Radiology Midterm Flashcards
Capsule endoscopy
Phleboliths
Gastric lap band
Upright abdominal radiography
Supine Abdominal Radiography
Emphysematous cholecystitis
Paralytic ileus
Continous Diaphragm Sign
Secondary to pneumoperitoneum
Small bowel obstruction
Describe how a small bowel obstruction would look on x-ray.
Proximal - dilated
transition point - obstruction
distal - collapsed
How do you treat a small bowel obstruction?
Lysis of adhesions
Differentiate valvulae conneventes from haustra on x-ray.
Valvulae are continuous (connect)
Haustra don’t
What constitutes a dilated small bowel on CT with contrast?
>2.5-3 cm
Diffuse dilation of the small and large bowel on x-ray?
Paralytic ileus
What is the modality of choice to diagnose renal, ureteral and bladder calculi?
CT abdomen without constrast
How do you follow/monitor renal calculi in family practice?
U/S - don’t want to expose somone to too much radiation, when you already know they have stones
What are phleboliths?
Calcification of the pelvic veins
Will you see the diaphragm on a supine (AP) or upright (PA) abdominal x-ray?
Upright - air under the diaphragm
Where does the air rise to in an upright abdominal x-ray?
Fundus of the stomach AND hepatic and splenic flexures
Where does the air rise to in a supine abdominal x-ray?
Body of the stomach and transverse colon
T/F: If you see an emphysematous cholecystitis on x-ray, confirm with U/S?
False - SURGICAL EMERGENCY - gas forming anaerobic infection in the wall of the gallbladder
What is the test of choice for diagnosing gallstones?
U/S - abdominal x-rays miss most stones
What will you see on an x-ray in a person with a pneumoperitoneum?
Continous diaphragm sign - air within the peritoneal cavity, under the diaphragm
When should you see the valvulae conneventes on an x-ray?
Abnormal - i.e. dilated portion proximal to an obstruction
What is the name of the large bowel fold pattern?
Haustrations/Haustra
What is the name of the small bowel fold pattern?
Valvulae conneventes
What is the name of the stomach fold pattern?
Rugae
What is the most commonly performed radiologic examination?
Chest x-ray
Explain the basic principles of a radiograph?
- A light source emits light photons towards the patient
- The photons penetrate the patient, depending on their density of the organs (some are transmitted, some are attenuated)
- Transmitted photons are captured by the detector, while attenuated photons cast a shadow on the detector.
Does air filled tissue (i.e. lungs) attenuate or transmit photons?
Transmit - maximally exposes the detector
Does dense tissue (i.e. bone) attenuate or transmit photons?
Attenuates - minimally exposes the detector
Does soft tissue (i.e. heart, vessels) attenuate or transmit photons?
Variable
What are the 5 radiographic densities?
Air
Fat
Fluid, soft tissue
Bone, calcium
Metal
T/F: Soft tissue and fat have the same density on x-ray?
False - soft tissue and FLUID have the same density on x-ray
What color is the original x-ray film? What color will be displayed on the radiograph if the beam is attenuated by a tissue?
The original x-ray film is white
If the beam is attenuated, it is absorbed by the tissue, and the resulting radiographic image will be white (i.e. bone)
Define radiolucent.
Black, lucency, dark, decreased density
Define radioopaque.
White, opacity, density, consolidation, increased density
(things that absorbed the x-ray beam)
Of the 5 radiographic densities, which are radiolucent?
Air
Fat
Of the 5 radiographic densities, which are radioopaque?
Fluid, soft tissue
Bone, calcium
Metal
Should the lungs be black void, like the atomospheric air?
No
If you see a very dense and calcified nodule in the lung, how what can you compare it to, to determine if it is a TB granuloma?
Adjacent rib - if the nodule is denser (whiter) than the adjacent rib, then you can diagnose it as a TB granulom
2 objects of DIFFERENT radiographic densities touch/border each other
Radiographic interface
2 objects of the SAME radiographic density touch/border each other
Silhouette sign - the border disappears
If there is fluid in the lungs (i.e. alveoli) and it is bordering the heart (soft tissue), there will be a silhouette sign where there should be an interface
What are the standard chest radiograph views? What type of patients are they used for?
PA & Lateral - patient who can stand
AP - supine patient
Semi-erect AP
What does “PA” chest radiograph mean?
Posterior to anterior - describes the direction of the beam through the patient (posterior to anterior) towards the detector
If you were not able to determine if the patient were standing or supine based on the air in the stomach/colon, where could you cheat and look?
At the arm - if they are in a bear hug the patient is standing PA
If they are by the patient’s side, they are supine
Is the heart size more acurate in a PA (upright) or supine radiograph? What is the ratio?
PA (upright) - 1:1 ratio - because the chest is directly against the detector
Is the PA (upright) or supine chest radiograph more sensitive for free air (i.e. pneumothorax)?
PA (upright)
If you are looking for free air in the colon, should you look under the right or left lung?
Right lung - so not to confuse any air in the colon with the air in the gastric air bubble (fundus)
How should the patient stand for a lateral chest radiograph?
Right to left (beam goes through the right then the left)
What should you do if you see a mass on radiograph?
Triangulate in the orthogonal plane (Rotate 90 degrees - Lateral chest radiograph)
When you see a mass you want to confirm it is a mass by triangulating it in the orthogonal plane because a mass will be spherical in all planes
Is the PA (upright) or supine chest radiograph less sensitive for fluid and free air?
AP (supine)
In which radiograph will the heart be magnified? Why?
Supine (AP) - manification increases with increased distance of the object from the detector
Which radiograph technique is the most sensitive for picking up fluid? The least?
Most - lateral decub (only need 5 mL of fluid)
Lateral (erect) - 75 mL
PA (erect) - 150 mL
Least - AP (supine) - (need 300 mL)
Which lung segment is in contact with the right heart border? Left heart border?
Right - middle (right) lobe
Left - lingula (left)
On PA CXR, which lung is being imaged? Anterior, postior, or both?
Anterior and posterior lungs - superimposed on PA and AP radiographs
On AP CXR, which lung is being imaged? Anterior, postior, or both?
Both antertior and posterior lungs - superimposed on PA and AP radiographs
What is the pneumonic to determine technical adequacy of looking at a CXR?
PAIR
Penetration
Angulation
Inspiration
Rotation
What is ideal penetration when looking at a CXR?
Adequate photos penetrate the patient and expose the radiograph - able to see the spine through the heart shadow
What is underpenetration when looking at a CXR? Who does this occur in?
Falsely increased opacity (white) in the retrocardiac region and bases
Vessels become more prominent
Occurs in overweight patients
What is overpenetration when looking at a CXR?
Falsely decreased opacity - pulmonary nodules disappear
Simulates emphysema or PTX
What is ideal rotation (R) of a CXR?
The spinous processes should lie equidistant from the medial ends of each clavicle
What is distorted when there is rotation in a CXR?
Triple H
Heart - False cardiomegaly
Hilum - spurious hilar masses
Hemi - falsely elevated hemidiaphragm
What is the orientation of the anterior ribs on CXR?
Downward