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Biomedical subjects

G L Tarolo

Publications and source records attributed to G L Tarolo.

At least 55 records · Page 3Linked to original sources
PubMed1987

Accuracy and reproducibility of the assessment of the global ejection fraction using 195mAu and a single-crystal digital gamma camera: influence of collimator design.

A sequence of RAO first-pass studies (first with 99mTc and then twice with 195mAu) was performed in 18 normal volunteers and in 12 CAD patients using two different types of collimator for medium energy: a standard collimator (MEMS) and a special high-sensitivity collimator (MEHS). The following data were compared: the peak count rate, the net LV end-diastolic counts and the LVEF. Using MEMS the end-diastolic counts acquired were so low (12% of 99mTc average value) that EF standard deviation had a mean value of 0.061 (range 0.045-0.081). With MEHS the following results were obtained: 1. the peak count rate and LV net end-diastolic counts with 195mAu were 55% and 50% respectively, of 99mTc values; 2. a good correlation was shown between LVEF values either with 99mTc and 195mAu (r = .97), or with 195mAu sequential studies (r = .98).

Adult↗
PubMed1985

Computerized analysis of equilibrium radionuclide ventriculography time-activity curve in the assessment of left ventricular performance: comparison of two methods.

Two methods for the analysis of left ventricle time-activity curve (TAC) of equilibrium gated ventriculography were compared in three groups of subjects [8 controls, 13 patients with coronary artery disease (CAD), 11 patients with myocardial infarction (MI). The first method was based on third-degree polynomial fitting, the second on Fourier analysis. The following parameters were calculated: peak ejection rate (PER), peak filling rate (PFR), time to PER and PFR, and filling fraction at the first third of diastole. A preliminary study of changing values of PER and PFR and of the mean error with increasing number of harmonics summed in order to obtain the best fitting of TAC demonstrated that beyond the sum of the first four harmonics there was no further significant improvement. The advantages of Fourier analysis are as follows: it is independent of the operator and fits only one function to the whole cardiac cycle; it requires less computer time; it provides better differentiation between controls and CAD patients. All of the 13 CAD patients had abnormal PFR on Fourier analysis, only 9 on polynomial analysis. At rest, 9 of the CAD patients had wall motion abnormalities, while only two had an abnormal ejection fraction.

Adult↗
PubMed1985

Radionuclide assessment of right-ventricular involvement in inferior acute myocardial infarction: clinical correlations and in-hospital follow-up.

We studied 33 patients (28 males, 5 females) with first inferior acute myocardial infarction (AMI) and 12 normal volunteers. They underwent first-pass (FP) and equilibrium-gated radionuclide angiography (EGRA) within 4 days of the onset of symptoms. The parameters [ejection fraction (EF), peak ejection rate (PER), peak filling rate (PFR)] of the time-activity curve (TAC) of both ventricles [left ventricle (LV), right ventricle (RV)] were computed. The regional wall motion (RWM) was evaluated by parametric images (amplitude and phase). In 43% of the patients with AMI, we found a depressed RVEF, while the LVEF was decreased in only 33%. The sensitivity of diastolic parameters was shown to be clearly superior to that of the systolic parameters (RVPFR, 78%; LVPFR, 79%). The abnormalities of the overall performance of both ventricles were significantly correlated with those of the RWM. The abnormal RVEF allowed us to assess the necrotic involvement of the RV, while a depressed RVPFR suggested an impaired RV compliance mostly on an ischemic basis. Congestive heart failure (CHF) and shock syndrome were significantly correlated with depressed RV parameters, while the LVEF, despite RWM abnormalities, was in the normal range. EGRA with computation of the TAC parameters of both ventricles appeared to be useful for in-hospital prognostic evaluation, therapeutic planning and clinical follow-up of patients with inferior myocardial infarction.

Adult↗
PubMed1985

Diagnosis of coronary artery disease by radionuclide ventriculography during stress: handgrip and cold pressor.

Radionuclide ventriculography during stress has been shown a useful and non invasive technique for detecting left ventricular dysfunction induced by ischemia in association with coronary artery disease. The aim of this study was to assess the usefulness of handgrip and cold pressor test as alternative stresses because of the limits that bicycle exercise presents when it is combined with multigated radionuclide ventriculography. A resting cardiac imaging was performed in 8 healthy volunteers and in 21 patients with coronary artery disease. All of them repeated the examination during handgrip; 6 controls and 11 patients also underwent cold pressor test. Abnormal regional wall motion was observed in 17 of the 21 patients with coronary artery disease who underwent handgrip, while all the controls maintained a normal motility. The test elicited no significant difference in average ejection fraction in both patients and normal subjects. All but one the patients who performed the cold pressor test showed an abnormal motility during the stress. Mean ejection fraction decreased significantly (p less than 0.05). All the controls had a normal response to cold pressor. Our results confirm that these two tests can be alternative to stress testing for detecting coronary artery disease by means of radionuclide ventriculography.

Adult↗
PubMed1985

Value of hepatobiliary scintigraphy and ultrasonography in the differential diagnosis of jaundice.

In order to compare the reliability of hepatobiliary scintigraphy using DISIDA (DHS) and ultrasonography (US) in the diagnosis of obstructive jaundice, 36 consecutive patients clinically suspected for obstruction were examined with both methods. Sixteen patients who were definitively shown to have obstruction, were all correctly detected with DHS; US was positive in 15 cases, revealing the cause of the obstruction in four cases. The site of obstruction was predicted in eight cases by DHS and in 11 cases by US. Associated gallbladder diseases were evaluated better by US than by DHS, but a perforation was only demonstrated clearly by DHS. In the 20 patients with nonobstructive disease the false positive results were found in one case using DHS and in two cases using US. In this series of patients DHS and US showed high sensitivity and specificity, which were further increased when the two techniques were combined.

Adult↗
PubMed1984

Clinical value of phase and amplitude images and left ventricle time-activity curves in assessing patients with acute myocardial infarction.

The purpose of this study was to assess the clinical usefulness of phase and amplitude images and of the left ventricle time-activity curve (LVTAC) obtained by equilibrium gated radionuclide ventriculography (EGRV) in patients with acute myocardial infarction (AMI). Fifty-six patients were studied within 4 days of the onset of AMI by EGRV; of these 49 also underwent first-pass (FP) angiocardiography, for comparison with EGRV, and 21 underwent repeated EGRV 3 months after AMI. Phase and amplitude images were obtained by Fourier analysis. LVTAC analysis was performed by a third degree polynomial fitting to determine peak ejection rate (PER) and peak filling rate (PFR). A substantial equivalence of EGRV and FP methods was demonstrated, as regards left ventricle ejection fraction (LVEF), while a sharp superiority of EGRV with Fourier analysis was shown with regard to the sensitivity of RWM abnormality detection. With only one exception all the cases showed RWM abnormalities, while LVEF was normal in 21 of 27 patients with less than three affected segments. The most sensitive global function index was the LVPFR. In the acute phase regional dyskinesis was observed in 14 of 56 patients. About 40% of our cases showed an improvement of the kinetic abnormalities 3 months after AMI. The highest rate of improvement was observed in the group with ECG patterns of limited infarction and with normal LVEF.

Adult↗
PubMed1984

Ejection fraction and regional wall motion at rest and during stress in the diagnosis of coronary artery disease.

Stress radio nuclide ventriculography is used to determine ejection fraction and changes in regional wall motion for the detection of ischemia-induced left ventricular dysfunction in patients with coronary artery disease. We have evaluated the relative sensitivity of regional wall motion and of ejection fraction during hand-grip and cold pressor test, in 21 patients with angina pectoris and documented coronary artery disease at angiography. Regional wall motion appeared a more sensitive index than global ejection fraction producing only two false negative cases. Ejection fraction showed great variability among the patients during both hand-grip and cold pressor test. This might be explained by the fact that both tests do not produce a sufficient degree of ischemic stress on the left ventricle. Hand-grip and cold pressor tests appear useful alternative to dynamic exercise in the diagnosis of coronary artery disease being also safe and simple to perform.

Adult↗
PubMed1982

Detection of left atrial myxoma by Fourier phase image.

A case of left atrial myxoma shown on an equilibrium radionuclide ventriculography is presented. A peculiar abnormality of the Fourier phase image appears more reliable than the other findings previously revealed by first-pass or equilibrium studies. The findings were perfectly consistent with the gross anatomy of the tumour.

Adult↗
PubMed1981

Comparative quantitative evaluation of hepatic clearance of diethyl-IDA and para-butyl-IDA in jaundiced and non-jaundiced patients.

A method for comparative measurement of hepatic clearance of different hepatobiliary agents is described and the clinical use of diethyl-IDA and parabutyl-IDA is discussed. The study was performed with both radiopharmaceuticals in 13 patients with hepatobiliary disease with serum bilirubin ranging from 0.3 to 16.4 mg/100 ml. Diethyl-IDA is preferable for a qualitative evaluation of hepatobiliary disease because of its higher hepatic clearance and faster biliary excretion rate. Parabutyl-IDA is superior for measuring the hepatocytic uptake function, due to the low urinary excretion and the absence of an apparent re-entry from liver to plasma, even in patients with obstructive jaundice. In contrast, an appreciable re-entry can be demonstrated for diethyl-IDA.

Adult↗
PubMed1981

[The predictive value of serial scintigraphy and computerized tomography in the diagnosis of brain lesions (author's transl)].

Six characteristic initial clinical neurological patterns were defined and their incidence was determined in one year caselist of patients hospitalized in the Neurology Department of the General Hospital of Saronno. Since the predictive value of a diagnostic procedure depends not only on sensitivity and specificity but also on the prevalence of disease in the population sampled, the prevalence of surgical brain lesions was evaluated retrospectively in this caselist for each of the clinical patterns previously defined, in order to evaluate the predictive value of serial brain scintigraphy and of brain computerized tomography. In this caselist the most frequent clinical patterns (stroke, skull trauma) show a low prevalence of surgical lesions, unlike it happens in the Neurosurgery Department of another hospital chosen as reference. It follows that in the sample of population constituted by the patients hospitalized for "stroke" in the Neurology Department of this hospital the Bayes' theorem yields a predictive value of brain scintigraphy not significantly inferior in respect of computerized brain tomography. In addition a review of the positive scans of patients with cerebral infarction has shown the possibility of a correct diagnosis in 95%. Therefore the serial scintigraphy is thought to keep a high value as a screening tool in this kind of patients where, after a simple clinical selection, the prevalence of brain lesions needing of surgery is low.

Brain Injuries↗
PubMed1981

[Clinical usefulness of thallium-201 myocardial scintigraphy with dipyridamole pharmacodynamic test in ischemic heart disease (author's transl)].

A clinical evaluation of the dipyridamole in the myocardial perfusional scintigraphy (MPS) was carried out in a series of patients, comprehensive of cases of unstable angina, aiming to assess the feasibility and diagnostic validity of the test and to state its possible role in comparison with exercise stress test. On the whole, 107 subjects were examined (34 with stable angina, 23 with unstable angina, 19 with recent myocardial infarction, 15 with atypical angina, 10 with chest pain of uncertain origin and 6 healthy volunteers), performing 108 scintigraphic studies (48 after dipyridamole infusion and 37 after bicycle exercise). In the studies with physical or pharmacologic stress a redistribution scintigraphy was also performed (4 hour after the injection). The dipyridamole stress test was well tolerated by patients with unstable angina too and showed a diagnostic sensitivity equivalent to that with exercise stress, although the latter appears better as regards image quality and can give an increase of sensitivity provided electrocardiographic findings are evaluated. Post-stress redistribution of 201 Tl in delayed scans was shown either after dipyridamole or after exercise in patients with typical angina without prior infarction. The computation, by the Bayes's theorem, of the predictive value of the two tests leads the Authors to the following conclusions: in atypical angina (prevalence of CAD: about 40%) the association MPS + exercise ECG is preferable; in patients with chest pain of uncertain origin or with asymptomatic electrocardiographic alterations (prevalence of CAD: about 15%) it is better to take into account only the scintigraphic findings obtained after exercise or pharmacologic stress, to avoid an excess of false positive results.

Angina Pectoris↗