PURPOSE:To compare the accuracy with which simulated solitary pulmonary nodules can be identified on digital images of the chest that are unprocessed, processed with adaptive spatial filtering, or processed with global filtering.MATERIALS AND METHODS:Six experienced chest radiologists evaluated 408 test radiographs (136 from each of the three types, half with simulated nodules) and judged whether a nodule was present. Data from the 2,448 observations were evaluated by means of a receiver operating characteristic curve with location methods.RESULTS:Accuracy was significantly better with the adaptive filter technique than with the global technique (P < .05), and it was better with adaptive filtering than with no processing in the detection of pulmonary nodules in the mediastinal-subdiaphragmatic areas (P < .05). No significant difference was found between no processing and global filtering.CONCLUSION:Adaptive filtration is superior to global filtration in the identification of solitary pulmonary nodules and is superior to no processing in nodules projected over the radiopaque areas of the thorax on digital images.

Two dosages of Teione II-B (1,3-dichloropropene) at 3.4 and 6.7 mL/kg of stump and root biomass were tested to determine the efficacy in reducing Phellinusweirii (Murr.) Gilb. inoculum in infected Douglas-fir, Pseudotsugamenziesii (Mirb.) Franco, stumps. After 21 months, both doses of Teione II-B proved equally effective and significantly (p < 0.05) reduced residual P. weirii mycelium in infected roots. Fumigation reduced residual endotrophic P. weirii in the large-diameter root classes nearest the stump, but survival of the fungus was less affected with increasing distance from the stump and in the smaller root diameter classes. Treated stumps also had significantly (p < 0.05) fewer roots with ectotrophic mycelium than untreated stumps. Four weeks after application, soil samples taken near treated stumps revealed no evidence of the fumigant. These findings suggest that application of Teione II-B could be used as an effective control measure for P. weirii.

The roentgenographic changes in the chest in asbestosis may be both pleural and parenchymal, but in most reported series the former are far more striking than the latter.

A prototype digital unit dedicated to chest radiography was used to examine 50 selected patients for a comparison study of the capability of digital images and conventional chest radiographs to reveal normal anatomic structures and a variety of pathologic states. The images in both modes were submitted for interpretation to seven experienced radiologists and a standardized questionnaire completed for each. Visibility of seven anatomic structures in the mediastinum was consistently better on the digital images than on the conventional radiographs. With minor exceptions, pathologic states were equally well seen in the two systems. Despite the less familiar viewing format of the digital images, the mean confidence levels achieved were higher than for those on the conventional radiographs; this difference was statistically significant both for normal anatomic structures (p = 0.001) and pathologic states (p = 0.01). The advantages and disadvantages of the digital technique are discussed.

A series of experiments was carried out on 28 dogs in which the following aspects were investigated: in 9 dogs, the special configuration of acute lobar atelectasis; in 10 dogs, the pressure-volume characteristics of collapsed and non-collapsed diaphragmatic lobes; in 12 dogs, the wet-weight/dry-weight ratios of atelectatic contralateral lobes; in 6 dogs, the amount of blood sequestered in atelectatic diaphragmatic lobes was estimated. The relationships of an atelectic lobe closely resemble those described in man. Loss of apposition between visceral and parietal pleural surfaces was never observed. The W/D weight ratio of the collapsed lobe invariably was higher than that of the non-collapsed contralateral lobe indicating a slight increase in the volume of fluid in the atelectatic lobe. No pressure-volume differences were found between atelectatic and non-collapsed lobes.

Acute pulmonary edema was induced in anesthetized vertically suspended dogs by inflating a ballon catheter in the descending thoracic aorta and infusing saline. Indices measured included pulmonary arterial pressure, left ventricle end-diastolic pressure, and cardiac output. Pulmonary blood-flow distribution was determined in frozen tissue after injecting radioactive macroaggregates labelled with 125-I, 131-I, and 99m-Tc. Randomized serial chest roentgenograms were interpreted by three radiologists not taking part in the physiologic studies. When left ventricular end-diastolic pressure was raised initially, roentgenograms usually revealed only interstitial edema. As alveolar edema increased, blood-flow to the lung bases decreased as measured physiologically. The roentgenographic and physiologic data show that in acute experiments on normal lungs, blood-flow redistribution occurs in association with alveolar edema rather than interstitial edema.

The clinical, radiological, pathophysiological, and morphological features of seven patients with chronic airways obstruction characterized by chronic cough and expectoration are described. All had a reticular pattern on their chest roentgenogram. None had severe or extensive emphysema. Hypercapnia was chronic in four and transient in two. The lungs were not hyperinflated, but residual volume was increased. Pulmonary function tests showed airways obstruction. Mucous plugging, narrowing, and peribronchial fibrosis were variably present. The only morphological abnormality common to all was inflammation of small bronchi and bronchioles. These morphologic lesions may be principally responsible for the functional and possibly the roentgenographic abnormalities in these patients. Similar abnormalities are seen in small airways of patients dying from chronic bronchitis and emphysema and may be responsible for many of the functional derangements in these disorders.