| volume averaging | In computed tomography or magnetic resonance imaging, the effect of expressing the average density of a voxel as a pixel in the image; the greater the slice thickness, the more averaging is necessary, with loss in density resolution. (05 Mar 2000) |
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| volume-controlled respirator | A respirator that provides a predetermined volume of gases during inhalation, with the pressure required to move that volume remaining variable, depending upon resistance. (05 Mar 2000) |
| volume element | See: voxel. (05 Mar 2000) |
| volume index | An indication of the relative size (e.g., volume) of erythrocytes, calculated as follows: haematocrit value, expressed as per cent of normal ÷ red blood cell count, expressed as per cent of normal = volume index. (05 Mar 2000) |
| volume loading rate | The rate of raw materials put into a fermenter or aerobic digester, expressed in terms of material weight per unit volume per unit time. (09 Oct 1997) |
| volume substitute | Infusion of cell-free or volume-expanding fluids such as dextran for replacement of fluid lost from the circulation as part of the prevention or treatment of circulatory shock. (05 Mar 2000) |
| volume unit | A unit of a logarithmic scale for expressing the power level of a complex audio-frequency electrical signal, such as that transmitting music or speech; the power in volume unit's equals the decibels of power above a reference level of one milliwatt, as measured with an appropriate meter. (05 Mar 2000) |
| respiratory minute volume | The minute volume of breathing; the product of tidal volume times the respiratory frequency. See: pulmonary ventilation. (05 Mar 2000) |
| resting tidal volume | The tidal volume under normal conditions, i.e., in the absence of exercise or other conditions that stimulate breathing. (05 Mar 2000) |
| right ventricular volume overload | <radiology> Atrial septal defect, partial/total APVR, tricuspid insufficiency, pulmonary insufficiency, congenital/aquired absence of pericardium, Ebstein anomaly (not truly RV) (12 Dec 1998) |
| minute volume | The volume of any gas or fluid moved per minute; e.g., cardiac output or the respiratory minute volume. (05 Mar 2000) |
| closing volume | The lung volume at which the dependent lung zones cease to ventilate presumably as a result of airway closure. (12 Dec 1998) |
| plasma volume | Volume of plasma in the circulation. It is usually measured by indicator dilution techniques. (12 Dec 1998) |
| pressure-volume index | Method of evaluating the cerebrospinal fluid hydrodynamics. (05 Mar 2000) |
| specimen interaction volume | <microscopy> The volume inside the specimen in which all specimen interactions occur during electron beam irradiation. (05 Aug 1998) |