Imaging Flashcards
(26 cards)
List the descending order of attenuation value.
Metal, bone, water, muscle, fat, air.
Where is the x-ray detector placed in a PA radiograph?
On the patient’s chest.
Where is the x-ray detector placed in an AP radiograph?
On the patient’s back.
Which are preferred, AP or PA, and why?
PA, because the shorter distance between the detector and the organ results in a more accurate depiction of the anatomy, whereas an AP may magnify certain organs.
Should x-rays be taken at full expiration or full inspiration?
Full inspiration.
How many posterior and anterior ribs should be visible?
10 posterior ribs, 6 anterior ribs.
What is very important when it comes to reading chest x-rays?
Having a systematic approach when looking at an x-ray.
What is a silhoutte sign?
The loss of normal borders between two structures on a radiograph, when they are very similar in density.
Approximately where is the I-line? What does it separate?
It goes right through the carina/sternal angle (T4), between ribs 4 and 5. Anything above it is upper lobe, any thing below is lower lobe.
Which lung has a middle lobe? Between which ribs is it located?
The right lung. Ribs 4 and 6.
What ribs to the minor fissure and the major/oblique fissure run along side?
Minor fissure: rib 4, oblique fissure: rib 6
What does the minor fissure separate? major/oblique fissure?
The minor fissure separates the upper and middle lobes in the right lung. The oblique fissure distinguishes the inferior lobe in both lungs.
What are the boundaries of the anterior, middle and posterior mediastinum?
Anterior: posterior surface of sternum to anterior surface of pericardium, aorta and brachiocephalic veins.
Posterior: posterior surface of pericardium and great vessels to anterior surface of spine.
Middle: between anterior and posterior. Contains the heart and great vessels.
Where is the line that distinguishes the superior and inferior mediastinum drawn?
At T4, through the sternal angle.
Where can the superior vena cava be found?
To the right of where the trachea bifurcates. This is only visible when there is pathology.
Which hemidiaphragm should be slightly higher than the other.
The right should be higher than the left, due to the liver.
True or false: the heart should not exceed 50% the width of the thorax.
True.
If the patient is standing upright, where in the lungs will the pulmonary vasculature be more prominent?
In the lower lobes, due to the effect of gravity on the circulating blood.
On lateral films, why is the thoracic spine easier to visualize as you go from top to bottom of the lungs?
There is more soft tissue in the apices and more air in the bases.
What causes pulmonary edema?
Increased hydrostatic pressure of lung capillaries or increased capillary permeability Fluid can accumulate in the interstitium or alveoli.
What is an early sign of pulmonary edema?
Kerley B lines. They indicate interstitial edema.
What pattern does alveolar edema have in the lungs?
A butterfly pattern, with puffy white areas, characterized by a central predominance of shadows with a clear zone at periphery lobes.
What is the most common non-cardiogenic type of pulmonary edema?
Neurogenic. It is caused by sympathetic vasoconstriction, leading to an increase in pulmonary venous pressure and a shift of blood from systemic to pulmonary circulation, increasing pulmonary capillary pressure and permeability.
What can go wrong in the pleural capillaries that leads to pleural effusion?
Too much hydrostatic pressure on the arterial side or too little osmotic pressure on the venous side.
