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Biomedical subjects

D Mathieu

Publications and source records attributed to D Mathieu.

At least 253 records · Page 14Linked to original sources

Hyperintense benign liver lesions on spin-echo T1-weighted MR images: pathologic correlations.

BACKGROUND: To determine the incidence of hyperintensity on T1-weighted spin echo (SE) images in benign liver lesions, value of fat-suppressed magnetic resonance (MR) imaging for the detection of fat within these lesions, and the causes of hyperintensity by correlation to pathologic examinations. METHODS: Five hundred forty-nine patients with 805 benign liver lesions including 585 hemangiomas, 188 focal nodular hyperplasias (FNHs), 14 hepatic adenomas (HAs), 14 focal fatty infiltrations (FFIs), two biliary cystadenomas, and two hemorrhagic cysts were examined by T2-weighted and T1-weighted SE MR imaging. For hyperintense lesions on T1-weighted SE images, fat-suppressed images were obtained by selective presaturation of fat. RESULTS: Thirty-two lesions (four FNHs, 10 HAs, 14 FFIs, two biliary cystadenomas, and two hemorrhagic cysts) appeared hyperintense on T1-weighted SE images; 21 of these became hypointense on the fat-suppressed T1 weighted SE images (one FNH, six HAs, and 14 FFIs) and contained fat at pathological examination. The other 11 lesions remained hyperintense on fat-suppressed T1-weighted SE images and had no fat deposition. Causes of hyperintensity in these cases were sinusoidal dilatation, copper deposition, hemorrhage, and high protein content. CONCLUSION: Among benign liver lesions, hyperintensity on T1-weighted SE images is rare (3.9%). Causes of this hyperintensity are fat deposition, copper accumulation, sinusoidal dilatation, bemorrhage, and high protein content. Fat-suppressed imaging can distinguish fat deposition from other causes of hyperintensity.

Adenoma↗

Determination by 1H NMR spectroscopy of paraquat in urine from acutely poisoned patients. Comparison with second-derivative spectroscopy method.

The application of 1H nuclear magnetic resonance (NMR) spectroscopy to characterize and quantitate paraquat in urine is described. Characterization was performed taking advantage of two NMR spectroscopy parameters: chemical shifts and coupling patterns. Without any pretreatment of the biological samples, herbicide was detected by its aromatic doublets at 8.49 and 9.02 ppm. Quantitation of the xenobiotic was realized by relative integration of the dipyridyl protons to an internal standard. After a validation step using control urine samples, quantitation was performed in urine obtained from two poisoned patients. On admission, mean paraquat concentrations were 985 (patient 1) and 500 (patient 2) micromol/L. Results are compared and found to be in good agreement, using a second-derivative spectroscopy method.

Adult↗

Tetrachloroethylene and trichloroethylene fatality: case report and simple headspace SPME-capillary gas chromatographic determination in tissues.

We describe a simple, precise, and sensitive assay of tetrachloroethylene and trichloroethylene in tissues, suitable both for emergency cases and forensic medicine. The method employs headspace solid phase microextraction-capillary gas chromatography and electron capture detection. The case is relative to a 45-year-old woman discovered unconscious in a laundry area. The concentrations of the solvents in tissues were determined and compared to other previously published fatalities.

Chromatography, Gas↗

Computed tomography of thoracic aortic dissection: accuracy and pitfalls.

During a 5 year period, 137 patients with suspected acute aortic dissection were screened by CT. The radiologic diagnosis of dissection was made in 54 cases and eliminated in 76. There were seven false-negative CT examinations. Surgical and angiographic correlations or clinical follow-up were obtained with all patients.

Acute Disease↗

Postoperative CT follow-up of aortic dissection.

Computed tomography with contrast enhancement permits noninvasive follow-up of patients treated for aortic dissection. We used CT to examine 52 patients with aortic dissections for up to 14 years postoperatively. The mean interval between surgery and CT was 32 months. Computed tomography demonstrated the aortic graft in 45 patients. Persistent patency of a false lumen was observed in 40 cases. In one case, CT demonstrated extension of the dissection. No rupture or thoracic pseudoaneurysm was noted in our series.

Adult↗

Epithelioid hemangioendothelioma of the liver: MR and CT findings.

The MR imaging features in five patients with hepatic epithelioid hemangioendothelioma (EHE) were correlated with CT and pathologic findings. Two hemangioendotheliomas appeared as multiple nodular lesions with a predominantly peripheral location in the liver. In three more extensive cases, the tumors formed confluent peripheral lesions with macroscopic invasion of portal or hepatic veins (n = 3), signs of portal hypertension (n = 3), and nodular hypertrophy of uninvolved liver (n = 2). These findings, suggestive of EHE, were well demonstrated by MR imaging and CT. The internal architecture of the tumors was clearly depicted on T2-weighted MR images. Viable tumor peripheries appeared moderately hyperintense relative to liver. The center of the tumors consisted of one or several concentric zones. Hyperintense central zones were composed of loose, edematous connective tissue. Hypointense zones contained mainly coagulation necrosis, calcifications, and scattered hemorrhages. Except for the presence of calcifications, the internal architecture of EHE was better defined by MR imaging than by CT.

Adolescent↗

Castleman disease mimicking liver tumor: CT and MR features.

We report the CT and MR features of two localized abdominal forms of Castleman disease mimicking hypervascular liver tumors due to their unusual location in the porta hepatis and the portacaval space. The MR appearance of Castleman lymph nodes is emphasized, including their characteristics on dynamic turbo-fast low angle shot (FLASH) sequences after Gd-DOTA bolus injection. Our report suggests that the CT and MR features of Castleman lymph nodes in these locations cannot enable their differentiation from other hypervascular masses such as benign liver tumors.

Adult↗

MRI of intralesional hemolysis in focal nodular hyperplasia of the liver.

A case of Kasabach-Merritt syndrome caused by focal nodular hyperplasia of the liver is presented with atypical magnetic resonance findings due to intratumoral hemosiderin deposition. The high sensitivity of magnetic resonance imaging for iron served to identify the site of hemolysis in this patient with Kasabach-Merritt syndrome.

Adult↗

Detection of malignant primary hepatic neoplasms with gadobenate dimeglumine (Gd-BOPTA) enhanced T1-weighted hepatocyte phase MR imaging: results of off-site blinded review in a phase-II multicenter trial.

OBJECTIVE: To investigate the efficacy of gadobenate dimeglumine (Gd-BOPTA) enhanced MR imaging for the detection of liver lesions in patients with primary malignant hepatic neoplasms. MATERIALS AND METHODS: Thirty-one patients with histologically proven primary malignancy of the liver were evaluated before and after administration of Gd-BOPTA at dose 0.05 or 0.10 mmol/kg. T1-weighted spin echo (T1W-SE) and gradient echo (T1W-GRE) images were evaluated for lesion number, location, size and confidence by three off-site independent reviewers and the findings were compared to reference standard imaging (intraoperative ultrasound, computed tomography during arterial portography or lipiodol computed tomography). Results were analyzed for significance using a two-sided McNemar's test. RESULTS: More lesions were identified on Gd-BOPTA enhanced images than on unenhanced images and there was no significant difference in lesion detection between either concentration. The largest benefit was in detection of lesions under 1 cm in size (7 to 21, 9 to 15, 16 to 18 for reviewers A, B, C respectively). In 68% of the patients with more than one lesion, Gd-BOPTA increased the number of lesions detected. CONCLUSION: Liver MR imaging after Gd-BOPTA increases the detection of liver lesions in patients with primary malignant hepatic neoplasm.

Adenoma, Liver Cell↗

[Biomarkers for toxicity and metabolic abnormalities of the main severe poisonings. Clinical and toxicologic symptoms. Conservative determination].

The members of the joint group "Toxicology and Clinical Biology" of the French Society of Clinical Biology (SFBC), the French Society of Analytical Toxicology (SFTA), and the Society of Clinical Toxicology (STC), suggest guidelines to meet the requirements of clinical biologists who are not specialized in toxicology. Based on good laboratory practice they propose a number of guidelines. Three synthetic tables have been established. They are not only toxicity biomarkers and metabolic disorders associated with the main severe intoxications, but also clinical signs that are observed during these intoxications, finally biological sampling as a precautionary measure. The table also takes into account approximately fifty xenobiotics: main clinical signs emergency, identification or quantification of the suspected product, useful biological markers, therapeutic, quantitations necessary to take into consideration patient care, and poison antidotes, are described. Recommendations regarding medical and forensic techniques are also proposed by the group. It is also necessary to collect and store biological samples when the individual patients are in charge. These samples will be analyzed or not depending on the individual case history.

Biomarkers↗

[Hyperbaric oxygenation therapy and cicatrization].

HOT is a very useful therapeutic addition in chronic wounds presenting a healing problem and for which usual treatment were unsuccessful. In order to be fully effective, HOT must be included in a strategy of care, taking into account, not only the wound itself but the underlying disease. Peripheral delivery of oxygen and induction of tissue hyperoxygenation with HOT may be verified by measurement of the TcPO2 under HOT. The predictive value of these measurements is helpful in the decision for treatment and its management.

Aged↗

[Minima corticoid eyedrops in inflammatory outbreak of herpetic keratitis].

Seven patients having repeated inflammatory relapses of herpes simplex keratitis have been treated by small dosages of steroid eyedrops (from 0.25% prednisolone once a week to 1% prednisolone once a day). In these patients these doses were almost always sufficient. There was no complications (especially there happened 7 intercurrent dendritic ulcers which were unaffected by the steroids).

Adult↗

Magnetic resonance imaging of human orthotopic heart transplantation: correlation with endomyocardial biopsy.

The ability of magnetic resonance imaging (MRI) to detect allograft rejection was studied concomitantly in two centers. In 29 patients MR images performed on a 0.5 T imager were compared with pathologic findings obtained by transvenous right ventricular endomyocardial biopsies. Eight patients had grade 1 or 2 acute rejection, and their myocardium thickness was increased significantly compared with values obtained in normal volunteers, in normal heart allograft patients, and in patients during the resolving phase of an acute rejection episode, whereas no abnormal signal intensity was found in the myocardium of heart allograft patients with acute rejection. This finding is quite in opposition to what was found in experimental models. This could be the result of the immunosuppressive regimen of those patients including cyclosporine, whereas few experimental studies included cyclosporine treatment. For chronic rejection or fibrosis, MRI did not allow the diagnosis because the MRI appearance was close to normal. Finally, MRI appears as a complementary technique to B-mode ultrasound in detecting nonimmunologic complications such as pericardial effusions and endocavitary processes. These data suggest that MRI could be used in the future to monitor rejection, to guide the timing of endomyocardial biopsy, and to assess the response after immunosuppressive treatment.

Adolescent↗