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Biomedical subjects

C Pharaboz

Publications and source records attributed to C Pharaboz.

At least 19 recordsLinked to original sources
PubMed1995

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↗
PubMed1995

[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↗
PubMed1995

[The temporomandibular joint meniscus in MRI].

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.

Adolescent↗
PubMed1995

[Principles of magnetic resonance angiography].

Magnetic resonance angiography is a modality of functional imaging which can only be interpreted on the basis of a good understanding of vascular physiology and the physical principles of image acquisition. Magnetic resonance angiography is based on flow-related "artefacts". The oldest method is based on renewal of the image by proton flow: the flight time effect. Dephasing of the protons travelling in magnetic field gradients results in phase-contrast angiography. These two methods of angiography each have respective advantages and disadvantages: they are not mutually exclusive, but complementary.

Hemodynamics↗
PubMed1994

[Role of MRI in pre-clinical breast lesions. Preliminary results].

The purpose of this study is to assess the value of MR imaging in nonpalpable breast tumors. Thirty-two women whose mammogram showed opacity, architectural distorsionor microcalcifications, underwent preoperative dynamic MR studies with quantitative evaluation of contrast enhancement. MR showed early contrast enhancement in 10/12 breast cancers (2 false-negative) and in 6/20 benign lesions (false-positive). Quantitative study of contrast enhancement does not allow clear differentiation between these lesions. Further studies are required to confirm these findings and purpose MR imaging for aid in detection of carcinomas. Multifocal sudden enhancements are possible in benign lesions and incite to limit MR to focal mammographic abnormalities.

Adult↗
PubMed1992

[Thrombosis of the cerebral veins. X-ray computed tomography and MRI imaging. 11 cases].

11 cases of cerebral venous thrombosis in adults are reported. Main clinical signs are: intracranial hypertension (headache, nausea, papilledema in 7 cases, loss of consciousness in 6 cases, neurological deficit in 6 cases, seizure in 4 cases. 1 patient is dead, who did not receive heparin treatment. Delay before diagnosis is between 2 and 20 days, and is shortened when arteriography or MRI are available and prescribed. At least one (or several) CT examination was performed in 10 patients. Direct signs of thrombosis are uneasily detected without contrast injection, seen here in 4 cases. Empty delta sign is observed in 7 patients, lately in 4 cases, and once only afterwards. Cerebral infarction is visualized in 7 cases over 10. Its features frequently seem evocative for cerebral venous thrombosis: triangularin 4 cases or nodular shape in 3 cases with hemorragic infarct in 7 cases, with bilateral topography in 6 cases, in frontal or central areas in 7 cases. 6 patients had a MRI examination. All cerebral infarctions appeared haemorragical, even at early stages. During subacute period, venous thrombosis is constantly and easily detected by the mean of methemoglobin high signal intensity on T1 weighted images. The prediagnosis delay is short, without necessity of arteriography. MRI should take the place of CT and arteriography in investigation of a clinically suspected cerebral venous thrombosis.

Adult↗
PubMed1992

[MRI techniques for the study of the temporal lobe and its environment].

The MR study of the temporal lobe and its environment requires a good knowledge of the anatomy in order to select the views adapted to the disease investigated. The authors propose a series of protocols according to the region examined. An understanding of the principles of MR sequences is also essential to avoid the problems of investigation associated with this complex anatomical region. The principal sequences are reviewed together with their advantages and disadvantages.

Cerebellopontine Angle↗
PubMed1991

[Disk highlighting after injection in MRI. Macroscopy and histology of 25 postoperative recurrences].

400 cases of failed back syndrome were examined with MRI in a prospective study (SE w Rho and T2, SE wT1 before and after injection of paramagnetic contrast agent in axial and sagittal planes). After second time surgery, 70 cases of herniated disks were found. 25 herniated disks were studied in microscopy and results correlated with enhanced herniated disks. Authors describe 4 types of enhancement: veinous plexus (5/24), inflammatory or granulomatous tissue (12/24), degenerative disc with fibrosis (5/24) and osteophytosis (2/24). The criterions of each pattern are described.

Adult↗
PubMed1991

[Relations between neurinoma of the VIII cranial nerve and the porus of the internal auditory meatus. Apropos of 110 cases].

110 cases of neurinomas of the VIIIth with APC extension (104 patients) were studied using MRI or CT. Classically, it is said that the tumoral mass is centered on the IAC. In our study, among 110 cases of neurinomas, only 9 were centered along the axis of IAC on axial slices and only 23 on coronal slices. The anterior development of the tumor is never more than 1 cm, except in 3 cases of large and multicystic neurinoma. We suggest that the anterior development of large tumors is limited by the VIIth nerve.

Adolescent↗
PubMed1989

[Rhinopharyngeal craniopharyngioma. CT X-ray and MRI aspects].

The authors report about a rare site of craniopharyngioma, purely extracerebral and located in the sphenoid sinus and the rhinopharynx. No CT or MRI sign is pathognomonic for the lesion, but the presence of a fleshy process containing calcifications and cystic formations must lead to evoking this diagnosis. MRI assesses the extent of the lesions perfectly, but fails to detect small calcifications or ossifications accurately.

Adult↗
PubMed1989

[The diagnostic importance of different imaging technics in temporomandibular joint dysfunction].

Various imaging techniques enable to explore the Temporo-mandibular joints (T.M.J.). The physicians prescribing them, must be perfectly aware of the informations they provide as well as their costs, for a judicious formulation of their indications. Conventional radiography is absolutely necessary and, most of the time, sufficient, since it simply permits to evaluate the bony structures. An orthopantomogram and modified Schüller views of each T.M.J., "open mouth" and "closed mouth" will be performed. Conventional tomograms are no longer indicated. They will be abandoned for Computed Tomograms. This examination permits, at a relatively low cost, to analyse a bony abnormality and explore the muscular soft tissues. It may also be possible to assess the meniscus, its position and displacement when the mouth is opened. In fact, if a meniscal or articular pathology is considered, which could result in surgical or endoscopic procedure, it is absolutely necessary to perform: -either an arthro-tomography, with contrast material, -or a magnetic resonance examination. The latter provides perfect anatomical and pathological informations of the joint and meniscus, in an atraumatic fashion for the patient. Its only contraindication is in the cost of the examination. It will be possible to look for a dislocation, a malformation or a structural alteration of the meniscus which could result in a perforation, a rupture of the posterior frenulum, adhesions or joint extravasation. A necrosis or early osteochondritis of the condyle will be ruled out.

Humans↗
PubMed1988

[Aneurysmal bone cyst of the ethmoid. Apropos of a case].

Repeated epistaxis in a 12 year old child revealed an aneurysmal bone cyst of ethmoid, an exceptional localization for this lesion. Modern imaging techniques (CT scan, NMR) provided precise data on its extent, primordial for decision as to surgical approach. NMR imaging was more effective than the CT scan for diagnosis, since blood lakes were identified, and for determination of extent, since tumoral elements were distinguished from sinusal retentions.

Bone Cysts↗