Investigation of choice for bronchiectasis

**Core Concept**
Bronchiectasis is a chronic respiratory disease characterized by permanent dilation of the bronchi, leading to impaired lung function and recurrent infections. The investigation of choice should ideally provide detailed information about the extent and severity of bronchiectasis, as well as any associated complications.

**Why the Correct Answer is Right**
High-resolution computed tomography (HRCT) is the investigation of choice for bronchiectasis because it offers high spatial resolution and can detect even mild bronchiectasis. HRCT can show the extent and severity of bronchiectasis, identify any associated complications such as cystic lesions or lung nodules, and guide treatment decisions. The images obtained from HRCT can also be used to monitor disease progression and response to treatment.

**Why Each Wrong Option is Incorrect**
* **Option A:** Chest X-ray is not sensitive enough to detect bronchiectasis and is often normal in early cases.
* **Option B:** Sputum culture is used to identify the causative organism in respiratory infections but does not provide information about the extent or severity of bronchiectasis.
* **Option D:** Pulmonary function tests (PFTs) may show impaired lung function in bronchiectasis but do not provide information about the extent or severity of bronchiectasis.

**Clinical Pearl / High-Yield Fact**
HRCT is essential for diagnosing bronchiectasis, and it is recommended that patients with suspected bronchiectasis undergo HRCT as soon as possible. This can help guide treatment decisions and improve patient outcomes.

**Correct Answer: C. High-resolution computed tomography (HRCT)**