Surgical Radiology Flashcards
What defines a technically adequate CXR?
RIPE:
Rotation (clavicular heads are equidistant from the thoracic spinous processes)
Inspiration (diaphragm is at or below ribs 8-10 posteriorly and ribs 5-6 anteriorly)
Penetration (disk spaces are visible but there is no bony detail of the spine, bronchovascular structures are seen through the heart)
Exposure (make sure all of the lung fields are visible)
How should a CXR be read?
Tubes and lines (check placement); Patient data (name, date, history number); Orientation (up/down, left/right); Technique (AP or PA, supine or erect, decubitus); Trachea (midline or deviated, caliber); Lungs (CHF, mass); Pulmonary vessels (artery or vein enlargement); Mediastinum (aortic knob, nodes); Hila (masses, LAD); Heart (transverse diameter should be less than half the transthoracic diameter); Pleura (effusion, thickening, PTX); Bones (fractures, lesions); Soft tissues (periphery and below the diaphragm)
What CXR is better: PA or AP?
PA, less magnification of the heart (heart is closer to the XR plate)
Classically, how much pleural fluid can the diaphragm hide on upright CXR?
Up to 500 cc
How can CXR confirm that the last hole on a chest tube is in the pleural cavity?
Last hole is through the radiopaque line on the chest tube.
Thus, look for the break in the radiopaque line to be in the rib cage.
How can a loculated pleural effusion be distinguished from a free-flowing pleural effusion?
Ipsilateral decubitus CXR.
If fluid is not loculated (or contained), it will layer out.
How do you recognize a PTX on CXR?
Air without lung markings is seen outside the white pleural line (best seen in the apices on an upright CXR)
What XR should be obtained before feeding via a NG or nasoduodenal tube?
Low CXR to ensure the tube is in the GI tract and not in the lung
What C-spine views are used to rule out bony injury?
CT
What is used to look for ligamentous C-spine injury?
Lateral flex and extension C-spine films, MRI
What CXR findings may provide evidence of traumatic aortic injury?
Widened mediastinum (> 8 cm); apical pleural capping; loss of aortic knob; inferior displacement of left main bronchus; NG tube displaced to the right; tracheal deviation; hemothorax
How should a CT scan be read?
Cross section with the patient in supine position looking up from the feet
How should an AXR be read?
Patient data (name, date, history number); Orientation (up/down, left/right); Technique (AP or PA, supine or erect, decubitus); Air (free air under the diaphragm, air-fluid levels); Gas dilatation (3, 6, 9 rule); Borders (psoas shadow, per peritoneal fat stripe); Mass (organomegaly, kidney shadow); Stones (urinary, biliary, fecalith); Stool; Tubes; Bones; Foreign bodies
How can you tell the difference between a SBO and an ileus?
In SBO there is a transition point between the distended proximal bowel and the distal bowel of normal caliber (may be gasless), whereas the bowel in ileus is diffusely distended
What is the significance of an air-fluid level?
Seen in obstruction or ileus on an upright XR.
Intraluminal bowel diameter increases, allowing for separation of fluid and gas
What are the normal calibers of the small bowel, transverse colon, and cecum?
Small bowel: < 3 cm
Transverse colon: < 6 cm
Cecum: < 9 cm
What is the “rule of 3s” for the small bowel?
Bowel wall should be < 3 mm thick
Bowel folds should be < 3 mm thick
Bowel diameter should be < 3 cm wide
How can the small and large bowel be distinguished on AXR?
By the intraluminal folds.
The small bowel plicae circulares are complete, whereas the plicae semilunares of the large bowel are only partially around the inner circumference of the lumen.
