It is estimated that over 90% of children infected with human immunodeficiency virus (HIV) live in the developing world and particularly in sub-Saharan Africa. Pulmonary disease is the most common clinical feature of acquired immunodeficiency syndrome (AIDS) in infants and children causing the most morbidity and mortality, and is the primary cause of death in 50% of cases. Children with lung disease are surviving progressively longer because of earlier diagnosis and antiretroviral treatment and, therefore, thoracic manifestations have continued to change and unexpected complications are being encountered. It has been reported that 33% of HIV-positive children have chronic changes on chest radiographs by the age of 4 years. Lymphocytic interstitial pneumonitis is common in the paediatric HIV population and is responsible for 30-40% of pulmonary disease. HIV-positive children also have a higher incidence of pulmonary malignancies, including lymphoma and pulmonary Kaposi sarcoma. Immune reconstitution inflammatory syndrome is seen after highly active antiretroviral treatment. Complications of pulmonary infections, aspiration and rarely interstitial pneumonitis are also seen. This review focuses on the imaging findings of non-infective chronic pulmonary disease.

Chylothorax is a rare clinical entity characterized by a milky white aspirate with increased triglyceride levels. The commonest aetiology is malignancy and trauma. Pulmonary tuberculosis is an extremely rare cause of chylothorax. Two children with chylothorax and pulmonary tuberculosis are described. One child had bilateral and the other unilateral chylous effusions. Extensive mediastinal and hilar lymphadenopathy was demonstrated. Diseased lymph nodes may infiltrate other intrathoracic structures such as the thoracic duct, and they can also obstruct the cisterna chyli and thoracic duct. A possible explanation for the development of a chylothorax in our patients is obstruction of the thoracic duct by tuberculous lymphadenopathy with subsequent increase in pressure in the surrounding lymphatic system and leaking of chyle into the pleural space.

Diagnosis of pulmonary tuberculosis (PTB) in children is challenging and radiographs are often normal or non-specific. Access to the chest using ultrasound is difficult, but access to the abdomen is simple and carries no radiation burden. Diagnosis of PTB using abdominal lymphadenopathy as a surrogate for mediastinal lymphadenopathy may present a simple and accurate additional diagnostic technique that is of value in developing countries. We determined the prevalence of abdominal lymphadenopathy in paediatric patients with confirmed TB presenting with respiratory symptoms. Chest radiographs and abdominal ultrasounds of 47 children with confirmed TB and respiratory symptoms were reviewed. The prevalence of abdominal TB was determined and comparisons made between thoracic and abdominal lymphadenopathy to determine the relative value of ultrasound. On ultrasound, the prevalence of abdominal lymphadenopathy was 19% and solid organ involvement was found in 23% of patients. Some 70% of children had thoracic lymphadenopathy on chest radiography, with 89% of patients having evidence of PTB. If chest radiography were to be considered the radiological reference standard, abdominal ultrasonography had a sensitivity of 18% (95% CI 7.0–35.5%) with a specificity of 79% (95% CI 49.2–95.1%) for thoracic lymphadenopathy. Ultrasound and chest radiography in combination detected a total of 36 patients with lymphadenopathy, with a 6% improvement in the rate of lymphadenopathy detection; however, this was not statistically significant. The prevalence of abdominal TB of 23% is noteworthy. We suggest that abdominal ultrasound has a definitive adjunctive role in investigating children with suspected TB.

Infection of the lungs and airways by viral, bacterial, fungal and protozoal agents, often producing atypical radiographic features, is common in children with human immunodeficiency virus (HIV) infection. Conventional chest radiography and chest CT remain the most useful imaging modalities for evaluation of the immunocompromised patient presenting with a suspected pulmonary infection. In this review the radiological features of acute lung infections in this population are discussed.

Renal tuberculosis is relatively uncommon in children. Imaging of renal tuberculosis in children differs from adults in that intravenous urography is rarely performed for urinary symptoms in childhood because of radiation dose considerations. Modern imaging modalities include cross-sectional techniques such as ultrasound, CT and MRI, which successfully show renal, calyceal, ureteric and bladder pathology of renal tuberculosis in children.