![]() Place patient with nose and forehead against Bucky so the orbitomeatal line is perpendicular to the film. ID should be in lower corner of collimation field. Slide the caliper arm until it rests lightly at the nasion. Place caliper base at the back of the skull. Remove any artifacts in the desired field (e.g., earrings, dentures, hair appliances) Routine skull: PA Caldwell, AP Towne, Lateral Skull Technical tips are also included to aid in obtaining optimal studies. ![]() The “Additional Information” section describes other views that may be done to better demonstrate the desired anatomy. A suggested kV and mAs range is also provided for systems described in the previous section on technique. If detailed or nongrid is listed, a slower speed film screen combination is suggested, such as those found in extremity cassettes or 100-speed cassettes. If the use of a grid is listed, a fast film screen combination such as rare earth is suggested. The kV and mAs section lists the type of film screen combination used and whether the study is performed with the use of a grid or tabletop. For each setup in the tables, there is a picture demonstrating the position and central ray placement and another to exhibit the anatomy demonstrated by the setup. To conserve x-ray film and facilitate viewing, sometimes the film is divided so that multiple views of a body part are seen on a single film ( Fig. In E, the patient is in a left anterior oblique (LAO) position, and in F, the patient is in a right anterior oblique (RAO) position, both corresponding to PA oblique projections.Įach table explains the position setup, central ray placement, tube angulation, optimal film size, and focal-film distance for each view. For example, C indicates a lateral projection in a right lateral position, and D indicates a lateral projection in a left lateral position. Position denotes the placement of the patient’s body, specifically the portion of the patient’s anatomy that is in contact with the Bucky. However, when one deals with the head, neck, or body trunk, the lateral and oblique projections are further clarified by the specific “position” of the patient. In the extremities, lateral projections are similarly described by the direction of the central ray hence, mediolateral and lateromedial projections are possible. For example, A denotes an anteroposterior (AP) projection and B a posteroanterior (PA) projection. The term radiographic “projection” references the path of the central ray as it exits the x-ray tube and passes through the patient’s body. An increase in mAs is required if the bony detail is present but the overall appearance of the film is too light.įIG 3-4 Radiographic views. When a film is critiqued, if the bony detail is too light so as to appear nonexistent, a 15% increase in kVp provides the necessary penetration. There may be instances when a change in penetration, or kVp, is necessary. Corrections for individual variations in machines are made by adjusting the mAs only because the chart was formulated using the fixed kV technique. The techniques contained in the chart provide a starting point of adequate exposures for a radiographic system similar to the one listed. ![]() When a fixed kV system is used, only one exposure factor, the mAs, needs to be changed to correct for errors. The reverse is true for films that are overexposed. To correct the exposure factors in a film that is underexposed, the mAs must be changed by a minimum of 30% to note a detectable change or by 100% for a significant change. In this system, the milliampere-seconds (mAs) is variable, and corrections in exposure factors require changing the mAs only. In smaller patients, the lower spectrum of the kV range is used in larger patients, the upper range of kV is used. The suggested technique is within a fixed kilovolt (kV) range per body part. Extremity detail screens with matched films †.400-speed rare earth screens with matched film or.
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