Hydrostatic versus increased permeability pulmonary edema.
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Capillary Permeability↗
Biomedical subjects
E N Milne
Publications and source records attributed to E N Milne.
Objective radiographic criteria to differentiate cardiac, renal, and injury lung edema.
To assess the value of the chest radiograph in differentiating various types of pulmonary edema, we retrospectively analyzed 119 films of patients with pulmonary edema caused by left heart decompensation (group 1;N = 56), renal failure (group 2; N = 19), and lung microvascular injury (group 3; N = 44). Chest radiographs were examined independently by two trained observers, unaware of the clinical diagnosis, according to a standardized reading table. The two observers assigned chest films to the corresponding group with an accuracy of 86% and 90%, respectively. To test the observers' objectivity, we used radiographic findings as input variables for discriminant analysis. Computer-generated numerical functions identified pulmonary edema etiology with an accuracy of 88% when considering the three groups together. When groups were compared as pairs, percentages of correct classification were 91% (group 1 vs. group 2), 93% (group 1 vs. group 3), and 100% (group 2 vs. group 3). Thus, a standardized reading of chest radiographs may be considered a reliable clinical method for identifying pulmonary edema etiology.
Heart Failure↗
A case report of segmental bronchial atresia: radiologic evaluation including computed tomography and magnetic resonance imaging.
Bronchial atresia is a rare anomaly that characteristically presents with a pulmonary nodule and hyperinflation of the lung distal to the nodule. To make this diagnosis definitively, invasive studies have been required. Now with the combined use of computed tomography and magnetic resonance imaging, a diagnosis can be made without resorting to invasive techniques. This article describes a case of bronchial atresia illustrating the noninvasive approach.
Adult↗
Role of imaging and interventional techniques in the diagnosis of respiratory disease in the immunocompromised host.
A pure "pattern-recognition" approach to lung diseases in immune compromised patients as seen on the chest film is of limited value since any infection can present with several different patterns, and processes such as embolism, aspiration, edema, and hemorrhage may give appearances similar to infection. However certain pulmonary infections do occur commonly in association with one type of immunosuppression but rarely with others. Knowledge of these associations assists in narrowing down the differential diagnosis and in deciding upon the most appropriate next confirmatory diagnostic step.
Acquired Immunodeficiency Syndrome↗
Splenic size on routine chest films in AIDS: diagnostic and prognostic significance.
Sixty-nine percent of AIDS patients show evidence of splenomegaly on their plain chest film. This splenomegaly is not related to severity of AIDS, to intravenous drug abuse or to any specific infection or neoplasm but correlates well with severity of anemia, pancytopenia, and thrombocytopenia. Increasing splenomegaly usually indicates worsening of AIDS. The triad of splenomegaly, interstitial lung disease sparing the bases, and very thin chest wall soft tissues is highly specific for the diagnosis of AIDS. The sensitivity of the plain film for diagnosing AIDS can be increased by including AIDS in the differential diagnosis of all patients with splenomegaly, intrathoracic lymphadenopathy, cachexia, or bilateral interstitial lung disease of unknown cause.
Acquired Immunodeficiency Syndrome↗
Assessment of cardiac size on portable chest films.
Using both anthropomorphic phantoms and human patients, the authors have shown that the effects on cardiothoracic (CT) ratio of changing from the posteroanterior (PA) to the anteroposterior (AP) projection are much greater than the effect of reducing the anode-to-film distance (AFD). This is because, in the AP projection, not only is the transverse diameter (TD) of the heart much farther from the film (and its image is therefore enlarged), but the TD of the chest is usually closer to the film and its image is reduced in size. These factors, operating in different directions, cause a major change in the CT ratio. The authors have shown that small hearts are magnified more than large hearts by changing from PA to AP, and that the position of the TD of the thorax (whether it is farther anterior or farther posterior) markedly affects what happens to the CT ratio when the AFD is changed. Because of this, it is impossible to predict accurately what effects a given AFD and projection will have on the CT ratio. However, using approximate correction factors (-12.5% of CT ratio for a 40 in AFD, AP film and -10% of CT ratio for a 72 in AFD, AP film) a clinically useful determination can be rapidly made as to whether the heart is enlarged or not.
Cardiomegaly↗
Factors affecting regional pulmonary blood flow in chronic ischemic heart disease.
To assess the effect of left heart disease on pulmonary blood flow distribution, we measured mean pulmonary arterial and wedge pressures, cardiac output, pulmonary vascular resistance, pulmonary blood volume, and arterial oxygen tension before and after treatment in 13 patients with longstanding ischemic heart failure and pulmonary edema. Pulmonary edema was evaluated by a radiographic score, and regional lung perfusion was quantified on a lung scan by the upper to lower third ratio (U:L ratio) of pulmonary blood flow per unit of lung volume. In all cases, redistribution of lung perfusion toward the apical regions was observed; this pattern was not affected by treatment. After treatment, pulmonary vascular pressures, resistance, and edema were reduced, while pulmonary blood volume did not change. At this time, pulmonary vascular resistance showed a positive correlation with the U:L ratio (r = 0.78; P less than 0.01), whereas no correlation was observed between U:L ratio and wedge pressure, pulmonary edema, or arterial oxygen tension. Hence, redistribution of pulmonary blood flow, in these patients, reflects chronic structural vascular changes prevailing in the dependent lung regions.
Blood Volume↗
Blood supply of pulmonary metastases.
There is a widely held belief that metastases to the lung (like primary lung tumors) are supplied by the bronchial arteries and that pulmonary neovascularization does not occur. In 17 human lungs, we have demonstrated, both in vitro and in vivo, pulmonary circulation to metastases. We have confirmed this in a series of animal studies in which we implanted tumors of various histologies into rats' tails and induced metastases from these tumors into the lungs. Forty-eight percent of these metastases had an entirely pulmonary circulation, 36% a primarily pulmonary circulation with a small bronchial component, and only 16% of metastases, located in the central one third of the lung, had an exclusively bronchial circulation. We have now shown that these supplying pulmonary vessels to metastases can be clearly demonstrated on thin-section computed tomography of the lungs. This may prove to be a helpful, noninterventional diagnostic criterion for distinguishing a primary from a metastatic lesion.
Animals↗
Interstitial pulmonary hemorrhage from mediastinal hematoma secondary to aortic rupture.
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Aortic Rupture↗
A physiological approach to reading critical care unit films.
Radiologic assessment of pulmonary vascular pressure and flow and quantitation and determination of the etiology of pulmonary edema is reviewed and new data provided to calculate "true" cardiac size from portable films. The quantitation of changes in intra- and extravascular water and a more accurate approach to the assessment of left atrial pressure are discussed and new anatomical observations offered to explain post-operative left lower lobe atelectasis, and severe soft tissue emphysema which may follow chest tube insertion in a patient with very stiff lungs. Radiographic data have now been shown to be sufficiently objective so that when a discrepancy occurs between the radiologic analysis and laboratory data, the laboratory data should be cross-checked and its accuracy confirmed before treatment based on these data alone is instituted.
Blood Pressure Determination↗
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↗
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↗
Model of allergic bronchoconstriction in the guinea pig. I. Characteristics of the system.
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Administration, Intranasal↗
A highly accurate focal spot camera--laboratory and field model.
A device has been developed to determine accurately and quickly the shape, size, and intensity distribution of an x-ray tube focal spot. The pinhole device weighs only 1 kg and is portable, enabling it to be used either as a field unit or in a laboratory. The special design obviates any risk of irradiation danger to the investigator, or thermal overloading of the x-ray tube under investigation. The degree of accuracy with which the central beam can be located is better than +/-250 micron, well beyond the requirements of the latest NEMA standards regarding dimensional measurements of diagnostic x-ray tube focal spots. A star test pattern picture may be taken instead of the pinhole picture if required. The device is described and areas of application are discussed.
Radiography↗
Some new concepts of pulmonary blood flow and volume.
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Adult↗
The production of apparent image bifurcation.
It is well known that x-ray focal spots with split-intensity distributions can produce radiographs exhibiting image bifurcations. The authors observed such bifurcations in optical analogue images which were produced with both split- and uniform-intesity focal spots. The bifurcations observed with the split focal spot were real, while those observed with the uniform focal spot were not observed in photometer scans of the object. The authors explain these bifurcations by a consideration of the response function of the eye.
Technology, Radiologic↗
The diagnostic quality of optically processed radiographs.
The diagnostic quality of optically processed radiographs was compared with that of unprocessed radiographs, using the number of lesions detected as a criterion. It was found that merely removing phase-shifted information with either a binary or focal spot filter alone did not improve image quality, however, use of the focal spot filter plus removal of all phase-shifted frequencies did lead to the detection of an increased number of lesions. The authors suggest that currently available optical filtration techniques should be evaluated with caution, as they may actually degrade diagnostic quality by increasing the visibility of phase-shifted information.
Filtration↗