganglion or in the internal acoustic meatus are well known but rare. We present two cases of hemangiomas located at the porus acusticus, an even more rare site.