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Ground-glass opacity (GGO) is a finding seen on chest x-ray (radiograph) or computed tomography (CT) imaging of the lungs. It is typically defined as an area of hazy opacification (x-ray) or increased attenuation (CT) due to air displacement by fluid, airway collapse, fibrosis , or a neoplastic process . [ 1 ]
Radiolucency or hypodensity indicates greater passage (greater transradiancy) to X-ray photons [1] and is the analogue of transparency and translucency with visible light. Materials that inhibit the passage of electromagnetic radiation are called radiodense or radiopaque , while those that allow radiation to pass more freely are referred to as ...
A radiation source is positioned behind the patient at a standard distance (most often 6 feet, 1,8m), and the x-ray beam is fired toward the patient. In anteroposterior (AP) views, the positions of the x-ray source and detector are reversed: the x-ray beam enters through the anterior aspect and exits through the posterior aspect of the chest.
Dual-energy X-ray absorptiometry (DXA, or DEXA [1]) is a means of measuring bone mineral density (BMD) with spectral imaging. Two X-ray beams, with different energy levels, are aimed at the patient's bones. When soft tissue absorption is subtracted, the bone mineral density (BMD) can be determined from the absorption of each beam by bone. Dual ...
These cases result in immediate onset (usually) painless swelling of the face and neck; crepitus (crunching sound) typical of subcutaneous emphysema is often present and the subcutaneous air will be visible on X-ray. [24] One of the main causes of subcutaneous emphysema, along with pneumothorax, is an improperly functioning chest tube. [2]
Low-dose high-resolution (1.25 mm) chest CT. HRCT is performed using a conventional CT scanner. However, imaging parameters are chosen so as to maximize spatial resolution: [1] a narrow slice width is used (usually 1–2 mm), a high spatial resolution image reconstruction algorithm is used, field of view is minimized, so as to minimize the size of each pixel, and other scan factors (e.g. focal ...
CT scan in a patient with usual interstitial pneumonia, showing interstitial thickening, architectural distortion, honeycombing and bronchiectasis.. In radiology, honeycombing or "honeycomb lung" is the radiological appearance seen with widespread pulmonary fibrosis [1] and is defined by the presence of small cystic spaces with irregularly thickened walls composed of fibrous tissue.
The dashed line indicates the probability density function of the X-ray intensity. An X-ray image results from the absorbance of X-rays as they pass through the sample. The attenuation of X-rays is calculated by the following exponential formula: J = J 0 ⋅ ϵ − D {\displaystyle J=J{\scriptstyle {\text{0}}}\centerdot \epsilon ^{-D}} .