The dysmorphic lung: imaging findings

Posterior Lung Herniation in Pulmonary Agenesis and Aplasia: Chest Radiograph and Cross-Sectional Imaging Correlation

Objective

To describe the anatomic locations and imaging features of posterior lung herniation in unilateral pulmonary agenesis and aplasia, focusing on radiograph-CT/MRI correlation.

Materials and Methods

A total of 10 patients (seven with pulmonary agenesis and three with pulmonary aplasia, male: female = 1:9, mean age 7.3 years, age range from 1 month to 20 years) were included. Chest radiographs (n = 9), CT (n = 9), and MRI (n = 1) were reviewed to assess the type of lung underdevelopment, presence of anterior and posterior lung herniation, bronchus origin, supplying artery, and draining vein of the herniated lung.

Results

Pulmonary agenesis/aplasia more commonly affected the left lung (n = 7) than the right lung (n = 3). Anterior lung herniation was observed in nine of the 10 patients. Posterior lung herniation was observed in seven patients with left pulmonary agenesis/aplasia. Two patients showed posterior lung herniation crossing the midline but not beyond the aorta, and five patients showed the posteriorly herniated right lower lobe crossing the midline to extend into the left hemithorax farther beyond the descending thoracic aorta through the space between the esophagus and the aorta. This anatomical configuration resulted in a characteristic radiographic finding of a radiolucent area with a convex lateral border and a vertical medial border in the left lower lung zone, revealing a tongue-like projection on CT and MRI.

Conclusion

Posterior lung herniation occurs in unilateral left lung agenesis/aplasia. Approximately 70% of the cases of posterior lung herniation reveal a unique radiolucent tongue-like projection in the left lower lung zone on imaging studies, which is caused by the extension of the posteriorly herniated right lung farther beyond the descending aorta.

Radiological findings of unilateral tuberculous lung destruction

Objectives

The aim of this report is to identify the radiological findings of unilateral tuberculous lung destruction (UTLD).

Materials and methods

Thirteen patients with (UTLD) were reviewed from 1999 to 2014. Only patients with radiological evidence of absence of pulmonary parenchyma preserved were included. Clinical and demographic data were obtained and radiological studies (chest radiograph and CT) were retrospectively reviewed.

Results

The left lung was more commonly involved (85%). The following radiological findings were found in all cases: a decrease in the diameter of the pulmonary vessels of the affected lung, herniation of the contralateral lung and hypertrophy of the ribs and/or thickening of extrapleural fat. Two radiological patterns were identified: UTLD with cystic bronchiectasis (85%) and UTLD without residual cystic bronchiectasis (15%). Forty-six per cent of cases had respiratory infection symptoms with presence of air-fluid levels in the affected lung as the most common finding in these patients.

Conclusions

Total unilateral post-tuberculous lung destruction is an irreversible complication with the following main radiological features: predominantly left-sided location, decreases in the diameter of the ipsilateral pulmonary vessels, herniation of the contralateral lung and hypertrophy of the ribs and/or thickening of extrapleural fat.

Teaching Points

• Unilateral tuberculous lung destruction is an irreversible complication of tuberculosis.

• Left-side predominance and herniation of the contralateral lung are characteristic.

• Decreased diameter of the ipsilateral pulmonary vessels occurred in all patients.

• The pattern with residual cystic bronchiectasis is the most frequent.

• Superimposed non-tuberculous infections may affect the destroyed lung.

Congenital lung malformations: radiological findings and clues for differential diagnosis

Congenital lung malformations encompass a wide spectrum of conditions with a broadly varying clinical presentation. They are often a source of morbidity in infants and children. Their management depends on the type of malformation and its clinical presentation. Usually, the diagnosis requires an imaging evaluation. Classifications of bronchopulmonary malformations have undergone significant revision in recent years and several theories have attempted to explain their confusing pathogenesis. There are considerable degrees of overlapping and hybrid conditions are common, with interrelated malformations showing various radiologic and pathologic features. Attending to the pathophysiological mechanisms and structures involved, lung malformations can be divided into three categories: bronchopulmonary anomalies, combined lung and vascular abnormalities, and vascular anomalies. The purpose of this article is to review the current imaging techniques for evaluating lung malformations in pediatric patients and their characteristic imaging findings. Moreover, this review discusses a useful classification and offers some clues to facilitate the differential diagnosis.

Congenital abnormalities of intrathoracic airways

Multidetector CT has broadened the potential of imaging to demonstrate anomalies of the lung and the tracheobronchial tree with increasing frequency. Two-and three-dimensional reformatting improve the understanding of complex tracheobronchial anomalies. Most congenital tracheobronchial anomalies are rare and almost always nonsymptomatic; however, some may be confused with or even responsible for respiratory disease. Tracheal and accessory cardiac bronchi are among the most frequent anomalies, but other ectopic or supernumerary lung buds, developmental tracheobronchial interruption, obstruction, or compression, communicating bronchopulmonary foregut malformations, and bronchial malformations associated with anomalies of situs can be detected, even late after birth.

Incidentally found right pulmonary aplasia in an adult patient: the 64-slice MDCT findings

A 60-year-old woman was referred for 64-slice multidetector computed tomography because of the incidental findings of abnormality on a chest radiograph. Her computed tomography showed an absent right lung and a rudimentary main bronchus ending in a blind pouch; this established the diagnosis of pulmonary aplasia. We report here on a rare case of incidentally found right pulmonary aplasia, and we include a brief review of the relevant literature.

Imaging Evaluation of Congenital Lung Abnormalities in Infants and Children

Congenital lung abnormalities include a wide spectrum of conditions and are an important cause of morbidity and mortality in infants and children. This article discusses focal lung abnormalities and the dysmorphic lung. Pulmonary arteriovenous malformations have been included at the end of the article. Anomalies affecting the pulmonary parenchyma, its arterial supply, and venous drainage are thus discussed.

Congenital bronchial abnormalities revisited

Bronchial anatomy is adequately demonstrated with the appropriate spiral computed tomographic technique on cross-sectional images, multiplanar reconstruction images, and three-dimensional reconstruction images. Contrary to the numerous variations of lobar or segmental bronchial subdivisions, abnormal bronchi originating from the trachea or main bronchi are rare. Major bronchial abnormalities include accessory cardiac bronchus (ACB) and "tracheal" bronchus. An ACB is a supernumerary bronchus from the inner wall of the right main bronchus or intermediate bronchus that progresses toward the pericardium. Fourteen ACBs were found in 17,500 consecutive patients (frequency, 0.08%). The term tracheal bronchus encompasses a variety of bronchial anomalies originating from the trachea or main bronchus and directed to the upper lobe. In a series of 35 tracheal bronchi, only eight originated from the trachea, three originated from the carina, and 24 originated from the bronchi. Displaced tracheal bronchi (27 of 35) are more frequent than supernumerary tracheal bronchi (eight of 35). Minor bronchial abnormalities include variants of tracheal bronchus, displaced segmental bronchi, and bronchial agenesis. The main embryogenic hypotheses for congenital bronchial abnormalities are the reduction, migration, and selection theories. Knowledge and understanding of congenital bronchial abnormalities may have important implications for diagnosis, bronchoscopy, surgery, brachytherapy, and intubation.