AART BASIC PATIENT CARE TERMINOLOGY

BASIC PATIENT CARE TERMINOLOGY

Verbal communication speaking using clear, concise language

understood by the patient

Nonverbal communication communicating with facial expressions,

eye contact, or body motions

Diversity factors that distinguish humans from one another,

including age, gender, race or ethnicity, sexual preference,

traditional versus nontraditional families, nuclear versus

extended families, marital status, socioeconomic background,

political beliefs, religious beliefs, geographic origin

or residence, generation, physical or mental disability

Patient education providing the patient with information

regarding the procedure being performed, other imaging

procedures, or other medical center services

Torts personal injury law

Assault action that causes fear or apprehension in the patient

Battery inappropriate touching or harm done to the patient

False imprisonment unjustified restraint

Invasion of privacy violation of any aspect of patient

confidentiality

Libel written defamation of character

Slander spoken defamation of character

Negligence unintentionally omitting reasonable care

Respondeat superior an employer is responsible for the

employee’s actions

Res ipsa loquitur cause of the negligence is obvious

Implied consent assumes the patient would approve of care if

Conscious Informed consent patient provides consent after being fully

informed of need, risks, and alternatives

Patient bill of rights establishes rights for patients regarding

diagnosis, treatment, privacy, prognosis, and alternatives

Health Insurance Portability and Accountability Act

(HIPAA) establishes legal regulations regarding confidentiality

of patient records

Do not resuscitate order (DNR) no code

Advance directive document used by patient to provide directives

regarding medical care before becoming incapacitated

Durable power of attorney patient provides for another person

(personal representative) to make decisions regarding

medical care if the patient is unable to communicate

Patient history provides information for the radiographer

about the extent of a patient’s injury and the range of

motion the patient can tolerate

Medical asepsis microorganisms have been eliminated as

much as possible Surgical asepsis complete removal of all organisms from equipment and environment

Standard precautions first tier of transmission-based isolation

precautions; uses barriers to prevent contact with blood, all

body fluids, nonintact skin, and mucous membranes when

there is a chance that infection could be transmitted

Airborne precautions particulate respirator required for individuals

entering a patient’s room

Droplet precautions mask required for persons coming in close

contact with a patient

Contact precautions gloves and gown required for individuals

coming in contact with a patient Direct contact transmission infected person touches susceptible Host Indirect contact transmission inanimate object containing

pathogenic organisms is placed in contact with a susceptible

person

Airborne transmission droplets and dust

Droplet transmission primarily transmission by coughs,

sneezes, or other methods of spraying onto a nearby host

Common vehicle transmission primarily transmission by contaminated

items such as food, water, medications, devices,

and equipment

Vector-borne transmission an animal contains and transmits

an infectious organism to humans

Handwashing most effective method to prevent the spread of

infection

Infection control barriers gloves, protective clothing, masks,

eye protection

Temperature normal adult oral temperature is 98° F to 99° F

Pulse normal adult pulse is 60 beats per minute

Tachycardia heart rate more than 100 beats per minute

Bradycardia heart rate less than 60 beats per minute

Respiration normal adult rate is 12 to 16 breaths per minute

Blood pressure normal adult blood pressure is 120/80 mm Hg

Sphygmomanometer device used to measure blood pressure

Systolic pressure measurement of the pumping action of the

heart

Diastolic pressure measurement of the heart at rest

Oxygen administration usual oxygen flow rate is 3 L to 5 L per

Minute

Suction unit used to maintain patient’s airway

Cardiac arrest cessation of heart function

Crash cart used in cardiac arrest; contains medications, airways,

sphygmomanometers, stethoscopes, defibrillators, cardiac

monitors

Respiratory arrest cessation of breathing

Shock failure of circulation in which blood pressure is inadequate

to oxygenate tissues and remove by-products of metabolism

Hypovolemic shock follows loss of a large amount of blood or

plasma

Septic shock occurs when toxins produced during massive

infection cause a dramatic decrease in blood pressure

Neurogenic shock causes blood to pool in peripheral vessels

Cardiogenic shock secondary to cardiac failure or other interference

with heart function

Allergic shock (anaphylaxis) allergic reaction to foreign proteins

after injection of an iodinated contrast agent

Trauma serious and potentially life-threatening injuries

Ventilators mechanical respirators attached to tracheostomies

Nasogastric (NG) tube tube inserted through the nose and

down the esophagus into the stomach

Chest tube tube placed to remove fluid or air from the pleural

space

Negative contrast agent most commonly used negative contrast

agent is air

Positive contrast agent iodine or barium

Aqueous iodine compound water-soluble sterile contrast

agent

Iodinated ionic contrast agents salts of organic iodine compounds;

composed of positively and negatively charged ions

Iodinated nonionic contrast agents agents that do not ionize

into separate positive and negative charges

Anaphylactic reactions flushing, hives, nausea

Cardiovascular reactions hypotension, tachycardia, cardiac

arrest

Psychogenic factors may be caused by patient anxiety

Hypodermic needle gauge unit of measurement that indicates

diameter; the larger the gauge, the smaller the diameter of

the needle opening

Intravenous (IV) catheter combination unit with a needle

inside a flexible plastic catheter

Biohazardous materials—possible routes of entry inhalation,

swallowing, absorption through the skin or mucous

membranes

Material safety data sheets (MSDS) provide direction for

handling precautions, safe use of the product, cleanup and

disposal of biohazardous materials

PPE personal protective equipment

OSHA Occupational Safety and Health Administration

CDC Centers for Disease Control and Prevention

MRI CONTRAST MEDIA

MRI CONTRAST MEDIA
Introduction
Contrast enhancement is extremely valuable in many disease processes including tumours, inflammation and infection. Although these pathologies contain a high water content and are often visualized in T2 weighted images, sometimes there is insufficient contrast between the lesion and surrounding tissue. In addition, T1 weighted images demonstrate a higher SNR and are therefore advantageous, but water and pathology are commonly isointense in these sequences. Therefore it is sometimes necessary to selectively enhance pathology by administering
contrast agents. This can be done either indirectly via the intravenous (IV), oral or rectal routes or directly into a structure such as a joint. Only a brief overview is provided here. There are
two types of contrast agents: those that produce positive contrast and those that result in negative contrast.

Positive contrast agents
The most common positive contrast agent used in MRI is gadolinium (Gd). Gadolinium is a paramagnetic substance that has a relatively large magnetic moment. When introduced into the body, its presence causes increased fluctuations in the magnetic fields of water protons so that they tumble near to the Larmor frequency. As a result there is a transfer of energy to the surrounding lattice and both T1 and T2 relaxation times
are reduced. Since T2 relaxation is much shorter than T1, a high concentration of agent is required to produce significant shortening of T2. However, much smaller doses are effective at shortening the T1 relaxation time of water protons thereby increasing their signal intensity on T1 weighted images. Gadolinium is therefore known as a T1 enhancement
agent. Gadolinium is a heavy metal and binds to certain elements in the body such as membranes and the osseous matrix. Therefore gadolinium cannot be excreted unless it is attached to a chelate. This chelate surrounds the gadolinium ion and enables its excretion, mainly through the kidneys. The most common chelate in use is diethylene triaminepentaacetic acid
(DTPA), which binds to eight of the nine binding sites in the gadolinium ion and leaves the last free to facilitate the close approach to water molecules. Other examples of chelates used with gadolinium are gadopentetate dimeglumine, HP-DO3A, DTPA-BMA and DOTA. Gadolinium may be given intravenously (IV), orally or rectally or injected directly into a joint. The recommended IV dose of Gd-DTPA and Gd-DTPA-BMA is 0.1 mmol/kg and 0.3 mmol/kg for Gd-HP-DO3A. Oral gadolinium provides positive contrast of the gastrointestinal tract
to label the bowel thereby increasing the visualization of abdominal organs such as the pancreas. Oral gadolinium has a neutral taste and is easily mixed with water prior to ingestion. Problems may arise from the bowel ‘whiting out’, although this can be minimized by careful adjustment of the dose and optimum timing of the scan sequence post-ingestion. Gadolinium may also be injected directly into a cavity such as a joint. Magnetic resonance arthrography is an important technique, especially in
the hip, shoulder and ankle. Other positive agents include manganese, an IV agent used in liver imaging and hyperpolarized helium a T1 ventilation agent used for the evaluation of the lungs.

Negative contrast agents
Superparamagnetic agents such as iron oxides and manganese are termed T2 enhancement agents. This is because their presence causes a shortening of T2 decay times and reduced signal intensity. They are taken up by the reticulo-endothelial system and transported to the Kupffer cells of the liver parenchyma. Like gadolinium, superparamagnetic agents are dangerous in their pure form. However, unlike gadolinium, chemical barriers are not used. Instead the iron oxide particles are coated with either hydrophilic polymer or arabinagalactin to provide a physical barrier.
These agents dramatically shorten the T2 relaxation times of normal liver so that it appears dark and lesions appear bright on T2 weighted images. They are, therefore, specifically used for liver imaging and are given IV. A recommended dose is 0.56 mg of iron per kg of body weight. This is diluted in 100 ml of 50% dextrose and given over a 30 min period at a rate of 2–4 mm/min through a 5 micron filter. Other negative contrast agents include oral agents known as Gastromark ™, blueberry juice and air, which are used for bowel imaging to delineate the large bowel in pelvic examinations.
Blood pool agents
Intravascular (blood pool) agents differ from standard gadolinium agentsin several areas. First and foremost is their persistence in the vessels for an extended period of time rather than diffusing out of the blood stream as occurs with standard extra-cellular fluid space agents. When imaging with standard agents, maximum concentration, and therefore maximum signal, persists only for several seconds resulting in a small window of opportunity for obtaining high-resolution images. With intravascular agents, not only can data be acquired in the ‘first-pass’, as with standard
agents, but high resolution images can be acquired in the ‘equilibrium’ phase as well, with high signal persisting well over 30 minutes. The second major difference is in relaxivity. Relaxivity is an expression of the amount of T1 and T2 shortening provided by the contrast agent. Increasing relaxivity can be obtained by several means; however, in the case of intravascular agents it is accomplished by the reversible binding of the agent to human albumin in plasma. This results in slowed molecular tumbling of the hydrogen protons in albumin and a markedly increased
relaxivity and therefore increased signal.

BASICS OF MRI

Based on complex interaction between

—— Protons in human body

—— Magnetic field  

—— Radiofrequency energy

 Object to be imaged is placed in a powerful, uniform magnetic field,(B0).

The spins of atomic Nuclei are characterized by

Nuclei align parallel or anti-parallel to B0

As the RF pulse continues, the spins change lower energy to higher energy state.

This leads to “tipping” of the net magnetization toward the transverse plane.

¢¢ Spins phases are coherent (aligned with each other).

¢¢ When Rf is shut off - Spins lose their phase coherence & the signal decays. This process is called transverse relaxation

—— TR (Repetition Time ): Interval between Rf pulses.

—— TE (Echo time): Time between Rf pulse & signal reception.

BASIC IMAGING SEQUENCES

¢¢ T 1 WI

¢¢ T 2 WI

¢¢ T2 * WI

¢¢ GRADIENT ECHO

¢¢ FLAIR

¢¢ STIR  

IMAGING CHARACTERISTICS 

¢¢ T1 WI: TR & TE short

T2 WI: TR & TE long

¢¢ T1 WI: Dark - Water, CSF, edema, Calcium (can be pradoxically bright because of crystalline structure of calcium)  

           Bright - Lipid ,Gadolinium,subacute

blood, protein, Mn,  melanin

¢¢ T2 WI: Dark - Calcium, bone  

       Bright - CSF, water, edema 

¢¢ ECHOPLANAR IMAGING:  

¢¢Single excitation used to collect all multiple images

(40ms)

¢¢Used in applications highly sensitive to even minor proton movement.

USED IN:

vv Diffusion MR vv Perfusion MR vv Functional MR

GRADIENT ECHO

- An excitation pulse with a flip angle lower than

90°  

- No 180° rephasing pulse  -TR is very short and  scan time very less (sec)

-Visualise   hemosiderin and ferritin

-USED IN   ØØMRA  ØØCISS  (Constructive interference in

steady state

T1-WEIGHTED MRI 

¢¢ Use a  (GRE) sequence - short TE and TR.  

¢¢ Due to the short repetition time (TR) this scan can be run

very fast allowing the collection of high resolution 3D datasets.

¢¢ Basic types of MR , contrast used, is a commonly run

clinical scan.  

¢¢ The T1 weighting can be increased (improving contrast)

with the use of an inversion pulse as in an MP-RAGE sequence. ¢¢ Provide good gray matter/white matter contrast.

(ANATOMY)

T2-WEIGHTED MRI 

ØØUse a Spin Echo (SE) -long   T E and  T R.

ØØSE  less susceptible to inhomogeneity in      the magnetic field.

ØØ Well suited to edema as they are sensitive      to water content (edema is characterized by      increased water content):PATHOLOGY T*2-WEIGHTED MRI 

¢ T*2 -  (GRE) sequence- long TE and long TR.

¢ Gradient echo sequence used.  

¢ Does not have the extra refocusing pulse used in        spin echo

¢ So it is subjected to additional losses above the normal T2 decay (referred to as T2′), these taken together are called T*2.  

¢ Increase contrast for certain types of tissue, such as venous blood

FLUID ATTENUATED INVERSION RECOVERY(FLAIR)

 Sequence used to null signal from fluids.

E.g.CSF so as to bring out lesions at fluidparenchyma interface  

 Choosing the inversion time TI (the time between the inversion and excitation pulses), the signal from any particular tissue can be suppressed

CLEAR FLUID  in a CLOSED SPACE will be supressed

FAST FLAIR: Fast spin echo plus flair      

 USES

1. For periventricular & subcortical

abnormalities:  (Cortical & juxtacortical multiple sclerosis lesions,  degenerative diseases).

2. In seizure disorders (e.g MTS):  

—— Sensitive for detecting signal abnormalities demonstrating size asymmetry & abnormal signal within the atrophied hippocampus