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M G Bonetti

Publications and source records attributed to M G Bonetti.

At least 37 records · Page 2Linked to original sources
PubMed1990

[High-resolution rapid multiplanar reconstructions in the CT study of the spine. Our experience].

The authors describe the utility of fast and high-resolution multiplanar CT reconstructions in the study of the rachis. Their experience is reported with an up-to-date software with 2 different representation modalities (CMR 01B). A "package" of contiguous axial images is obtained in a standard way; the images are then reformatted by computer to obtain (in just a few seconds) high-resolution reconstructed images in different planes (coronal, sagittal, and oblique). In the authors' opinion the method, in spite of some limitations, yields in most cases additional information which is not provided by conventional CT. Reconstructed images are most useful in the study of complex anatomical structures (such as vertebral metameres) along their anatomical planes.

Humans↗
PubMed1990

[Comparison of traditional methods and digital technics in the study of the biliary and pancreatic systems using endoscopic retrograde cholangiopancreatography (ERCP)].

ERCP holds a key role in the diagnosis of pancreatic-biliary disease. In this technical paper the authors report their experience with computed radiography (CR) in ERCP diagnostic imaging. A stimulable phosphor system was employed (Toshiba TCR-201). Fifteen pancreatic-biliary patients were studied with both conventional and CR techniques. With the same diagnostic output and radiological system, CR was superior to conventional technique in: dramatic exposure-time reduction, image post-processing (exposure error amendment, contrast change, spatial filtering, zooming, gray-scale inversion, etc.), patient exposure reduction, and digital archiving.

Aged↗
PubMed1989

[Radiological study of the thorax. Evaluation of efficacy-efficiency of a large-field image intensifier in mass screening].

Chest X-ray is the most frequent examination in radiology and accounts for a considerable portion of total population radiation exposure, mostly in screening programs. The ideal radiographic system is the one providing the best image quality together with the lowest dose to the patient, at a low cost. In this paper the authors analyze the potentials of a new chest X-ray examination unit equipped with a large-screen image intensifier (TS 57-Siemens). Two-thousand subjects were examined with this unit. The technical aspects of everyday practice are analyzed from the radiologist's point of view, together with the dose to the patient, image quality, and costs.

Adult↗
PubMed1987

Pulmonary involvement in progressive systemic sclerosis: a multidisciplinary approach.

In an attempt to define the early features and the natural evolution of lung involvement in progressive systemic sclerosis (PSS), we planned a multidisciplinary study of these patients using radiological, scintigraphic and functional methods. As yet we have studied 21 subjects, all affected by PSS according to the American Rheumatism Association criteria. A well-defined restrictive functional pattern was present only in 10 patients out of 21; an increased elastic recoil may be present before a significant decrease of the transfer test for carbon monoxide; an increased alveolar-capillary permeability assessed by the 99mTc-diethylene-triamine-pentacetic acid (99mTc-DTPA) clearance rate has been detected in almost all the patients (13 out of 14) in at least one lung field; no significant correlation has been found between the radiological lung involvement and the 99mTc-DTPA clearance rate. We think that these preliminary results are consistent with an alveolar and interstitial inflammation rather than with a vasculitic process.

Adult↗
PubMed1987

[Assessment of uteroplacental circulation with radioisotopes].

The authors have evaluated placental blood flow using a non-invasive radioisotopic approach, with the intravenous administration of 1 mCi 113mIn. The method is evaluated in 20 normal pregnancies, in 24 patients with intrauterine growth retardation, in 8 patients with iso-Rh-immunization and in 9 patients with gestational diabetes. In the group with intrauterine growth retardation 2 pregnancies with extensive fetal malformations were included. In one case without evident histological placental alteration the index was 3.94 at 34 weeks of gestation and 5.62 at 36 weeks of gestation. In the second one with placental infarcts the index was 3.46 at 38 weeks of gestation. Normal pregnancies showed a flow index of 5.50 +/- 1.57 (1 s.d.) units compared to the pathological pregnancies value of 2.74 +/- 0.90 (1 s.d.) units. (p less than 0.001). The conclusions drawn are: The method is very well suited to clinical evaluation of placental blood flow. The evaluation of placental blood flow cannot be directly equated with fetal development as it is not its only determinant. This method is a indirect index of placental function in small for gestational age fetuses with malformations.

Congenital Abnormalities↗
PubMed1987

[Dynamic pulmonary scintigraphy with Tc99m radioaerosol for the evaluation of the permeability of the alveolo-capillary barrier].

Pulmonary clearance of small droplet 99mTc-DTPA radioaerosol was studied in 100 patients (12 normal subjects, N; 10 asymptomatic healthy smokers, FA; 31 patients with interstitial lung diseases, IP; 47 patients with chronic obstructive lung disease, BPCO). The first seven minutes of clearance were described with the function At = Ao*exp (-K*t) and the time constant K was considered representative of the 99mTc-DTPA clearance rate and hence of the alveolar-capillary barrier permeability. Groups FA, IP and BPCO showed a significant (p less than 0.05) or a highly significant (p less than 0.01) increase in permeability when compared to group N. No correlation was found between permeability and bronchial obstruction tests. The following conclusions were drawn: --99mTc-DTPA dynamic lung scanning is an easy, non-invasive method to assess derangements of alveolar-capillary barrier permeability secondary to epithelial damage; --permeability increase is a very early effect of cigarette smoke damage to the epithelium; --other mechanisms of epithelial injury are present in diffuse lung disease; --while the clinical role of this new pathophysiological test is not yet clear, it is likely that it may become a very early marker of pulmonary epithelial damage in diffuse lung disease.

Adult↗
PubMed1987

Sacroiliitis in seronegative polyarthritis: CT analysis.

Sacroiliac joint abnormalities were evaluated by computed tomography (CT) in 29 patients with psoriatic arthritis and in 15 with colitic arthritis. CT showed a better sensitivity than conventional X-ray analysis in the evaluation of the articular space alterations in psoriatic and colitic arthritis as well as in detecting erosions and ankylosis of sacroiliac joints in patients with ankylosing spondylitis or psoriatic arthritis. Thus, CT appears a promising tool for the early detection of the pathological changes of sacroiliac joints.

Adult↗
PubMed1986

Correlation of functional parameters derived by equilibrium radionuclide angiocardiography and left ventricular size in patients with old myocardial infarction.

A total of 131 patients with old (over 6 months) myocardial infarction (MI) and 18 normal subjects underwent equilibrium radionuclide angiocardiography at rest (rERNA). The following rERNA parameters were assessed: left ventricular ejection fraction (LVEF), peak ejection rate (PER), peak filling rate (PFR), regional wall motion and a left ventricular size index. The patients with old MI were divided into four groups (I to IV) according to increasing left ventricular (LV) size, and the behaviour of the numerical parameters (LVEF, PER, PFR) was evaluated in each group. LVEF proved to be the most sensitive numerical parameter of overall LV performance. PFR decreased significantly from group I to group III but not from group III to group IV, suggesting that for extreme degrees of left ventricular enlargement some compensatory mechanism acts to prevent a too large fall in LV compliance. The effects of the site of the previous MI on LV performance were also evaluated. Both LV size and performance were least affected by postero-inferior MI. The LVEF was, however, a better predictor of LV size than the site of the MI.

Adult↗
PubMed1986

Equilibrium radionuclide angiocardiography to select inotropic therapy in patients with left ventricular aneurysm.

Fourteen patients with postinfarctual ventricular aneurysm underwent equilibrium radionuclide angiocardiography at rest (ERNA) before and after oral digoxin administration in order to evaluate the effects of increasing myocardial contractility upon both ventricular aneurysm mechanical behaviour and global ventricular function. The ejection fraction (EF) was not significantly affected by digoxin therapy. However, digoxin induced changes in EF (delta EF) correlated inversely with changes in aneurysm size and directly with changes in the extent of the hypokinetic area. Two types of aneurysm were observed: high-compliance aneurysm the size of which increased after digoxin administration while both EF and the extent of the hypokinetic area fell, and low compliance aneurysm for which opposite changes occurred. This different behaviour of ventricular aneurysm may have important practical implications as surgery would be probably more effective than medical treatment in improving resting ventricular function in patients with high-compliance aneurysm.

Adult↗
PubMed1986

The use of digitalis in patients with chronic respiratory failure.

The effect of slow digitalization was tested by radioisotopic angiocardiography in 33 patients with stable and compensated chronic obstructive pulmonary disease (COPD); most of these had severe chronic respiratory failure (CRF). After a 10 days course of digoxin, 0.25 mg/die per os, both the left ventricular ejection fraction (LVEF) and the peak ejection rate (PER), initially slightly abnormal, improved significantly (t = -3.474, p less than 0.005; t = -2.438, p less than 0.025), while right ventricular ejection fraction (RVEF) and peak filling rate (PFR) did not. Ventricular diastolic interdependence and abnormal myocardial calcium kinetic are likely to account for PFR behaviour. Digoxin effects upon RVEF and LVEF suggest that the right ventricular systolic function is to some extent independent from the left one when blood gas derangement and abnormal thoracopulmonary mechanics are the major determinant of right ventricular afterload. The lack of significant correlation between digoxin effects on right and left ventricular function indices confirms this hypothesis. Digoxin can improve the left ventricular ejection phase indices, when these are initially abnormal, while its effect on RVEF is unpredictable.

Adult↗
PubMed1986

[Scintigraphy of pulmonary ventilation with 99mTc-DTPA radio-aerosol. I. Semiotics of the static images].

Papers on deposition pattern analyses of radio-aerosol lung scans are few and not easy to interpret as there is a general lack of technical standardization and the number of patients studied is not large. Moreover these reports have been generally obtained with non-hydrosoluble radioaerosols. In the present study 43 patients underwent conventional pulmonary function testing and lung scanning using small droplet (equal or less than 2 microns) polydisperse 99mTc-DTPA radioaerosol produced with the "Settling Bag System"--Medi 400 (Sorin). The scans were analysed by two methods: a semiquantitative method proposed by Taplin (SQT); an original simpler semiquantitative method (SQM). Correlations of SQT and SQM with FEV1 and MEF75 resulted highly significant (p less than 0,001). SQM proved to be superior to SQT as far as reproducibility is concerned. The following conclusions can be drawn: small particle 99mTc-DTPA aerosol can be easily and cheaply produced by a commercial device; such a radioaerosol is well suited for the evaluation of small and large airways patency, as reflected by MEF75 and FEV1 respectively, with a diagnostic yield comparable to non-hydrosoluble radioaerosols; the original semiquantitative description of the deposition patterns proposed and validated in this study is quite easy to implement and it yields a high correlation with pulmonary function tests; moreover such an approach does not require digital data processing; the sensitivity of 99mTc-DTPA for the diagnosis of bronchial obstruction is very high and superior to routine pulmonary function tests; in addition the ventilation scan allows the topographical localization of the obstructions themselves.

Adult↗
PubMed1986

Right ventricular wall motion and performance in stabilized chronic respiratory failure evaluated by equilibrium radionuclide angiocardiography.

Equilibrium radionuclide angiocardiography (ERNA) was performed at rest in 30 patients with chronic respiratory failure (CRF) in order to evaluate right ventricular performance and wall motion. The usual indices of left ventricular performance were also recorded and correlated with right ventricular parameters. Only CRF patients without clinical, electrocardiographic or echocardiographic criteria suggestive of congenital, valvular, hypertensive or ischemic heart disease were studied. A RV dyskinesis was detected in 5 of the 30 patients, occurring however only in stage II-III CRF, as if a longstanding RV pressure overload were necessary for a RV dyskinesis to develop. No significant differences were found between patients with and without RV dyskinesis for all the functional ERNA parameters (i.e. LVEF, RVEF, PER, PFR). On the other hand, a significant correlation between the stage of the CRF and RVEF was observed.

Cardiac Output↗
PubMed1986

The effects of chronic hypoxia on left ventricular peak filling rate evaluated by equilibrium radionuclide angiocardiography.

Left ventricular peak filling rate (PFR) was measured by equilibrium radionuclide angiocardiography (ERNA) in 15 patients with Stage II stabilized chronic respiratory failure (CRF) without evidence of coexisting heart diseases and in 18 patients with coronary artery disease (CAD) without myocardial infarction. The study was designed to assess the effects of severe hypoxia and of ischaemia on the calcium-dependent early diastolic filling. PFR was found to be impaired in both groups of patients (mean = 1.72 EDVs-1 and S.E.M. = 0.07 in CAD; mean = 2.35 EDVs-1 and S.E.M. = 0.14 in CRF) but significantly less (p less than 0.001) in CRF patients while the left ventricular ejection fraction (LVEF) values were not significantly different between the two groups (mean = 60.0% and S.E.M. = 1.4 in CAD; mean = 62.0% and S.E.M. = 1.6 in CRF). As PFR is known to be a sensitive index of left ventricular performance the results obtained in this human model are consistent with findings obtained in animal models suggesting that hypoxia is less efficient than ischaemia in depressing left ventricular function.

Adult↗
PubMed1985

Non-invasive radioisotopic evaluation of placental blood flow.

The authors have evaluated placental blood flow using a non-invasive radioisotopic approach. The procedure involves the intravenous administration of 113mIn and the technique is a modified version of a previously reported method for a non-diffusive tracer kinetics analysis. The method is presented in detail and its performance is evaluated in 17 normal and 32 pathologic pregnancies (19 intrauterine growth retarded patients; 7 patients with iso-Rh immunization; 5 patients with gestational diabetes, and 1 pregnancy with extensive fetal malformation which was not included in any group). The normal pregnancies showed a flow index of 5.34 +/- 1.64 (1 SD) units compared to the pathological pregnancies value of 2.73 +/- 0.73 (1 SD) units (p less than 0.001). The conclusions drawn are: (1) the method is very well suited to clinical evaluation of placental blood flow; (2) the evaluation of placental blood flow cannot be directly equated with fetal development as it is not its only determinant, and (3) no other independent test to evaluate the radioisotopic study in terms of accuracy exists.

Adult↗
PubMed1985

99mTc-DTPA clearance in bullous emphysema.

The degree of permeability of the alveolar-capillary barrier to low molecular weight solutes has been supposed to depend upon the radius of the epithelial pores. The bullous emphysema is a natural model in which this radius may increase because of the high tension in the bulla. Accordingly, the 99mTc-DTPA clearance may be expected to be faster than normal in lung fields including bullae. Results of the present study in which 99mTc-DTPA clearance was measured in six patients with bullous emphysema, seem to confirm this hypothesis at least to some extent. In fact, either increased or normal 99mTc-DTPA clearances were found over the lung fields including bullae communicating with the bronchial tree. Differences in both the size and the inner tension of the bullae as well as in the anatomical and functional conditions of the surrounding parenchyma are likely to account for such varying behaviour.

Capillary Permeability↗
PubMed1985

Left ventricular diastolic performance at rest in patients with angina and normal systolic function--assessment by equilibrium radionuclide angiography.

The aim of the study was to correlate diastolic function, as evaluated by peak filling rate (PFR) and relative time (TPFR), with the severity of ischemic heart disease, as evaluated by exercise electrocardiography. Accordingly, 83 ischemic patients with effort angina, but normal ejection function at rest and normal left ventricular size, were studied by equilibrium radionuclide angiocardiography within two weeks from the exercise ECG. Diastolic dysfunction, as determined from PFR and, to a lesser extent, from TPFR, is common in patients with ischemic heart disease and normal systolic function. The prevalence and severity of such dysfunction is related more to the severity of the ischemia, as evaluated by the exercise ECG, than to the presence of an old myocardial infarction. Such findings are consistent with the hypothesis that PFR reflects mainly the early diastolic active uncoupling process.

Adult↗