Assessment of ventricular function in arterial hypertension with radionuclide ventriculography.

Diastolic function of the left ventricle was assessed in 29 untreated patients with mild to moderate hypertension and in 21 normotensive control subjects using gated radionuclide ventriculography. In hypertensive patients, the time to peak filling rate was significantly longer (p less than 0.01) than that in control subjects, and first-third filling fraction and peak filling rate were significantly reduced (p less than 0.001). The ejection fraction and peak ejection rate were also significantly reduced in hypertensive patients (p less than 0.001). No relation was observed between diastolic functional impairment and age, cardiac hypertrophy, or severity of hypertension. Thus, early impairment of ventricular filling is present in hypertension, even in young patients without evidence of cardiac hypertrophy.

Cigarette smoking and platelet function.

To assess the influence of cigarette smoking on platelet activation, we studied the changes in intraplatelet and platelet-released serotonin (5-HT) and plasma levels and platelet-associated production of thromboxane B2 (TXB2), in 6 non smokers and 6 habitual smokers, before and after acute exposure to smoke. Before smoking, habitual smokers showed slightly higher, albeit not significantly, 5-HT platelet concentrations and TXB2 plasma levels, as well as lower TXB2 platelet production after collagen and even more after ADP stimulation (0.59 +/- 0.27 vs 1.35 +/- 0.46 and 0.99 +/- 0.47 vs 2.08 +/- 0.51 ng/10(8) platelets for habitual smokers vs controls, 4 and 10 min after ADP, p less than 0.02). No significant differences in platelet 5-HT release were observed. Acute smoking did not induce any significant change from baseline in either 5-HT or TXB2 for controls, while significantly reduced TXB2 production from ADP-challenged platelets from habitual smokers (0.30 +/- 0.15 vs 0.59 +/- 0.27 ng/10(8) platelets, immediately after smoking vs baseline, p less than 0.01). Ninety min after the completion of the smoking, the values had returned to baseline. Immediately after smoking, significant differences were found between habitual smokers and controls for TXB2 platelet production (2.76 +/- 1.78 vs 6.42 +/- 1.60, p less than 0.025 and 3.01 +/- 1.90 vs 6.44 +/- 2.26 ng/10(8) platelets, p less than 0.05, for habitual smokers vs controls, 4 and 10 min after the addition of collagen; 0.30 +/- 0.15 vs 1.20 +/- 0.84 and 0.79 +/- 0.50 vs 1.70 +/- 0.74 ng/10(8) platelets, p less than 0.05, after ADP stimulation). Differences were no longer significant 90 min after smoking. Our data indicate that cigarette smoking is associated with platelet dysfunction, which seems due to impairment of metabolic platelet capacity rather than increased platelet activation in vivo.

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).

Angioscintigraphic assessment of arterial and portal liver blood flow: comparison with splanchnic angiography.

In order to validate an angioscintigraphic method for the evaluation of the components of hepatic blood flow, the results of angioscintigraphy were compared with splanchnic angiography in 25 cirrhotics. Two indices of hepatic portal perfusion and a splenohepatic arterial index were calculated. These were correlated with portal diameter and hepatic artery diameter, respectively. No correlation was found between grades of portal perfusion according Nordlinger's criteria and these indices. The method is very simple and could be applied to evaluate the changes of liver hemodynamics induced by drugs or shunt surgery.

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.

Angioscintigraphic assessment of hemodynamic effects of penbutolol in cirrhotics with portal hypertension. A double-blind, randomized, controlled study.

This randomized double-blind controlled study analyzed the hemodynamic effects of penbutolol, a new levorotatory beta-blocker, using radionuclide angiography. Twenty cirrhotics with esophageal varices were randomized to two groups: 10 received 40 mg/day of penbutolol orally and the others placebo. Angioscintigraphy was performed before and after an 8-day treatment period. Three cases in the penbutolol group were lost due to software damage, hence the data of 17 patients were analyzed. The two groups were matched for age, sex, etiology of cirrhosis and hepatic function. The index of portal perfusion decreased significantly (-29%; p = 0.018) and the hepatic artery index increased significantly (+23%; p = 0.018), while no changes were observed after placebo. The heart rate decreased significantly after penbutolol (-9%; p = 0.028), while neither penbutolol nor placebo modified the ejection fraction. In conclusion, penbutolol decreased portal perfusion index (the compensatory increase in the hepatic artery index confirmed this change) without major modification of total hepatic blood flow or systemic hemodynamics. Angioscintigraphy is reasonably accurate, reproducible, safe and can be considered suitable for routine use in the assessment of liver hemodynamics.

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.

[The noninvasive assessment of the effects of penbutolol on liver hemodynamics in cirrhotic patients using angioscintigraphy. A randomized controlled double-blind study]. / Valutazione non-invasiva delgi effetti del penbutololo sull'emodinamica epatica nei cirrotici mediante angioscintigrafia. Studio randomizzato, controllato, in doppio cieco.

This randomized double-blind controlled study analyzed the hemodynamic effects of penbutolol, a new levo-rotatory betablocker, using radionuclide angiography. Twenty cirrhotics with esophageal varices were randomized: 10 received 40 mg/day of penbutolol orally and the others a placebo. Angioscintigraphy was performed before and after an 8-day treatment period. Three cases in the penbutolol group were lost due to software damage, hence the data of 17 patients were analyzed. The two groups were similar for age, sex, etiology of cirrhosis and hepatic function. The index of portal perfusion decreased significantly (-29%; p = 0.018), and the hepatic artery index increased significantly (+23%; p = 0.018), whereas no changes were observed after placebo. The heart rate decreased significantly after penbutolol (-9%; p = 0.021); while neither penbutolol nor placebo modified the ejection fraction. In conclusion, penbutolol decreased portal perfusion index (the compensatory increase of hepatic artery index confirmed this change) without significant modification of total hepatic blood flow and systemic hemodynamics. Angioscintigraphy is reasonably accurate, reproducible, safe and can be considered suitable for routine use in the assessment of liver hemodynamics.

[Cross-reactivity of milk proteins: statistical analysis of RAST results]. / Reattività crociata fra le proteine del latte con l'analisi statistica dei risultati del RAST.

RIA dosages of specific IgE antibodies to cow milk, alpha-lactalbumin, beta-lactoglobulin, casein, cheddar and mould cheese were determined in 440 patients. Statistic analysis has been carried out with: 1) the linear regression and correlation coefficient r2: 2) U test of Mann-Whitney and then S test of Kendall Results show that casein has low allergenicity in comparison to other cow's milk proteins. It could be unnecessary to quantify specific IgE to cow milk and cheeses. From the observed data we could suppose that the formulas with casein/blood protein ratio similar to maternal milk may be more allergenic than casein based ones.

99mTc-MAG3 versus 131I-orthoiodohippurate in the routine determination of effective renal plasma flow.

99mTc-mercaptoacetyltriglycine (MAG3) has been proposed as an alternative to 131I-orthoiodohippurate (OIH) for the scintigraphic determination of effective renal plasma flow (ERPF). The purpose of this study was to compare the ERPF values determined simultaneously with MAG3 and OIH by a dual channel technique in a large group of subjects with widely ranging renal function. During the last two years, we administered a simultaneous injection of 74 MBq of MAG3 and 0.74 MBq of OIH to each subject who underwent a renal scintigraphic study in our hospital. They were 53 females and 50 males (mean age: 52 years; range: 18-70 years), either normal (30) or with a diagnosis of essential hypertension (53), chronic renal failure (14), renal calculi (5), or renal transplant (1). Plasma clearance and ERPF were calculated with both radiocompounds by using the exponential formula of Tauxe and coworkers and a single plasma concentration determination sampled 44 min after injection of the two tracers. The time-activity curves for kidney and blood were of the same bi-exponential type. The mean ratio between the two plasma clearances was 0.49. The linear regression of the ERPF values obtained with the two radiocompounds was highly significant (r = 0.69; p less than 0.0001) and is expressed by the equation: ERPF (MAG3) = 0.453 ERPF (OIH) + 25.7. These data suggest that the routine calculation of ERPF from MAG3 clearance is consistent with the results obtained from OIH clearance. In conclusion, MAG3 appears to be a good predictor of ERPF in routine clinical practice.

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.

Dermatophagoides and storage mites: statistical analysis of RAST results.

R.I.A. dosages of specific IgE antibodies to Dermatophagoides pteronyssinus, Dermatophagoides farinae (house dust mites), Acarus siro, Lepidoglyphus destructor, and Tyrophagus putrescentiae (storage mites) in 467 unselected patients were statistically analyzed. A significant noncorrelation between specific IgE antibodies to storage mites and those to house dust mites has been found, suggesting that storage mites have their own allergenic specificity.

[Proposal for a quality control procedure for rotating gamma camera tomographic systems]. / Proposta di procedura di controllo di qualità per sistemi tomografici a gamma camera rotante.

Single photon emission computerized tomography using a rotating gamma camera needs accurate calibration of electromechanical components, detection system and reconstruction software. A complete group of quality control procedures, developed on the basis of experience and experimental data acquired using a series of widely used gamma camera SPECT systems is presented. The procedures are divided into controls related to the rotational movement. of the detector and controls on the principal physical parameters characterizing a tomographic image. All quality controls here presented were performed with commercial phantoms.

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.

[The predictive value of serial scintigraphy and computerized tomography in the diagnosis of brain lesions (author's transl)]. / Analisi comparativa del valore predittivo della scintigrafia seriata e della tomografia computerizzata nella diagnosi delle lesioni cerebrali.

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.

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.

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.