Tree-in-bud sign

Tree-in-bud Sign

CT scan showing tree-in-bud sign in a patient with primary ciliary dyskinesia.

The tree-in-bud sign is a radiological finding typically observed on high-resolution computed tomography (CT) scans of the chest. It is characterized by small centrilobular nodules and branching linear structures that resemble a budding tree. This pattern is indicative of endobronchial spread of infection or inflammation, often seen in various pulmonary conditions.

Pathophysiology

The tree-in-bud sign represents the presence of material, such as mucus, pus, or fluid, within the bronchioles. This material causes the bronchioles to become dilated and filled, leading to the characteristic appearance on CT scans. The sign is most commonly associated with infectious processes, particularly those involving the small airways.

Causes

The tree-in-bud sign can be seen in a variety of conditions, including:

• Bronchiectasis
• Cystic fibrosis
• Tuberculosis
• Atypical mycobacterial infection
• Viral bronchiolitis
• Aspiration pneumonia
• Primary ciliary dyskinesia

Clinical Significance

The presence of a tree-in-bud pattern on a CT scan can help clinicians narrow down the differential diagnosis for a patient presenting with respiratory symptoms. It is important to correlate the radiological findings with the patient's clinical history, physical examination, and laboratory results to arrive at an accurate diagnosis.

Diagnosis

Diagnosis of the underlying cause of the tree-in-bud sign involves a combination of imaging studies, laboratory tests, and sometimes bronchoscopy. High-resolution CT scans are the primary imaging modality used to identify this pattern. Additional tests may include sputum cultures, blood tests, and pulmonary function tests.

Treatment

Treatment of the tree-in-bud sign depends on the underlying cause. For infectious causes, appropriate antibiotic or antiviral therapy is administered. In cases of bronchiectasis or cystic fibrosis, management may include airway clearance techniques, bronchodilators, and other supportive measures.

Related Pages

• Bronchiectasis
• Cystic fibrosis
• Tuberculosis
• Primary ciliary dyskinesia