[MR imaging of the temporomandibular joints]. / Exploration en IRM des articulations temporo-mandibulaires.

Disorders of the TMJ are best evaluated with MR. Anatomy and morphology of the meniscus are key features of the imaging evaluation conducted using coronal and sagittal views with open and closed mouth. There is no direct correlation between symptoms and MR imaging findings. Anterior or lateral meniscal displacement, permanent or reversible, are described. Arthroscopy or arthrography may help in diagnosis of meniscal adhesion or perforation. HRCT is an adjunct to study degenerative bone changes.

[Inner ear and subarachnoid spaces: relations and diseases]. / Oreille interne et espaces sous-arachnoïdiens.

The purpose of this article is to describe, with 5 clinical cases, the physiological communications between the inner ear and the subarachnoid spaces (SAS) and present the imaging features with regard to. Therefore we briefly illustrate abnormal communications between SAS and perilymphatic fluids in certain cochlear and internal acoustic meatus (IAM) malformations and their consequences. Imaging features may depict diffusion pathway of bacterial meningitis to membranous labyrinth via the cochlear aqueduct or via the IAM. Rarely, in some patients referred for cochleovestibular symptoms, imaging features may display skull base tumors involving the area of cochlear or vestibular aqueduct aperture. Therefore, in patients referred for cochleovestibular symptoms, MR and CT study should carefully scrutinise not only the IAM but also the aperture of the cochlear and the vestibular aqueducts and the cerebellopontine meninges.

[Postoperative monitoring of free fibular grafts by dynamic magnetic resonance imaging. Preliminary results in three cases of mandibular reconstruction]. / Surveillance postopératoire des lambeaux libres osseux de péroné ou fibula par IRM dynamique. Résultats préliminaires à propos de trois cas en reconstruction mandibulaire.

The vascularized free fibular graft has been used in mandibular reconstructive surgery since 1975. This technique has been progressively developed, and it is now the procedure of choice for mandibular reconstruction although in certain postoperative circumstances it can be difficult if not impossible to monitor bone vitality. However, bone vascularization can be detected by dynamic magnetic resonance imaging (MRI), as this technique has been experimentally and clinically validated in the early diagnosis of osteonecrosis. The aim of this study was to evaluate the efficacy of MRI for the postoperative monitoring of vascularized free fibular grafts in human mandibular reconstruction. Dynamic contrast-enhanced MRI was used to study the variation in contrast over time following injection of gadolinium contrast medium, and to evaluate the degree of bone marrow perfusion of the fibular graft. This variation in signal intensity was visualized in the form of a curve, i.e., a perfusion curve for the bone marrow region. An examination was performed in three patients at different postoperative times and under different conditions. In one case, MRI confirmed the presence of fibula blood supply in spite of the necrosis of the adjacent fascio-adipose layer. In this article, the methodological difficulties have been discussed, particularly as regards data processing, and the present results have been compared with the findings in the literature. Dynamic MRI is a simple, reliable, non-invasive technique and its use in the postoperative monitoring of bone marrow perfusion and vascularized free fibular grafts permits a determination of the status of the latter following surgery, i.e., whether there is an adequate blood supply or not.

CT and MRI findings in primitive pituitary abscess: a case report and review of literature.

Pituitary abscess is not rare. Clinical and radiological features in a primitive pituitary abscess are reported. Transphenoidal surgery revealed an abscess. Preoperative diagnosis of pituitary abscess remains difficult. Sellar round cystic mass isointense to grey matter on T1, high intensity signal on T2, with a peripheral rim enhancement following gadolinium injection associated with thickened stalk and diabetes insipidus may be suggestive of pituitary abscess.

MR of 732 TMJs: anterior, rotational, partial and sideways disc displacements.

OBJECTIVE: The purpose of this study was to determine the prevalence of anterior, sideways, rotational and partial anterior disc displacements, as well as degenerative changes in patients with clinical signs and symptoms of internal disorders. MATERIALS AND METHODS: 732 MR Images of temporomandibular joints (TMJ) were produced for 366 symptomatic patients. Image analysis included assessment of disc positions and mobility, as well as recapture in coronal and mediolaterally divided sagittal planes in closed and open positions. RESULTS: Of these images, 545 TMJ showed an internal derangement comprised of 52% anterior disc displacements without reduction, 26% anterior disc displacements with reduction, 11% partial anterior disc displacement, 5% pure sideways displacements and 4% stuck discs. Rotational disc displacements were observed in 34% of the anterior disc displacements without reduction group and in 53% of the anterior disc displacements with reduction group. A total of 97% of the partial anterior disc displacement occurred laterally. Degenerative changes increased with age, mainly in the anterior disc displacements without reduction group. CONCLUSION: Magnetic resonance imaging (MRI) investigations show that the disc is subject to a great variety of displacements and that there is a need for further research to refine the clinical therapy for TMJ internal derangements.

[MRI study of temporomandibular joint disk behavior in chilren with hyperpropulsion appliances]. / Etude I.R.M. du comportement discal de l'A.T.M. des enfants porteurs d'hyperpropulseur.

Orthodontic and orthopaedic effects of hyperpropulsors have been studied, evaluating the possible adaptation of the temporo mandibular joint. Before the event of MR imaging, the positional modification of the disc could not be seen. The study has been carried out on 15 subjects, skeletal Class II, with a mean age of 11.6 years (SD = 1 year). A bilateral MR investigation has been done before and after the wear of an activator (Herbst or Monobloc with Head Gear). All patients underwent bilateral imaging in sagittal and modified coronal planes in closed and opened mouth. The qualitative analysis of the temporo-mandibular joints reveals the appearing of internal derangements, often asymptomatic, in one case out of five; the disc being anteriorly displaced on an average of 8.3 degrees (p = 0.023). These results need to be confirmed on larger samples but may modified functional approach of orthopaedic treatments in order to take into account the TMJ change.

Kinetic magnetic resonance imaging analysis of swallowing: a new approach to pharyngeal function.

The emergence of turbo-FLASH MR sequences allows us to acquire five 10-mm sections each second and thus to catch images of the soft tissues during function. One can trace the pathway of a liquid between the tongue, the soft palate, the epiglottis and the pharyngeal apparatus and analysis the role of the anatomic structures during swallowing. Restricted to the sagittal plane for the purpose of this preliminary study, this technique can be extended to the other planes to provide a three-dimensional analysis of oropharyngeal function or dysfunction.

Nasopharyngeal teratoma: CT and MR findings.

Teratomas of the nasopharynx occur usually in neonates. We present a case of teratoma which was discovered in an adult, and which relapsed after 34 years. The conventional radiograms, CT, MR, and histologic appearances are described.

[Pituitary abscess. A rare complication of sinusitis]. / L'abcès hypophysaire. Une complication rare des sinusites.

This report is of a pituitary abscess arising from chronic sinusitis. The MRI suggested a pituitary tumor with suprasellar extension and diagnosis was made operatively. Pituitary abscesses are rare entities. Despite the advent of MRI, diagnosis is often only made operatively.

[Disseminated tuberculosis of unusual locations]. / Tuberculose floride avec localisations rares.

We report a case of disseminated tuberculosis involving the middle ear, the central nervous system, the spine and the lung. The tuberculous epidural abscess and otomastoiditis don't have any specific imaging features. But their coexistence with an other tuberculous involvement might suggest their tuberculous nature. The epidural abscess may result from direct extension from otomastoiditis.

[Magnetic resonance imaging in the warm and cold forms of algodystrophy of the foot]. / L'imagerie par résonance magnétique dans les formes chaudes et froides de l'algodystrophie du pied.

PURPOSE: To report magnetic resonance imaging abnormalities in reflex sympathetic dystrophy of the foot. METHODS: Retrospective study of 22 algodystrophies of the foot, in warm phase in 17 cases, in cold phase in 5. RESULTS: Algodystrophy in warm phase: Bone medullary abnormalities were noted in 17 cases (decrease of signal intensity was found in T1 weighted images, increase of signal intensity in T2 weighted images, in T1 and T2 with fat-saturation, in T1 with gadolinium), located at the increased uptake technetium site in 16 cases. T1 and T2 weighted images with fat-saturation and T1 with fat-saturation after injection of gadolinium were pathological in all cases, T1 was normal in 2 cases. Soft tissues abnormalities were noted in 11 cases, joint effusion in 8 cases, synovial hypertrophy enhanced by gadolinium in 2 cases and a subchondral linear area of hypointense signal on T1 and T2 images was not present after gadolinium injection in 1 case. Six fractures were detected. Algodystrophy in cold phase: no bone edema, no synovial hypertrophy, no joint effusion, no soft tissues abnormalities, no fractures are detected. CONCLUSION: The results suggest that the MRI has a considerable value in diagnosis during the warm phase of reflex sympatetic dystrophy of the foot. The normal MRI findings during the cold phase could be important to understand its etiology.

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.

[The temporomandibular joint meniscus in MRI]. / Le ménisque de l'ATM en IRM.

The continuing improvement of the MRI's equipment and software led us to a continuous adaptation of the exam technique. We use today a bilateral coil technique, 3 inches in diameter. Four slices are performed for each articulation (4 mm thick) in the true sagittal plane. A fast spin echo, balanced in proton density, for one minute, allows the study of 15 steps inside a full open/close cycle. Oblique coronal cuts are also performed parallel to the long axis of the condyle in a T1-weighted spin echo sequence in close and half-open positions. The analysis of 350 subjects allows to detail more precisely the meniscal displacement. Beside the classic anterior luxation, the meniscus slips medially, laterally and may rotate. These different situations may be isolated or combined. The dynamic study is specifically useful in the displacement with reduction exams. It enables permits to point out the timing of the disk disturbance: this information may be of great help in therapeutic decisions.

[Congenital neck masses. Embryonic origin and diagnosis. Report of the CIREOL]. / Pathologie cervicale congénitale. Origine embryologique et diagnostic. Rapport du 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.