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Biomedical subjects

K Marsot-Dupuch

Publications and source records attributed to K Marsot-Dupuch.

At least 19 recordsLinked to original sources

CT and MR findings of Michel anomaly: inner ear aplasia.

In 1863, Michel described a condition characterized by a total absence of differentiated inner ear structures associated with other skull base anomalies, including an abnormal course of the facial nerve and jugular veins. Michel aplasia clearly differs from Michel dysplasia, in which arrest of embryologic development occurs later. Recently, the role of otic capsule formation on mesenchymal differentiation was reported as well as the impact of the genetic deletion of the homeobox gene on the development of the ear, cranial nerves, and hindbrain. We report two patients with a total absence of inner ear structures bilaterally, illustrating the characteristic appearance of Michel aplasia and associated skull base anomalies.

Adolescent

Slow-growing labyrinthine masses: contribution of MRI to diagnosis, follow-up and treatment.

We report the use of MRI in the diagnosis, follow-up and therapeutic management of three cases of intralabyrinthine Schwannoma. The diagnosis was based on the history and initial and follow-up MRI findings. The main feature suggesting the diagnosis was a nodular intralabyrinthine mass of low signal intensity on T2-weighted images, and high or isointense signal on T1-weighted images (relative to cerebrospinal fluid), which showed contrast enhancement. Follow-up imaging showed growth of the tumour in one patient. One patient underwent surgery for severe tinnitus. To detect these lesions, MRI should be focussed on the inner ear, using thin-section T2-weighted and T1-weighted images before and after contrast medium. MRI allowed informed surgical planning.

Adult

Perichiasmatic granuloma occuring after radical mastoidectomy: MR findings.

A case of chronic chemical meningitis occurring after a radical mastoidectomy is reported. Imaging and surgical findings were suggestive of a dissemination of cholesteatoma debris within the subarachnoid spaces. Chemical meningitis has been described in epidermoid and dermoid cyst rupture. This report illustrates that clinicians should be aware of this possible complication. Skull base imaging is mandatory before considering the diagnosis of idiopathic meningitis. Only treatment of the abnormal communication between cerebrospinal fluid and middle ear may eradicate the origin of this rare meningitis.

Adult

[Magnetic resonance angiography of the carotid artery: artifacts, anatomy, diseases].

Magnetic resonance angiography is now a technique commonly used in neurologic practice. We give a brief overview of the biophysical principles of this technique. Recent refinements and technical innovations are also noted. After some anatomic considerations about the carotid artery, we provide some data about the role of MRA in atherosclerotic and non atherosclerotic diseases (dissections, aneurysms, arteritis, post operative follow-up...) of the extra and intracranial carotid arteries. The purpose of this review is to concentrate on the role of magnetic resonance angiography in patients with various carotid artery diseases and to specify possibilities, limitations and risk of misinterpretation. Magnetic resonance angiography is a major, still evolving technique.

Adult

[A report of two familial cases of Michel syndrome (bilateral agenesis of the inner ear)].

In two siblings, wearing conventional hearing aid, presenting profound but not total congenital deafness, with no particular antecedents, the imaging destined to confirm the indication of a cochlear implant revealed a total bilateral agenesis of the inner ear. In one of the children, this imaging was confirmed by an exploration of the middle ear performed during a tonsillectomy that was otherwise necessary. We will summarize the literature concerning Michel's Disease, exceptional in its princeps form, and we will discuss the manner of action of conventional devices in these cases which are a priori without any sensorial element.

Adolescent

[Artifacts in magnetic resonance angiography].

Magnetic resonance angiography (MRA) has become a major tool in the management of vascular diseases. However, many artifacts that may lead to misinterpretations are encountered with this imaging modality. The purpose of this paper was to enumerate, explain and illustrate each kind of artifact encountered with "time of flight" or "phase contrast" imaging methods. For each artifact, we tried to provide one or several techniques to minimize its consequences.

Artifacts

Idiopathic granulomatous hypophysitis: clinical and imaging features.

Idiopathic pituitary granuloma is a rare disorder similar to lymphocytic adenohypophysitis. Few cases have been reported. We report a new histologically case proven with MRI. The patterns of clinical and radiological presentation and the management of this disorder are discussed. MRI findings suggestive of this condition include an intensely enhancing pituitary mass, associated with dural enhancement. Steroid therapy may be suggested avoiding unnecessary surgery.

Adenoma

Papillary adenoma of endolymphatic sac origin: a temporal bone tumor in von Hippel-Lindau disease. Case report.

This report describes a patient with von Hippel-Lindau disease who presented with an 8-year history of a slow-growing, locally invasive vascularized lesion of the temporal bone involving the cerebellopontine angle. The mass, studied by computerized tomography scanning and magnetic resonance imaging techniques, was partly cystic in appearance. After removal of the mass, pathological studies confirmed a papillary cystic tumor with characteristics that have been described in tumors with an endolymphatic sac origin. These rare neoplasms constitute a distinct pathological entity and deserve wider recognition.

Adenoma

[Imaging of ORL diseases in acquired immunodeficiency syndrome].

More than 50% of patients with acquired immunodeficiency syndrome (AIDS) present a lesion affecting parotid gland, lymph nodes, paranasal sinuses, pharyngo-larynx or temporal bone. In about 20% out of cases affected patients present different head and neck lesions at the time of evaluation. Most often, clinical examination and endoscopy are sufficient to perform diagnosis and to manage the disease. Imaging studies (CT or MRI) are indicated when the nature of the disease is unknown or when a map of the process is mandatory for therapeutic approach. Some imaging features are strongly suggestive of HIV infection: parotid cysts associated with hyperplasia of the nasopharynx and cervical lymph nodes enlargement; labyrinthitis and multinevritis; and head and neck squamous cell carcinomas in non alcoolo-tobacco addicted patients. Such diseases suggest the need for knowledge of the patient's seropositivity status.

Acquired Immunodeficiency Syndrome

[Persistent facial paralysis: contribution of imaging to identification of perineural infiltrating tumor].

To describe imaging features suggestive of retrograde perineural spread in progressive facial palsy without known tumoral origin. Two reports of perineural infiltration by salivary malignant tumors were diagnosed on abnormal enhancement of the facial nerve associated with an abnormal nerve enlargement (1/2). These unsuspected tumors were located in parotid gland (1/2) and the sub-maxillary gland (1/2). ENT tumors (especially adenoid cystic carcinomas) should be carefully searched in case of perineural spread, as these tumors may be misdiagnosed due to their size, location and signal. Therefore, imaging studies of facial palsy should include temporal bone, skull base, parotid gland, submaxillary gland and sub cutaneous areas of the face. A sub-maxillary gland tumor should be searched in case of facial palsy associated with glossodynia.

Carcinoma, Adenoid Cystic

Magnetic resonance imaging assessment of labyrinthine pathology.

Membranous labyrinth pathologies are quite rare. They were until recently difficult to demonstrate by imaging technics, CT being the modality of choice. Our purpose was to stress the interest of MR examination for investigating patients complaining of vertigo, tinnitus, and profound sensorineural hearing loss. Normal anatomy as well as the main pathologically encountered changes are illustrated.

Ear Diseases

Rhinoscleroma with orbital extension: CT and MRI.

We describe the MRI features of a rhinoscleroma with orbital extension. This benign bacterial and granulomatous lesion of the paranasal sinuses gave homogeneous low intensity on T2-weighted images and enhanced with gadolinium. It could simulate a malignant sinonasal tumour or a fungal sinusitis; the diagnosis must be considered in patients from endemic areas.

Adult

[Cerebral arteritis in AIDS. Demonstration with MRA in 2 patients].

Two cases of cerebral arteritis related to varicella-zoster virus in seropositive patients are presented. Diagnosis of arteritis was made by conventional angiography. However, 3D Time of Flight MR Angiography demonstrated an excellent sensitivity in detection of cerebral arterial stenosis located at the skull base.

AIDS-Related Opportunistic Infections

Imaging of the vestibule.

PURPOSE: State-of-the-art imaging of the normal and pathologic vestibule. METHODS AND MATERIAL: This study is based on the experience of three French imaging centers (Val de Grâce, Bégin, and Saint-Antoine hospitals) working with 1- and 1.5-tesla magnetic resonance units and high-resolution computed tomography, and it includes a review of the literature. Computed tomography is performed with a high-resolution program, matrix 512 x 512, field of view 9.6 cm, joined 1-mm section, overlapped sections every 0.5 mm, axial and coronal sections, or reformatted images. High-resolution magnetic resonance imaging (matrix 512 x 384), field of view 18 cm, is used with fast T2-weighted sequences (sections 3 or 2 mm thick, constructive interference in steady state, T2-weighted gradient echo sequence three-dimensional Fourier transformation). A joined section of 0.7 mm in any direction is obtained if necessary. Superimposition of computed tomography and magnetic resonance imaging with a stereotactic technique by identification of identical anatomic points is sometimes used. RESULTS: We review the interest and place of computed tomography and magnetic resonance imaging in the diseases of the labyrinth and internal auditory canal related to abnormal vestibular functions: inflammatory labyrinthitis, vestibular hemorrhages, sclerosing and ossifying labyrinthitis, traumatism, malformations, perilymphatic fistulas, otosclerosis, tumors, cochleovestibular neuritis, and hydrops of the endolymphatic system.

Humans

[Congenital neck masses. Embryonic origin and diagnosis. Report of the CIREOL].

Various congenital cervical anomalies are found in the neck region including defects of the branchial apparatus (branchial, thymic and parathyroid anomalies) and vascular anomalies. They manifest as cystic masses, sinuses, fistulas and as ectopic glands. This multicentric retrospective imaging study done in 5 different radiological centers (4 adult radiological departments and 1 pediatric radiological department) shows the result in understanding the congenital cervical anomalies and include 63 patients. The age of the patients varied between 24 days-81 years with a mean age of 23 years. This study included 27 patients having congenital branchial pouch anomalies (4 cases of anomalies of obliteration of the 4 th arch), 14 cases of cervical cystic hygromas, 11 thyroglossal tract cyst cases, 1 congenital laryngocele case, 1 case of jugular ectasia, 3 cases of capillary haemangioma. The embryologic basis of these different malformations were reviewed. Their characteristic findings and sites were illustrated together with their typical et atypical appearances. The frequency of occurrence of each branchial anomaly were plotted, the second branchial cleft cyst being by far the most common congenital cystic neck mass (70%). The study revealed the role of different imaging modalities in the diagnosis of various congenital cervical anomalies, especially in some particular complicated cases of congenital neck masses presenting in adult. Imaging study helps the clinician to anticipate any difficulties in unforeseen circumstances that may arise including infection haemorrhage, or parapharyngeal extension. Understanding the various radiologic appearances of these anomalies is greatly aided by familiarity with their embryologic origin. Moreover, considering the anatomic location and radiologic appearance, the precise embryologic origin can be accurately predicted.

Adolescent

[Post-radiation necrosis of the cricoid cartilage: an uncommon case].

Radiation therapy is considered as the treatment of choice for early stage laryngeal cancer. However, a few patients, after several years, develop severe life threatening complications, like edema or chondronecrosis. The clinical examination or endoscopy follow up may be difficult. CT and MR imaging can show the exact diagnosis depicting exquisitely the anatomy of the larynx. But at the beginning, the abnormalities are radiographically subtle and their diagnosis may be difficult because of artefacts due to patient dyspnea and mucous secretions. The main suggestive imaging features for suspecting a chondronecrosis seem to be the lost of normal signal hyperintensity on T1 MR imaging or a focal lack of cortical bone on CT scans, just adjacent to a focal swelling of the pharyngo-larynx mucosa. The barium pharyngography remains the best imaging diagnosis procedure for depicting associated abnormal communication between the digestive tract and the adjacent spaces or the cartilages of the larynx. Therefore, when the diagnosis is delayed, only salvage total laryngectomy can stop the infectious process. We report one case of a cricoid cartilage chondronecrosis eleven years after radiation therapy for laryngeal cancer.

Cricoid Cartilage