Re-emergence of ebola haemorrhagic fever in Gabon.
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Biomedical subjects
Publications and source records attributed to D Drevet.
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PURPOSE: To understand the behavior of stents during contrast-enhanced magnetic resonance angiography (MRA). MATERIALS AND METHODS: Seven different types of stents are explored in vitro with spin echo (SE) T2 sequence and MRA sequences using classification of the intra-prothesis signal. Six patients with 11 different proximal stents are studied by Gadolinium enhanced MRA with the same classification. RESULTS: Stent material is not the only determinant of behavior. In this way, one stainless steel stent produced less intra-luminal hyposignal than a nitinol device. Nevertheless, only a nitinol stent did not alter the intra-prothesis signal and allowed an appreciation of patency, despite a decrease of diameter and presence of edge artifacts. CONCLUSION: Even if stent compatibility is well known with MRI, even with Gadolinium, cannot be used alone to depict stenosis or diameter reduction. Even patency based on the presence of a constant signal, cannot be confirmed routinely with confidence: indeed, only a single stent does not modify intra-arterial signal.
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PURPOSE: To evaluate Doppler ultrasound (US), Helical CT, Magnetic Resonance (MR) angiography in the detection of carotid bifurcation atherosclerotic disease and comparison with angiography. MATERIALS AND METHODS: After a Doppler US procedure, 56 carotid bifurcations were included (symptomatic stenosis greater than 60% or asymptomatic stenosis greater than 30%). Helical CT, MR angiography and selective arteriography were performed. Stenosis were measured with NASCET criteria. Sensitivity and specificity were calculated and compared to arteriographics findings for each procedure and each grade of stenosis. RESULTS: Helical CT and MR angiography had their best sensitivity in grade 3 (70-99%), 92%, 100% respectively, their specificity was identical (91%). All the occlusions were depicted by the three procedures. CONCLUSION: Association of Doppler US and MR angiography may replace in the future selective angiography in the evaluation of extracranial atherosclerotic disease. Arteriography would be performed only in case of discordance between these two procedures.
Peritoneal invasion by a malignant mesothelioma is less frequently encountered than pleural localization. We report a case of a double pleural and peritoneal localization. CT and MR may be suggestive, especially when pulmonary asbestosis is associated, but pathology (fine needle aspiration or surgical biopsy) is necessary to assess the diagnosis. When possible surgery is performed, with or without associated radiotherapy. Prognosis is nevertheless very poor.
A case of large and non-functioning malignant adrenal tumor is reported. It was discovered incidentally during a check-up ordered because of sciatic pain caused by an osteolytic lesion of the sacrum. This huge abdominal tumor was suspected to be an adrenal tumor one the basis of the CT and MR findings. Histological analysis of percutaneous biopsies were unable to define the site and etiology of these two masses. Only histo-pathological examination of the surgical specimen allowed the diagnosis of adrenal cortical carcinoma.
We report a case of spontaneous rupture of the rectosigmoid junction demonstrated by surgical and histological examination. This rare complication of chronic constipation is difficult to confirm except in the case of the typical clinical presentation with lower abdominal pain after defaecation and evisceration of small intestine loops through the anus. No radiological procedure is usually performed except for plain abdominal radiograph, to demonstrate inconstant (retro)peritoneal emphysema. CT scan could detect free air outside of the rectosigmoid lumen, suggesting parietal rupture and allowing appropriate surgical treatment on the lower digestive tract.
Duplication of the gallbladder is a rare congenital anomaly, which must be depicted by sonography, although false positive and negative diagnosis could still be made. Usually abdominal sonography allows duplication diagnosis as reported in our case and a cholecystography may be performed to determine the type of the anomaly. When a surgical procedure needs to be performed, especially in case of coelioscopic technique, surgeon needs to know the exact anatomic type of the anomaly and the number of gallbladders he will find.
Filter complications are quite common. The most frequent are distal or proximal migration, angulation, vena cava thrombosis or perforation. We report one case of filter struts fracture and their migration in the right kidney. This complication could require a surgical procedure and demonstrates the importance of filter follow-up with regular abdominal plain X-rays and possibly CT scan and/or cavography.
We present a retrospective study of ten patients presenting non specific clinical manifestations in whom the diagnosis of pulmonary embolism was documented by CT scan and/or MRI. Results of CT scan and/or MRI were compared to DSA bi-selective pulmonary angiography findings. In a large number of cases, CT scan and MRI allowed the detection of the obstruction within the right and left pulmonary arteries (RPA and LPA). Although these techniques did not permit the diagnosis of peripheral clots, pulmonary infarcts were usually depicted by these two procedures. CT scan and/or MRI could be performed as first-line investigations in case of atypical clinical symptoms because of their high relevance for proximal pulmonary artery obstruction, although these two non-invasive procedures cannot indicate the aetiology of the obstruction etiology.
Extramedullary haematopoiesis is a compensatory response of bone marrow to abnormal haematopoietic tissue formation: the commonest etiology is thalassemia (generally intermedia). The thorax is a rare site and the posterior mediastinum is usually involved. CT scan completes standard chest radiology and allows fine needle aspiration to provide adequate cytologic material for the diagnosis of extramedullary haematopoiesis, especially when an intercurrent pathology is present and could involve paravertebral areas. Thoracotomy may be necessary in rare cases of complications.
The authors report the results of national surveys conducted in 5 Central Africa states: Cameroon, Congo, Gabon, Equatorial Guinea and RCA. The method used was cluster sampling among random populations. Only adults (greater than 15 years of age) took part in the study. The prevalence rates were between 6 and 14 per thousand. They are markedly higher than the official data.
Kim-Ray filter complications are usually benign, such as angulation or slight migration. We report and compare with the literature one case of vena cava perforation associated with a small bowel lesion. The follow-up with regular abdominal plain X-rays allows detection of filter angulation, the first step before vena cava perforation. Cavography or CT scan depicts this perforation. Complete or partial surgical removal of the filter may be necessary.
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Benign mediastinal teratomas are rare entities, representing 8 to 18% of all mediastinal tumors. Two cases of benign teratomas with a rapid growth suggesting malignancy are reported. CT and MR allowed precise characterization of the multi-tissue composition of the tumor (various CT densities were noted corresponding to adipose, cystic, calcified and hemorrhagic components), and definition of the extension of the process before surgical removal. The per-operative pathological analysis in one patient confirmed the benign nature of the lesion based on the absence of immature tissue, allowing complete surgical removal. The final pathological examination showing mucus secretion by bronchial glandular tissue and intra-tumoral hemorrhage may explain the rapid growth of this kind of lesion. The post-operative follow-up of these benign teratomas is favourable.
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