Maximal thickness of the normal human pericardium assessed by electron-beam computed tomography.

The purpose of this study was to determine the maximal value of normal pericardial thickness with an electron-beam computed tomography unit allowing fast scan times of 100 ms to reduce cardiac motion artifacts. Electron-beam computed tomography was performed in 260 patients with hypercholesterolemia and/or hypertension, as these pathologies have no effect on pericardial thickness. The pixel size was 0.5 mm. Measurements could be performed in front of the right ventricle, the right atrioventricular groove, the right atrium, the left ventricle, and the interventricular groove. Maximal thickness of normal pericardium was defined at the 95th percentile. Inter-observer and intra-observer reproducibility studies were assessed from additional CT scans by the Bland and Altman method [24]. The maximal thickness of the normal pericardium was 2 mm for 95 % of cases. For the reproducibility studies, there was no significant relationship between the inter-observer and intra-observer measurements, but all pericardial thickness measurements were

Fibrinogen and its relations to subclinical extracoronary and coronary atherosclerosis in hypercholesterolemic men.

The association between plasma fibrinogen and the presence of carotid, femoral, and aortic plaque (high-resolution B-mode ultrasonography) and coronary calcium deposit (ultrafast computed tomography scanner) was determined in 693 hypercholesterolemic, never-treated men free of previous or current clinical symptoms of cardiovascular disease. The number of subjects with extracoronary disease sites and coronary calcification deposits was significantly higher in the upper than in the lower tertile of fibrinogen. Plasma fibrinogen increased according to the number of diseased sites. The odds ratio of the upper to lower fibrinogen tertile for the presence of arterial lesions was 2.6 (1.7 to 4) for carotid, 2.2 (1.5 to 3.2) for aorta, 2.2 (1.5 to 3.1) for femoral, 1.8 (1.3 to 2.6) for coronary, and 3.6 (2.3 to 6.1) for one of four diseased sites. Adjustment for age, total cholesterol, HDL cholesterol, triglycerides, current smoking, and systolic pressure slightly reduced the association between fibrinogen and atherosclerosis. A synergistic effect between fibrinogen and total cholesterol/ HDL cholesterol (TC/HDL) ratio seemed to be operating on atherosclerosis, because nearly all of the individuals (98%) had a diseased site when fibrinogen and TC/HDL tertiles were the highest. This result suggests that fibrinogen is involved in the subclinical phase of extracoronary and coronary atherosclerosis and may potentiate the atherogenic effect of hyperlipidemia.

Hypertension promotes coronary calcium deposit in asymptomatic men.

Despite its important role in coronary disease, coronary atherosclerosis has been poorly investigated in uncomplicated hypertension. Therefore, we evaluated the presence and amount (score) of coronary calcium with ultrafast computed tomography in 73 pairs of age-matched asymptomatic hypertensive or normotensive men. We also estimated the extent of peripheral atherosclerosis as the number of arterial sites (carotid, aortic, femoral) with echographic plaque. Compared with normotensive men, hypertensive men had more frequent coronary calcium (63% versus 47%), a higher calcium score (57 +/- 111 versus 18 +/- 38), and an odds ratio of calcium deposit of 1.95 (with confidence intervals [CI] 95%, 1.01 to 3.79) for any score and of 2.38 (95% CI, 1.02 to 5.52) or 4.84 (95% CI, 1.53 to 15.3) for scores above 50 or 100, respectively. Hypertensive men showed correlations of calcium score with age and hypertension duration but not with the height of blood pressure, and the odds ratio of calcium deposit between extensive and minor peripheral atherosclerosis was 4.67 (95% CI, 1.41 to 15.45) for any score and 8.63 (95% CI, 2.10 to 35.5) or 8.13 (95% CI, 1.64 to 40.3) for scores above 50 or 100. Thus, high blood pressure and in particular its duration rather than its value promotes the presence and overall extent of coronary calcium, a potential predictor of sudden coronary death, in parallel with the extent of peripheral atherosclerosis. The mechanisms of the interaction of hypertension and coronary calcification may be multifactorial and not specific to hypertension.

Reproducibility of coronary calcification detection with electron-beam computed tomography.

If coronary calcification scores obtained with electron-beam computed tomography (EBT) were proved to be correlated to coronary atherosclerosis, the reproducibility of the technique had to be assessed before being used for patient follow-up. A total of 150 patients, selected as a result of a cholesterol screening programme, were studied by EBT. Twelve contiguous 3-mm-thick transverse slices beginning on the proximal coronary arteries were obtained through the base of the heart. The amount of calcium was evaluated as the calcified area weighted by a coefficient depending on the density peak level. The value was expressed as a logarithmic scale. Intra-observer, inter-observer and inter-examination reproducibilities were calculated. They were 1.9, 1.3 and 7.2%, respectively. These results were good enough to allow the use of EBT for longitudinal studies. The influence of acquisition and calculation conditions on score computation were also analysed.

Evaluation of the sialic acid content of LDL as a marker of coronary calcification and extracoronary atherosclerosis in asymptomatic hypercholesterolemic subjects. PCVMETRA Group.

Recent studies have shown that the sialic acid content of LDL isolated from patients with angiographically demonstrated advanced coronary atherosclerosis is lower than that of LDL isolated from healthy subjects. These observations raise the question as to whether LDL sialic acid content could be used as an early marker of atherosclerosis. We screened for carotid, aortic, and femoral plaques by ultrasonography and for coronary calcifications by ultrafast computed tomography in 160 hypercholesterolemic subjects free of cardiovascular disease to investigate the relation between LDL sialic acid content and the prevalence of these early atherosclerotic lesions. LDL sialic acid values varied from 19.6 to 46.6 nmol/mg LDL protein (33.9 +/- 4.4, mean +/- SD) in the whole population, but the distribution was very similar: (1) in subjects with no plaque (34.1 +/- 4.9) relative to those with one or several plaques at one (34.2 +/- 4.4), two (33.0 +/- 3.6), or three (34.8 +/- 3.4) different arterial sites; (2) in subjects with (33.9 +/- 3.7) and without (34.1 +/- 4.8) coronary calcification; and (3) in subjects with both extracoronary and coronary lesions (33.8 +/- 3.9) relative to those with no arterial lesions (34.2 +/- 4.5). LDL sialic acid content was not related to sex, age, body mass index, smoking, blood pressure, or serum total cholesterol and lipoprotein(a) levels but correlated negatively with serum triglyceride levels (P < .001). These results suggest that LDL sialic acid content is not a discriminant marker of early atherosclerosis in asymptomatic hypercholesterolemic subjects.

[Value and future of electron beam computed tomography]. / Intérêt et avenir de la tomodensitométrie à faisceau d'électrons.

Mecanic computed tomography would probably never reach the acquisition brevity obtained by EBT. This machine is the best for exploration of cardiovascular diseases, and non cooperative patients, and for cine and flow studies. Morever, there are never tube cooling delays or interruptions in any procedures. Its disadvantages are the price, the impossibility to tilt the gantry, and the computer which are to be improved. With "Evolution", Siemens proposes now improvements with the CVS mode and a computer release without increasing of the price.

[Electron canon computed tomography. Technique and clinical applications in cardiac imaging]. / TDM à canon à électrons. Technique et applications cliniques en imagerie cardiaque.

Electron Beam CT (EBCT) was initially devoted to both dynamic and morphological cardiac studies. ECG gated slices acquired in 100 milliseconds produce cardiac images without motion artefacts. Intracavitary tumors and thrombus are clearly detected and EBCT contributes to the stagging and follow-up of masses. Exploration of congenital abnormalities such as pulmonary atresia can be performed even in newborns. EBCT allows the diagnosis of tiny modifications of coronary arteries, endocardium or pericardium. EBCT offers a new modality of cardiac imaging which gives complementary informations to other modalities.

[Electron beam scanner and thoracic transplantation]. / Scanner par faisceau d'électrons et transplantation thoracique.

To follow an heart transplantation, EBCT is more precise than ultrasonography and scintigraphy to calculate a stroke volume. In lung transplantation, it is important before surgery to know the value of right ventricule stroke volume in order to choice the surgical protocol. After lung transplantation SFE helps to follow the patient to look after complications, to drain a collection or to guide a biopsy. SFE contribution is discussed in rejection, infectious diseases, detection of immuno-induced carcinomas, in bronchiolitis obliterans and recurrence of the primitive disease.

[Detection and significance of coronary calcinosis]. / Dépistage et signification des calcifications coronaires.

Coronary calcifications (CC) are the witness of atheromatous disease because they lies in intima. This is a best stamp of coronary atheromatosis than all the well know risk factors. CC scores is perfectly estimated by EBT. The reproductibility expressed in logarithm data is 7.2% in inter-examination, 1.3% in inter-observers, 2% in intra-observers [4]. CC detection is more specific in young population than in old population because CC appear and increase with age in asymptomatic patients [12]. But the score curve raised higher in symptomatic than in asymptomatic subjects. A patient with an abnormal score for his age will have 5 to 10% of ischemic cardiac disease during the following 6 months [11].

[Angioscanner analysis using Imatron C100 in 44 cases of hepatic tumors]. / Analyse angioscanner par Imatron C100 de 44 cas de tumeurs hépatiques.

We studied 44 patients with focal benign (n = 13) or malignant (n = 31) liver tumors prouved by histology or follow-up. The flow mode was acquired by electron beam CT (EBCT) after injection (35 cc at 6 ml/sec): 20 slices with a 400 ms exposure time. We looked for abnormal vessels and density curves inside the tumor, liver and aorta. We describe arterial vascularization in most cases (type 1) and particularly in all the hepatocarcinomas (n = 15) associated with abnormal vessels, and also in rare tumors (n = 4). For benign lesions like angiomas (n = 9) we showed surrounding the mass arterial vascularization in add to the typical aspect (type 3); for nodular hyperplasia (n = 3) arterial blush was associated with the last part of the tumoral curve at the same level as liver. Most often metastasis (n = 13) had no central vascularization and a slight peripheral density increased (type 2). Flow mode by EBCT allows a good density curves analysis particularly at arterial time.

[Detection of coronary calcifications and coronary disease]. / Détection des calcifications coronaires et maladie coronarienne.

OBJECTIVES: The diagnosis of clinically silent coronary artery disease would be a major step in preventing episodes of acute cardiac ischaemia. We screened asymptomatic patients with hypercholesterolaemia with electron computed tomography (ultrafast CT) to determine the effectiveness of this method in detecting calcium deposits in coronary arteries. METHODS: During a 3-year period, 1000 male subjects with hypercholesterolaemia were selected among the general population consulting for systematic work-shop check-ups. Electron computed tomography was performed in all selected subjects to detect coronary atheroma and those with major pathological results then underwent coronarography. RESULTS: Calcium deposits in the coronary arteries were observed in 66% of the subjects with hypercholesterolaemia. Twenty cases with particularly pathological results were selected for coronarography which revealed that coronary narrowing was greater than 50% in 10 of them. CONCLUSION: Electron computed tomography (formerly called ultrafast CT) is an effective method for detecting calcium deposits in coronary arteries and as such is a useful tool in predicting silent coronary artery disease.

[The transplanted kidney. Role of imaging in early non-functioning grafts]. / Rein transplanté. Place de l'imagerie dans les non-fonctions précoces.

Renal failure following transplantation can be classified in two groups: initial non function characterized by the absence of renal function after transplantation and delayed secondary non function after an initial improvement. In the first group, the most frequent etiology is an acute tubular necrosis (30 to 50% of the cases) which usually heals within three weeks. Arterial thrombosis are rare but of very bad prognosis. In the second group, the most frequent cases are acute rejection, urological complications, renal artery stenosis, urinary infections and cyclosporine, intoxication. Diagnostic imaging, and especially the color Doppler flow, is very effective in obtaining diagnosis. Vascular or urological complications are to be confirmed by contrasted opacifications. In the absence of vascular or urological obstruction renal failure must be related to a renal parenchymal disease. This may be acute tubular necrosis, a rejection, a pyelonephritis or a medicinal intoxication depending on clinical symptoms, the time of their apparition and the results of biological examinations.

[Biliary cystadenocarcinoma. Apropos of a case]. / Cystadénocarcinome biliaire. A propos d'un cas.

Biliary cystadenocarcinoma is rare biliary ductal neoplasm, usually occurring in middle-aged women, which arises in a healthy liver, with a better prognostic than other malignant tumors of the liver. We report a new case documented by echography, CT scan and MR. Echography showed multiple heterogeneous and septate masses with fluid-fluid level and dilatation of the intra-hepatic biliary ducts. CT showed multilocular cystic masses with internal septa and papillary excrescences showing contrast enhancement and no calcification. MR displayed a rather intense and variable signal in some parts of the masses on T1 weighted images, flasching on T2 weighted images, corresponding to a hemorrhagic fluid, confirmed by surgery. On T1 weighted images after gadolinium administration, the masses were less well visualized.

Serum Lp(a) as a discriminant marker of early atherosclerotic plaque at three extracoronary sites in hypercholesterolemic men. The PCVMETRA Group.

To investigate the role of lipoprotein (a) (Lp[a]) as an atherogenic condition related to hypercholesterolemia, we studied the serum concentration of Lp(a) as measured by immunonephelometry in relation to the presence of asymptomatic echographic plaques in the peripheral arteries of 103 untreated hypercholesterolemic, normotensive, middle-aged men. Plaque was found at carotid, aortic, and femoral sites in 36%, 51%, and 53% of subjects, respectively. The Lp(a) level was higher in the group with carotid plaques than in the group without (0.29 +/- 0.20 versus 0.17 +/- 0.14 g/l, p < 0.01), not significantly higher in the group with aortics plaque than in the group without (0.24 +/- 0.19 versus 0.19 +/- 0.16 g/l), and not different between groups with and without femoral plaques (0.21 +/- 0.18 versus 0.22 +/- 0.17 g/l). A logistic regression analysis confirmed that Lp(a) was associated with carotid plaques (p = 0.004), independent of other risk factors. However, in patients with low density lipoprotein cholesterol values above the group median value (4.7 mmol/l), Lp(a) was associated not only with carotid plaques (p < 0.01) but also with aortic plaques (p < 0.05), as well as with the number of diseased sites (p = 0.02). In contrast, in patients with low density lipoprotein cholesterol levels below or equal to 4.7 mmol/l, Lp(a) only remained associated with carotid plaques (p < 0.05). Thus, in symptom-free, hypercholesterolemic men, early atherosclerosis was influenced by serum Lp(a), particularly in the carotid arteries, as well as by the presence of a higher level of low density lipoprotein cholesterol.

Vascular complications in the adult kidney transplant recipient.

Vascular complications of renal transplantation occurred in 15% of the cases. They are thrombotic infarct, arterial stenosis, arterio-venous fistula, and chronic arterial diseases. From 900 renal transplantations performed, only 120 (made since 1989) were studied with color flow Doppler (CFD). Lack of arterial signal is indicative of main arterial thrombosis (or of renal infarct if thrombosis is limited). At the site of arterial stenosis, high velocity and turbulence are found. If the stenosis is more than 70%, the rising systolic time is longer than 0.07 sec in the post-stenotic artery. Arterio-venous fistulas are frequent after renal biopsy. They provoke vibrations transmitted to peri-vascular tissues and seen with CFD as a large area of turbulence. In the feeding artery, Fast Fourier Transformation (FFT) showed a high velocity with a low resistive index and pulsed flow in the outgoing vein. Chronic arterial diseases include cyclosporine A intoxication and chronic rejection. These two diseases cannot be diagnosed by CFD alone.

[Hypertension has no effect on coronary calcifications in asymptomatic patients with hypercholesterolemia]. / L'hypertension artérielle n'influence pas les calcifications coronaires chez l'homme hypercholestérolémique asymptomatique.

Since calcium in coronary artery walls is considered as an indicator for atherosclerosis, we used ultrafast computed tomography to quantify it non invasively in 111 hypercholesterolemic men. They were selected at worksite by a cholesterol screening program, had total cholesterol (TC) above 5.2 (6.88 +/- 0.82, SD) mmol/l, were aged from 30 to 63 (46 +/- 5 years), had never been treated with lipid lowering or antihypertensive drug, and had no clinical coronary heart disease. Body mass index, blood pressure, smoking and other serum lipids as HDL cholesterol, triglyceride (TG) were evaluated. Calcium score of proximal coronary arteries was calculated on 30 contiguous 3 mm slices from areas and peak density of calcium lesions. The mean score was 30 +/- 69 and ranged from 0 to 440. A zero score was found in 39 subjects who differed from the 72 others only by TG levels (1.44 +/- 0.60 vs 1.85 +/- 0.80; p < 0.05). A multiple regression analysis showed that elevated calcium score was associated independently to age (F = 6.6; p < 0.05) and TG (F = 6; p < 0.05) but not to blood. Thus 65% of these asymptomatic subjects had a non-zero calcium score in coronary arteries. Elevated calcium score was influenced independently by age and triglyceride level, but not by other risk factors, such as blood pressure. This potential adverse effect of moderate triglyceride elevation on large coronary arteries merits attention in the assessment of the risk of coronary heart disease.

Coronary calcification and its relation to extracoronary atherosclerosis in asymptomatic hypercholesterolemic men. The PCV METRA Group.

BACKGROUND: The prevalence of coronary calcifications and extracoronary plaques was studied in patients with asymptomatic hypercholesterolemia. METHODS AND RESULTS: Ultrafast computed tomography for coronary calcification (presence or absence: calcium score) and echographic assessment of carotid, aortic, and femoral plaques were performed in 111 hypercholesterolemic men: 65% had coronary calcification, 72% had extracoronary plaque. The two lesions were associated as: 1) compared with subjects without coronary calcification, those with calcification had a higher prevalence of aortic (p less than 0.05) and femoral (p less than 0.01) plaque and of two diseased sites (p less than 0.05); 2) the prevalence of coronary calcification was higher in the presence than in the absence of aortic (p less than 0.05) or femoral (p less than 0.01) plaque and higher in two (p less than 0.01) and three diseased (p less than 0.05) sites than in no diseased site; 3) the calcium score was higher in the presence than in the absence of carotid (p less than 0.05), aortic (p less than 0.05), or femoral (p less than 0.001) plaque, higher in two (p less than 0.001) and three diseased (p less than 0.05) sites than in no diseased sites, and higher in two (p less than 0.01) than in one diseased site; and 4) the calcium score correlated with femoral plaque (p less than 0.001). Overall, the presence of two or three diseased extracoronary sites versus no or one diseased site showed a power of 78% for predicting coronary calcification. Coronary calcium score correlated with age (p less than 0.01) and triglycerides (p less than 0.05). CONCLUSIONS: The close relation between coronary calcium and extracoronary plaques suggests that echography of extracoronary vessels could aid in the screening of coronary atherosclerosis in high-risk, asymptomatic individuals.