HRCT - High Resolution Computed Tomography

Definition: High Resolution Computed Tomography (HRCT) is a computed tomography (CT) technique that generates detailed images of the internal structures of the body, particularly the lungs. It uses thin slices (usually 1-2 mm) and high-resolution reconstruction algorithms to provide enhanced spatial resolution compared to conventional CT scans.

How it Works: HRCT scans are typically obtained with the patient lying still while the CT scanner rotates around the body. The X-ray beam passes through the body, and detectors on the opposite side of the scanner measure the amount of radiation that emerges. The data is then processed by a computer to create cross-sectional images.

Applications in Pulmonary Medicine: HRCT is widely used in the diagnosis and management of various lung diseases. It can detect small nodules, identify patterns of interstitial lung disease, assess airway abnormalities, and help in the evaluation of emphysema. For example, in patients with suspected lung cancer, HRCT can provide detailed information about the size, location, and characteristics of lung nodules, aiding in the decision-making process for further diagnostic tests and treatment planning.

Advantages: The high spatial resolution of HRCT allows for the detection of subtle lung abnormalities that may not be visible on conventional chest X-rays or standard CT scans. It provides valuable information for accurate diagnosis and treatment monitoring.

Limitations: HRCT is a relatively expensive imaging modality and involves exposure to ionizing radiation. Additionally, the interpretation of HRCT images requires specialized training, as the images can be complex and may show a variety of normal and abnormal findings.