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Biomedical subjects

J F Paul

Publications and source records attributed to J F Paul.

At least 19 recordsLinked to original sources
PubMed2005

[Multislice computed tomography to detect coronary stenosis among asymptomatic patients with cardiovascular risk factors and equivocal prior stress test: preliminary study].

UNLABELLED: Multislice computed tomography (MSCT) is a non-invasive and validated technique to detect coronary stenoses. Some questions remain about its accuracy to detect coronary stenoses (CS), especially for asymptomatic patients (P) when a prior stress test isn't conclusive. METHODS: MSCT was performed among 45 asymptomatic men (mean age: 58,3 +/- 16), with a high ten year risk of fatal cardiovascular disease (SCORE 2003 data for low-risk regions of Europe), without any previous coronary history and with previous non conclusive exercise testing. When significant (> 50%) CS was suspected at MSCT, an angiocoronarography (AC) was done. RESULTS: Eighteen MSCT were normal, unsignificant CS (< 50%) were detected on 14 MSCT and significant coronary stenoses (SCS) for 13 P. Among this 13 P, 19 SCS were identified: 2 SCS of left main coronary artery (CA), 9 of the left descending CA, 6 of the right CA and 2 of the left circumflex CA. 13 CS were confirmed at AC. Finally, because of critical angiographic lesions +/- ischemia at nuclear tomoscintigraphy (NT), 9 P had coronary revascularization (7 catheter based, 2 surgical bypass), 4 P had medical treatment. DISCUSSION: Benefits of this preliminary study are obvious: 9 coronary revascularization/45 P. However, the place of MSCT for the screening of CS is uncertain, but may be usefull as a complement for the screening of coronary arterial disease.

Aged↗
PubMed2004

[Visualization of coronary tree and detection of coronary artery stenosis using 16-slice, sub-millimeter computed tomography: preliminary experience].

PURPOSE: multislice CT has been shown as a promising tool for coronary artery imaging. Our goal was to investigate the value of the new sixteen-slice, CT technology for non-invasive visualization of coronary arteries and assessment of coronary stenosis. MATERIALS AND METHODS: we assessed coronary artery visualization in 30 consecutive patients using 16-slice CT and compared the findings with conventional coronary angiography. The whole heart was scanned using 0.75 millimeter slices after injection of contrast medium. Retrospective ECG-gated reconstructions were performed and images were analyzed using axial CT, maximum intensity projection and 3D images, blind to the conventional angiography findings. Seventeen main coronary segments of more than 1.5 mm were analyzed and stenosis was graded on a four-point scale. RESULTS: CT angiography attained diagnostic quality for the whole coronary artery tree in 90% (27/30) of patients. Sixteen of 493 segments (4%) were not interpreted because of substantial motion artifacts (n=12) or heavy calcifications or stenting (n=4). Thirty seven of the 43 cases of significant stenosis (>50%) identified on coronary angiograms were correctly identified with multislice CT. All 6 false negatives involved stenosis of the circumflex artery or branches. Five false positive stenoses were found in 432 non stenotic segments. The sensitivity was thus 86%, specificity 99% for stenosis of more than 50%. CONCLUSION: 16-slice CT provides an excellent visualization of the coronary tree in most patients, allowing accurate non-invasive detection of significant coronary stenosis. Stenoses of the left circumflex artery remain more difficult to detect.

Aged↗
PubMed2004

[Diagnosis of acute myocardial infarction using multislice computed tomography in emergency room].

Managing chest pain in emergency remains a diagnostic challenge because of the speediness and the accuracy that request. The authors report the case of a 40 years old patient admitted for chest pain with suspected aortic dissection. Multislice computed tomography (sixteen-slice CT) was performed at the patient's admission, initial diagnosis was rapidly corrected, showing both and accurately show both antero-septal defect perfusion and an acute occlusion of the proximal left anterior descending artery. Angioplasty was performed in emergency within the 6 first hours after onset of the symptoms. Multislice computed tomography was able to identify accurately not only the chest pain etiology but also to show the culprit artery, leading to quick and oriented percutaneous coronary intervention.

Adult↗
PubMed2004

[A rare form of aortic arch anomaly: left aortic and right descending aortic arch].

Among aortic arch anomalies, the circumflex aortic variety, involving left aortic and right descending aortic arch, is a rare situation. Two children were recently sent to the CCML for signs of tracheobronchial compression leading to the discovery of this anomaly. The younger child, aged 2 months, had been intubated since birth, and angiography presented a constrictive form of the disorder due to the presence of a small arterial canal linking the pulmonary tree to an aberrant right subclavian artery arising from a voluminous Kommerel diverticulum. Removal of the obstacle was achieved by section of the arterial channel approached via a right posterior thoracotomy. The second patient, aged 7 years, had chronic bronchopneumonia with severe obstructive syndrome. Multislice CT investigation with three-dimensional reconstruction showed obstruction at two levels: the first concerned the lower part of the trachea related to the posterior transverse segment of the aortic arch; the more severe second obstruction was due to a vascular pinch formed by the descending aorta and the right pulmonary artery. Improvement in functional signs with time reported by the parents had led to temporisation in this case. In adults this anomaly is often a fortuitous finding during radiological investigations performed for slight functional signs. In all cases of aortic anomalies and associated lesions, the importance of precise and thorough investigation using modern radiological techniques must be stressed.

Aorta, Thoracic↗
PubMed2004

[Anomalies in myocardial contrast uptake revealed by multislice cardiac CT during acute myocarditis].

Acute myocarditis can display many various clinical appearances. Endomyocardial biopsy is an invasive investigation for which the sensibility is insufficient in mild cases and when it is performed too early. Multislice cardiac CT with ECG synchronisation and injection of contrast medium allows visualisation of the coronary arteries and the study of myocardial contrast uptake. We report the cases of two patients with a mild myocarditis where multislice CT performed early showed multiple areas of increased myocardial contrast uptake consistent with a diffuse inflammatory disorder. Coronary angiography was normal in these two patients. Multislice cardiac CT could be a useful non-invasive investigation for the early diagnosis of this disease.

Acute Disease↗
PubMed2003

[Non-invasive coronarography: myth or reality].

Slice Imaging technology progress allows a good approach of coronary arteries. MRI and Multislice Computed Tomography (MSCT) are in competition. Inspite of important progress, MRI of coronary artery disease remains "disappointing". With this imaging technology, there is a good plaque burden and myocardium visualisation. MST, and particularly with 16 slice technology, allows a good coronary stenosis identification. This technology enables soft plaque and myocardial ischemia detection. It is now possible to detect coronary heart disease with MSCT, which can replace or help a coronary angiogram in some indications.

Angioplasty, Balloon, Coronary↗
PubMed2002

Location of protons in anhydrous Keggin heteropolyacids H(3)PMo(12)O(40) and H(3)PW(12)O(40) by (1)H[(31)P]/(31)P[(1)H] REDOR NMR and DFT quantum chemical calculations.

HeteroPolyAcids (HPA's) are a class of solid acids that have broad applications in many fields of science and technology, including catalysis and chemical engineering. The proton locations within the thermally stable and commonly known Keggin unit, which is the primary structure building unit/block, has remained undetermined in anhydrous HPAs, despite numerous theoretical and experimental efforts. However, Rotational Echo DOuble Resonance (REDOR) NMR and Density Functional Theory (DFT) quantum chemical calculations offer a new opportunity to determine the exact locations of protons within the Keggin unit. The crucial experimental evidence is provided for the basic and very extensively studied acidic form of H(8-n)X(n+)M(12)O(40), X = Si, P and M = Mo, W, belonging to the Keggin structure. While showing that the acidic protons are located in the bridging oxygen positions (R(P-H) = 520 +/- 20 pm) in H(3)PMo(12)O(40) and in the terminal oxygen positions (R(P-H) = 570 +/- 20 pm) in H(3)PW(12)O(40), REDOR measurements also provide for the first time the structural basis to consistently rank the acid strength for the important class of Keggin solid catalysts.

Journal Article↗
PubMed2002

[Three-dimensional multislice CT scanner: value in patients with pulmonary atresia with septal defect].

The aim of this study was to evaluate the interest of multislice CT scanning using three-dimensional reconstructions for pre- or postoperative management of patients with pulmonary atresia with ventricular septal defect. Twenty-one consecutive patients (median age: 8 months, median weight: 5.6 kg) with pulmonary atresia with ventricular septal defect were explored by multislice CT. Standard protocol consisted in one helical thoracic acquisition, associated with an injection of 2 to 3 mL/kg of iodinated contrast medium at a flow rate from 0.5 to 1 mL/s. Three-dimensionnal reconstructions were systematically performed. Before operation, status and size of central pulmonary arteries, major aorto-pulmonary collateral arteries, and associated anomalies were analyzed. In 13 operated patients, the permeability of palliative anastomosis and postoperative anatomical changes were studied. The status of central pulmonary arteries was assessed in all cases and the sizes found were in agreement to surgical findings. Main aorto-pulmonary collateral arteries were depicted and their relative position to central airways was assessed. Various associated anomalies were found: right aortic arch, anomalous coronary artery, abnormal pulmonary venous return, left superior vena cava. The anastomosis and the surgical connections (unifocalization, complete repair) were clearly analyzed. The multislice CT with three-dimensional reconstructions is a complementary imaging technique, reliable, useful to pre-operative management and postoperative follow-up of patients with pulmonary atresia with ventricular septal defect.

Adolescent↗
PubMed2001

Unilateral renal artery stenosis: perfusion patterns with electron-beam dynamic CT--preliminary experience.

Renal dynamic computed tomographic (CT) data for 16 patients with unilateral renal artery stenosis were compared with those for 12 control subjects. Three patterns of perfusion were distinguished in stenotic kidneys: pattern A, symmetric time-attenuation curves; pattern B, asymmetric time-attenuation curve with similar perfusion; and pattern C, asymmetric time-attenuation curve with impaired perfusion. Additional functional data can be obtained from the initial timing scan in a CT study of unilateral renal artery stenosis.

Adult↗
PubMed2001

[Value of helical CT in Takayasu arteritis].

In the past, the diagnosis and course of Takayasu arteritis were monitored by following angiographic findings, in addition to clinical symptoms and biological tests. More recently, cross-sectional imaging techniques especially Computed Tomography (CT) depicted mural changes in aorta and main vessels in this disease. Within the same acquisition, spiral mode also allows to show luminal changes, similarly to conventional angiography. In addition to its diagnostic value especially in the early phase of the disease, CT seems accurate in the follow-up of treated patients and may be proposed as a therapeutic guide. CT features are presented, according to the stage of the disease and the vessels involved.

Diagnosis, Differential↗
PubMed2000

Spontaneous renal artery dissection revealed by helical CT angiography.

Spontaneous renal artery dissection is rare and may be misdiagnosed because its clinical presentation is confusing. Diagnosis is usually made by intra-arterial angiography. We report a case where a spontaneous renal artery dissection was initially misdiagnosed as a renal abscess. Diagnosis was made later with helical CT for suspicion of renal artery stenosis in a patient with recent onset of hypertension. This unusual case shows that helical CT can be useful for non-invasive diagnosis of renal artery dissection.

Abscess↗
PubMed2000

The role of B-mode ultrasonography and electron beam computed tomography in evaluation of Takayasu's arteritis: a study of 43 patients.

OBJECTIVES: To evaluate the capacity of B-Mode ultrasonography (B-Mode US) and electron-beam computed tomography (EBCT) to detect arterial changes in Takayasu's arteritis. METHODS: EBCT angiography of the thoracoabdominal aorta and pulmonary artery, and B-mode US of large superficial arteries (common carotid, subclavian, and common femoral arteries) were performed prospectively in 43 consecutive patients with established Takayasu's arteritis. The arterial wall thickness was measured, and lumen changes (stenosis, aneurysm) were noted. RESULTS: The combined results of B-Mode US and EBCT examinations showed that every patient had at least one abnormality at the studied sites. The median score of abnormal sites was 7. The most frequent lesion was a characteristic long, homogeneous, circumferential thickening, visualized in 52% of examined sites and in all patients but one (98%). Stenosis was detected by US and by EBCT, respectively, in 44% and 32% of patients, and aneurysm in 0.4% and 68%. CONCLUSIONS: In Takayasu's arteritis, B-Mode US and EBCT was able to visualize the classical caliber abnormalities (stenosis, aneurysm) and, in contrast to angiography, to depict vessel wall thickening, a major pathologic feature of the disease. Both these safe techniques seem more useful than angiography to characterize and map the vascular lesions of Takayasu's arteritis.

Adolescent↗
PubMed2000

[Pulmonary embolism: is scintigraphy useful after initial angio-CT?].

PURPOSE: To assess the value of ventilation-perfusion scintigraphy after an initial helical CT with absence of pulmonary embolism (PE). MATERIAL: and methods. Twenty eight consecutive patients with clinical suspicion of pulmonary embolism underwent helical CT scan to look for an intra-luminal clot. When the CT-scan was positive for PE, diagnosis was retained. If the result was negative, a ventilation-perfusion scintigraphy was performed. If the result was also negative, diagnosis of PE was excluded. In case of discrepancy, a pulmonary angiography was performed and used as gold-standard. RESULTS: Twenty-one patients showed PE at CT-angio and 7 did not. Two of these 7 had normal or low probability scintigraphy, excluding diagnosis of PE. One had intermediate V/P scan and 4 had high probability V/P scan. For these 5 discrepancies, none of them had PE on angiography. CONCLUSION: In this population, scintigraphy was not appropriate after a negative CT-angio for PE. In case of persistent doubt after a normal initial helical CT, pulmonary angiography is required

Aged↗
PubMed2000

[Left ventricular thrombus revealed by electron bean computed tomography, in a patient with antiphospholipid syndrome].

The authors report a case of a 48 year old woman admitted to hospital because of digital ischemia, in a context of antiphospholipid syndrome. The electrocardiogram-triggered electron beam computed tomography revealed an apical thrombus associated with a thinning left ventricular wall, suggesting painless myocardial infarction. The diagnosis was secondary confirmed by coronarography.

Antiphospholipid Syndrome↗