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M Dondi

Publications and source records attributed to M Dondi.

59 records · Page 4Linked to original sources
PubMedDate not supplied

Regional left ventricular ejection fraction with single crystal gammacamera and gated equilibrium technique: repeatability and inter-observer variability.

Regional left ventricular ejection fraction calculated by means of gated blood pool scintigraphy was compared with that obtained from contrast ventriculography in a group of 20 patients, submitted to both procedures within a month. To evaluate repeatability both at rest and during stress, a second scintigraphic study was carried out after three weeks, with no change in drug regimen. Inter-observer variability was assessed in a randomly selected subgroup of 16 patients, in whom a computation was repeated by a second operator. Comparison of scintigraphic results showed a satisfactory agreement, and measurement agreement for global left ventricular ejection fraction was very good. As regards interobserver variability, each of the three myocardial segments examined (septal, lateral and infero-apical) showed good agreement. As regards repeatability, global left ventricular ejection fraction, proved readily reproducible both for rest and stress studies, with relatively small differences in observed values. Regional ejection fraction, on the other hand, had a high variability, especially during stress. It is suggested that for regional ejection fraction evaluation, reproducibility studies should be performed in order to better correlate result changes to clinical outcome after medical or surgical therapy.

Aged↗
PubMedDate not supplied

Diagnostic accuracy of single photon emission computed tomography with thallium-201 for the identification of diseased coronary arteries. Comparison between dipyridamole infusion and exercise stress test.

Myocardial perfusion imaging with 201Tl and single-photon emission computed tomography (SPECT) was carried out in two groups of patients, subsequently submitted to diagnostic coronary angiography. SPECT was performed in group 1 (41 patients) after slow i.v. infusion of dipyridamole and in group 2 (162 patients) after tracer injection at maximal ergometric exercise. To evaluate the diagnostic capability of SPECT in the detection of diseased coronary vessels, the left ventricular myocardium was subdivided into 6 segments related to the three major coronary arteries. Sensitivity for the left anterior descending artery was 77% in group 1 and 79% in group 2; specificity was 80% and 96%, respectively. Sensitivity for the right coronary artery was 91% in group 1 and 85% in group 2; specificity was 81% and 73%. For the left circumflex artery sensitivity was 65% for group 1 and 67% for group 2, while specificity was 89% and 88%, respectively. Myocardial SPECT results after ergometric exercise and dipyridamole infusion turned out to be almost superimposable. Dipyridamole stress might be considered appropriate as a provocative test when physical exercise cannot be carried out.

Adult↗
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Carotid endarterectomy. Pre- and post-operative monitoring with cerebral SPECT.

In the pre-operative evaluation of carotid endarterectomy, the knowledge of ischemic areas may be helpful to reduce the operative risk. A positive CT scan is often correlated with an increased operative risk. The single photon emission computed tomography (SPECT) allows us to visualize ischemic areas not shown by the CT; these areas are almost always correlated to neurological symptomatology. In patients with positive CT scan, the ischemic areas shown by SPECT are generally larger, because this technique visualize the ischemic area surrounding the cerebral infarct (penumbra). After carotid EA, SPECT is useful to show the hemodynamic modifications induced by this operation. In a series of 15 patients we observed an improvement of the cerebral blood perfusion characterized by the normalization of the blood flow in 7/12 (58%) of the ischemic areas observed pre-operatively), an improvement in 3/12 and a normalization or an improvement in the contralateral hemisphere in 5/7 of the areas. In conclusion SPECT is a useful technique to study the cerebral pathophysiology of both cerebrovascular disease and its surgical treatment.

Aged↗
PubMedDate not supplied

[Quality controls for the gamma camera with single photon emission tomography].

Some tests and quality controls to assess the initial conditions and the working performance of a SPET system (Single Photon Emission Tomography), are described. Suitable tomographic phantoms were designed and built. We outline the methods to check MTF, stability of the photoelectric peak, centre of rotation, spatial uniformity, spatial resolution, sensitivity. NEMA tests should first be carried out to check the planar scintigraphic performance of the gamma-camera. This study allows to comprehensively evaluate the qualitative and quantitative performance of the SPET system and the correct check frequency of investigated parameters.

Quality Control↗