Radiology I, Ii; Sids And Infant Apnea

Front 1

What are the 5 basic densities on a chest radiograph?

Back 1

In order of darker (least dense) to whiter (most dense):

1) Air
2) Fat
3) Water (blood or muscle)
4) Bone
5) Metal

Front 2

When two overlapping structures are visible we say that we see the _______ of the two structures

Back 2

silhouette

Front 3

What is the silhouette sign?

Back 3

When the distinction between two structures, formerly of different densities, is lost because they are now of the same density.

Front 4

What is the direction of the xray beam in
A) PosteroAnterior (PA)
B) AnteroPosterior (AP)
view?

Back 4

A) Xray beam first passes thru the patient's back, then anterior chest wall, then film.
B) First goes through anterior, then posterior, then film.

Front 5

Why are films of healthy individuals taken in the PA position?

Back 5

Places the heart closer to the film and minimizes magnification.

Front 6

T/F Left atrium is easily seen on normal front view

Back 6

F. visualization of this structures indicates that there is enlargement that is caused by pathologic process.

Front 7

Lateral chest radiographs are taken with the patients ________ side against the film.

Back 7

Left. This is to position the heart closer to the film and minimize magnification

Front 8

Masses that occur in the anterior mediastinum (4Ts)

Back 8

1) Thymoma (most common)
2) Teratoma
3) Thyroid Mass
4) "terrible" lymphoma

Front 9

____ heart chambers are more posterior, while _____ heart chambers are more anterior

Back 9

Left; right

Front 10

Extends from anterior wall of trachea and posterior heart border back to anterior vertebral column

Back 10

middle mediastinum

Front 11

Most common middle mediastinal mass

Back 11

Hilar adenopathy (from a variety of causes)

Front 12

Most common posterior mediastinal (From anterior aspect of vertebral bodies to posterior chest wall) masses

Back 12

Neurogenic in origin, like neurofibroma, ganglioneuroma, neuroblastoma.

Front 13

When is a chest radiograph taken in breath cycle?

Back 13

During deep inspiration.

Front 14

When are expiratory films useful and why?

Back 14

Evaluation of pneumothorax. Will make the pneumothorax appear larger.

Evaluation of foreign body inhalation. Air has difficulty exiting the lung. Expiration view will demonstrate this air trapping on the side of the bronchial obstruction, the normal side getting smaller.

Front 15

What are decubitus views? How are they obtained?

Back 15

With patient lying on either the right or left ride. Gravity will allow a pleural effusion to layer along the dept chest wall.

Front 16

What is apical lordotic view used to assess?

Back 16

The lung apices, which are sometimes obscured by clavicles and overlying ribs.

Front 17

What is the advantage of thorax ct?

Back 17

Visualization of small nodules, particularly in most inferior aspect of lower lobes (can be obscured in normal CXR)

Front 18

What is the disadvantage of thorax ct?

Back 18

Cost (>$1k for full chest).

IV contrast can cause problems when renal function isn't good.

Front 19

What is thorax MRI useful for?

Back 19

Less useful than CT.

Best for evaluation of CV system, principally pericardial disease, intracardiac shunts, valve problems, aortic dissection/aneurysms. Can be used in pregnancy.

Front 20

What is the secondary pulmonary lobule?

Back 20

fundamental unit of lung structure, and it reproduces the lung in miniature. Airways, pulmonary arteries, veins, lymphatics, and the lung interstitium are all represented at the level of the secondary lobule.

Each secondary pulmonary lobule is separated from its neighbor by a connective tissue sheath, the interlobular septum that contains the pulmonary veins and lymphatics.

Front 21

Two large categories the lung is divided into

Back 21

Air spaces: alveoli

Interstition: structures supporting the air spaces (visceral pleural surface, interlobular septae, CT sheath)

Front 22

What are signs of air space disease on CXR?

Back 22

Opacity. This is because the majority of total lung volume of secondary pulmonary lobule consists of alveolar spaces.

Poor margination.

Coalescence (processes that tend to begin in an area and then expand)

Air bronchogram

Butterfly/batwing pattern

Front 23

What is air bronchogram?

Back 23

Term referring to tubular lucencies running through air space opacity in the lung fields.

Front 24

What is the butterfly/batwing pattern?

Back 24

Characteristic of air space disease processes (edema) to cause opacity in perihilar regions

Front 25

Differential diagnosis of air space disease in acutely ill patient

Back 25

Water

Pus

Blood

Front 26

Chronic air space disease by defn last > _______

Back 26

1 month

Front 27

What is Kerley's line?

Back 27

Linear densities resulting from fluid within the interlobular septae.

Extend from the periphery of the chest inward ~1 cm.

Front 28

What is honeycombing?

Back 28

Associated with pulmonary destruction within the secondary pulmonary lobule and condensation of the surrounding interlobular septum from interstitial fibrosis.

White ring with lucent center.

Front 29

Peribronchial/perivascular thickening: what causes it?

Back 29

Accumulation of fluid of other pathologic process in the axial connective tissue sheaths make the margins of these structures hazy and ill-defined.

Front 30

Hilar haze: what is it and why does it occur?

Back 30

Poor definition of the central pulmonary vessels. Can occur on the same basis as peribronchial/perivascular thickening.

The usually distinct hilar pulmonary vessels become indistinct as fluid collects in the interstitium arround them.

Front 31

Subpleural edema: what is it and why does it occur?

Back 31

accumulation of fluid deep to the visceral pleural surface. Causes a thin white line that parallels the expected position on a major or minor fissure of the lungs.

Front 32

What accounts for the vast majority of nodular patterns seen on chest films?

Back 32

Malignancy and granulomatous processes (both infectious and non-infectious)

Front 33

Generally, how do metastatic nodules appear?

Back 33

Sharply defined (but may be ill-defined if very vascularized)

Front 34

How do granulomatous infectious disease processes appear?

Back 34

Well-defined margins, particularly in chronic form. Tend to be calficied, which is a sign of benign disease.

Miliary (very small) nodules are seen with tuberculosis. Sarcoidosis and lymphoma can cause air space nodules, with air bronchograms.

Front 35

What are the 3 main patterns of pulmonary abnormalities visualized on CXR?

Back 35

1) Nodular

2) Interstitial

3) Alveolar

Front 36

What view is best for:

Evaluate Lung Apices

Back 36

Apical lordotic

Front 37

What view is best for:

Mobile Pleural Effusion

Back 37

Decubitus film

Front 38

What view is best for:

Foreign Body - air trapping
Pneumothorax

Back 38

Expiratory film

Front 39

Achalasia: defn

Back 39

incomplete low esophageal sphincter (LES) relaxation, increased LES tone, and lack of peristalsis of the esophagus

Front 40

What is the Split Pleura Sign? What does it indicate?

Back 40

The split pleura sign is seen with pleural empyemas and is considered the most reliable CT sign helping to distinguish an empyema from a peripheral pulmonary abscess

Front 41

Mycetoma: defn

Back 41

fungus ball

Front 42

Kerley Lines A and B
Honeycombing
Peribronchial/Perivascular thickening
Hilar Haze
Subpleural edema


Are all characteristic of what?

Back 42

Interstitial disease

Front 43

Normal lung architecture replaced by small cystic spaces

Back 43

honeycombing

Front 44

absence of airflow at nose and mouth

Back 44

apnea

Front 45

absence of oronasal airflow in the presence of continued respiratory effort lasting longer than two respiratory cycles

Back 45

obstructive apnea

Front 46

cessation of respiratory effort lasting at least two respiratory cycles

Back 46

central apnea

Front 47

Most important factor in central control of ventilation

Back 47

Arterial pCO2

Front 48

Generates inspiratory APs.

Receives input thru chemoreceptors via CN X and CN IX

Back 48

Dorsal respiratory group in medulla (DRG)

Front 49

Inhibits the dorsal respiratory group and thus helps control rate and pattern of breathing

Back 49

Pneumotaxic center

Front 50

responsible for abdominal expiratory movements during times of high levels of respiration

Back 50

ventral respiratory group in medulla (VRG)

Front 51

T/F O2 is typically unimportant for direct control of the respiratory center.

Back 51

T

Front 52

Peripheral chemoreceptors respond to (increases, decreases) in arterial pO2 and pH and (increases, decreases) in arterial pCO2

Back 52

decreases; increases

Front 53

What is the Hering-Breuer inflation reflex?

Back 53

There are receptors in the walls of bronchi and bronchioles that, during overinflation, signal thru CN X that switches off inspiratory ramp

Front 54

What are J receptors (Juxta-capillary)?

Back 54

J-receptors respond to events such as pulmonary edema, pulmonary emboli, pneumonia, and barotrauma, which cause a decrease in oxygenation and thus lead to an increase in ventilation/respiration. They may be also stimulated by hyperinflation of the lung as well as intravenous or intracardiac administration of chemicals.

May be involved in sensation of dyspnea.

Front 55

decreased breathing associated with ≥50% reduction in airflow

Back 55

obstructive hypopnea

Front 56

most important receptors in minute to minute control of respiration

Back 56

central chemoreceptors. on ventral surface of medulla

Front 57

What do central chemoreceptors sense?

Back 57

Increased CO2.

When CO2 diffuses across blood-brain barrier, it reacts with water forming carbonic acid which increases [H+].

Front 58

Main receptors in response to hypoxemia

Back 58

Peripheral chemoreceptors (aortic arch, carotid bodies)

Front 59

Involved in Hering-Breuer reflex
They discharge in response to lung inflation.
This reflex is important in neonates and infants, but is inactive in adults at normal tidal volumes.

Back 59

pulmonary stretch receptors

Front 60

Two areas of the Medullary Respiratory Center and what they do

Back 60

Dorsal: inspiration

Ventral: expiration (may do some inspiration in increased ventilation)

Front 61

area where all or most of the dorsal respiratory group neurons are located in the medulla.

Back 61

nucleus of solitary tract

Front 62

area where the ventral respiratory group of neurons reside rostrally

Back 62

nucleus ambiguus

Front 63

T/F hypoxemia is not as strong a driving force as hypercapnia

Back 63

T

Front 64

T/F Almost all apnea, regardless of abnormality occurs during sleep

Back 64

T

Front 65

A prolonged >20 second respiratory pause, or shorter pause associated with bradycardia or cyanosis in the preterm infant with no identifiable cause


Thought to relate to dysfunction of respiratory neurons 2ndary to immaturity

Back 65

apnea of prematurity

Front 66

T/F apnea of prematurity is a risk factor for SIDS

Back 66

F

Front 67

apnea of prematurity: tx

Back 67

tactile stimulation
methylxanthines
assisted ventilation
home monitoring

Front 68

An episode characterized by a combination of apnea, color change, change in muscle tone, choking, or gagging

Back 68

Apparent Life Threatening Event (ALTE). Previously called "near miss SIDS"

Front 69

sudden death of an infant, unexpected by history, and unexplained by autopsy

Back 69

Sudden Infant Death Syndrome (SIDS)

Front 70

What position is highest risk for SIDS?

Back 70

prone (stomach)

Front 71

When is SIDS most common?

Back 71

peaks at 2 - 3 months, rare in the first month and after 5 months

Front 72

T/F Maternal and paternal smoking is a risk factor for SIDS

Back 72

T

Front 73

Characteristic (but not specific) autopsy findings of SIDS

Back 73

1) Intrathoracic petechiae in 3/4 of victims

2) Histologic evidence of minor respiratory infection (IL1 and IL6 production stimulate deep sleep and therefore apnea)

3) Prior episodes of hypoxia evidenced by abnormal persistence of HbF, astroglial proliferation, hypoxanthine in vitreous

4)

Front 74

Prevention of SIDS

Back 74

"back to sleep"

Reduction of cigarette smoke

Avoid overdressing

Prenatal care

Discouraging cosleeping

Front 75

Why Does the prone position represent such a risk?

Back 75

Unclear, but

Increased diaphragm thickness and
Laryngeal chemo reflex (LCR):

Elicited by direct fluid stimulation of the laryngeal mucosa


Both seem to play a role in increasing risk.

Front 76

characterized by downward herniation of posterior fossa contents below the level of the foramen magnum

Back 76

chiari malformation