Category: F

The area on the anode of an x-ray tube or the target of an accelerator that is struck by electrons and from which the resulting x rays are emitted. The shape and size of a focal spot will influence the resolution of a diagnostic image. The area on the x-ray tube target that is bombarded…

In NMR imaging, the amount of rotation of the macroscopic magnetization vector produced by a radiofrequency pulse with respect to the direction of the static magnetic field.  

A benchmark in the evaluation of response to therapy for cancer patients. The raw data are corrected for expected deaths from other causes by actuarial methods.  

A mathematical technique used in NMR imaging and computed tomography to create images from a set of multiple projection profiles.  

A measure of the geometrical relationship of a radiofrequency coil used in NMR imaging and the body. This relationship affects the efficiency of irradiating the body and detecting NMR signals, and thereby affects the signal-to-noise ratio and, ultimately, image quality. Achieving a high filling factor requires fitting the coil closely to the body, thus potentially…

The physical attack or abuse of one family member by another; also called domestic violence. Violence that occurs in families includes partner abuse, elder abuse, child abuse, and child neglect. All of these acts are crimes. Forms of violence that include spouse abuse, sexual abuse, marital rape, child abuse, and neglect.  

A break in the cranial (skull) bones. A fractured skull may involve visible damage to the cranial bones, including heavy bleeding; but a skull fracture can be hidden by the hair. Symptoms of a skull fracture can include bruising or discoloration behind the ear or around the eyes; blood or clear fluid leaking from the…

Any of the air-containing spaces in the bones of the face. There are four pairs of facial sinuses: the frontal sinuses in the bone of the forehead, just over the eye sockets; the maxillary sinuses in the cheekbones under the eyes; the ethmoid sinuses on either side of the bridge of the nose; and the…

A seizure experienced by a child with a high fever. A febrile seizure generally follows a rapid rise in body temperature. The affected child experiences a tonic-clonic (or grand mal) seizure, characterized by jerking of the arms and legs, stiffening of the body, and a loss of consciousness that lasts from 30 seconds to 5…

A broken rib bone that may be caused by forceful trauma, such as a fall or a blow to the chest, or by the pressure of intense coughing or sneezing. Symptoms include pain that intensifies when a breath is taken, tenderness and shallow breathing, and bruising at the site of the injury. In most cases,…