Radiologic Specialties Final Exam Review

Question 1

Define CT:

Answer 1

Computed tomography scan. Detailed images of internal organs are obtained by this type of sophisticated X-ray device. CT stands for computed tomography. The CT scan can reveal anatomic details of internal organs that cannot be seen in conventional X-rays.

Question 2

Differentiate between pixels and voxels:

Answer 2

Pixels: picture elements. 2d element assigned a gray value in the form of a CT #

Voxel: 3d picture element that reps a volume of tissue in reconstructed CT image. voxel size depends on 3 things= slice thickness, matrix size, and FOV. voxel size is determine by multiplying pixel size by slice thickness

Question 3

What is window width and window level and what does each control?

Answer 3

WW: range of ct numbers displayed in the image represented by gray scale. determines max # of shades of gray display and controls contrast. wide ww-less variation between tissues of similar density.

WL: designates mid point of CT #s and controls brightness. high WL makes image darker.

Question 4

What are CT numbers aka Houndsfield units and what do they represent?

Answer 4

gray scale number seen on the image, various shades of gray

Question 5

Explain how the CT image is created:

Answer 5

The tube and the detector array rotate around the patient and thousands of measurements are taken to determine the radiation attenuation value for each tissue volume element. When that has been determined the data is converted into CT #s for display purposes.

Question 6

What are the components of the CT equipment?

Answer 6

imaging system, computer and operator console

Question 7

define pitch, how does pitch affect CT dose?

Answer 7

pitch increases=image quality improves=pt dose decreases. the pitch is distance the table travels during one revolution of the xray tube.

Question 8

Define MRI:

Answer 8

Magnetic resonance imaging (MRI) is a technique that uses a magnetic field and radio waves to create detailed images of the organs and tissues within your body.

Question 9

atom that provides MRI signal:

Answer 9

hydrogen

Question 10

contraindications/safety issues with the magnet:

Answer 10

No projectiles, heating, or electrical interferences

Question 11

differentiate between T1, T2,

in MRI:

Answer 11

The T1 and T2 relaxation times define the way that the protons revert back to their resting states after the initial radiofrequency pulse. The most common effect of flow is loss of signal from rapidly flowing arterial blood. The most common pulse sequences are T1 weighted and T2 weighted spin-echo sequences. T1 weighted sequence uses a short TR and Short TE. T2 weighted sequence uses a long TR and long TE.

Question 12

define frequency, spin density and signal strength:

Answer 12

F- the location of origin of the mRI signal

SD- the quantity of hydrogen nuclei that are present in a given volume of tissue.

SS- received by an antenna or coil, is used to define the brightness of each point on the image.

Question 13

How are resonance and precession created?

Answer 13

R-radiowaves affect the nuclei bc of the time varying magnetic field of the radio wave changes at the same rate as the nuclei precess. As the nucleus rotates the magnetic field appears at just the proper time to have maximum effect in pushing the nucleus away from the static magnetic field.

P-When the proton of a hydrogen nucleus spins around its own axis giving it an angular moment. It’s a wobbling motion that occurs when a spinning object is the subject of an external force. It’s is also known as the strength of the magnetic field

Question 14

define angiography, venography and interventional radiography:

Answer 14

A-The radiographic examination of vessels after the injection of contrast media

IR- Radiologic procedures that intervene in a disease process, providing a therapeutic outcome.

V-Examination that uses an injection of contrast media to show how blood flows through the veins. This procedure helps to find blood clots, identify a vein for use in a bypass procedure or dialysis access

Question 15

indications for cerebral angiography and venography:

Answer 15

Vascular stenosis (narrowing) and occlusions (blockage)
Aneurysms
Arteriovenous malformations
Neoplastic disease
Confirm brain tumor
Find a clot that may have caused a stroke

Question 16

explain the process of accessing the arteries

Answer 16

The patient is lying down on an x-ray table
The head is held in place using a strap, tape, or sandbags to prevent movement
A mild sedative is given to help the patient relax
An Electrocardiogram (ECG) is used to monitor heart activity during the test
An area of the body, usually the groin, is cleaned and numbed with a local anesthetic
A thin, hollow tube called a catheter is placed through an artery. The catheter is carefully moved up through the main blood vessels in the abdomen and chest into an artery in the neck:
common carotid artery, internal carotid artery, external carotid artery and vertebral artery

Question 17

know the steps involved in the Seldinger procedure

Answer 17

Insert compound (Seldinger) needle

2. ) Place needle in lumen of vessel
3. ) Insert guidewire
4. ) Remove the needle
5. ) Thread catheter through the vessel to the area of interest
6. ) Remove the guidewire

Question 18

differentiate between catheters and guidewires

Answer 18

Catheters are chosen based on the area of interest, how the catheter will be traveling through the vessel.
Guidewires allow for safe introduction of the catheter through the vessel to the area of interest.

Question 19

define PICC line, IVC filter, PTA, and embolization

Answer 19

PICC-A peripherally inserted central catheter, a form of intravenous access that can be used for a prolonged period of time (e.g., for long chemotherapy regimens, extended antibiotic therapy, or total parenteral nutrition)

IVC Filter-inferior vena cava filter is a type of vascular filter, a medical device that is implanted by interventional radiologists or vascular surgeons into the inferior vena cava to presumably prevent life-threatening pulmonary emboli

PTA-percutanous trasluminal angioplasty-A vessel is entered through the skin (percutaneous) and the catheter is moved into the blood vessel through the same vessel or one that communicates with it (transluminal)

Embolization- A procedure that utilizes chemical agents or metallic coils to stop bleeding and treat hemorrhage, cranial tumors, and aneurysms

Question 20

risks associated with angiography

Answer 20

Bleeding at the puncture site: controlled by applying pressure.
Thrombus formation: of a blot clot in the vessel that may disrupt the flow to the distal parts.
Embolus formation: a piece of plaque may be dislodged from a vessel wall by the catheter.
Dissection of a vessel: the catheter may tear the intima of a vessel.
Infection of the puncture site: caused by contamination of the sterile field.
Contrast media reaction: may be mild, moderate, or severe.

Question 21

What is French number, how does it affect catheter lumen size

Answer 21

Terms used to describe the size of the catheter.
Refers to the measurement of the outside
Diameter of the catheter.
Measures multi- lumen catheters.

Question 22

define radiation oncology

Answer 22

uses ionizing radiation (such as megavoltage X-rays or radionuclides) in the treatment of cancer.

Question 23

identify the equipment used and the purpose of the linear accelerator

Answer 23

its the machine most often used in tele therapy which employs electricity to cast a stream of fast moving subatomic particles which produces high energy radiation that can be used in the treatment of cancer

Question 24

common side effects of the treatment for oncology

Answer 24

early ones are nausea, loss of appetite, fatigue, skin damage. late effects are hair loss, memory loss, fibrosis, damage to bowels, infertility, second cancer, tooth decay, sexual problems, menopause, bladder problems, dry mouth, skin color changes.

Question 25

differentiate between brachytherapy and teletherapy

Answer 25

brachytherapy is internal radiation therapy used to get radiation directly to the tumor without irradiating all the surrounding tissues. two kinds are inter cavity when the source is placed in the body cavity and interstitial when the source is just placed in or near the tumor. tele therapy is external beam radiation therapy. It uses an xray beam to deliver high doses of radiation to the tumor. It is the most common.

Question 26

different uses (treatments) that may be performed using radiation therapy

Answer 26

Palliative treatments are not intended to cure. Instead, they relieve symptoms and reduce the suffering caused by cancer. Some examples of palliative radiation therapy are: Radiation given to the brain to shrink tumors formed from cancer cells that have spread to the brain from another part of the body (metastases).
PCI is the use of moderate doses of radiation therapy to the entire brain in an effort to prevent cancer recurrence in or metastasis to the brain. It is well known that the brain is often the first, and sometimes the only, site of small cell lung cancer recurrence after successful chemotherapy +/ – chest radiotherapy

Question 27

define nuclear medicine

Answer 27

he branch of medicine that deals with the use of radioactive substances in research, diagnosis, and treatment.

Question 28

most commonly used radionuclide

Answer 28

technetium 99m

Question 29

most common Nuc Med procedure

Answer 29

cardiac profusion

Question 30

risk factors for breast cancer

Answer 30

Being a women
Age
Genes
Family history of breast cancer
Personal history of breast cancer
Ethnicity. White women are more at risk.
Menstruation before age 12 or menopause after age 55
Radiation to chest
Being overweight or obese
Never having children or getting pregnant after the age of 30
Taking hormonal birth control
Environmental factors such as chemicals that mimic estrogen in the body
Alcohol consumption
Smoking

Question 31

routine screening projections

for mamo

Answer 31

Craniocaudal and mediolateral oblique

Question 32

kVp range, importance of compression in mamo

Answer 32

o decrease thickness of the breast and make it more uniform.
To bring the breast structures as close to the image receptor as possible.
To decrease the dose needed and the amount of scattered radiation.
To decrease motion and geometric unsharpness.
To increase contrast by allowing a decrease in exposure factors.
To separate breast structures that may be superimposed.

24-28 KV w/ high MA

Question 33

define ultrasound

Answer 33

sound or other vibrations having an ultrasonic frequency, particularly as used in medical imaging.

Question 34

define transducers, echogenic, anechoic

Answer 34

t-the main part of the ultrasound machine that makes the sound waves and received the echoes.

E- anatomic structure or region of the body that highly projects sound energy

A-anatomic structure or region of the body that doesn’t produce any echoes.

Question 35

what doesn’t U/s demonstrate well

Answer 35

abdominopelvic cavity (bc air) and bone

Question 36

What organs are best demonstrated by sonography?

Answer 36

heart, blood vessels, liver, gall bladder, spleen, pancreas, kidney, bladder, uterus, ovaries, eyes, thryroid, scrotum. infant brains, and infant hips.