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J C Roucayrol

Publications and source records attributed to J C Roucayrol.

At least 19 recordsLinked to original sources
PubMed1989

In vivo MR spectroscopic imaging of the adrenal glands: distinction between adenomas and carcinomas larger than 15 mm based on lipid content.

The usefulness of MR spectroscopic imaging for discriminating between lipid and water was applied to the in vivo differentiation of adrenal adenomas from carcinomas. By using the Dixon sequence in 20 patients, the lipid content of 22 adrenal tumors larger than 15 mm was determined. The mean percentage of lipid in 15 adenomas was 13.4% (standard deviation, 8%), compared with 3.5% lipid (standard deviation, 2%) in seven carcinomas. Only one lesion would have been misclassified on the basis of in vivo measurements of lipid content. After surgery, in vitro MR spectroscopy was used to determine the percentage of lipid in excised samples of nine of the 22 tumors. These in vitro measurements confirmed the in vivo results on lesions larger than 20 mm in diameter. Respiratory artifacts appeared to decrease the accuracy of in vivo measurements in smaller lesions. In vivo MR spectroscopic imaging of adrenal tumors appears to be useful for differentiating between adrenal carcinomas and adenomas.

Adenoma↗
PubMed1988

[Magnetic resonance imaging in the diagnosis of adrenal pathology].

M.R.I. allows a good delineation of adrenals, due to the high contrast with fat and to the use of frontal planes. We showed on post operative adrenal lesions samples that the lipid percentages, high in normal and hyperplasic glands, was still high in most benign adenomas, and very low (under 5%) in adrenal carcinomas. MRI, with Dixon sequence, allows to evaluate this lipid percentage in adrenal lesions. Post-operative controls show a good agreement between in vivo and in vitro measurements. This simple technique should allow to discriminate between malignant and benign adrenal cortex lesions.

Adenoma↗
PubMed1988

Nicardipine improves myocardial perfusion in systemic sclerosis.

Primary scleroderma myocardial disease may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. We evaluated the effect of the calcium channel blocker nicardipine on myocardial perfusion assessed by thallium-201 scanning in 16 patients with systemic sclerosis. Thallium-201 single photon emission computerized tomography was performed at baseline and 90 min after 40 mg of oral nicardipine. The mean (+/- SD) number of left ventricular segments with perfusion defects significantly decreased from 6.0 +/- 2.0 at baseline to 4.1 +/- 2.3 after nicardipine (p less than 0.01). The mean global perfusion score significantly increased from 10.2 +/- 1.9 at baseline to 11.9 +/- 2.6 after nicardipine (p less than 0.02). Our study demonstrates short-term improvement in thallium-201 myocardial perfusion with nicardipine in patients with systemic sclerosis.

Adult↗
PubMed1987

In vitro adrenal cortex lesions characterization by NMR spectroscopy.

Percentage of lipid content of 22 adrenal cortex lesions and their water proton longitudinal relaxation time were measured in vitro at 60 MHz. Although water relaxation times obtained on benign and malignant samples overlap each other, measurements of the percentage of lipids performed on the same tissues allow us to distinguish the two pathologies. The specific tool of characterization should be possible to obtain through in vivo spectroscopic imaging techniques.

Adenoma↗
PubMed1986

Nifedipine and thallium-201 myocardial perfusion in progressive systemic sclerosis.

Heart disease in patients with progressive systemic sclerosis may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. To determine whether abnormalities of myocardial perfusion in this disorder are potentially reversible, we evaluated the effect of the coronary vasodilator nifedipine on myocardial perfusion assessed by thallium-201 scanning in 20 patients. Thallium-201 single-photon-emission computerized tomography was performed under control conditions and 90 minutes after 20 mg of oral nifedipine. The mean (+/- SD) number of left ventricular segments with perfusion defects decreased from 5.3 +/- 2.0 to 3.3 +/- 2.2 after nifedipine (P = 0.0003). Perfusion abnormalities were quantified by a perfusion score (0 to 2.0) assigned to each left ventricular segment and by a global perfusion score (0 to 18) for the entire left ventricle. The mean perfusion score in segments with resting defects increased from 0.97 +/- 0.24 to 1.26 +/- 0.44 after nifedipine (P less than 0.00001). The mean global perfusion score increased from 11.2 +/- 1.7 to 12.8 +/- 2.4 after nifedipine (P = 0.003). The global perfusion score increased by at least 2.0 in 10 patients and decreased by at least 2.0 in only 1. These observations reveal short-term improvement in thallium-201 myocardial perfusion with nifedipine in patients with progressive systemic sclerosis. The results are consistent with a potentially reversible abnormality of coronary vasomotion in this disorder, but the long-term therapeutic effects of nifedipine remain to be determined.

Adult↗
PubMed1986

Pharmacodynamic effect of dipyridamole on thallium-201 myocardial perfusion in progressive systemic sclerosis with diffuse scleroderma.

We evaluated the effect of dipyridamole on thallium-201 myocardial perfusion in 23 patients with progressive systemic sclerosis (PSS) with diffuse scleroderma. Thallium-201 single photon emission computed tomography (SPECT) was performed at rest and after coronary artery vasodilatation with intravenous dipyridamole (0.14 mg/kg/min for four minutes). The left myocardium was divided into nine segments; each segment was graded as 2.0, 1.5, 1.0, 0.5, 0 (zero represents no activity). Dipyridamole significantly improved resting thallium-201 myocardial perfusion: the mean (SD) number of segments with thallium defects decreased from 6.0 (2.1) at rest to 4.1 (2.5) after dipyridamole (p less than 0.0001); the mean (SD) score in segments with resting defects increased from 0.92 (0.24) at rest to 1.13 (0.38) after dipyridamole (p less than 0.0001); the mean (SD) global score per patient increased from 10.2 (1.8) at rest to 11.4 (2.1) after dipyridamole (p less than 0.02); the global score increased by at least 2.0 in 12 patients and worsened by at least 2.0 in three patients only (p = 0.05). The results of this acute study suggest that some drugs with potent vasodilator activity on small coronary arteries may be beneficial in the treatment of PSS patients with thallium-201 myocardial perfusion abnormalities.

Adult↗
PubMed1986

[Demonstration by spectroscopy NMR at 1,5 Tesla of changes in lipid/water ratio in pathology of the adrenal cortex].

By NMR proton spectrometry with a main field of approximately 1.5 Tesla the authors have studied on pieces obtained at surgery changes of the lipid/water ratio in the cortex of diseased adrenal glands. On the basis of 58 samples taken from 20 different glands they show that this ratio is comparable in hyperplasias and adenomas but quite significantly reduced in carcinomas. They are therefore of the opinion that this ratio might serve as a malignancy index in spectroscopic imaging of patients bearing tumors of the adrenal cortex.

Adenoma↗
PubMed1986

Automated comparison of scintigraphic images.

New algorithms for automated comparison of scintigraphic images have been developed and are described here. The first step presented here is the registration of the images, performed by optimizing, with respect to the registration parameters (two translational shifts, one angle of rotation, the two parameters of a linear transformation of the gray levels), the stochastic sign change (SSC) criterion. The optimization of this criterion is demonstrated to be efficiently performed using the adaptative random search strategy; a more limited but less time-consuming method is also presented. The second step described is the point-by-point comparison of the registered images. The pixel-by-pixel application of Poisson variable statistical tests permits the generation of the significant image differences. From such images it is possible to detect modifications which escape visual inspection. Examples of applications are given in controlled and routine conditions. These algorithms are useful for the processing of many investigations and are proposed for implementation on all nuclear medicine data processing systems.

Bone and Bones↗
PubMed1985

Decreased coronary reserve in primary scleroderma myocardial disease.

We assessed coronary reserve, by measuring the increase in coronary sinus blood flow (CSBF) after intravenous administration of dipyridamole (0.14 mg/kg/minute for 4 minutes), in 7 patients with primary scleroderma myocardial disease (PSMD) and in 7 control subjects. Coronary reserve was greatly impaired in PSMD: before administration of dipyridamole, CSBF was similar in patients with PSMD (89 +/- 32 ml/minute/100 gm, mean +/- SD) and in controls (100 +/- 15 ml/minute/100 gm); after dipyridamole infusion, CSBF was significantly lower in patients with PSMD (191 +/- 45 ml/minute/100 gm) than in controls (399 +/- 58 ml/minute/100 gm) (P less than 0.01). Six of the 7 patients with PSMD had angiographically normal epicardial coronary arteries and normal left ventricular function. Decreased coronary reserve may be an important contributor to the pathogenesis of primary scleroderma myocardial disease.

Adult↗
PubMed1985

[Computerized comparison of imaging in scintigraphy; physiopathological applications].

The authors describe a method of treating scintigraphic data with which they can correctly compare images of a structure that were obtained in different conditions. This method comprises two steps which are fully computerized. During the first one known as the "registration" step and intended to make a comparison possible they maximise a new similarity criterion by a series of random trials in a five parameter space. During the second, which is the actual comparison, they use an appropriate statistical test to recognise those homologous pixels with a significantly different contents which will be the only ones retained to build up the final image. They give then two examples of what the method brings in the medical field which are the detection of adenomatous parathyroid glands and the follow-up of lung perfusion in case of embolism.

Adenoma↗
PubMed1982

[Angioscintigraphy in venous pathology. Comparison of isotope angioscintigraphy and radiologic examination].

Results of vascular radiology and isotope examinations were compared in 48 patients with suspected ileocaval lesions (37 cases) or affections of the veins of the upper limb or superior vena cava (11 cases). Isotopic examination, which can be performed in ambulatory patients, respects normal hemodynamic conditions, is painless, and can be repeated, was found to give valid results, positive correlations with radiological investigation findings being present in 43 cases. Lack of correlation in the remaining 5 patients could have resulted from the period of time elapsed between the two examinations or the techniques employed during each investigation.

Diagnosis, Differential↗
PubMed1979

[Value and limitations of sequential technetium 99m angiocardiography in the detection, localization and quantification of left-right intracardiac shunts apropos of 110 cases].

A comparative study of the diagnosis of intracardiac left-to-right shunts by isotope radiography on the one hand and oxymetry, abnormal catheter trajectory and angiocardiography on the other, was performed on a series of 110 patients, comprising 12 normals, 46 valvulopathies or cardiomyopathies without shunts, 23 ASDs, 22 VSDs, and 7 other shunts. Intravenous injection of Technetium 99 m with scintigraphic imagery and interpretation of time-activity curves detected even small left-to-right shunts and appeared to be more sensitive than oxumetry. The estimation of the size of the shunt correlated well with oxymetry for VSDs but not for ASDs. The localisation of the shunt was more difficult. The atrial level of the defect was detected in some but not the majority of cases. The isotopic technique appeared unreliable in the presence of severe haemodynamic disturbances. The isotopic method is a quick means of detecting left-to-right shunts without measurable risk, particularly useful in the investigation of children and young adults thought to have left-to-right shunts.

Adolescent↗