brigs quiz 1 lab/rad

What is included on a lab slip

Pt name

DOB

Date ordered

ICD 10 code

CPT codes

Match ICD 10s

Needed for reimbursement

For elimination of fraud and abuse

Accuracy

closeness to the true value

precision

reproducibility of results

specificity

true negatives

useful for confirming new dx

will have few false positives if good

sensitivity

true positives

useful to exclude diagnoses

few false negatives

use of predictive values

determine whether or not a patient has a disease based on lab results

positive predictive value

indicates likelihood pt has disease

# of true positives

negative predictive value

indicates likelihood pt does not have disease

# of true negatives

BMP includes

Na

K

BUN

Creatinine

GFR

Glucose

Ca

Cl

Bicarb

what % of errors are pre-analytical

75%

Disadvantages of POCT

Quality

Results aren't as good

More expensive

neutrophils indicate

signs of infection or inflammation

usually bacterial

lymphocytes indicate

infections/immune response

more viral

hematological cancers

eosinophils indicate

allergies

basophils indicate

allergic reactions

autoimmune disease

Na indicates

fluid balance

nerve/muscle function

abruptly low = seizures

K indicates

muscle function

nerve signals

cardiac rhythms

What additional tests are in a CMP

Albumin

total protein

AST

ALT

Total bilirubin

ALP

best tests for liver function concern w/ abdominal pain

bilirubin

AST

ALT

3 causes of artifact

1. patient movement

2. hardware

3. software - or operator use

Positive contrast agents

enhance imaging

examples of positive contrasts

barium

iodinated agents

purpose of intravascular contrast agents

in CT - visualization of hypervascular tissue and vascular structures

most common generation of intravascular contrast

second generation

less adverse reactions, more tolerable

Omnipaque

third generation contrast agents

those with high risk of contrast-induced nephrotoxicity

Visipaque

Planar imaging

shadows of complex 3D objects

compressing large objects into 2D images

example of planar imaging

radiography

cross-sectional imaging

addresses 3D structures by making 2D slices

images can be 2D or 3D

examples of cross-sectional imaging

CT, US, MRI

most vs. least expensive scan

most = MRI

least = x-ray

radiography includes

x-ray

fluoroscopy

oldest radiology testing

radiography (x-ray)

best use of x-rays

observe bones

main disadvantage of x-ray

collapses 3D structures into 2D

fluoroscopy

projectional radiography for real-time observation of structures

uses of fluoroscopy

GI imaging (swallowing)

Interventional radiology (heart cath)

MSK radiology

CT scan

Cross-sectional imaging to ID greater range of abnormalities in the body

rapidly rotating x-ray tube

air embolism

risk of CT contrast

-rare

-large air bubble enters via hand injection

nephrotoxicity

risk of CT contrast

-acute renal dysfunction 2-3d after IV admin

-rare

contrast excavation

risk of CT contrast

-contrast is toxic to soft tissues

-localized inflammation

-ulcers, necrosis, compartment syndrome if severe

metformin and IV contrast dye

if acute renal failure develops, can lead to lactic acidosis

-hold metformin 48hrs before and after CT scan

It is important to check for this in women before giving CT scan

pregnancy

especially early! safer in later trimesters

what method has the most radiation exposure

CT scan

how does US work

passing sound waves into tissue and analyzing reflected waves

uses gray-scale

important uses of US

doppler analysis for blood flow

differentiation between cysts and solid lesions

contrast for US

definity or optison

used for evaluating the heart

bubble studies

US

cardiac use

helps look for holes in the heart

3 pieces of tech for US

transducer

console

CPU

limitation of US

depends on the tech being very skilled

what differentiates best between cysts and solid lesions

US

what is the gold standard to dx testicular and ovarian torsion

US

cons of US

-depends on operator skill

-limited eval of deep structures

-hard to see structures deep to gas - like lungs

use of contrast on MRI

enhance tumors and reduce inflammation

primary for MSK and spine imaging - distinguishes discs, muscles, ligaments, and tendons

MRA vs CTA

MRA = blood vessel visualization via MRI

CTA = blood vessel visualization via CT

most common MRI contrast

Gadolinium

Nephrogenic system fibrosis (NSF)

complication of gadolinium contrast in MRI

-high morbidity and mortality

-pt w/ stage IV or V CKD and AKI

pros of MRI

great for soft tissue contrast

no radiation exposure

patients to limit radiation in

pregnant women, especially early

patients of reproductive age

children

imaging with radiation

X-ray

CT

Nuclear medicine