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Biomedical subjects

R Itti

Publications and source records attributed to R Itti.

At least 73 records · Page 4Linked to original sources
PubMed1978

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.

Adult↗
PubMed1978

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.

Angiocardiography↗
PubMed1978

[Comparative study of left ventricular kinetics by gamma-cinecardiography and ventriculography].

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.

Adult↗
PubMed1977

The radiospirometric flow-volume diagram recording technique and comparative study with conventional spirometry.

The spirometric flow-volume diagram recorded for a forced expiration gives information which is used in assessing obstructive or restrictive pulmonary diseases. Regional data of the same kind can be achieved using a simple radiospirometric technique and scintillation camera. A series of images during inspiration and expiration are defined and a time-activity curve with an integration time constant of about 100-200 ms is obtained from the images during the forced expiration phase. The equivalent of the flow-volume diagram, i.e., the time derivative of the activity vs. activity is computed. There were 21 subjects studied in this series. Normal subjects or patients with various diseases underwent classical spirometry, so that the global radioactive diagram could then be compared to the spirometric flow-volume diagram and its parameters expressed in terms of volumes and flow: vital capacity, peak flow, mean flow, flow at mean volume. The correlation with classical spirometry is highly significant. Similarly regional data are consistent with the pulmonary results.

Adult↗
PubMed1976

Dynamic cardiac scintigraphy with a multi-imaging device.

Cardiac kinetics can be visualized in two ways after i.v. injection of radiopharmaceutics for labeling either the myocardium or the cardiac chambers. The simpler way is the acquisition of the data in analog mode, using a multiimaging device. Thanks to a short time constant for the image advance, the cardiac cycle is divided into 16 frames, the first being triggered by the R wave of the ECG. The data of a large number of synchronized cycles are integrated on a film. This permits an almost continuous way to follow the kinetics of the studied compartments along the cycle. Several views can be registered successively. This procedure yields separately immediate information on the morphology and dynamics of the myocardium, and chambers. To evaluate quantitatively various parameters of left ventricular function a data processor is connected to the gamma camera. Examples of the two types of data are shown and demonstrate that both are useful for appreciating the value of kinetics though they are not yet accurate enough to replace in every case contrast radiologic techniques. Nevertheless, the indications for these procedures are continuously growing, due to technical progresses and the noninvasive nature of the investigation.

Angiocardiography↗
PubMed1976

[Study of congenital cardiopathies with left-right shunt using gamma-angiocardiography].

Red blood cells labelled with radioactive Technetium were injected intravenously, and the passage of the tracer through the cardio-pulmonary system recorded using a scintillation camera coupled with a numerical dosimeter. The results are presented as serial analoque pictures taken at the rate of two per second, as numerical tracings which are later processed, and as flow charts from predetermined areas of interest: the chambers of the heart, the lung parenchyma, and the aorta. This study is concerned with 58 patients with a left-to-right shunt, and about 40 normal examinations were used as a baseline for comparison. In cases of left-to-right shunt, the finding on the tracings is of abnormally prolonged activity in the lungs after a normal passage through the right side. The intensity-duration curves highlight this finding, and show an early recirculation peak in the right side of the heart and a slowing of pulmonary emptying, which can be evaluated numerically from the ratio C2/C1. A correlation has been found between this value and the ratio of pulmonary to systemic flow as calculated by oximetry. The correlation is even closer if a comparison is made between the curves of pulmonary radioactivity and the dye dilution curves. In certain cases, the shunt can be localised to the atrial or ventricular level. There are many indications for this safe investigation: --the diagnosis and monitoring of the flow through a left-to-right shunt in a child; --confirmation of the closure of septal defects after surgery; --clarification of an infudibulo-pulmonary syndrome.

Adolescent↗
PubMed1975

[Intracerebral hematoma in gamma-angio-encephalography].

The radionuclide angiography, of gamma-angio-encephalography (gamma-A.E.G.), a non invasive method, is able to bring specific information for the diagnosis of intracerbral hematoma (I.C.H.). In 25 out of 32 verified cases of I.C.H. the rapid sequential imaging shows from the arterocapillary time a deeply seated avascular area, which is a quite different aspect from the defect observed in ischemic A.C.V., or malignant tumors. The transit curves confirm the regional of circulating blood pool.

Brain Neoplasms↗