Teknik Radiografi II (Pharynx & Larynx)

PHARYNX AND LARYNX ( MERRILLS ATLAS OF RADIOGRAPHIC POSITIONS )

AP PROJECTION

Radiographic studies of the pharyngolaryngeal structures are made during breathing, phonation, stress maneuvers, and swallowing. To minimize the incidence of motion, the shortest possible exposure time must be used in the examinations. For the purpose of obtaining improved contrast on the AP projections, use of a grid is recommended.

Position of patient

• Except for tomographic studies, which require a recumbent body position. place the patient in the upright position, either seated or standing, whenever possible.

Position of part

• Center the midsagittal plane of the body to the midline of the vertical grid device.

• Ask the patient to sit or stand straight. If the standing position is used, have the patient distribute the weight of the body equal ly on the feet.

• Adjust the patient's shoulders to lie in the same horizontal plane to prevent rotation of the head and neck and resultant obliquity of the throat structures.

• Center the IR at the level of or just below the laryngeal prominence.

• Extend the patient's head only enough to prevent the mandibular shadow from obscuring the laryngeal area.

• Shield gonads.

• Respiration: Obtain preliminary radiographs (both AP and lateral) during the inspiratory phase of quiet nasal breathing to ensure that the throat passages are filled with air. To determine the optimum time for the exposure, watch the breathing movements of the chest. Make the exposure just before the chest comes to rest at the end of one of its inspiratory expansions.

Image receptor

 8 x t o inches ( 18 cm X 24 cm) or 24 cm X 30 cm lengthwise

Central ray

Perpendicular to the laryngeal prominence

EVALUATION CRITERIA

The following should be clearly demonstrated:

• Area from the superimposed mandible and base of the skull to the lung apices and superior mediastinum

• No overlap of the laryngeal area by the mandible

• No rotation of neck

• Throat fi lled with air in preliminary studies

• Radiographic density permitting visualization of the pharyngolaryngeal structures

LATERAL PROJECTION

R or L position

Position ot patient

• Ask the patient to sit or stand laterally before the vertical grid device.

• Adjust the patient so that the coronal plane that passes through or just anterior to the temporomandibular joints is centered to the midline of the IR .

Position ot part

• Ask the patient to sit or stand straight, with the adjacent shoulder resting firmly against the stand for support.

• Adjust the body so that the midsagittal plane is parallel with the plane of the IR.

• Depress the shoulders as much as possible, and adjust them to lie in the same transverse plane. If  needed, have the patient clasp the hands in back to posteriorly rotate the shoulders.

• Extend the patient's head slightly.

• Immobilize the head by having the patient look at an object in line with the visual axis.

Image receptor

 8 x 1 0 i nches ( 18 cm x 24 cm) lengthwise

Central ray

• Perpendicular to the lR, centering the lR ( I ) I inch (2 .5 cm) below the level of the external acoustic (auditory) meatuses for demonstration of the nasopharynx and for cleft palate studies, (2) at the level of the mandibular angles for demonstration of the oropharynx, or ( 3 ) at the level of the laryngeal prominence for demonstration of the larynx, laryngeal pharynx, and upper end of the esophagus (Fig. 1 5-34)

EVALUATION CRITERIA

The following should be clearly demonstrated:

• Soft tissue density of the pharyngolaryngeal structures

• Area from the nasopharynx to the uppermost part of the lungs in preliminary studies

• Specific area of interest centered in detailed examinations

• No superimposition of the trachea by the shoulders

• Closely superimposed mandibular shadows

• Throat filled with air in preliminary studies