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Contrasted CT scans of the chest are usually used to confirm diagnosis of for lung cancer and abscesses, as well as to assess lymph node status at the hila and the mediastinum. CT pulmonary angiogram , which uses time-matched ("phased") protocols to assess the lung perfusion and the patency of great arteries and veins , particularly to look for ...
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 ...
Drawing of CT fan beam and patient in a CT imaging system CT scan of the thorax. The axial slice (right) is the image that corresponds to number 2/33 on the coronal slice (left). Spinning tube, commonly called spiral CT, or helical CT, is an imaging technique in which an entire X-ray tube is spun around the central axis of the area being ...
Bolus tracking is a technique to optimize timing of the imaging. A small bolus of radio-opaque contrast media is injected into a patient via a peripheral intravenous cannula . Depending on the vessel being imaged, the volume of contrast is tracked using a region of interest (abbreviated "R.O.I.") at a certain level and then followed by the CT ...
State of the art modern CT scanners with a scan rate of up to 320 mm/s can acquire all the images within a 1-second X-ray exposure, avoiding the problems of respiratory motion, cardiac motion and contrast draining from the pulmonary circulation during the study. Even though the actual scan may be completed in 1 second or less, considerable ...
In modern (helical) CT, the source/detector makes at least a complete 180-degree rotation about the subject obtaining a complete set of data from which images may be reconstructed. Digital tomosynthesis, on the other hand, only uses a limited rotation angle (e.g., 15-60 degrees) with a lower number of discrete exposures (e.g., 7-51) than CT.
Mammography (also called mastography; DICOM modality: MG) is the process of using low-energy X-rays (usually around 30 kVp) to examine the human breast for diagnosis and screening. The goal of mammography is the early detection of breast cancer, typically through detection of characteristic masses, microcalcifications, asymmetries, and distortions.
Most radiation therapy is planned using the results of a 3D CT scan. A 3D scan largely presents a snapshot of the body at a particular point in time, however due to the time of the acquisition, in which the patient is likely to have moved in some way (even if only breathing), there will be an element of blurring or averaging in the 3D scan. [ 6 ]