| RBF | regional blood flow; regional bone mass; renal blood flow |
|---|---|
| RNSC | radionuclide superior cavography |
| RSO | radiation safety officer; Resident Surgical Officer; right superior oblique [muscle] |
| RSR | regular sinus rhythm; relative survival rate; right superior rectus [muscle] |
| RSVC | right superior vena cava |
| line of fixation | A line joining the object (or point of fixation) with the fovea. (05 Mar 2000) |
|---|---|
| line of Gennari | A prominent white line appearing in perpendicular sections of the visual cortex (Brodmann's area 17) at about mid-thickness of the cortical gray matter, corresponding to the particularly well developed outer line of Baillarger of that cortical area, and composed largely of tangentially disposed intracortical association fibres. Synonym: Gennari's band, Gennari's stria, stripe of Gennari. (05 Mar 2000) |
| line of Kaes | A band of horizontal myelinated fibres in the most superficial part of the third layer of the isocortex. Synonym: Bechterew's band, layer of Bechterew, line of Bechterew, line of Kaes. (05 Mar 2000) |
| line of occlusion | The alignment of the occluding surfaces of the teeth in the horizontal plane. See: occlusal plane. (05 Mar 2000) |
| line of vision | The straight line extending from the object seen, through the centre of the pupil, to the macula lutea of the retina. Synonym: line of vision. (05 Mar 2000) |
| line pairs | A unit of resolution of radiographic screens and films or photographic films. (05 Mar 2000) |
| line precedence | <zoology> When two different names for the same taxon are first published in the same publication, then the one which appears on the earlier line has line precedence. Line precedence does not necessarily mean priority as well - this is determined by the action of the first reviser. (09 Jan 1998) |
| line spread function | A measure of the ability of a system to form sharp images; in radiology, determined by measuring the spatial density distribution on film of the X-ray image of a narrow slit in a dense metal, such as uranium; from this can be calculated the modulation transfer function. (05 Mar 2000) |
| line test | A test for rickets, based on observation of the lines of calcification in the growing ends of rachitic long bones in rats given vitamin D preparations under standard test conditions; used in biological assay of vitamin D by the USP. (05 Mar 2000) |
| line-tying | <radiobiology> Connection of field lines from the end of an open-ended device (such as a mirror system) to a conducting plate. The rigidity of field lines trapped in the plate can be transferred to the high-field region of the mirror by using a cold, moderately-dense plasma in between. Line-tying helps to stabilise against interchange instabilities. (09 Oct 1997) |
| low lip line | The lowest position of the lower lip during the act of smiling or voluntary retraction, the lowest position of the upper lip at rest. (05 Mar 2000) |
| acute reflex bone atrophy | Atrophy of bones, commonly of the carpal or tarsal bones, following a slight injury such as a sprain. See: causalgia, reflex sympathetic dystrophy. Synonym: acute reflex bone atrophy, posttraumatic osteoporosis, Sudeck's syndrome. Origin: L. English sweat (05 Mar 2000) |
| air-bone gap | The difference between the threshold for hearing acuity by bone conduction and by air conduction. (05 Mar 2000) |
| Albrecht's bone | A small bone between the basioccipital and basisphenoid. (05 Mar 2000) |
| allogeneic bone marrow transplant | <haematology, procedure> A bone marrow transplant using marrow collected from a matched healthy donor, usually a brother or sister. The risks associated with the transplant increase with age and 50 years of age is generally regarded as the upper limit. (13 Nov 1997) |