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M C Eybalin

Publications and source records attributed to M C Eybalin.

14 recordsLinked to original sources
PubMed1995

Long-term risk stratification with dipyridamole imaging.

This study was undertaken to assess the reliability of clinical parameters and dipyridamole-thallium 201 images for predicting the occurrence of future cardiac events (nonfatal myocardial infarction or cardiac death). Dipyridamole myocardial perfusion imaging is routinely performed in patients who have possible or known coronary disease and a low exercise tolerance. A total of 753 patients underwent clinical assessment and semiquantitative dipyridamole-201TI imaging and were followed up as outpatients. Patients who underwent coronary revascularization during the follow-up period were excluded from the study because the decision to intervene would have been based at least in part on the test itself. There were 82 cardiac events and 54 noncardiac deaths, and 11 patients were lost to follow-up after a mean follow-up of 15 months. With use of a quantitative index reflecting the amount of jeopardized myocardium, patients could be stratified by dipyridamole imaging into subsets with coronary morbidity and mortality rates ranging from 1% to 89%, (p = 0.0001). When clinical and scintigraphic variables were subjected to backward stepwise logistic regression analysis, the significant predictors of cardiac events were the jeopardized myocardium index by scintigraphy (p < 0.0001), left ventricular hypertrophy on the electrocardiogram (p = 0.0009), and transient dipyridamole-induced left ventricular cavitary dilatation (p = 0.0073). Quantitative dipyridamole-201TI imaging appears to be a powerful predictor of future cardiac events in patients with coronary disease and a low exercise tolerance and is a potentially useful contributor to risk-profile assessment and to the treatment of these patients.

Aged↗
PubMed1994

Artificial intelligence versus logistic regression statistical modelling to predict cardiac complications after noncardiac surgery.

The traditional approach to developing models predictive of cardiac events has been to perform logistic regression (LR) analysis on a variety of potential predictors. An alternative to use an artificial intelligence system called a neural network (NN) which simulates biological intelligence. To evaluate the potential applicability of the latter method, we compared the ability of LR and NN techniques to predict cardiac events after noncardiac surgery. A total of 200 patients (training group) underwent cardiac risk assessment before major noncardiac surgery using 17 clinical parameters and 7 quantitative indices based on dipyridamole-thallium imaging. There were 21 post-operative myocardial infarctions and/or cardiac deaths. Data from the training group were used to develop two predictive models: one based on backward stepwise LR multivariate statistical analysis and the other one using a neural network. Both models were then validated on a second group of 160 consecutive patients also referred for preoperative risk stratification (validation group). The NN consisted of 14 input, 29 hidden, and 1 output neurons and used a back-propagation algorithm (learning rate 0.2, training tolerance 0.5, sigmoid transfer function). The sensitivity, specificity, positive and negative predictive accuracies for the prediction of postoperative events in the validation group of 160 patients were, respectively, 67% (6/9), 82% (124/151), 18% (6/33), and 98% (124/127) for LR, and 67% (6/9), 96% (145/151), 50% (6/12), and 98% (145/148) for the NN, with a difference in specificity which attained statistical significance (p < 0.01). Artificial intelligence may provide a useful alternative to conventional LR statistical analysis for the purpose of preoperative cardiac risk assessment.

Artificial Intelligence↗
PubMed1994

Normal qualitative and quantitative Tc-99m sestamibi myocardial SPECT: spectrum of intramyocardial distribution during exercise and at rest.

Exercise myocardial perfusion imaging with Tc-99m sestaMIBI is routinely used to detect underlying coronary stenoses. Ischemia is diagnosed in regions that display decreased tracer uptake during exercise as compared to rest. Tc-99m sestaMIBI SPECT images of 42 healthy volunteers were assessed both qualitatively (tomographic slices) and quantitatively (sectored polar map) for potential sources of misinterpretation. On the myocardial tomographic slices, the most common culprit artifacts were diaphragmatic attenuation and bowel interposition, which caused fixed or reversible "perfusion defects" in the inferior and posterior regions (in 19/35 abnormal segments), and artifacts related to the presence and shift of hot spots (observed in 11/28 men; in women, they were more difficult to demonstrate because of the overriding effect of breast attenuation). Hot spots shifts between exercise and rest usually resulted in pseudo-reversible defects in the anterolateral and lateral walls. The quantified polar map display of the myocardium showed a physiologic decrease in sestaMIBI activity in the basal anterolateral and basal posterolateral areas in men during exercise. There are many normal variants that may mimic coronary artery disease on tomographic sestaMIBI images. Before reporting an area of decreased activity as either a fixed or reversible perfusion defect, the interpreter should ensure that it does not represent an artifact or a normal variation in the intramyocardial distribution of sestaMIBI during exercise.

Adult↗
PubMed1994

Prognostic implications of transient left ventricular cavitary dilation during exercise and dipyridamole-thallium imaging.

OBJECTIVE: To determine the prognostic implication of exercise and dipyridamole-induced transient left ventricular cavitary dilation (TLVD). DESIGN: TLVD was observed and a follow-up obtained in 61 patients after exercise and in 62 patients following dipyridamole infusion. PATIENTS: There was no statistical difference between groups in terms of sex, history of hypertension, diabetes, renal failure, previous myocardial infarction, severity of angina syndrome, congestive heart failure, resting electrocardiographic (ECG) abnormalities, clinical or ECG signs of ischemia during stress, number of reversible perfusion defects on thallium images or duration of follow-up (21 months). RESULTS: Dipyridamole patients were slightly older (64 versus 57 years) and displayed more thallium redistribution (P = 0.002). After a mean follow-up of 21 months, both fatal and nonfatal (myocardial infarction or cardiac death) cardiac events were more frequent in the dipyridamole group (50% versus 9%, P = 0.0001). CONCLUSIONS: Patients with dipyridamole-induced TLVD are at greater risk than those with exercise-induced TLVD at the authors' institution.

Aged↗
PubMed1991

In vivo glomerular filtration rate measurement based solely on image processing.

A simple and reliable technique was developed to measure split renal glomerular filtration (GFR) based solely on image processing of the standard 20-minute Tc-99m DTPA renogram. It requires neither syringe counting nor blood or urine sampling. Using three sequential blood samples in 36 patients, GFR values correlated well (r = 0.92) with in vitro GFR measurements.

Adult↗
PubMed1989

Bone imaging after cementless press fit total hip arthroplasty.

In view of the high rate of loosening of conventional cemented hip prostheses, cementless implants are gaining popularity in Europe and North America. Smooth-surfaced "press fit" prostheses are designed for autolocking in the femoral canal at the time of installation. Fifteen patients were prospectively followed by bone imaging with Tc-99m MDP at three-month intervals after cementless "press fit" hip arthroplasty to define the "normal" distribution of mechanical stress to the surrounding bone, as well as the incorporation of bone allografts used for reconstruction of resorption sites in cases of revision surgery.

Adult↗
PubMed1988

[Chondromyxoid fibroma: radiologic and radioisotope aspects].

Chondromyxoid fibroma is a relatively rare benign bone tumor whose histologic and radiologic patterns are well known. In this article, we describe a 16-year-old boy with such a tumor in his left tibia. Scintigraphically, this tumor is represented by a "doughnut sign". This aspect, though not pathognomonic, has been reported sporadically in a few diseases: osteoporosis circumscripta cranii, angioblastic meningioma, cranial coccidioidomycosis, and aseptic necrosis of frontal bone. Because of their sites, it is easy to reject these diagnoses in our patient. The most pertinent differential diagnosis with regard to the clinical, radiological, and scintigraphic aspects in the patient is that of a giant cell tumor.

Adolescent↗
PubMed1984

Duplication of the superior vena cava: detection by radionuclide angiography.

The authors report three cases of duplication of the superior vena cava which were demonstrated by radionuclide angiography. Nuclear imaging was performed in order to demonstrate a left-to-right intracardiac shunt. Injection into the left external jugular vein demonstrated the presence of a duplication of the superior vena cava in addition to the presence of a shunt.

Adult↗
PubMed1983

Lymphoscintigraphic demonstration of intestinal lymphangiectasia.

The authors report a case of intestinal lymphangiectasia that was clearly demonstrated during abdominal lymphoscintigraphy using Tc-99m Sb colloid. Although lymphoscintigraphy has been used in many different clinical situations, this is, to our knowledge, the first scintigraphic description of this disease. Clinical and pathologic presentations of intestinal lymphangiectasia are briefly reviewed. Some possible approaches to the confirmation of the presence of a protein-losing gastroenteropathy are mentioned.

Adult↗
PubMed1983

131I-iodocholesterol (NP-59) scintigraphy in adrenocortical diseases.

The diagnostic usefulness of adrenal imaging with 131I-iodocholesterol (NP-59) is now well established. In order to correlate histopathology with the adrenal scan the authors examine and report their experience in 37 patients with surgically proven adrenal lesions or pituitary adenomas. This series included 24 patients with Cushing's syndrome: 14 caused by benign adrenal adenoma and 10 due to bilateral pituitary-ACTH-dependent adrenocortical hyperplasia. Ten patients with primary aldosteronism were submitted to surgery which confirmed the presence of aldosterone-producing adrenal adenomas. Two women with hyperandrogenism (due to virilizing ovarian tumors) had normal adrenals but the ovarian stromal luteoma markedly concentrated the iodocholesterol while the arrhenoblastoma did not. A patient with adrenal hematoma is also included in this report. The overall histopathological correlation with the radiocholesterol scintiscan yields an accuracy in our series of 97% (36/37). The false-negative adrenal scan (also missed by other non-invasive techniques) occurred in a patient with an aldosterone-producing adrenal adenoma measuring 1.0 X 1.5 cm.

19-Iodocholesterol↗