A chest (thoracic) ultrasound visualises structures at and just below the chest wall: pleural fluid (effusions), pleural thickening or plaques, lung consolidation such as pneumonia, pleural-based masses, and chest-wall lesions. It detects pneumothorax by assessing lung sliding and diaphragmatic movement, guides procedures (thoracentesis, drain placement), and evaluates superficial lymph nodes. It cannot reliably image deep aerated lung tissue.

Choice of chest scan depends on the clinical question. A chest X‑ray is the usual first‑line test. CT chest (including high‑resolution CT or CT pulmonary angiography) provides the most detailed assessment of lung disease, nodules, and pulmonary embolism; low‑dose CT is used for lung‑cancer screening in high‑risk people. MRI aids cardiac or mediastinal evaluation, while ultrasound detects pleural effusion.

Yes. Lung ultrasound can detect chest infections by showing subpleural consolidations, dynamic air bronchograms and pleural effusions. It is more sensitive than chest X-ray for peripheral consolidations and useful at the bedside for children, pregnant patients and critically ill people. Limitations include operator dependence and reduced sensitivity for deep or central lesions obscured by aerated lung; CT may be needed.

Ultrasound cannot reliably diagnose pulmonary TB because air-filled lungs block sound waves. It is useful for extrapulmonary TB: detecting pleural or pericardial effusions, abdominal TB, enlarged or necrotic lymph nodes, and guiding biopsies or drainages. Ultrasound findings are suggestive, not definitive; microbiological tests (sputum/GeneXpert/culture) and chest X-ray or CT are needed for confirmation.

The most common reason for an ultrasound is obstetric assessment — to confirm and date pregnancy, monitor fetal growth and position, check for multiple pregnancies, and screen for major structural abnormalities. Routine prenatal ultrasounds also assess placental location and amniotic fluid. Ultrasound is favored in pregnancy because it is safe, noninvasive, and provides real-time images useful for guiding prenatal care.

Chest ultrasound is safe. It’s a non-invasive, painless test using sound waves instead of ionizing radiation, and is suitable for adults and pregnant people. Risks are minimal—occasional discomfort or skin irritation from the probe. Limitations include operator dependence and reduced accuracy for air-filled lung or behind bone, but it’s widely used to assess pleural effusion, pneumothorax and chest wall abnormalities.