Rounded atelectasis in an asbestos exposed worker

The case history is presented of a 51-year-old electrical power worker with a history of asbestos exposure presenting with rounded atelectasis. No other radiological markers of asbestos exposure were present. A documented history of asbestos exposure and exclusion of other causes of rounded atelectasis led to the diagnosis of asbestos related rounded atelectasis. It is important to understand that rounded atelectasis can be an isolated finding due to asbestos exposure. This facilitates investigation of lung masses of unknown etiology and initiation of appropriate follow up of patients at risk for future development of more debilitating asbestos related pathology.

Questions concerning low intensity reduction in lung compliance

From the very early stages of reduction in lung compliance, the thoracic organs may be forcibly displaced, be subject to attraction or be prevented from fully carrying out their normal movement. By evaluating these changes on a chest radiogram we may assess, at least broadly, the existence of reduced compliance and to some extent its degree. Given that reduction of lung compliance can constitute the initial sign of establishment of a secondary neoplasm or other pathological condition in the lung, the potential of chest radiograms becomes wider both in the diagnostic sphere and in that of pathophysiological research. The more frequent displacement of the trachea to the right is, we believe, due to the greater overall mass of the right lung, so that in homogenous reduction of the lung compliance the total attraction to the right may be greater. The rising of the hemidiaphragms usually starts in their frontal region. This, we consider, is due to the different resistance to the reduction in lung compliance of the adjacent areas of the lung resulting from their different structure. The reduction of compliance in segments or subsegments adjacent to the hemidiaphragms produces local rising of them. When these segments are adjacent to the osseous thoracic wall they cause pleural thickening by activating the suction mechanism. The reduction in lung compliance may cause S-shaped distortion of the bronchovascular bundles of the lower lobes, displacement of the hili, blunting of the angle of the carina, curvature of the main bronchi and of the intrathoracic part of the trachea. All these changes can be seen on a chest radiogram.

Alveolar septal collapse in the transitional infant lung: a possible common mechanism in sudden unexpected death in infancy

Sudden unexpected death in infancy (SUDI) is a category used to represent the largest single group of infant deaths. Although there are several theories, the cause of SUDI remains unknown and the mechanism of co-sleeping associated deaths are also undetermined. We investigate a possible biomechanical mechanism which may be common in SUDI and may provide an explanation for the association of the known risk factors for SUDI such as co-sleeping, prematurity, prone sleeping position, overwrapping, overheating and maternal smoking. The neonatal lung has few, if any, true septa but from about four weeks of age, a period of rapid alveolarisation commences. The developing alveolar walls (septae) have little fibre support against surface tension forces as they grow but are supported by a double layer of capillaries. Until the elastin/collagen supporting network is laid down these nascent septal walls are vulnerable to collapse against sac or duct walls during this transitional period. We hypothesise that such collapse will prevent one side of the septa, and the wall it overlays, from alveolar gas exchange and a functional left-right shunt is formed which may result in hypoxia. Furthermore, lung stretch receptors in bronchi running through or adjacent to collapsed regions will be activated, falsely signalling lung inflation to the brain stem with resultant respiratory inhibition, so precipitating further collapse. The process will continue until lung volume falls below residual capacity, when normal tidal breathing efforts will no longer result in significant air flow, even if stretch receptor signals have not produced complete apnoea. Large inspiratory efforts are then required to break the surface tension seal, which damages capillaries to produce petechial haemorrhages. Many epidemiological risk factors for SUDI could influence such a mechanism, leading to the proposal that Alveolar Septal Collapse in Infancy (ASCI) is a core mechanism via which these factors act.

[Congenital lobar emphysema - a radiological diagnosis at first glance?]

Congenital lobar emphysema (CLE) is a malformation of the lung of unknown etiology. The characteristic overdistension of the affected lobe leads to compression and displacement of adjacent normal lung tissue and mediastinum. In the majority of cases, symptoms appear during the neonatal period or in early childhood. Clinically, children present with signs of respiratory distress, frequently occurring with a superimposed lower respiratory tract infection that aggravates air trapping and renders the patient symptomatic. Rarely, CLE is diagnosed in adult patients who did not experience any symptoms during childhood. Knowledge of the disease is of importance because in the majority of cases a plain chest radiograph together with clinical signs is sufficient to diagnose the disease correctly. The article draws attention to this condition by presenting two children and one adult with congenital lobar emphysema. Possible clinical symptoms and diagnostic strategies are reviewed.

Electrical impedance tomography using the extended Kalman filter

In this paper, we propose an algorithm that, using the extended Kalman filter, solves the inverse problem of estimating the conductivity/resistivity distribution in electrical impedance tomography (EIT). The algorithm estimates conductivity/resistivity in a wide range. The purpose of this investigation is to provide information for setting and controlling air volume and pressure delivered to patients under artificial ventilation. We show that, when the standard deviation of the measurement noise level raises up to 5% of the maximal measured voltage, the conductivity estimates converge to the expected vector within 7% accuracy of the maximal conductivity value, under numerical simulations, with spatial a priori information. A two-phase identification procedure is proposed. A cylindrical phantom with saline solution is used for experimental evaluation. An abrupt modification on the resistivity distribution of this solution is caused by the immersion of a glass object. Estimates of electrode contact impedances and images of the glass object are presented.

Follow-up of acute pulmonary complications in cystic fibrosis by magnetic resonance imaging: a pilot study

The aim of this pilot study was to obtain information on the value of MRI in the follow-up of atelectasis and pneumonic infiltrates in cystic fibrosis (CF). Six patients aged 5-15 y were initially examined using chest X-ray and magnetic resonance imaging (MRI). Both methods provided identical information. During follow-up, MRI proved suitable to monitor pulmonary complications.

CONCLUSION

MRI of the lung is feasible and valuable in the follow-up of atelectasis and pulmonary infiltrates in CF.

An evaluation of pulmonary atelectasis and its re-expansion

RATIONALE AND OBJECTIVES

Atelectasis, the collapse of small airways, is a significant clinical problem. We use hyperpolarized (HP) 3He magnetic resonance imaging (MRI), or HP 3He MRI, to describe atelectasis in the normal Yorkshire pig, the pig with atelectasis, and the pig with re-expansion of atelectasis. We compare HP 3He MRI findings with depictions of atelectasis by proton MRI.

MATERIALS AND METHODS

During end-expiration in the anesthetized and paralyzed Yorkshire pig (n = 6), HP 3He gas produced by the optical pumping spin-exchange method, was delivered via an endotracheal tube. For two separate groups, atelectasis was either induced by Fogarty-catheter occlusion balloon inflation (n = 3), or lateral chest wall administration of sodium hydroxide (NaOH) (n = 3). MRI was performed at time zero, at 5, 9, 13, 15, and 19 minutes after atelectasis production, 30 minutes after balloon deflation, and 10 and 30 minutes after recruitment of atelectatic areas with increased tidal volumes and added positive end-expiratory pressure. High-resolution, cross-sectional MR images were procured, and comparison was made with the traditional proton MRI.

RESULTS

Atelectatic areas by HP 3He MRI were easily distinguishable in both subject groups, and correlated with those located by proton MR. HP 3He MR images showed absence of ventilation, whereas proton MR images depicted dense, white areas. Re-expansion of atelectasis was well delineated by HP 3He MRI.

CONCLUSION

HP 3He MRI may overcome many of the shortcomings of other well-established radiographic methods. HP 3He MRI is a novel, informative method for describing atelectasis and its re-expansion.

[Reformation as proposed solution for the problem of sectioning different levels with 3He-MRT and HR-CT of the chest]

PURPOSE

3He-MRI of the lung has been shown to be a sensitive method for functional imaging of the lung. A previous study compared 3He-MRI (coronal planes) with CT (transverse planes) by looking for ventilation defects and their pathomorphologic correlation. Anatomic structures, such as lobar fissures and hilar vessels, were used for orientation, but the reliable assignment of ventilation defects to lung segments is problematic. The present work compares multiplanar reformations of 3He-MRI and HR-CT, which were generated from planes determined by the respective method, and investigates their suitability as a solution of this problem.

MATERIALS AND METHODS

A total of 16 data sets taken from 15 patients with unilateral lung transplantation and one patient with lung emphysema were retrospectively evaluated. Transverse planes of 3He-MRI and coronal planes of HR-CT were reformatted on an external workstation and images evaluated by two readers in consensus. The evaluation searched for ventilation defects on 3He-MRI and their corresponding defects on HR-CT. The defects were related to anatomic structures, with hilar vessels and tracheobronchial tree selected for 3He-MRI reformations and lobar fissures for HR-CT reformations.

RESULTS

All cases were successfully reformatted and all ventilation defects were correctly assigned to anatomic structures. On HR-CT reformations, the lobar fissures were partially visible in 12 of 16 cases and completely visible in the remaining 4 cases. Since reformation compromises the spatial resolution, the reformatted images should be evaluated together with the source images.

CONCLUSION

Looking at HR-CT and 3He-MRI images and their reformations enables the detection of ventilation defects and their assignment to lung segments, facilitating the correlation of ventilation defects with a pathomorphologic pattern on HR-CT.

[Atelectasis in the clinical picture of intrathoracic tuberculosis]

The authors examined 85 patients with intrathoracic tuberculosis in whom the tuberculous process had been complicated by tuberculosis of the bronchi with their developed obstruction and as a result of atelectasis. Then the atelectasis-affected area became fibrotic. It was found that with the developed atelectasis, there was a persistent cession of bacterial isolation occurred, closure of decay cavities in the lung tissue, resolution of fresh focal and infiltrative changes. The presence of scarring bronchial stenosis and fibrotic atelectasis suggests of a full clinical recovery from intrathoracic tuberculosis.

Successful salvage of a long-standing collapsed lung by bronchoplasty in three children

BACKGROUND

The authors report successful salvage of the ipsilateral lung by a bronchoplastic procedure in 3 patients with a long-standing, totally collapsed lung.

METHODS

The 3 patients were 1, 5, and 6 years of age, and the left lung had been collapsed totally for periods of 13 months to 5 years. The origin of atelectasis was congenital in 2 patients and traumatic in one patient. Bronchoscopy showed complete obstruction of the left main bronchus. In each patient, the left lung was small and appeared as a liverlike organ. Entire length of the main bronchus was resected. The left lung was not aerated in spite of aggressive bagging through an endotracheal tube inserted into the distal bronchial stump. The bifurcation of the upper and lower segmental bronchi was anastomosed to the trachea by interrupted sutures. Histology of the resected bronchus in the cases of congenital origin showed bronchial rings represented by islands of immature cartilage.

RESULTS

Chest x-ray showed complete aeration of the left lung at 3, 4, and 5 months, respectively, after surgery in the 3 children. Bronchoscopy disclosed a well-reconstructed airway in all patients. Two of the 3 patients have been free from respiratory distress during a 3- to 4-year follow-up. The latest patient to have this surgery is undergoing home ventilation because of chronic lung disease.

CONCLUSIONS

A long-standing collapsed lung in children may reexpand if bronchial continuity is restored. Insufficient inflation of the lung at surgery is not an indication for pneumonectomy. When at all possible, a child's lung should be preserved.

[Atelectasis following cesarean section. Personal experience]

Purpose of this paper is to evaluate the risk of ateletasis in patients that underwent surgery of the abdomen (cesarean section), since the reflex of cough in these patients is notably altered for the limitation of the diaphragmatic excursions, due to analgesic contracture. The inhibition of cough's reflex causes retention of secretions with consequent bronchial obstruction and atelectasis. Personal experience in 6 cases of atelectasis following cesarean section is reported.

Modeling sound transmission through the pulmonary system and chest with application to diagnosis of a collapsed lung

A theoretical and experimental study was undertaken to examine the feasibility of using audible-frequency vibro-acoustic waves for diagnosis of pneumothorax, a collapsed lung. The hypothesis was that the acoustic response of the chest to external excitation would change with this condition. In experimental canine studies, external acoustic energy was introduced into the trachea via an endotracheal tube. For the control (nonpneumothorax) state, it is hypothesized that sound waves primarily travel through the airways, couple to the lung parenchyma, and then are transmitted directly to the chest wall. In contradistinction, when a pneumothorax is present the intervening air presents an added barrier to efficient acoustic energy transfer. Theoretical models of sound transmission through the pulmonary system and chest region to the chest wall surface are developed to more clearly understand the mechanisms of intensity loss when a pneumothorax is present, relative to a baseline case. These models predict significant decreases in acoustic transmission strength when a pneumothorax is present, in qualitative agreement with experimental measurements. Development of the models, their extension via finite element analysis, and comparisons with experimental canine studies are reviewed.

Bronchial leiomyoma with atelectasis in the left lower lobe

Bronchial leiomyoma with atelectasis in the left lower lobe occurred in a 44-year-old woman. The leiomyoma was diagnosed by bronchofiberscopy, and left lower sleeve lobectomy was performed. The histopathology of the tumor revealed a leiomyoma with no evidence of malignancy. An early accurate diagnosis is thought to be important for a more conservative treatment.

[Diagnostic and therapeutic value of fiberbronchoscope for the adult in the children with respiratory diseases]

OBJECTIVE

To understand the diagnostic and therapeutic value of fiberbronchoscope for the adult in the children with respiratory diseases.

METHODS

The results of diagnostic and therapeutic use in 107 child cases using fiberbronchoscope for adult were analysed.

RESULTS

Pathogenic diagnosis was acquired in 107 cases; 17(17/21) cases of bronchial foreign bodies were extracted; 22 cases underwent bronchoalveolar lavage locally.

CONCLUSION

Various type of BF of fiberbronchoscope for adult can be used in children at various ages, and to diagnose the child's diseases. Fiberbronchoscope for adult is safe and effective in the removing of foreign body and reliable in the treatment of atelectasis caused by inflammation, post-operation, and aspiration of foreign bodies. Fiberbronchoscope for adult can replace fiberbronchoscope for child unless the latter is used generally.

Aspergillus bronchitis causing atelectasis and acute respiratory failure in an immunocompromised patient

Aspergillus tracheobronchitis is an uncommon clinical form of invasive aspergillosis with fungal infection limited entirely or predominantly to the tracheobronchial tree. We report a case of Aspergillus fumigatus bronchitis, diagnosed by fiberoptic bronchoscopy, with fungal growth completely occluding the left main bronchus leading to lung collapse and acute respiratory failure in a 60-year-old male with erythroleukemia and profound granulocytopenia.