(AP) adj. from the front to the back. In radiography, AP denotes a radiograph in the *coronal plane taken when the X-ray beam is directed from the front to the back of the patient with the X-ray film or detector at the back to capture the image. Compare decubitus; posteroanterior.
n. a special standardized X-ray picture of the craniofacial area that can be used to measure alterations in the growth of skull bones, as used especially during orthodontic treatment. A lateral cephalometric radiograph is used to analyse skeletal, dentoalveolar, and soft tissue relationships in the anteroposterior and vertical dimensions.... cephalogram
a pair (anterior and posterior) of ligaments inside each knee joint, which help to prevent excessive anteroposterior glide. Damage to the cruciate ligaments is a common *sports injury, especially in football players.... cruciate ligaments
n. measurement of the four internal diameters of the pelvis (transverse, anteroposterior, left oblique, and right oblique) on an X-ray image or by means of CT or MR scanning. Pelvimetry may be used to determine if a vaginal delivery will be possible, but it is an unreliable predictor of obstetric outcome and its use is outmoded. Clinical pelvimetry is a means of assessing pelvic capacity through a vaginal examination; it is subjective and its results must be used with caution.... pelvimetry
(PA) adj. from the back to the front. In radiography it refers to the direction of the X-ray beam (i.e. from the back to the front of the patient); thus a PA radiograph is taken with the X-ray film in front of the patient. Normally, a chest radiograph will be PA: since the heart is in the front of the chest, its size can be most accurately assessed if the X-ray film is in front of the chest. Compare decubitus; anteroposterior.... posteroanterior
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