[Ultrasonographic study of the cerebral circulation in elderly subjects (author's transl)]. / Etude de la circulation cérébrale du sujet agé par ultrasons.

The amount of diastolic blood flow in the carotid and vertebral axes determines the tolerance capacity of the cerebral circulation to physiological variations. In the elderly subject this "circulatory reserve" is modified by increases in cerebral circulation resistance, but also by various common cardiac or blood pressure disorders. Furthermore, direct visualization of the atheromatous plaques and calcifications in the vessel walls by ultrasonography can reveal lesions that have no clinical expression.

[Thyroid nodules. A report on 320 cases (author's transl)]. / Les nodules thyroïdiens. Résultats de 320 observations.

An analytical study of 320 case reports of patients with one or more thyroid nodules, 246 of whom had been operated upon, revealed the presence of 32 cancers, 15 toxic nodules, and 195 inactive benign uni- or multilobular goitres. Complementary examinations (scintigraphy with technetium, thermography, ultrasonography) cannot definitely establish the benign nature of a nodule. As long as cytological examination after needle biopsy, which requires the services of a highly specialised cytologist, will not become a routine procedure, histological examination is essential for correct diagnosis. Any nodule should be excised, therefore, and the thyroid explored completely.

[Study of dynamics and left ventricular function using radioisotopic technics in the heart cavities]. / Etude de la dynamique et de la fonction ventriculaire gauche par l'examen radio-isotopique des cavités cardiaques.

The imaging of the cardiac cavities with appropriate tracer materials (99 m Technetium or 113 m Indium), the recording of intracardiac dilution curves by radionuclide angiography and dynamic studies by gamma cinecardiography give global and regional parameters of left ventricular function which are reliable and reproducible: an index of cardiac output, intracardiac circulation times and ventricular volumes. The assessment of left ventricular contraction and global and regional ejection fractions is facilitated by coupling the gamma camera and the electrocardiogramme and computer analysis of the results. "First passage" recordings may be used to differentiate the right from the left heart chambers. "Equilibrium" studies give detailed information at rest, under stress (or leg-raising) and under pacing and/or trinitrin. Average and maximal rates of contraction derived from the ejection fraction and left ventricular contraction times are indices comparable to the rate of fibre shortening. The calculation or regional parameters point by point such as the ejection fraction, contraction time and ejection volume gives a more accurate and sensitive estimation of left ventricular function than the global left ventricular indices. They are many practical applications in cardiology especially in coronary artery disease: monitoring the changes in the acute phase of myocardial infarction, the selection of patients for aorto-coronary bypass surgery and their pre- and post-operative controls. These non-invasive, easy and reliable cardiac studies justify the development of laboratories of nuclear cardiology within departments of cardiac physiological investigation.

[Radioisotopes in cardiology. Introduction]. / Les radio-isotopes en cardiologie. Introduction.

During the last fifteen years scientists in France and in other countries have developed several isotopic research techniques to the stage of current cardiological investigations. The most important advances have come in the last few years with the introduction of new tracer substances and computer-assisted imaging systems. Isotope techniques occupy an intermediary but quite separate position between the so-called "invasive" contrast radiological methods and the essentially "non-invasive" ultrasound investigations. The physical and biological basis of nuclear cardiology explains the complexity of these new methods, but also the quality of information which may be obtained. The proposed clinical usage necessitates a choice modulated by the properties of the radiopharmaceutical substances, the technical possibilities of the imaging system and the capacity of the associated computers. Several options are available from modern radio cardiographic probes to heavy tomographical systems with positron emitters, the choice depending on whether the study is to be limited to an assessment of global ventricular function using radioactivity/time curves, or whether detailed analysis of regional myocardial function by tomodensitometry is required. A satisfactory compromise may be obtained with a computer-assisted standard gamma-camera, equiped with a collimator for gamma tomodensitometry, in addition to the conventional scan projections. The price of this equipment is about one half that required for an X-radiological installation but the tt in all conditions with no risk apart from that of the "multiplication" of diagnostic procedures.

[Isotopic methods and primary congestive cardiomyopathies]. / Méthodes isotopiques et cardiomyopathies primitives congestives.

28 patients with primary congestive cardiomyopathy in heart failure identified by cineangiographic criteria (end-diastolic volume greater than 120 ml/m2; parietal thickness less than 11 mm; normal coronary angiography), underwent 131-Cesium and 201-Thallium myocardial scintigraphy in antero-posterior and LAO projections, and 17 also underwent angiocardiography with 99 Technetium labelled albumin. This condition usually gives an appearance of an enlarged heart with diffuse or localised (antero lateral wall) hypofixation, dilatation of the left ventricular, left atrial and right ventricular cavities and a very low ejection fraction with diffusely hypokinetic wall motion. Radio-Isotopic methods may help discriminate primary and ischaemic cardiomyopathy but are not diagnostic. A low ejection fraction and marked diffuse hypofixation are poor prognostic indices. Radio-Isotopic methods are valuable in the classification of primary cardiomyopathy.

Topograhic relation between the myocardial uptake of radiothallium and left ventricular kinetics in myocardial infarction.

Myocardial images with thallium 201 are recorded on a computer with the ECG tracing and the cardiac cycle divided into 16 consecutive images. The patients then recieve 99Tcm albumin for first pass and a subsequent ECG gated series for comparison with the myocardial studies. These images can be superimposed and allow the topographic relationships of thallium uptake and ventricular contractility as reflected by the blood pool, to be seen. Quantitative parameters such as ejection fraction and stroke volume are also obtained. Examples in clinical practice are given.

[Comparative study of left ventricular kinetics by gamma-cinecardiography and ventriculography]. / Etude comparée de la cinétique ventriculaire gauche par gamma-cinécardiographie et ventriculographie.

50 patients were investigated by both left ventricular cine-angiography, and "balanced" gamma-cine-cardiography in the frontal and LAO positions. Measurements of the ejection fraction and the mean and maximal speeds of contraction were made by the two techniques. The correlation was good (r = 0.89 for the ejection fraction). A morphological analysis of the dynamic findings in the two methods in the 12 cases with discordered left ventricular kinetics showed that once again the results were very similar. A numerical presentation of the data from the radioisotope studies was made either as a group of sequential ventricular contours successively from diastole to systole, or to give a functional picture which would provide the value for one kinetic paramter at any one time (for example, the regional equivalent of the ejection fraction). To overcome the problems of superimposition in the RAO position in the "balanced" technique, the recordings of the first radioisotope study in RAO were combined with a study of balance in 50 other patients, and the correlation was excellent. These two isotope techniques, which can be carried out in the same examination and which may be repeated without risk, perfectly complement each other, and very few of the results were incapable of interpretation.

The contribution of nuclear medicine and ultrasounds in cardiac surgery.

The constant progress in surgical techniques during the last few years have prepared the way for important developments in the field of noninvasive cardiac exploration. Their non-traumatic character, appreciable in diagnostic and preoperative examinations, become indipensable whenever there is a need to repeat the examination in order to evaluate the effects of a treatment or to monitor progress both in the short and long term. In order that such methods be adopted in cardiac surgery it is important that not only must they be without risk but also that the results obtained be clearly presented, if possible in the form of images, and allow a quantitative interpretation. It is necessary also that the results can be justified both by clinical experience and also by comparison with other examinations. No procedure, not even radiologic, can at the same time explore the myocardium and its perfusion, the central circulation and the cardiac haemodynamics. By reason of their respective principles, radioisotopic methods and ultrasounds tackle cardiac problems in different ways and facilitate, by appropriate choice of methods, the selection of one diagnostic response from among several. This paper contains first of all, a resume of the principal nuclear and ultrasonic techniques used together with their basic principles. Next we try to show how these non-invasive techniques, most with dynamic imaging, can assist cardiac surgery. For this, we successively look at the different pathologies, working from the exterior (pericardium) towards the interior (intracardiac structures and central circulation) and covering the different aspects of the myocardial pathology. In each case the mutual contributions of physical techniques is specified as well as the preference for either isotopic or ultrasonic methods.