Comparing three-dimensional volume-rendered CT images with fibreoptic tracheobronchoscopy in the evaluation of airway compression caused by tuberculous lymphadenopathy in children.

BACKGROUND: Lymphobronchial tuberculosis (TB) causes airway compression in 38% of patients. The airway obstruction is conventionally assessed with fibreoptic tracheobronchoscopy (FTB). Multidetector-row spiral computed tomography (MDCT) with three-dimensional volume rendering (3-D VR) has significantly improved the imaging of the airways. No previous studies have assessed the accuracy of 3-D VR in determining the degree of airway compression in children due to TB lymphadenopathy. OBJECTIVE: To compare 3-D VR CT to FTB for the assessment of airway compression due to TB lymphadenopathy in children. MATERIALS AND METHODS: Included in the study were 26 children presenting with symptoms of airway compression caused by pulmonary TB. MDCT of the chest and FTB were performed in all patients. Retrospective 3-D VR reconstruction of the major airways was performed from the original CT raw data and used to evaluate the tracheobronchial tree for site and degree of airway compression and then compared to the FTB findings. FTB was used as the reference standard RESULTS: By FTB 87 sites of airway compression were identified. Using the 3-D VR technique, 138 sites of airway compression were identified, of which 78 (90%) matched with the sites identified by FTB. The sensitivity and specificity of 3-D VR when compared with that of FTB was 92% and 85%, respectively. In four patients (15%), severe narrowing of the bronchus intermedius made FTB evaluation of the right middle and right lower lobe bronchi impossible. VR demonstrated significant distal obstruction in three of these four patients CONCLUSION: 3-D VR demonstrates a very good correlation with FTB in determining airway compression caused by TB lymphadenopathy in children. In combination with FTB, 3-D VR adds confidence to the bronchoscopy findings and complements FTB by adding additional information on the status of the airway distal to severe obstructions unreachable by FTB.

Non-infective pulmonary disease in HIV-positive children.

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.

Central nervous system manifestations of HIV infection in children.

Vertically transmitted HIV infection is a major problem in the developing world due to the poor availability of antiretroviral agents to pregnant women. HIV is a neurotrophic virus and causes devastating neurological insults to the immature brain. The effects of the virus are further compounded by the opportunistic infections and neoplasms that occur as a result of the associated immune suppression. This review focuses on the imaging features of HIV infection and its complications in the central nervous system.

Pulmonary infections in HIV-positive children.

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.

Unusual forms of spinal tuberculosis.

OBJECTIVE: The incidence of tuberculosis (TB) is increasing in both developing and developed worlds, and children, in particular, represent a high-risk group for acquiring the disease. TB of the central nervous system is the most severe, life-threatening form of TB in infants and children. Approximately 10% of all patients with TB have central nervous system involvement. MATERIALS AND METHODS: We have selected four pediatric cases of unusual spinal TB that presented to our institution during the last 5 years. These include TB arachnoiditis, intramedullary spinal cord tuberculoma, TB spondylitis of the odontoid peg, and one child with tuberculous extradural abscess. CONCLUSION: TB may involve the intramedullary, extramedullary intrathecal compartment, or the extrathecal vertebral compartment in the form of an arachnoiditis, abscess, and spondylitis, respectively, often with unusual imaging presentations.

CT features of tuberculous intracranial abscesses in children.

BACKGROUND: Intracranial tuberculous (TB) abscesses still cause a diagnostic dilemma on both CT and MRI as they may mimic neoplasms. Recognition of TB abscesses may prompt further imaging and appropriate trial of therapy, and may reduce the need for biopsy. OBJECTIVE: To report the CT features of eight intracranial TB lesions in children initially diagnosed as neoplasms and eventually treated as TB abscesses. MATERIALS AND METHODS: We undertook a 3-year retrospective review of children with an initial CT diagnosis of intracranial neoplasm who were subsequently diagnosed as having TB abscesses. RESULTS: Eight patients out of 60 with an initial diagnosis of a neoplasm on CT were misdiagnosed and were ultimately determined to have TB abscesses after biopsy or a trial of anti-TB therapy. The most consistent constellation of findings for the lesions were low density (n = 5), ring enhancement (n = 8), cerebral hemisphere location (n = 7), mass effect (n = 6), surrounding oedema (n = 5) and absence of a soft-tissue-density mass (n = 8). CONCLUSION: In endemic regions, intracranial lesions with these appearances on CT should undergo further imaging and possibly a trial of anti-TB therapy before considering biopsy.

Pulmonary Kaposi sarcoma in six children.

BACKGROUND: Pulmonary involvement in Kaposi sarcoma is rare in children and can be difficult to distinguish from other pathology. OBJECTIVE: To describe the radiological findings in paediatric pulmonary Kaposi sarcoma. MATERIALS AND METHODS: Sequential chest radiographs of six children and CT scans of four of these children were evaluated retrospectively. Their ages ranged from 18 months to 10 years; four were male and two were female. All six children were HIV-positive. The observers were two radiologists. RESULTS: Chest radiographs revealed air-space (100%) and reticular (83%) opacification in the mid- and lower lung zones; pleural effusions were present in 83% of the children. All the children showed progressive air-space opacification on follow-up radiography. CT demonstrated bilateral air-space opacification in a perihilar distribution in all the children; reticular opacification was seen in 75%. All the children had mediastinal and axillary lymphadenopathy; 75% had bilateral hilar lymphadenopathy. CONCLUSION: In both adults and children, chest radiography demonstrates perihilar and lower zone involvement. Pleural effusions are more common on radiographs in children. Air-space disease and lymphadenopathy are much more common on CT in children than adults.

Localized basal meningeal enhancement in tuberculous meningitis.

BACKGROUND: Focal basal meningeal enhancement may produce a confusing CT picture in children with suspected tuberculous meningitis (TBM). OBJECTIVE: To demonstrate the incidence, distribution and appearance of localized basal meningeal enhancement in children with TBM. MATERIALS AND METHODS: CT scans of patients with definite (culture proven) and probable (CSF suggestive) TBM were retrospectively evaluated by two observers. Localized basal enhancement was documented as involving: unilateral cistern of the lateral fossa (CLF), unilateral sylvian fissure, unilateral CLF and sylvian fissure in combination, unilateral CLF and sylvian fissure with ipsi- or contralateral ambient cistern and isolated quadrigeminal plate cistern. RESULTS: The study included 130 patients with TBM (aged 2 months to 13 years 9 months). Focal basal enhancement was seen in 11 patients (8.5%). The sylvian fissure was involved most commonly, followed by the lateral fossa cistern. The ambient cistern was involved in three patients and the quadrigeminal plate cistern in one. Focal areas of enhancement corresponded to the areas of infarction in every patient. CONCLUSION: Focal basal meningeal enhancement is common (8.5%) in paediatric TBM. This must be kept in mind when evaluating CT scans in children presenting with focal neurological findings, seizures or meningism in communities where TBM is endemic.