Investigation of choice for bronchiectasis is-
**Core Concept**
Bronchiectasis is a chronic respiratory disease characterized by permanent dilatation of parts of the airways due to chronic inflammation and infection. The investigation of choice should be able to visualize the airway abnormalities and assess the extent of lung involvement.
**Why the Correct Answer is Right**
High-resolution computed tomography (HRCT) of the chest is the investigation of choice for bronchiectasis as it provides detailed images of the airways, enabling the detection of dilatation, wall thickening, and bronchial tapering. HRCT scans can also help identify the extent of lung involvement, including the presence of cystic changes or mucus plugging. The spatial resolution of HRCT is superior to other imaging modalities like chest X-rays or conventional CT scans, making it essential for diagnosing and staging bronchiectasis.
**Why Each Wrong Option is Incorrect**
* **Option A:** Chest X-ray is not sensitive enough to detect bronchiectasis and may show non-specific signs like hyperinflation or pleural thickening.
* **Option B:** Conventional CT scans may not provide the same level of detail as HRCT, making them less useful for diagnosing bronchiectasis.
* **Option D:** Pulmonary function tests (PFTs) are useful for assessing lung function but do not provide direct visualization of airway abnormalities.
**Clinical Pearl / High-Yield Fact**
HRCT scans are essential for diagnosing and staging bronchiectasis, and the presence of bronchiectasis on HRCT is a key criterion for diagnosing this condition.
**Correct Answer:** C. High-resolution computed tomography (HRCT) of the chest.