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Orthovoltage ("superficial") X-rays are used for treating skin cancer and superficial structures. Megavoltage X-rays are used to treat deep-seated tumors (e.g. bladder, bowel, prostate, lung, or brain), whereas megavoltage electron beams are typically used to treat superficial lesions extending to a depth of approximately 5 cm.
Digital dermatoscopy (videodermatoscopy) is used for monitoring skin lesions suspicious of melanoma. Digital dermatoscopy images are stored and compared to images obtained during the patient's next visit. Suspicious changes in such a lesion are an indication for excision. Skin lesions, which appear unchanged over time are considered benign.
Electron tomography (ET) is a tomography technique for obtaining detailed 3D structures [1] of sub-cellular, macro-molecular, or materials specimens. Electron tomography is an extension of traditional transmission electron microscopy and uses a transmission electron microscope to collect the data.
The rectangular screen on the right side of the gantry is a cone beam x-ray detector, which is used to help position a patient prior to treatment. The gantry is supported by a drive stand, which rotates the gantry on a fixed horizontal axis as the linac revolves around a patient.
The Straton tube, by Siemens Healthineers (formerly Siemens Medical Solutions), Erlangen, Germany, is the first X-ray tube from the class of rotating envelope tubes (RET) to be used for computed tomography.
The major benefit of the increased power density level for the metal-jet X-ray tube is the possibility to operate with a smaller focal spot, say 5 μm, to increase image resolution and at the same time acquire the image faster, since the power is higher (15-30 W) than for solid-anode tubes with 10 μm focal spots.
Fish bone pierced in the upper esophagus. Right image without contrast medium, left image during swallowing with contrast medium. To obtain an image with any type of image detector the part of the patient to be X-rayed is placed between the X-ray source and the image receptor to produce a shadow of the internal structure of that particular part of the body.
An illustration of the heel effect in an x-ray tube. In X-ray tubes, the heel effect or, more precisely, the anode heel effect is a variation of the intensity of X-rays emitted by the anode depending on the direction of emission along the anode-cathode axis.