hounsfield units
this is the HU for water
0
1500, -600
lung window
this type of contrast used in CT is preferred due to decreased risk of reactions
LOCM / water soluble iodinated contrast
this is the scan delay for an enhanced head in order to get past the BBB
5 minutes
an unenhanced abdomen is a common order for this pathology
renal colic
this is the HU for cortical bone
+1000
150, +30
liver window
this value will need to be decreased when the patient's only accessible vein is in the hand
flow rate and thus scan delay
a PE is scanned with this type of "delay"
bolus tracking
a patient suddenly presents with trouble speaking and dizziness, this is the first scan that will need to be done
unenhanced head to determine if tpa can / should be used
this is the hounsfield unit for cerebrospinal fluid
0-15
350, +50
mediastinum window, also accepting soft tissue
this is the amount of oral contrast needed to drink for a barium enhanced abdomen
450-900 ml
this is the scan delay for the abdomen
65 seconds
this is a low-contrast chest ct to evaluate small spots in the lung
nodule
chronic / old blood in the brain will show up as this colour on CT
dark grey / black
80, +40
brain window
hypertension, dyspnea, mild lryngeal edema are all examples of this type of contrast media reaction
moderate
the nephrogenic phase occurs after this many seconds
100
this type of scan is done to differentiate ischemic tissue from salvageable tissue in the brain
perfusion
a structure that is +600 HU will show up as this colour on a CT with a WL of +250 and WW of 500
white
1800, +400
spine bone window
these are normal values for BUN, creatinine, and eGFR
BUN: 7-20
creatinine: male 0.8-1.5, female 0.6-1.3
eGFR: 60-90
this is the first phase of contrast enhancement that occurs after 15-20 seconds after injection
early arterial phase
this study often includes a 10 minute delay after injecting contrast
urography