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121

The outermost layer of the pleura is referred to as the

parietal pleura

122

Which of the following is not a mediastinal structure?
Thymus gland
Esophagus
Trachea
Epiglottis

Epiglottis

123

What is body habitus?

Refers to the common variations in the shape of the human body. It is based on a 1917 study by WR Mills of 1000 patients.

124

How is body habitus used in radiology?

Body habitus determines size, shape, and position of organs in thoracic & abdominal cavities.

125

Body habitus directly affects the location of which organs?

Heart, lungs, Diaphragm, Stomach, Large intestine, Gallbladder.

126

What are the four types of body habitus?

Sthenic
Hyposthenic
Asthenic
Hypersthenic

127

What does one need to keep in mind when taking an image of a hypersthenic person?

Massive build, thorax is broad side to side, thorax is deep front to back, and thorax has shallow vertical dimensions.

128

What does on need to keep in mind when taking an image of an asthenic person?

Slender build, thorax narrow from side to side, thorax shallow from front to back, thorax is very long in vertical dimension.

129

During inspiration, the thoracic cavity increases in what three dimensions?

Vertical diameter (Diaphragm moves downward and increases thoracic volume.), transverse diameter (diameter ribs swing outward and upward) anterioposterior diameter by raising the ribs; especially ribs 2-6.

130

How many ribs should one see on a good PA chest radiograph?

a minimum of 10.

131

How is a patient prepped for a radiograph?

Removal of opaque objects, clothing artifacts, long hair fasteners, and O2 lines and pacemaker leads not in lung fields.

132

The higher the kVp, the more:

Greys.

133

Technical factors for a chest x-ray (concerning kV):

kVp between 110-125 demonstrates many shades of grey needed to visualize lung markings. Low contrast, long scale contrast, and high kV requires use of grids.

134

Technical factors for a chest x-ray (concerning mAs):

High mA & short exposure times reduces motion. *Sufficient mAs is needed to provide optimum density of lungs and mediastinal structures.*

135

Optimal density for a chest x-ray:

Able to see faint outlines of at least mid and upper vertebrae and posterior ribs through the heart and other mediastinal structures.

136

Placement of film markers on a chest x-ray:

Top lefthand corner. "L"

137

Pediatric Applications for chest xray. Newborns:

AP supine or dorsal decubitus.

138

Pediatric Applications for chest xray. When child can support own head:

Erect PA and laterals. Use Pigg-o-Stat.

139

Technical factors for pediatric chest xray:

Lower kVp 60-70, less mAs, shortest exposure time possible (to reduce motion.)

140

Geriatric applications for a chest xray: CR location:

A little higher CR location may be required because older patients have less inhalation capacity (center around T6-T7).

141

Common geriatric pathologic conditions of chest are:

pneumonia and emphysema.

142

Pneumonia:

inflammation of lungs resulting in an accumulation of fluid within certain sections of the lung creating increased radiodensities in these regions. Generally requires some increase in exposure factors to penetrate and visualize these areas.

143

Emphysema:

Alveoli become enlarged because of alveolar wall destruction and loss of elasticity. Air tends not to be expelled during exertion. Causes: smoking and long term dust inhalation. Radiographically evident by increased lung dimension. Lung fields radiolucent. Requires decrease in exposure factors from normal chest.

144

Instructions on patient handling for geriatric patients:

More care, time, and patience is frequently required in explaining breathing and positioning requirements. Helping and supporting theses patients in the positioning process is important. Arm supports for lateral projection.

145

Breathing instructions:

Hold breath on second "full" inspiration. Not "deep," which will cause distortion.

146

Indications for full inspiration and full expiration comparison radiographs:

small pneumothorax
fixation or lack of movement of diaphragm
presence of foreign body
distinguish between opacity in rib or lung
atelectasis

147

Atelectasis:

A condition in which collapse of all or portion of a lung occurs as a result of an obstruction or the bronchus, or a puncture of an air passageway. With less than normal air in the lung, this region appears more radiodense and may cause the trachea and heart to shit to the affected side.

148

Reason for erect chest position:

*Allows diaphragm to move down farther.
*Demonstrates air-fluid levels (Minimum of 5 mins allows fluid to settle or air to rise).
*Prevents engorgement and hyperemia of pulmonary vessels.

149

Minimum SID for erect chest position:

72 inches to minimize heart magnification of heart and to obtain greater recorded detail of the delicate lung structures.

150

A 72 inch SID magnifies less because:

the X-ray beam has less divergence. (Picture the shadow of your finger as you move the flashlight closer and then further away.)