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Biomedical subjects

J F Bonneville

Publications and source records attributed to J F Bonneville.

At least 19 recordsLinked to original sources

[Imaging of the extracranial carotid arteries: when, how and why?].

The indications for treating carotid artery stenosis are related to the symptomatic nature of the lesion and the degree of stenosis. Duplex sonography is adequate for screening. While some groups believe that Duplex US alone or in combination with transcranial Doppler imaging may be sufficient for presurgical evaluation, it often is recommended to complete the evaluation with either MRA or CTA. Both techniques are advantageous since they allow evaluation of the cervical and intracranial arteries as well as cerebral parenchyma hence providing valuable information prior to definitive management. Catheter angiography remains indicated in patients with multi-vessel disease and ischemic cardiomyopathy, when results at non-invasive evaluation are discordant or in an emergency setting. Duplex US is used for routine follow-up of non-surgical lesions and after endarterectomy. Transcranial Doppler as well as advances in MRA and CTA techniques will be reviewed. Even though the treatment of atherosclerotic carotid artery stenoses remains primarily surgical, specific considerations related to angioplasty will be reviewed. Finally, diseases of the intracranial carotid artery and non-atherosclerotic diseases (dissection...) will also be discussed.

Angiography↗

[Pituitary gland imaging in Cushing's disease].

Specific MR techniques are required for optimal detection of adenocorticotropic hormone secreting adenomas responsible for Cushing's disease. Adequate MR sequences, high resolution coronal T1 and T2 - weighted images, dynamic MR imaging, post-gadolinium delayed images, dose of gadolinium adjusted for each sequence can routinely demonstrate pituitary adenomas less than 3 mm in Cushing's disease.

Adenoma↗

[Symptomatic venous congestion of the brain stem after embolization for dural fistula of the cavernous sinus].

We report the case of a 60-year old woman presenting, 3 days after arterial embolization of a dural arteriovenous fistula, with diplopia and gait disturbance in relation with right oculomotor nerve palsy and cerebellar dysfunction. On T2 weighted MR images, several hyperintense areas appeared in the pons and the midbrain. After one month, clinical symptoms and diffuse hyperintense areas resolved spontaneously, as the patient was treated by anti-vitamin K. This complication probably corresponds to reversible pontine venous congestion caused by poor venous drainage of the dural arteriovenous fistula.

Brain Edema↗

[Gadolinium in arteriography and interventional radiology: 39 patients].

OBJECTIVE: To report the experience of using various Gadolinium chelates as contrast media in digital subtraction angiography in patients with relative or absolute contraindications for iodinated contrast agents. MATERIAL: and Methods. Forty-two arteriograms were performed in 39 consecutive patients using Gadolinium chelates (gadoteridol, gadodiamide, and gadopentetate dimeglumine). The vasculature of the brain, of the upper and lower limbs and the renal arteries were examined. Among these 39 patients, 17 were treated by various endovascular procedures. RESULTS: In 40 examinations out of 42, the angiographic result was satisfactory, allowing either a diagnostic evaluation or an endovascular therapeutic procedure. Clinical tolerance was excellent. In one case of renal failure that was reported after angiography, the patient had received both iodine and gadolinum-based contrast agents. CONCLUSION: Gadolinium appears to be an interesting alternative for arteriography in patients with absolute or relative contraindication to iodinated contrast agents, and also seems to demonstrate efficacy during endovascular therapeutic procedures.

Aged↗

Dural enhancement in pituitary macroadenomas.

We describe the normal dural enhancement patterns of the sellar region and determine whether the duramater is affected by pituitary macroadenomas. Dural enhancement appeared to be usually abnormal in 20 patients with pituitary macroadenoma compared with 20 control patients, mainly at the planum sphenoidale and carotid sulcus. However dural changes are subtle and their recognition requires knowledge of the normal enhancement patterns. Dural changes, reported in a variety of inflammatory and infectious dural diseases and after surgery, are not specific and may be also seen in pituitary macroadenomas.

Adenoma↗

[Pituitary adenomas: value of MR imaging].

MR imaging has become the imaging modality of choice for diagnosis of pituitary adenomas. In order to optimize MR evaluation, dedicated pulse sequences must be utilized and knowledge of diagnostic pitfalls and normal variants is mandatory. The MRI features of pituitary adenomas may vary based on their volume, but also on their cell-type. Postoperative MR imaging based on a pre-established schedule is useful to detect residual and/or early recurrent tumor.

Adenoma↗

[Wegener's disease and central diabetes insipidus].

Vasculitis with central diabetes insipidus is a rare condition which must be recognized for proper management. We report a case of Wegener's granulomatosis with diabetes insipidus and review the literature concerning the clinical and radiological features of this association. We examined the data supporting the efficacy of cyclophosphamide in diabetes insipidus. Diabetes insipidus is inaugural in 46% of cases. Wegener's granulomatosis has no distinctive features when associated with diabetes insipidus. MR imaging reveals an enlargement of the posterior pituitary in 100% of cases. Cyclophosphamide is effective in 80% of cases. In Wegener's granulomatosis, pituitary vasculitis is a rare condition. MR imaging is the most accurate method for pituitary exploration. Cyclophosphamide is effective in the treatment of vasculitis lesions in Wegener's granulomatosis.

Aged↗

[Transcranial Doppler and cerebral vasospasm].

Increase in transcranial Doppler ultrasound flow velocities in the major basal arteries correlates with symptomatic vasospasm. Transcranial Doppler examinations are performed using a pulsed Doppler Probe via the trans temporal approach. Transcranial colour-coded real time sonography can be useful and help to identify the cerebral arteries. Maximum flow velocities of > 200 cm/sec are associated with cerebral ischemia and infarction. A maximum rise in Doppler velocity of more than 50 cm/sec/24 h is correlated with poor outcome. Using a diagnostic cutoff of 130 cm/sec a 87% positive predictive value can be obtained using TCD in the middle cerebral artery. Numerous factors affect Doppler flow velocities and may lead to erroneous conclusions about the presence or absence of vasospasm. Flow velocity is directly related to cerebral blood flow. Intracranial pressure, blood pressure and volume, hematocrite and subarachnoid hemorrhage affect Doppler flow velocities. False-negative examinations of vasospasm using TCD are associated with distal vasospasm, severe spasm of the carotid siphon, chronic high blood pressure and increased intracranial pressure.

Blood Flow Velocity↗

Myelography with a dimeric (iodixanol) and a monomeric (iohexol) contrast medium: a clinical multicentre comparative study.

The purpose of this study was to evaluate and compare the radiographic efficacy and safety of iodixanol (Visipaque; 270 and 320 mg I/ml) and iohexol (Omnipaque; 300 mg I/ml) in myelography. The study was randomized, double-blind and comparative including 398 patients from five European university clinics. The radiographic visualisation was evaluated as poor, good or excellent. Adverse events were recorded by interviewing the patients after the myelography, and each patient was given a questionnaire to be returned after 1 week. In cervical myelography with cervical puncture more films with excellent quality was obtained after iodixanol 320 mgI/ml compared with iohexol 300 mgI/ml (p = 0.009). Also in lumbar myelography iodixanol 320 mgI/ml compared favourably with iohexol 300 mgI/ml (p = 0.006). The most frequent adverse event was headache, which occurred in 5-35 % of patients during the first 24 h and in 19-61 % within the first 7 days, depending on the centre. There was no difference in frequency and severity of the adverse effects between the contrast media.

Adolescent↗