Œdème aigu du poumon postobstructif après extubation trachéale au réveil d'une anesthésie générale

We report two cases of postobstructif pulmonary oedema occurring after extubation at the recovery of general anaesthesia and presenting some similarities. The young age of the patient and the occurrence of upper airway obstruction after extubation, as well as the radiologic nondependent distribution of alveolar pattern are typical. The underlying pathophysiology seems to be the mechanical disruption of the alveolar-capillary membrane.

Pulmonary hypoplasia in a 52-year-old woman

Pulmonary hypoplasia is a bronchopulmonary foregut anomaly characterized by a decreased number of alveoli and decreased alveolar air space. At autopsy, pulmonary hypoplasia is one of the important causes of death in newborns and infants. Pulmonary hypoplasia is rare in adults. In this paper, we present a case of pulmonary hypoplasia in a 52-year-old, asymptomatic woman. We discuss pulmonary hypoplasia and review the literature findings.

Airway identification within planar gamma camera images using computer models of lung morphology

PURPOSE

Quantification of inhaled aerosols by planar gamma scintigraphy could be improved if a more comprehensive assessment of aerosol distribution patterns among lung airways were obtained. The analysis of planar scans can be quite subjective because of overlaying of small, peripheral airways with large, conducting airways. Herein, a computer modeling technique of the three-dimensional (3-D) branching structure of human lung airways was applied to assist in the interpretation of planar gamma camera images.

METHODS

Airway dimensions were derived from morphometric data, and lung boundaries were formulated from scintigraphy protocols. Central, intermediate, and peripheral regions were superimposed on a planar view of the 3-D simulations, and airways were then tabulated by type, number, surface area, and volume in each respective region.

RESULTS

These findings indicate that the central region, for example, consists mostly of alveolated airways. Specifically, it was found that alveolated airways comprise over 99% of the total number of airways, over 95% of the total airway surface area, and approximately 80% of the total airway volume in the central region.

CONCLUSIONS

The computer simulations are designed to serve as templates that can assist in the interpretation of aerosol deposition data from scintigraphy images.

Detection of alveolar epithelial injury by Tc-99m DTPA radioaerosol inhalation lung scan in rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a systemic autoimmune disorder primarily involving the joints. Lung alterations in RA may be primary or secondary to pharmacological treatments and may involve the alveoli, interstitium, airways and/or pleura. Technetium-99m diethylenetriaminepentaacetic acid (Tc-99m DTPA) aerosol inhalation scintigraphy is a sensitive and noninvasive test commonly employed to assess pulmonary epithelial membrane permeability. The purpose of the this study was a) to investigate the changes of pulmonary alveolar epithelial permeability in patients with RA, b) to determine the relationship between the clearance rate of Tc-99m DTPA and pulmonary function test (PFT) results, and c) to determine the relationship between the clearance rete of Tc-99m DTPA and clinical parameters of disease. Twenty-five patients with RA but without lung alterations were included in the study. The patients were 22 females, and 3 males; mean age 53.6 +/- 8.7 years. Technetium-99m DTPA aerosol inhalation scintigraphy was performed on the study and healthy control groups. Clearance half times (T1/2) were calculated by placing a mono-exponential fit on the curves. Penetration index (PI) was calculated on the first-minute image. There were no significant differences in the mean T1/2 or mean PI values between the RA patients and control subjects. No correlation was found between the mean T1/2 values of Tc-99m DTPA clearance and activity of RA, clinical values, or the spirometric measurements except FEV1/FVC and functional status in RA patients (p = 0.02, p = 0.01, respectively). However, a weak correlation was found between duration of disease and T1/2 values of Tc-99m DTPA clearance (p = 0.006). PI values tended to correlate with FEF25-75, although, this was not statistically significant (p = 0.057). This study shows that no changes occur in alveolar-capillary permeability in RA patients without lung alterations.

Pulmonary alveolar microlithiasis: CT and pathologic findings in 10 patients

BACKGROUND AND AIM

To evaluate CT findings of pulmonary alveolar microlithiasis and correlate the CT with the pathologic findings.

METHODS

The study included 10 patients with pathologically proven microlithiasis. Two independent observers evaluated the presence, extent and distribution of the CT findings. CT findings were compared with those at autopsy in two patients and with transbronchial biopsy in eight patients.

RESULTS

All patients had a myriad of calcified nodules measuring approximately 1 mm in diameter. Close apposition of the nodules resulted in areas of ground-glass attenuation and consolidation, which were the predominant abnormality on CT in all 10 patients, involving 41% +/- 16.3 (mean +/- SD) and 30% +/- 4.8 of the lung parenchyma, respectively. Calcifications were also seen along interlobular septa, bronchovascular bundles and pleura. Other findings included interlobular septal thickening, thickening of bronchovascular bundles, nodules, and subpleural cysts. There was a solid agreement between the observers for the presence (kappa value; 0.77) and extent (Spearman rank correlation; r = 0.81 to 1.0 p < 0.01) of abnormalities. Autopsy specimens demonstrated microliths in alveolar airspaces and along interlobular septa, bronchovascular bundles and pleura. Subpleural small cysts were shown to represent dilated alveolar ducts.

CONCLUSION

Pulmonary microlithiasis is characterised by the presence of numerous small, calcified nodules, calcifications along interlobular septa, bronchovascular bundles and pleura, ground-glass opacities, consolidation, and subpleural cysts. The cysts represent dilated alveolar ducts.

Micro-CT of the Human Lung: Imaging of Alveoli and Virtual Endoscopy of an Alveolar Duct in a Normal Lung and in a Lung with Centrilobular Emphysema—Initial Observations

The appearance of human lung parenchyma at the structural level of alveoli was investigated by the use of micro-computed tomography (CT). Approval for use of autopsy lungs was given by the head of the pathology institute of the university, in accordance with the requirements of the State Ministry of Science and Arts and without the need for institutional review board approval. Two human lungs (one normal lung and one lung with centrilobular emphysema of a mild to moderate degree) were inflated and fixed with hot formalin vapor. Lung specimens excised from the superior segment of the left lower lobe (B6) were stained with silver nitrate in a vacuum and investigated at a volume of interest of 4 mm for each side with a voxel size of 14 mum. Normal-size and enlarged alveoli became visible. A three-dimensional reconstruction of the terminal airspaces made virtual endoscopy of the alveolar ducts possible.

[Dyspnea and damaging thirst for knowledge. 67-year-old chauffeur]

Es wird ein 67-jähriger Ex-Raucher mit koronarer Herzkrankheit und Diabetes mellitus II sowie chronischer Niereninsuffizienz vorgestellt, der sich mit zunehmender Anstrengungsdyspnoe und Husten präsentiert. Im Thoraxröntgen findet sich eine Verschattung im Unterlappen rechts. Nach Durchführen einer CT-Thorax-Untersuchung kommt es zum akuten Nierenversagen. Entstehung, Risikofaktoren und Präventionsmöglichkeiten des Kontrastmittel-assoziierten Nierenversagens werden diskutiert.

Quantitative assessment of regional alveolar ventilation and gas volume using 13N-N2 washout and PET

Measurement of alveolar volume (Va) and regional ventilation (a) is crucial to understanding the pathophysiology of acute lung injury and ventilator-induced lung injury. PET has previously been used as a noninvasive, quantitative method to assess a, but formal validation of this technique in experimental lung injury is lacking. This study aims to validate Va and a regional assessment with PET, using inhaled (13)N-N(2) in pigs.

METHODS

Two normal and 2 oleic acid-injured pigs were tracheotomized, mechanically ventilated, and studied in 5 different levels of ventilation by changing respiratory rate. In each experimental condition, lungs were washed-in and then washed-out with (13)N-N(2) through an open circuit in the ventilator. Using this method, multiframe images were acquired with a dedicated PET camera. Regions of interest (ROIs) were drawn on each lung. Regional time-activity curves during washout were generated for each ROI and fitted to a mono- and a bicompartmental model. Validation of this method was performed in 2 ways. First, regional values of predicted Va (Va(emission)) were compared with regional volume obtained independently from density analysis on a transmission scan (Va(trans)). Second, regional values of predicted a were summed in each animal during each experimental condition and compared with minute-ventilation values set on the ventilator.

RESULTS

The bicompartmental model best fitted the experimental values in normal (94.7% [62.2%-100.0%] (median [interquartile range]) of the ROIs) as well as in injured animals (90.7% [81.6%-97.4%] of the ROIs) (P = 0.49). Va(emission) significantly correlated with Va(trans) (R(2) = 0.89, P < 0.001) but exceeded Va(trans) by 10%. Finally, a strongly and positively correlated with minute-ventilation in both normal (R(2) = 0.96, P < 0.001) and injured (R(2) = 0.96, P < 0.001) animals.

CONCLUSION

Measurement of (13)N-N(2) washout using PET is accurate to assess regional alveolar volume and ventilation during experimental acute lung injury.

Evaluation of alveolo-capillary permeability in thyrotoxicosis using Tc-99m DTPA aerosol scintigraphy

Surfactant secreted from type II pneumocytes plays an important role in alveolo-capillary permeability. In thyrotoxicosis, high levels of T3 receptors detected at these cells might affect the alveolo-capillary permeability due to increased serum thyroid hormone levels. The results by CO-diffusion capacity measurement in thyrotoxicosis are conflicting. Changes in alveolo-capillary membrane permeability resulting from thyrotoxicosis are not well established yet. This prompted us to investigate the alveolo-capillary permeability in thyrotoxic patients in comparison with CO-diffusing capacity. For this aim twenty-two non-smoking thyrotoxic patients (before treatment) and fifteen healthy voluntary controls underwent 99mTc-DTPA aerosol scintigraphy. CO-diffusing and pulmonary function tests were performed in all subjects. After ventilation of radiotracer through a nebulizer for 15 minutes, 30 dynamic images (1 frame/minute) were taken from both lungs. ROI's were drawn over both lung areas, and the time-activity curves were generated. Then clearance half time (CT1/2) for radioaerosol was obtained. CT1/2 of thyrotoxic patients did not differ from that of the controls: 77.9 +/- 25.9 min vs. 79.4 +/- 22.3 min; p > 0.05. Similar result was found for CO-diffusion parameters. Also there was no significant correlation between CT1/2 and CO-diffusion parameters. We concluded that in patients with thyrotoxicosis, the alveolo-capillary permeability is unaffected. Further experimental research is needed to establish the possible effects of thyroid hormones on alveolo-capillary membrane.

Absence of pulmonary uptake of Tc-99m methylenediphosphonate in alveolar microlithiasis

Pulmonary alveolar microlithiasis (PAM) is a rare disease of unknown etiology characterized by accumulation of calcific concretions in the alveolar spaces. The paper reports a case of PAM in a 56-year-old male. The patient had persistent dry cough, and gradually progressive dyspnea on exertion. The diagnosis was established on the basis of roentgenography and confirmed by the sputum and transbronchial biopsy findings. Scintigraphy revealed the absence of Tc-99m methylenediphosphonate uptake of lungs. Familial occurrence was not observed. Chest roentgenogram, pulmonary function, and clinical status of the patient have remained stable for 41 months. Radiological and clinical follow-up of the disease continues.

Localized morphometric deformations of small airways and alveoli in intact mouse lungs under quasi-static inflation

Localized morphometric deformations of small airways and alveoli during respiration have several biomechanical and physiological implications. We developed fast synchrotron radiation CT system to visualize the small airways and alveoli of an intact mouse lung without fixation and dehydration, and analyzed their localized morphometric deformations between functional residual capacity (FRC) and total lung capacity (TLC). The maximum resolution of 32.6lp/mm at the 5% modulation transfer function level can be achieved with 11.8-microm voxels and 7-min scanning. Compared with the values at FRC, the diameter and length for smaller airways (diameter at FRC <200 microm) increased by 68.8% and 29.5% (averaged value), and those for larger airways (diameter at FRC >400 microm) increased by 45.2 and 22.9% (averaged value), at TLC. Moreover we defined the volume behavior as the percentage of airway volume at FRC for TLC. The volume behavior for the small airways was not similar to that of the lung volume. These results indicated that all airways did not behave homogenously.

Subclinical alveolar involvement in ulcerative colitis

BACKGROUND

Although pulmonary dysfunction has been described in patients with ulcerative colitis (UC), the pathogenesis remains unclear. Our aim was to study alveolar epithelial damage using technetium-99m diethylene triamine penta acetic acid (Tc-99m DTPA) aerosol scintigraphy in patients with UC but without respiratory symptoms.

METHODS

We enrolled 32 patients (18 women and 14 men; mean age, 36.4 +/- 11.6 yr) with active UC, 10 patients with inactive UC (6 women and 4 men; mean age, 43.4 +/- 11.8 yr), and 31 healthy controls (24 women and 7 men; mean age, 40 +/- 10 yr). Tc-99m DTPA aerosol scintigraphy was performed on all patients and controls. The relationship between alveolar epithelial permeability and the activity, localization, and duration of the disease was studied.

RESULTS

There was a significant difference between alveolar epithelial permeability results in patients with active UC and those of the controls (P < 0.001). The same correlation was also found between the patients with inactive UC and the control group (P < 0.001). There was no correlation between Tc-99m DTPA alveolar scintigraphic test results and the stage of activity, localization, and duration of the disease.

CONCLUSIONS

A latent pulmonary involvement may exist in patients with active and inactive UC. The alveolar involvement may be the earliest pulmonary damage, and a DTPA clearance test may show the early changes in pulmonary epithelial permeability that precedes clinical symptoms. Increased alveolar epithelial permeability is an extraintestinal manifestation in patients with UC and is not related to the activity of the colitis.

Architecture of the lung: morphology and function

The architecture of the lung is discussed with special focus on lung parenchyma. The lung parenchyma is mainly comprised of numerous air-containing passages and intervening fine structures, corresponding to alveolar ductal lumens and alveoli, as well as alveolar septa and small pulmonary vessels occupying 10% of total parenchymal volume. The shapes and relative arrangements of alveolar ducts and alveoli are discussed in detail, which is followed by a brief description of bronchial circulation and pulmonary lymphatics.

Behçet Disease Complicated by Diffuse Alveolar Damage

We report an extremely rare case of Behçet disease complicated by diffuse alveolar damage, which was fatal in this patient. It manifested as progressive diffuse ground-glass attenuation in both lungs on chest radiographs and high-resolution CT. Ground-glass attenuation was confirmed histopathologically as diffuse alveolar damage without identified etiology by open lung biopsy.

[Recurrent alveolar hemorrhage in the course of Goodpasture's syndrome]

We describe the case of 24-years old man, smoking up to 60 cigarettes daily, with rapidly progressive crescentic glomerulonephritis in the course of Goodpasture's syndrome. The disease was initially presented with recurrent diffuse pulmonary hemorrhage with normal renal function and moderate proteinuria and haematuria on urinalysis lasting 2 months. Immunologic tests for ANCA and anti-GBM Ab were negative until the patient's renal function rapidly deteriorated during next 3 weeks. At the time of the diagnosis patient presented with renal insufficiency with oliguria requiring hemodialysis but without pulmonary hemorrhage. Renal biopsy showed cellular crescents in all glomeruli with linear deposition of IgG along the GBM. Repeated testing showed anti-GBM Ab. The patient received pulse cyclophosphamide, and pulse methylprednisolone continued by oral prednisone, and consecutive plasma exchange treatment but remained oliguric after 3 weeks of the treatment. The case confirm that in Goodpasture's syndrome even several days' delay in diagnosis and treatment has a strongly negative impact on outcome.

Clinicopathological differences between acute and chronic eosinophilic pneumonia

OBJECTIVE

Considerable confusion exists regarding the proper classification of idiopathic eosinophilic pneumonia (IEP). Furthermore, there are no reports describing the clinicopathological differences between the various forms of eosinophilic pneumonias.

METHODOLOGY

The histological findings in acute eosinophilic pneumonia (AEP) and chronic eosinophilic pneumonia (CEP) were examined and the clinical and radiological features were contrasted with them.

RESULTS

Radiologically, ground glass opacity and interlobular septal thickening were characteristic of the AEP cases, while air space consolidation was seen in all CEP cases. Histologically, interstitial oedema and fibrin deposition were prominent in the AEP cases. Type II cells were detached from the alveolar walls, although the basal lamina was predominantly intact. In CEP, in addition to cellular infiltration, there was prominent intraluminal fibrosis. Disruption of the basal lamina was observed and nests of intraluminal fibrosis were directly adjacent and connected to the alveolar walls.

CONCLUSIONS

An essential histological difference between AEP and CEP is the severity of basal lamina damage and the amount of subsequent intraluminal fibrosis. In AEP particularly, these findings explain the radiographical findings, as well as the rapid and complete improvement noted in such cases.

Pulmonary alveolar microlithiasis presenting with crazy-paving pattern on high resolution CT

Pulmonary alveolar microlithiasis (PAM) is an uncommon chronic disease characterized by calcifications within the alveoli and a paucity of symptoms in contrast to the imaging findings. We present a 59-year-old woman with a 4-year history of shortness of breath on exertion. Lung auscultation revealed random wheezes and fine and coarse crackles. Pulmonary function tests showed a restrictive pattern. The chest radiograph demonstrated a bilateral symmetric micronodular pattern. High resolution CT scan revealed diffuse ground-glass attenuation with superimposed septal thickening ("crazy-paving" pattern). The patient underwent a lung biopsy, which confirmed the diagnosis of PAM. Our case demonstrates that PAM needs to be considerate in the differential diagnosis of lung lesions that present with crazy-paving pattern on the high resolution CT.

Detection of alveolar epithelial injury by99mTc-DTPA radioaerosol inhalation lung scan following blunt chest trauma

DTPA clearance rate is a reliable index of alveolar epithelial permeability, and is a highly sensitive marker of pulmonary epithelial damage, even of mild degree. In this study, 99mTc-DTPA aerosol inhalation scintigraphy was used to assesss the pulmonary epithelial membrane permeability and to investigate the possible application of this permeability value as an indicator of early alveolar or interstitial changes in patients with blunt chest trauma. A total of 26 patients was chest trauma (4 female, 22 male, 31-80 yrs, mean age; 53+/-13 yrs) who were referred to the emergency department in our hospital participated in this tsudy. Technetium-99m diethylene triamine pentaacetic acid (DTPA) aerosol inhalation scintigraphy was performed on the first and thirtieth days after trauma. Clearance half times (T1/2) were calculated by placing a mono-exponential fit on the curves. Penetration index (PI) was calculated on the first-minute image. On the first day, mean T1/2 value of the whole lung was 63+/-19 minutes (min), and thirtieth day mean T1/2 value was 67+/-21 min. On the first day, mean PI values of the lung and 30th day mean PI value were 0.60+/-0.05, and 0.63+/-0.05, respectively. Significant changes were observed in radioaerosol clearance and penetration indices. Following chest trauma, clearance of 99mTc-DTPA increased owing to breakdown of the alveolar-capillary barrier. This increase in the epithelial permeability of the lung appears to be an early manifestation of lung disease that may lead to efficient therapy in the early phase.