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M Miniati

Publications and source records attributed to M Miniati.

54 records · Page 3Linked to original sources
PubMed1986

Kinetics of the intrapleural distribution of a radioactive bolus.

Through the use of a gamma-camera placed horizontally over the chest of 5 supine, anesthetized and spontaneously breathing dogs we studied the kinetics of the intrapleural spreading of 1 ml saline containing 2 mg of 99mTc labelled albumin (250 microCi/kg) injected at various points on the costal side. From the postinjection sequence of gamma-camera images, we defined, along the intrapleural spreading pathways, some regions of interest (ROI) displaying a preferential label accumulation. In all the animals the ROI roughly corresponded to the apical, mediastinal and latero-diaphragmatic regions. The kinetics of the intrapleural label distribution, estimated from the time course of the activity under the ROI, displayed an initial rapid phase, lasting a few minutes, followed by a marked slowing down of the exchange processes. At 30 min regional counts reached an apparent steady state, the activity values greatly varying (even by 10 fold) among the animals, for the ROI corresponding to the same anatomical region, independently on the site of injection. The mathematical modelling of the regional activity curves required the assumption of a progressive decrease in the exchange coefficients to account for a marked slowing down of the exchange processes with increasing time.

Animals↗
PubMed1986

Perfusion lung imaging in the adult respiratory distress syndrome.

In 29 perfusion lung scans (PLS) of 19 patients with ARDS, 20 of which were obtained within six days from the onset of respiratory symptoms, perfusion abnormalities were the rule. These included focal, nonsegmental defects, mostly peripheral and dorsal, and perfusion redistribution away from the dependent lung zones. PLS were scored for the presence and intensity of perfusion abnormalities and the scores of perfusion redistribution were validated against numerical indices of blood flow distribution per unit lung volume. PLS scores were correlated with arterial blood gas values, hemodynamic parameters, and chest radiographic scores of ARDS. Arterial oxygen tension correlated with the scores of both perfusion defects and redistribution. Perfusion defects correlated better with the radiographic score of ARDS, and perfusion redistribution with PAP and vascular resistance. ARDS patients exhibit peculiar patterns of PLS abnormalities not observed in other disorders. Thus, PLS may help considerably in the detection and evaluation of pulmonary vascular injury in ARDS.

Humans↗
PubMed1985

Regional protein absorption rates from the pleural cavity in dogs.

In five supine spontaneously breathing anesthetized dogs we injected into the pleural space 0.5-1 ml of saline solution containing 2 mg/ml albumin labeled with technetium-99m. By use of a gamma camera placed horizontally over the chest, we followed, up to 120 min, the activity over the whole lung and over the preferential accumulation areas of the label (regions of interest, ROI) that corresponded to the apical, mediastinal, and laterodiaphragmatic regions. Activities were corrected for the decay rate of the isotope used. On the average, the activity over the whole lung decreased by 27% up to 120 min. The overall activity over the ROI amounted to 44.3% after the injection and decreased to 24% of total at 120 min, thus accounting for 75% of the total decrease in activity. At 10 min, the activity per unit surface of the gamma camera image (As) was from 2.2- to 5.7-fold higher over the ROI than for the rest of the lung image. The decrease of As at 120 min was 18-, 13-, and 5-fold greater for mediastinal, diaphragmatic, and apical regions, respectively, compared with the rest of the lung image. The time course of the changes in As are discussed in terms of regional albumin egress rate based on the functional interaction between the Starling and the lymphatic mechanisms.

Absorption↗
PubMed1985

The radiologic distinction of cardiogenic and noncardiogenic edema.

Improvement in the ability to determine the specific cause of any given case of pulmonary edema would lead to more rapid and definitive treatment. "Wedge" pressures and measurements of cardiac output derived from Swan-Ganz catheterization assist in making this determination, but the procedure is invasive, expensive, associated with complications, and not infrequently inaccurate. A plain chest film is, however, almost invariably available in all patients with pulmonary edema, and as shown in this study, the cause of the edema can be determined with a high degree of accuracy by careful attention to certain radiographic features. An independent two-observer study was performed on 216 chest radiographs of 61 patients with cardiac disease, 30 with renal failure or overhydration, and 28 with capillary permeability edema. Three principal and seven ancillary features have been identified, all of which are statistically significant and permit the cause of the edema to be determined correctly in a high percentage of cases. The three principal features are distribution of pulmonary flow, distribution of pulmonary edema, and the width of the vascular pedicle. The ancillary features are pulmonary blood volume, peribronchial cuffing, septal lines, pleural effusions, air bronchograms, lung volume, and cardiac size. Differing constellations of these features occur, each of which is characteristic of a specific type of edema. Overall accuracy of diagnosis in this study ranged from 86% to 89%. The highest accuracy was obtained in distinguishing capillary permeability edema from all other varieties (91%), and the lowest in distinguishing chronic cardiac failure from renal failure (81%).

Blood Volume Determination↗
PubMed1985

[Not Available].

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Diagnosis↗
PubMed1985

The chest roentgenogram in pulmonary edema.

It has been shown that the chest roentgenogram is a sensitive and accurate pool for detecting and quantitating cardiogenic pulmonary edema. This can be done at the interstitial stage, when it cannot be detected by physical examination. At the same time the chest film can provide useful information about the circulating blood volume. In patients with the ARDS, a characteristic peripheral and patchy distribution of alveolar edema associated with an absence of peribronchial cuffing, septal lines and effusions has been shown. Enlargement of the right side of the heart and main pulmonary artery may precede actual development of edema in ARDS and provide the opportunity for early diagnosis. Radiographic "scoring" in cases of ARDS correlates well with PO2 (measured with an F1O2 = .21) standardized to a PCO2 of 40 mm Hg. The three main forms of lung edema (that is, cardiogenic, renal or overhydration, and injury edema) appear to have radiographic features that can be used to separate them. The accuracy and objectivity of this approach has been confirmed by taking the radiographic signs as input variables for discriminant analysis. Different hemodynamic conditions and changes of the extravascular protein osmotic forces may be the main factors underlying the radiographic patterns in the various types of pulmonary edema.

Blood Pressure↗
PubMed1984

Results of en bloc resections for lung cancer.

The results of en bloc resection carried out in 33 patients with lung cancer involving the chest wall are described. Microscopic examination of the lung specimen revealed large cell anaplastic carcinoma in 14 cases, squamous carcinoma in 10, adenocarcinoma in 5, microcytoma and fibrosarcoma in 2 cases respectively. The 5 year survival, calculated according to the actuarial method, was 32%, only slightly lower than the 5 year overall survival observed in our survey. The long-term prognosis was essentially related to the presence of lymph node metastases, which were found to occur at a late stage of the clinical evolution.

Actuarial Analysis↗
PubMed1984

The vascular pedicle of the heart and the vena azygos. Part I: The normal subject.

The widths of the systemic vessels extending from the thoracic inlet to the heart (the vascular pedicle) and of the azygos vein were measured in 83 normal volunteers and 42 patients with cardiac disease. Mean vascular pedicle width ( VPW ) (erect) was 48 +/- 5.0 mm and correlated well with body weight (r = 0.64) and surface area (r = 0.62). Rotation to the left reduced VPW and to the right increased it. Inspiration and expiration caused little change. The supine VPW increased an average of 20% (47 +/- 37% to the compliant venous right side and 7 +/- 48% to the less compliant arterial left). Supine azygos width (AW) increased 105 +/- 47%. Mean erect AW was 5.14 +/- 1.36 mm. AW did not correlate significantly with anthropomorphic characteristics. Because VPW correlates with the patient's physique, its normality can be estimated within clinically useful limits by inspection. Since AW has no such correlation, serial changes are of more value than initial absolute values.

Adult↗
PubMed1984

The vascular pedicle of the heart and the vena azygos. Part II: Acquired heart disease.

To establish the value of the chest radiograph in assessing the hemodynamic status of the systemic circulation, the vascular pedicle width ( VPW ) and vena azygos width (AW) were correlated with total blood volume (TBV) and other parameters in 61 cardiac patients. In both ischemic and valvular cardiac disease a highly significant linear correlation was found between VPW and TBV (r = 0.80, p less than 0.001). In patients with dilated neck veins VPW was greater than 62 mm (normal 48 +/- 5 mm). A less significant correlation was found between VPW and mean right atrial pressure ( MRAP ). Change in VPW correlated strongly (r = 0.93, p less than 0.001) with change in TBV (0.5-cm change in VPW = 1.0-liter change in TBV). Correlation between AW and TBV was poor (r = 0.50, p less than 0.01), but between AW and MRAP the correlation was stronger (r = 0.74, p less than 0.001). Changes in AW usually occurred in the same direction as changes in MRAP , but the correlation was not significant (r = 0.45). VPW and AW did not correlate with pulmonary blood volume, pulmonary arterial pressure, stroke volume, or heart rate. Radiologic assessment of VPW and AW adds an additional clinically useful dimension to the evaluation of cardiac disease.

Azygos Vein↗
PubMed1984

The vascular pedicle and the vena azygos. Part III: In trauma--the "vanishing" azygos.

The chest radiographs of 158 patients with widened vascular pedicles were examined. The vascular pedicle was measured and the presence or absence of the right paratracheal stripe and the vena azygos on the radiographs was noted. Increasing the systemic blood volume (or assuming the supine position) causes the vascular pedicle of the heart to widen predominantly to the right, and the vena azygos to enlarge simultaneously. In contrast, extravascular bleeding from aortic damage causes the pedicle to widen predominantly to the left of the midline; at the same time the paratracheal stripe and azygos "vanish." This combination of physiologic and pathologic, and intravascular and extravascular causes of widening of the pedicle. Extravasation of blood or saline from a traumatic right subclavian puncture can cause local bulging of the pedicle to the right and a vanishing azygos. Because the left side of the pedicle remains normal, this can be readily differentiated from an aortic tear.

Adult↗
PubMed1984

Pleural liquid pressure gradients and intrapleural distribution of injected bolus.

In supine anesthetized dogs we measured pleural liquid pressure (Pliq) in mediastinal, diaphragmatic, apical, and costal regions at different lung heights during eupneic breathing. At end expiration and at a given height, Pliq was similar in the costal and apical regions, but it was lower in the diaphragmatic and mediastinal compartments. Inspiratory swings toward lower values were progressively greater with increasing height and moving from costal to apical, diaphragmatic and mediastinal compartments. Thus during inspiration, at any height, the costomediastinal and costodiaphragmatic Pliq difference increased while a costoapical difference developed. One minute after injection of 0.5-1 ml of saline at different points within the cavity, end-expiratory liquid pressure became higher on the average by 0.45, 1.55, and 0.55 cmH2O in the apical, mediastinal, and diaphragmatic compartments, respectively, while no change was observed on costal side. These results suggested liquid accumulation in the compartments displaying a lower Pliq. This was confirmed by following, with a gamma camera, on a frontal projection of the lung, the intrapleural distribution of a bolus containing 99mTc-labeled albumin injected at various places.

Animals↗
PubMed1984

[Not Available].

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General Surgery↗
PubMedDate not supplied

[Quantification of pulmonary emphysema with computerized tomography. Comparison with various methods].

Computed Tomography (CT) has been proved to be the most accurate imaging modality to diagnose emphysema in vivo. Our study was aimed at comparing different CT methods for pulmonary emphysema quantification in patients with severe chronic obstructive pulmonary disease (COPD). Forty-six consecutive inpatients affected with COPD underwent high resolution CT (HRCT). Three scans were acquired at 3 preselected anatomic levels at both full inspiration and expiration. Three different observers were asked to subjectively evaluate, under blind conditions, the extent alone and both the severity and the extent of emphysema on the 6 scans. HRCT findings were also analyzed quantitatively by measuring the mean CT number in Hounsfield Units (HU) and the % of lung area with CT numbers < -900 HU (pixel index). Quantitative CT data were compared with reference values obtained in 7 normal nonsmokers. The CT visual score of emphysema exhibited medium-high interobserver reproducibility with correlation coefficients ranging from 0.80 to 0.96 and a good correlation with pulmonary function tests, particularly relative to the assessment of the extent of emphysema alone as expressed by one observer. CT quantification demonstrated an excellent correlation with functional indices of expiratory airflow, lung volumes and diffusion coefficients (p < 0.001). The expiratory measurements were better than the inspiratory ones while the analysis of both CT number and pixel index gave comparable results. Only the CT expiratory quantitative data allowed to differentiate the patients affected with COPD from the controls. In conclusion, the severity of emphysema as expressed by CT correctly reflects the functional impairment of patients with severe COPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗