Determination of lung volumes from chest films

The results obtained from two radiological methods of determining total lung capacity (TLC) (Kovach's parabo oid and Barnhard's ellipsoid) were compared with those obtained with the body plethysmograph. Determinations of TLC were made in four groups of subjects: group 1 consisted of 26 miners most of whom had simple pneumoconiosis; group 2 consisted of 12 normal subjects; group 3 consisted of eight subjects who had a variety of chest disease, but with no demonstrable parenchymal or pleural opacification; and group 4 consisted of 19 subjects with miscellaneous diseases, all showing demonstrable infiltration or opacification.     

The value of lung cancer detection by six-monthly chest radiographs

Results are reported of a prospective study, carried out by the Mass Radiography Service of the North-West Metropolitan Region for the purpose of evaluating early lung cancer detection by six-monthly chest radiographs. The lung cancer experience of a test group of 29,723 men aged 40 and over who were offered six-monthly chest radiographs over a period of three years is compared with a similarly constituted control group of 25,311 men who were radiographed only at the beginning and the end of the study. In the test group 29,416 men (98·9%) and in the control group 25,044 men (99%) were followed up. The methods employed to achieve this result are analysed. The six-monthly surveys of the test group yielded 65 cases of lung cancer, giving an annual incidence and detection rate of 0·9 per thousand examined. Of these cases 65% were resected. Of all cases of lung cancer in the test group, irrespective of their source of detection, 43·6% were operable, compared with 29% in the control group. The difference (P=0·03) is statistically significant. The annual mortality rate from lung cancer based on 62 deaths in the test group and 59 deaths in the control was 0·7 and 0·8 per thousand respectively. The conclusions are reached that since early detection by six-monthly chest radiographs has not significantly reduced the mortality from lung cancer in a population at risk, a policy of such large-scale surveys of men in the cancer age would not seem justified, but that the increased discovery of resectable lung cancer by this method forms a reasonable basis for encouraging individuals in high-risk groups to make regular use of existing mass radiography facilities.     

Estimation of regional gas and tissue volumes of the lung in supine man using computed tomography.

This study was intended to discover how well computed tomography could recover the volume and weight of lung like foams in a body like shell, and then how well it could recover the volume and weight of the lungs in supine man. Model thoraces were made with various loaves of bread submerged in water. Computed tomography scans recovered the volume of the model lungs (true volume range 250-12,500 ml) within +0.2 (SD 68) ml and their weights (true range 72-3125 g) within +30 (78) g. Scans also recovered successive injections of 50 ml of water, within +/- 5 ml. Scans in 12 healthy supine men recovered their vital capacities, total lung capacities (TLC), and predicted tissue volumes with comparable accuracy. At total lung capacity the mean tissue volume of single lungs was 431 (64) ml and at residual volume (RV) it was 427 (63) ml. Tissue volume was then used to match inspiratory and expiratory slices and calculate regional ventilation. Throughout the mid 90% of lung the RV/TLC ratio was fairly constant--mean 21% (5%). New methods of presenting such regional data graphically and automatically are also described.     

Influence of radiologic expertise in detecting lung tumors on chest radiographs

Purpose

To analyze the influence of radiologic expertise in detecting lung tumors on chest radiographs.

Semi-automatic determination of detailed vertebral shape from lumbar radiographs using active appearance models

Summary  

The vertebral endplates in lumbar radiographs were located by a semi-automatic annotation method using statistical shape models.     

The recognition of lesions on chest radiographs.

An approach to the recognition of lesions on chest radiographs is outlined. Four basic groups of abnormalities by means of which lesions can be recognized are mentioned and are briefly described, namely an opacity, an area of increased translucency, a combination of an opacity and an area of increased translucency, and, especially, an alteration in normal radiological anatomy.     

Post-mortem lung volumes.

The volumes of 78 adult human lungs at necropsy after fixation with intrabronchial 10% formaldehyde at a transpulmonary pressure of 25 cm of water (VL) were similar to their total lung capacity (TLC) as assessed radiologically (VX). Corrected for stature, VL and VX did not increase with age in non-emphsematous lungs, nor did the radio of VL to VX (VL/VX) change with age. VL and VX relative to body length increased with emphysema, and the increase even occurred in lungs from men with trivial or equivocal amounts of emphysema. Thus alteration of the mechanical properties of the lung may precede the appearance of obvious emphysema. VL/VX was not affected by the presence or severity of emphysema. The right lung formed 53% of VL with a range of 49-58% in apparently normal lungs. The amount of air in 13 human lungs at necropsy averaged 61% of TLC with a wide variation, indicating that this is not a useful point at which to measure lung dimensions. It is concluded that the volume of lungs fixed with formaldehyde at a transpulmonary pressure of 25 cmH2O closely approximates to total lung capacity.     

Interpretation of bronchograms and chest radiographs in patients with chronic sputum production.

Bronchograms and plain chest radiographs of 27 patients with chronic sputum production were reported separately in random order and independently by two pulmonary radiologists to establish the diagnostic rate of each investigation and to assess interobserver variation. Both radiologists agreed on the presence of bronchiectasis on bronchography in 19 of 27 (70%) patients and in 94 of 448 (21%) bronchopulmonary segments. One radiologist only interpreted the films as showing bronchiectasis in a further two (7%) patients and 26 (6%) segments. There was more disagreement about the presence or absence of individual bronchographic abnormalities. Two main groups of patients with bronchiectasis were identified by bronchography: 11 with bronchiectasis alone and eight with bronchiectasis and bronchographic features suggestive of "chronic bronchitis". There was no clinical difference between these two groups. Plain chest radiographs were insensitive, being diagnostic (both radiologists agreeing) of bronchiectasis in only nine of 19 (47%) patients with definite bronchiectasis on bronchography.     

Effect of salbutamol on lung function and chest wall volumes at rest and during exercise in COPD

BACKGROUND: Inhaled bronchodilators can increase exercise capacity in chronic obstructive pulmonary disease (COPD) by reducing dynamic hyperinflation, but treatment is not always effective. This may reflect the degree to which the abdomen allows dynamic hyperinflation to occur.Method: A double blind, randomised, crossover trial of the effect of 5 mg nebulised salbutamol or saline on endurance exercise time was conducted in 18 patients with COPD of mean (SD) age 67.1 (6.3) years and mean (SD) forced expiratory volume in 1 second (FEV1) of 40.6 (15.0)% predicted. Breathing pattern, metabolic variables, dyspnoea intensity, and total and regional chest wall volumes were measured non-invasively by optoelectronic plethysmography (OEP) at rest and during exercise. RESULTS: Salbutamol increased FEV1, forced vital capacity (FVC) and inspiratory capacity and reduced functional residual capacity (FRC) and residual volume significantly. OEP showed the change in resting FRC to be mainly in the abdominal compartment. Although the mean (SE) end expiratory chest wall volume was 541 (118) ml lower (p<0.001) at the end of exercise, the endurance time was unchanged by the bronchodilator. Changes in resting lung volumes were smaller when exercise duration did not improve, but FEV1 still rose significantly after active drug. After the bronchodilator these patients tried to reduce the end expiratory lung volume when exercising, while those exercising longer continued to allow end expiratory abdominal wall volume to rise. The change to a more euvolumic breathing pattern was associated with a lower oxygen pulse and a significant fall in endurance time with higher isotime levels of dyspnoea. CONCLUSIONS: Nebulised salbutamol improved forced expiratory flow in most patients with COPD, but less hyper-nflated patients tried to reduce the abdominal compartmental volume after active treatment and this reduced their exercise capacity. Identifying these patients has important therapeutic implications, as does an understanding of the mechanisms that control chest wall muscle recruitment.     

Introduction to the interpretation of chest radiographs during donor care

Organ procurement coordinators often provide independent interpretations of chest radiographs during donor care. Catheter or tube position, lobar atelectasis, extra-alveolar air, air bronchograms, pleural fluid, and other findings are important throughout donor care and when deciding if a lung is acceptable for transplantation. Technical factors, features of a normal chest radiograph, and abnormal radiographic findings are reviewed and examples are presented.     

Pattern of lung volumes in patients with sighing breathing.

BACKGROUND--Sighing breathing is observed in subjects suffering from anxiety with no apparent organic disease. METHODS--Lung volumes and expiratory flow rates were measured in 12 patients with a sighing pattern of breathing and in 10 normal subjects matched for age, gender, and anthropometric data. In both groups the measurements were made by spirographic and plethysmographic techniques. In normal subjects functional residual capacity (FRC) and residual volume (RV) were measured during normal breathing and again during simulated sighing breathing to exclude technical artifacts resulting from hyperventilation during measurement by the helium closed circuit method. RESULTS--Patients with a sighing pattern of breathing had a normal total lung capacity (TLC) but significantly different partitioning of lung compartments compared with normal subjects. The vital capacity (VC) was lower when measured by both spirographic and plethysmographic methods and RV was higher. The forced expiratory volume in one second (FEV1) was also lower in patients with sighing breathing. The FEV1/VC and the maximal expiratory flow rates at 50% and at 25% of the forced vital capacity (V50 and V25) were normal and similar in both groups. In normal subjects there were no differences in RV when measured during quiet or simulated sighing breathing. CONCLUSIONS--Subjects with sighing breathing have a normal TLC with a higher RV and lower VC than normal subjects. There was no obvious physiological or anatomical explanation for this pattern.     

Assessment of osteoporosis using standard radiographs of the wrist.

BACKGROUND: This study evaluated the ability of the orthopaedic surgeon to radiographically assess bone density in the wrist with sufficient accuracy to determine which patients require treatment for osteoporosis. METHODS: Thirty-eight patients with unilateral distal radius fractures, 30 of whom were female, were included in this study. The mean age was 55 years (range 45 to 82). Standard radiographs of the fractured and normal wrists were taken. Dual energy x-ray absorptiometry was performed on the normal distal radius of all patients within 1 week of their injury. The radiographs were viewed in blinded randomized fashion on two separate occasions by three orthopaedic surgeons and once by a fourth. The participants were required to determine the presence of osteoporosis. Visual analog scales (VAS) were used to evaluate (1) porosity, (2) cortical thickness, (3) trabecular thickness, and (4) the number of trabeculae in the ultradistal radius. RESULTS: Intraobserver agreement assessing osteoporosis averaged 81% (kappa of 0.5393). VAS assessment was unreliable for all four parameters. Radiographic determination of osteoporosis had a specificity of 61% and a sensitivity of 61% using x-rays of the uninjured wrist. CONCLUSION: We conclude that orthopaedic surgeons cannot predict with sufficient accuracy using plain x-rays whether a patient is significantly osteoporotic.     

Use of different magnification factors to calculate radiological lung volumes.

In previous papers from this laboratory, Pierce et al described a method of measuring lung volumes from routine chest radiographs. The images on the film are magnified, and this was taken into account in their calculations. Their findings have recently been confirmed by Rodenstein et al. It is important to measure magnification accurately because errors in linear dimensions are cubed when volume is calculated. This paper describes two simple methods of improving the accuracy of the calculation of magnification.     

An investigation of the chest radiographs in a controlled trial of busulphan, cyclophosphamide, and a placebo after resection for carcinoma of the lung.

A standard series of radiographs of 588 patients allocated at random to treatment with busulphan (B patients), cyclophosphamide (C patients), or a placebo (P patients) for two years after surgery for bronchial carcinoma were viewed in three stages (following procedures which avoided bias) by an independent assessor, unaware of the allocated treatment of any patient, with a view to identifying pulmonary changes due to busulphan. Radiographic appearances consistent with busulphan lung were not reported in any of the 195 B patients (receiving a mean dosage of 464 mg of busulphan over 301 days) or of the 192 C patients but were present in one of the 201 patients receiving placebo.     

Comparison of postoperative cardiopulmonary examinations and chest radiographs to detect pulmonary complications after adult tracheotomy.

OBJECTIVE: To prospectively evaluate the effectiveness of clinical cardiopulmonary examination compared with that of chest radiography in detecting postoperative pulmonary complications after tracheotomy in adults. METHODS: One hundred consecutive patients undergoing tracheotomy were evaluated. Pulmonary complications were recorded, and the effectiveness of the physical examination was compared with that of the chest x-ray in detecting these complications. Patient age, sex, diagnosis, urgency of the procedure, and anesthetic technique were evaluated to determine any relationship to postoperative complications. RESULTS: Of the 100 patients, 87 patients underwent postoperative chest radiography, and all patients had postoperative cardiopulmonary examinations. One patient (1%) had a bilateral pneumothorax, which was detected clinically and confirmed by a chest radiograph. Five patients had postoperative pulmonary edema confirmed by clinical examination and radiography. Additional minor complications were noted, including minor bleeding and stomal infection, for an overall complication rate of 13%. CONCLUSIONS: All postoperative pulmonary complications were detected by physical examination. Therefore routine postoperative chest radiographs in uncomplicated tracheotomies are not necessary if a thorough postoperative cardiopulmonary examination is performed. Cost analysis reveals a savings of approximately $19,000 with the proposed criteria for postoperative chest x-ray.     

Reliability of initial chest radiographs in the diagnosis of blunt diaphragmatic rupture

BACKGROUND AND AIMS: Preoperative diagnosis of blunt diaphragamatic rupture is difficult and missed injuries can lead to severe late complications. The aim of this study was to assess the value and reliability of initial chest radiographs in diagnosing blunt diaphragmatic rupture. MATERIAL AND METHODS: A retrospective analysis of initial radiographs of 18 patients with blunt diaphragmatic rupture treated at two Greek Trauma Centers was performed. The chest radiograph was the primary diagnostic radiological tool in all of cases, and the findings were confirmed at operation in all cases. RESULTS: The preoperative diagnosis of blunt diaphragmatic rupture on the basis of chest radiographs was made in 16 out 18 patients (89%). The presence of air-containing viscera and an elevated nasogastric tube above the level of the left hemidiaphragm were the most specific signs. Although elevation of the hemidiaphragm was seen in all 18 cases, it is non-specific. A marked elevation of the right hemidiaphragm (more than 6 cm above the level of the left diaphragm), however, was a strong sign of right diaphragmatic rupture. CONCLUSIONS: In spite of the availability of newer diagnostic imaging techniques, the initial chest radiograph is very reliable in detecting most cases with blunt diaphragmatic rupture, and together with high index of suspicion and sound clinical assessment remain the cornerstone in diagnosing these challenging injuries.     

Acute changes of lung volumes and lung mechanics in asthma and in normal subjects.

Lung volumes, pulmonary mechanics, and specific airway conductance (sGaw) were studied before and 15 minutes after 200 microgram of aerosol salbutamol in nine asthmatics undergoing mild spontaneous exacerbations of their disease and in five normal subjects. In addition, three of the normal subjects were studied after voluntarily breathing at high lung volumes for one minute. The normal subjects and four of the asthmatics showed no overall changes in lung volumes or pressure-volume (PV) curves after salbutamol, even though airway dilatation was produced in the asthmatic subjects. In another five asthmatics, salbutamol induced a significant fall in the total lung capacity (TLC) in three, and in the residual volume and functional residual capacity in all five. There was a significant displacement of the PV curve downwards and to the right in all five, with increased lung compliance (Cl stat) in two. The fall in TLC could be accounted for by the increase in lung elasticity. There is reason to believe that this change in lung mechanics could be due to the reversal of asthma-induced stress relaxation. Sustained breathing at high lung volume is known to cause stress relaxation of the lung. However, this breathing pattern did not alter the PV curve or TLC in two of three normal subjects, which is consistent with stress relaxation being rapidly reversible. The other normal subject had an acute shift of the PV curve upwards and to the left after breathing at high lung volume. It has been concluded that stress relaxation is usually rapidly reversed but that in some individuals it may only be slowly reversed. This more persistent form of stress relaxation may contribute to the acute changes of TLC found in some asthmatics.