Exam 1 CA Diagnostics Flashcards
2nd most common death in US is from what
CA
what is an ultrasound?
probes send high frequency sound into the body
reflection or echo of the sound returns to the probe- electronics transform the echos into a picture of the inside of the part of the body being examined
OR
Uses sound waves to create gray scale images of internal strctures
ultrasound purposes
- us of mass can indicate if its solid or cystic
- sometimes combined w/ doppler to assess blood flow in a vessel or organ
- used to guide insertion of bx needle
cystic
fluid filled sac or sacks
3 reasons to order US for ca w/u
- determine if cystic or solid
- guide needle bx for mass
- stage disease (check for mets)
kidney us might find
Mass (tumor either malignant or benign) Kidney stones Hydronephrosis Cyst Abscess Transplant rejection
us of gallbladder and near by bile ducts show
Cholelithiases (gall stones)
Polyps
Dilatation due to obstruction
Characteristics of malignant tumor on US
- Solid
- Invasive
- Taller than wide
- Heterogenous
- poor sound transmission (hypoechoic or acoustic attenuation), high vascularity
heterogeneous
diverse in character or content.
cancers tend to be vascular unless they’re big. If big, they may be
necrotic, avascular center
A patient has a 1 cm, homogeneous, cystic, hyperechoic mass in the kidney. It is most likely benign. (T or F)
TRUE
Many times, when you test with US, malignant vs bengin, tissues that reflect US are usually more cystic, so they can get through that, and those that cant get through are more solid and more likely cancerous
CT is what?
generated from images produced when multiple x-ray beams are passed through the body from different angles
done in “slices” each of which is a cross-section of the part of the body being examined
slices can be as close together as 1 mm
what lesions show up better on CT w/ contrast
vascular lesions
what are ct with PO contrast for
done to better outline lumen of stomach and bowels
ct scan concerns
radiation
radiation dose from CT of abdomen and pelvis equals
3 years of radiation from atmosphere and natural sources
CXR radiation equals about how much radiation exposure of natural sources
6 days
CT CI
Allergic to iodinated dye or shell fish Pregnancy Severe renal disease >300 lb may be contraindication Must be able to lay still and flat Claustrapohbia Metformin
Which of the following is NOT a good reason to order a CT of the abdomen?
a. stage a patient with known colon cancer
b. r/o kidney stones and renal cancer in a patient with hematuria
c. define an ovarian mass found on pelvic exam
d. r/o splenic rupture after an auto accident
C pay attention to location
MRI procedure
powerful magnet aligns the spin of atoms and sub-atomic particles. High frequency electronic signals perturb hydrogen ions in this state, and the minute amount of energy produced is captured by the MRI apparatus
Which imaging is better for bony structure, MRI or CT
CT
MRI or CT, which provides better soft tissue detail
MRI
MRI advantages compared to CT
better contrast between normal and abnormal tissue
fewer obscuring bone artifacts
blood provides a natural contrast because it appears very dark
views can be taken in any plane
no radiation
MRI CI
> 300 lb - open MRI may be needed
inability to be still for duration of exam
pts who need life support equipment (metal objects cannot be in room)
metal implants
hx claustrophobia (open MRI or sedation may be needed)
PET scan
show the metabolism of living tissue
nuclear scan
PET scans, what are characteristics of CA
areas with high metabolism
PET scan, CA survelliance
CA that has been treated may not show any shrinkage, but PET can show metabolism is gone indicating appropriately treated CA
PET scan procedure
radiotracer is injected or breathed into body
radiotracer will go to areas that use the natural chemical in the radiotracer ( i.e. glucose)
PET scan detects the energy emitted by positively charged particles (positrons)
As the radiotracer is broken down inside the patient’s body, positrons are created
appears as a 3-D image on a computer monitor
PET scan advantage
can reveal how a part of the patient’s body is functioning, rather than just how it looks
Metabolic activity
bone scan sensitivity and specificity
sensitivity and specificity are not as high as the clinician would like (0.8 and 0.75)
bone scan procedure
radioactive substance (tracer) is injected into a vein tracer travels through bloodstream and into bones scan of body
bone scan hot spots
areas of fast bone growth or repair absorb more tracer and show up as hot spots
bone scan hot spots indicate what
may point to problems like tumors, arthritis, fx, or infections
indications for bone scans
Cancer staging to check for bone mets
Osteomyelitis
Hairline fracture
Bone scan CI
pregnancy
lactation
tumor markers
Used to help diagnose cancer, predict a patient’s response to certain cancer therapies, check a patient’s response to treatment, or determine whether cancer has returned.
Substances produced by cancer or other cells of the body in response to cancer or certain benign (noncancerous) conditions
what are tumor markers used for
determining whether a tumor is responding to treatment or assessing whether it has recurred
CA 19-9
Look for Pancreatic cancer, gallbladder cancer, Bile Duct Cancer, and gastric CA
Analyze the Blood
Use to assess whether CA tx is working
Cancer antigen 125
cancer marker
protein is produced in large amounts in ovarian cancer
level in the blood rises with the onset of cancer and declines with successful treatment
a number of conditions that can cause an elevated CA 125 – endometriosis
could be used to detect ovarian cancer earlier than it would be found
carcinoembryonic antigen (CEA)
to follow the treatment of colon cancer
positive in about 80% of patients with colon cancer
also positive in patients with other adenocarcinomas, sarcomas, & some non-cancer diseases(ulcerative colitis)
can be elevated in patients who smoke
