Biomedical subjects
D Buthiau
Publications and source records attributed to D Buthiau.
[Clinical imaging of osteo-condensed metastases].
INTRODUCTION: Due to the occurrence of osteoblastic metastases in the course of various cancers, particularly in the course of prostate cancer, we are faced with diagnosis and follow-up issues different from those associated with lytic metastasis. We therefore analyzed the respective advantages of imaging techniques. CURRENT KNOWLEDGE AND KEY POINTS: Most of the time, osteoblastic metastases are evidenced by standard radiography. Due to its ability to demonstrate metastases localization, extent and signs, CT scan is not only of value when osteoblastic metastases are suspected but also for patient's follow-up. MRI provides further information in regard to both the lesion content and osteoblastic degree. Though MRI must be performed after all other imaging procedures, it is of value for multiplanar study of the whole spine. FUTURE PROSPECTS AND PROJECTS: Studies focusing on either the lesion content and volume or helical CT are in progress and aim at better monitoring follow-up, while the objective of dynamic MRI studies is to better analyze lesion content.
[Virtual endoscopy].
After a brief definition of Virtual Endoscopy (VE), the authors, by a personal experience and literature analysis, present the results of this new method in several applications: tracheo-bronchial tree, vessels, colon, bladder, central nervous system; patients were referred by standard endoscopy, advantages and limits were studied. We underline the atraumatic feature of VE and superiority of fibroscopy. Terminology is assessed. To compare two methods, one recent, is not actually specially justified. "VE" development is an undeniably interesting challenge for standard endoscopy. Is is absolutely conceivable that in the next future, an important number of purely diagnostic exams will be carried on by virtual technics (J. F Rey).
[Magnetic resonance angiography: fields of exploration, main indications and limitations].
Magnetic resonance angiography (MRA) has become a widely accepted technique with regards to the other available noninvasive techniques in the diagnosis of vascular disease. This paper proposes a review of the different indications of this technique in arterial and venous diseases. Among several MRA pulse sequences, the most frequently used until today consisted of a time-of-flight technique which provided angiograms without any injection of intravascular contrast medium. It required to be performed in a plane perpendicular to the main axis of the vessel to be optimal. New techniques, such as contrast medium bolus-enhanced acquisitions allow examination of vascular segments in a plane parallel to their course (coronal for the aorta and lower limb arteries). An increasing number of clinical applications has raised since the implementation of MRA techniques on MR devices; some of them are widely accepted, whereas some others remain under the scope of extensive validation. With a high level of accuracy in grading carotid artery stenosis, MRA is now routinely used in cerebral arterial occlusive diseases and has in part replaced contrast angiography. MRA of the venous system of the brain plays a major role in the diagnosis and follow up of dural venous thrombosis. Other vascular brain diseases, such as vascular malformations, yet have limited uses. Carotid artery dissections are fairly demonstrated with MRA, which can be used for diagnosis as well as for follow-up. The accuracy of MRA in the diagnosis of venous thrombosis of the cervical/mediastinal veins has been reported as high as 100%. Moreover, MRA allows a precise assessment of collateral vessels in case of complete cervical/mediastinal venous thrombosis.
Virtual tracheo-bronchial endoscopy: educational and diagnostic value.
The use of Helical CT significantly improves image quality of examinations in a number of clinical settings. It is particularly suited to the study of the tracheo-bronchial tree as a result of new ways of image processing (developed by GEMS research) which can produce virtual endoscopic images without the use of an endoscope. We present our initial anatamo-radiological findings and their educational value as well as our thoughts on potential future clinical applications.
The clinical measurement of volumes using helical CT.
The object of this preliminary study is to evaluate the new techniques of measurement by helical CT which allow direct assessment of the volume of a lesion in clinical practice particularly by obtaining direct macroscopic anatomical correlation. Its primary application is anatomical, with measurement of the volumes of organs or anatomical structures, the clinical importance of which relates primarily to oncology. We present our initial results, including their applications and limits, before extending this study to a larger series so that it may be compared with other multicentre evaluations.
[Spiral scanners: principles and clinical prospects].
Helical computed tomography (CT) involves continuous patient shifting during X-ray source rotation and data acquisition. As a result, a volume data set is obtained in a short period of time. An entire examination can be completed in a single breath hold, without additional radiation exposure, optimizing enhancement with intravenous contrast material. By overcoming some of the constraints of conventional CT, helical CT has advanced prospects, including multiplanar reconstruction and CT angiography, as reviewed in this article. There are undergoing studies to confirm these preliminary findings: its clinical applications are currently evolving.
[Endometrial cancer: progress in the evaluation of locoregional extension by imaging techniques].
In the evaluation of loco regional extension, MRI and ultrasound provide highly valuable information, with respect to the invasion of deep myometrium, which determines prognosis, being highly similar for the two techniques. This gives ultrasound techniques a role of primary intention for reasons of public health economics. MRI, however, improves the work-up of other types of loco regional extension, and CT scan remains an indispensable tool for evaluating overall lymph node involvement and visceral extension.
[Does solitary plasmacytoma still exist? Value of MRI of the spine].
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[Breast cancer: role of MRI in follow-up of cases treated].
Conventional imaging (CI) for breast cancer includes mammography and ultrasound. Its limited efficiency is especially manifest for breast cancer follow-up after breast-conserving therapy (i.e. exclusive radiation therapy) and after breast implant. Lack of evidence for definitive diagnosis increases the number of invasive explorations. To improve the specificity of the diagnosis between recurrence or fibrosis, we describe the interest of new imaging (NI) techniques: post-contrast MRI, and MR angiography (MRA), realized in 1 exam. Between October 1993 and December 1994, 82 patients were eligible for these investigations. All patients had an history of conservative breast cancer treatment of breast implant following mastectomy. In all cases CI was not contributive for a precise diagnosis; therefore a biopsy was performed and confirmed the diagnosis of breast cancer. NI was done before biopsy and compared results are following. 19 more patients were evaluated for primary chemotherapeutic response, including a total of 101 patients. Regarding the follow-up of prosthesis and conservative treatment, the correlation with histological control was obtained in 95% with four false diagnoses due to confusion between retroprosthesis relapse and inflammation. Historadiologic correlation were close to 90% for the evaluation of primary chemotherapeutic response. Studies are ongoing to confirm those preliminary findings. Though expansive, these techniques might be cost-effective if they result in a substantial decrease of unnecessary surgical invasive procedures.
[Cerebral thrombophlebitis in sarcoidosis].
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Fotemustine (S 10036) in the intra-arterial treatment of liver metastasis from malignant melanoma. A phase II Study.
Fotemustine is a new nitrosourea which has shown some efficacy on disseminated malignant melanoma (DMM) (24.2% response rate (RR) among 153 patients in a Phase II trial) but little activity on hepatic metastasis (8.8% RR). In order to improve those poor results, hepatic intra-arterial infusion (HIAI) of fotemustine was performed. After two years, thirteen patients, all in good general condition, were evaluable. Seven were pretreated and six had extrahepatic metastasis on entry into the study. All patients had a surgically implanted intra-arterial catheter. The induction cycle consisted of 100 mg/m2/week for 3-4 weeks, followed by 5 weeks rest and maintenance therapy of 100 mg/m2 every 3 weeks for stabilized or responding patients. Two complete responses (CR) (72+ and 145+ weeks) and six partial responses (PR) (7-18.5 weeks) were observed. The hepatic RR reached 61.5%. A RR of 42.8% was registered on preexisting EHM (one CR and one PR on cerebral lesions). Nevertheless, this treatment is limited by the high progression rate of 46.1% in extrahepatic disease. Toxicity was mainly hematologic (grade III-IV), comprising 36% neutropenia and 15% thrombopenia. Hepatic intra-arterial infusion of fotemustine is efficient therapy for liver metastases of DMM, but combination schedules (IV + HIA) are warranted.
[Malignant melanoma: hepatic intra-arterial chemotherapy].
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[The role of tomodensitometry in oral implantology].
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[X-ray computed tomography of lumbosacral roots and primary hypertrophic neuritis (Dejerine-Sottas disease)].
CT without contrast of lumbosacral nerve roots was performed in 13 patients with peroneal atrophy and 28 control subjects. Two series of 5 mm serial sections parallel to the plane of the disk were examined at the L4-L5 and L5-S1 levels, and the transverse diameter of the S1 nerve roots measured at the lower part of the lateral recess. Results showed frank bilateral, grossly symmetrical hypertrophy of lumbosacral roots in 8 of the 13 patients. This hypertrophy involved all roots examined (L4, L5, S1), except in one case where only S1 roots were involved. Hypertrophy was often more marked on the distal part of the roots and on spinal nerves, contrasting with the sometimes normal or only slightly altered appearance of the nerve roots emerging from the dural sac. In these 8 cases, the diameter of the S1 nerve roots was 8 to 18 mm, in contrast to a mean of 3.5 +/- 1 mm in the 28 controls. CT scan images were normal in the remaining 5 patients. The presence of a CT image of nerve hypertrophy was in all cases associated with a marked fall in nerve conduction rate (median nerve motor conduction rate less than 25 msec-1), and a decrease in number of myelinated fibers with numerous onion bulbs. In contrast, the absence of CT nerve hypertrophy could not predict the results of electrophysiological and histological examinations.
[The value of MRI in the management temporomandibular joint algo-dysfunctional syndromes. Preliminary study].
The authors report their initial conclusions regarding the value of M.R.I. in the investigation of temporo-mandibular joint dysfunction. This examination was performed for all varieties of symptomatology: musculo-ligamentary, menisco-ligamentary or meniscal. A detailed examination technic is given. M.R.I. enables meniscal abnormalities to be demonstrated: morphological and positional abnormalities (reducible and irreducible anterior luxations) and structural abnormalities similar to those seen in meniscal pathology within the knee joint.
[Value of modern imagery in the study of coronoido-malar malformations. Apropos of 2 cases].
We report two cases of mechanical limitation of buccal opening. CT scanning of bone anomalies diagnosed on standard radiography allowed to define malformation of the coronoid piston on the one hand, and the temporo-malar groove on the other: a combination of Langenbeck's and Jacob's disease in one case and Langenbeck's disease in the other. Coronoidectomy, systematically bilateral, demonstrated these morphological anomalies together with formation of coronoido-malar neo-arthrosis.
[Localized tracheobronchial amyloidosis. A new case studied with x-ray computed tomographic and nuclear magnetic resonance. Review of the literature].
We report a new case of localized primary tracheobronchial amyloidosis revealed by haemoptysis and effort dyspnea. The CT scan image was a homogeneous and circumferential thickening of the bronchial wall measuring 282 on the Hounsfield scale. At magnetic resonance imaging the amyloid substance was a slightly less intense than fat tissue in T1 and T2-weighted sequences. Treatment using Yag laser photoresection stabilized the lesions with one year follow-up. The review of the literature enables us to summarize the clinical, endoscopic, morphological, prognostic and therapeutic features of tracheobronchial amyloidosis, as well as pathogenic hypotheses and relationship with tracheobronchopathia osteoplastica.