Unit 6 + 7: Performing US Exams, Clinical Safety, Quality Assurance

Manage Patient Encounter

verify order, review patient records, patient interview, verity ID, complete findings report, send images, complete and bill

Hospital Information System (HIS)

computer system designed to manage healthcare data

Electronic Medical Record (EMR)

digital version of patient’s chart, health info/data, results management, order entry, clinical decision support/records, electronic communication, patient support, admin. processes

-communicates with other hospital systems

Radiology Information System (RIS)

manages imaging department data; talks to HIS

-exams are completed initiating billing process

-transfer data to work list

-tracks workflow in dept.

Managing Initial Patient Encounter

-once patient is checked in, the RIS informs sonographer that a patient is here

-sonographer must check the actual order matches exam scheduled and check indication

CPT vs. ICD-10

CPT: Current Procedural Terminology coding system

-uniform language for coding medical services maintained by the AMA

ICD-10: International Classification of Diseases

-classification system for medical diagnoses

-promotes internationally comparability in collection, processing, classification and presentation of mortality stats

Appropriate Use Criteria

-sonographers must ensure the indication is applicable for the exam

-insurance may reject if they don’t

-if an inappropriate procedure is ordered/billed, it can be considered fraud/abuse

Analyze Clinical History

use EMR to review—medical history/diagnoses, surgical history, previous imaging studies use to evaluate changes, lab results, medications

Worklist

patient info and exam sent to US machine; minimizes errors, faster, matches info sent to PACS

DICOM

Digital Imaging and Communications Machine

-format for medical images that allows for equipment, digital archives, workstations and servers from different vendors to share info

-makes images portable

PACS

Picture Archiving and Communication System

-medical imaging technology that provides storage and access to images from multiple modalities

Document Preliminary Findings

sonographers provide a technical impression of exam findings (not diagnosis)

-can either be paper, digital, of face-to-face

Incidents and/or Adverse Reactions

-always follow facility protocol

-sonographers work under physician supervision

-rereport and document

Patient Care Partenrship

comfort and safety, privacy and confidentiality, consent and refusal

Empathy

the ability to imagine or to have experienced what someone else is going through

Compassion

to empathize with someone and feel compelled to help

Communication

listening, respectful and friendly

-sonographers must communicate with patients, families, physicians, etc.

Good and Effective Communication

Good = the foundation of successful personal and professional relationships; both sender and receiver understand

Effective Communication = verbal comm. and no verbal comm.

Types of Communication

Social Communication: friendly exchanges or chitchat; establishes patient relationship

Supportive Communication: goal-oriented; patient info discussed

-involves listening, observing, clarifying, etc.

Communication Barriers

-talking too fast, using slang, medical vocab, brad generalizations

-talking down, insulting tones

-can be language/cultural

Interprofessional Education (IPE)

engagement of two or more health care professionals in an integrated learning environment to foster collaboration and health

-learn about other healthcare professionals and their duties; utilize teamwork

Team Development

Forming, Storming, Norming, Performing, Termination

Patient Safety and Comfort

you are responsible for a patient’s safety and comfort while in your care

Universal Infection Control

personal and patient standard precautions

Standard Precautions

applies to the care of ALL patients adn when there is eposure risk to blood, bodily fluids, non-intact skin membranes

Hand Hygiene

most important means to prevent transmission of disease

-wash with soap and water before and after contact with patients, after gloves are removed, before handling invasive device

PPE

personal protective equipment

-gloves, mask/goggles/etc.

-worn during procedures that may spray/splash

Isolation Precautions

for patients with know or suspected pathogens

Airborne Precautions

evaporated droplet nuclei

-patients placed in (-) pressure room

-respirators (N95)

Ex. measles, TB, varicella

Droplet Precautions

particles of respiratory secretions and remain suspended in air for limited time, transmission (3-6ft); private patient room

-masks

Ex. diphtheria, influenza, mumps, pertussis

Contact Precautions

pathogens spread by direct/indirect contact

-patient in private room with dedicated equipment

-gloves/gowns

Ex. conjunctivitis, staph, Hep A, Strep

Donning

PPE steps

1. gown, 2. mask 3. goggles 4. gloves

Doffing

PPE removal

1. gloves 2. goggles 3. gown 4. mask

Bioeffects

US is a form of energy and has potential consequences to tissues or biological structures exposed to US

-no evidence have proven detrimental bioeffects associated with DMU (100 mW/cm2 = unfocused; 1 W/cm2 = focused)

-FDA regulates US instruments output limits (720 mW/cm2)

Thermal Effects

attenuation is mostly caused by absorption = conversion of US to heat

-extent of temp. rise depends on intensity, frequency, focusing, and tissue perfusion

-higher intensity or frequency = higher heating

-temp. rise is considered significant if it exceeds 1.5 C

-hyperthermia has approx. 80 known bioeffects; depends on temp. and exposure time

Absorption Rates

absorption in body increases with increase in collagen

-highest = bone, tendons, fascia

-lowest = fluids

Intensity of US

SPTA = best indicator of thermal bioeffects

-lowest —> highest (SPTA) = b-mode, m-mode, color, PW, CW

Thermal Index (TI)

estimated max temp. rise expected; predicts “worst case”

TI = 1 —> max temp rise over time would be 1^o C

-relates attenuation (heat) and SPTA intensity

-TI is directly related to output power and exposure time

TIS, TIB, TIC

TIS (soft tissue) = increases with increase in frequency

TIB (bone) = increases with focal diameter (higher in bone, especially in fetus)

TIC (cranium) = important for fetal imaging

Mechanical Effects

radiation force, streaming, cavitation, transient cavitation

Radiation Force

force exerted by a sound beam on an absorber or reflector

Streaming

force causes flow in absorbing fluid; can cause stresses that deform/disrupt structures

Cavitation

production and behavior of bubbles in a liquid medium

Stable Cavitation = bubbles oscillate in diameter with passing pressure variations; expands under lower pressure, contracts under higher pressure

Transient Cavitation

bubble oscillations are so large that the bubble collapses which can cause significant destruction in surrounding tissue

-produces shock waves (pressure discontinuities); causes localized extremely high temps; light emission clear liquids

Intensity of US

because of the restrictions due to high SPTA, the transmit voltage is relatively low

-best indicator for cavitation is SPPA

-lowest to hightest (SPPA) = CW (8 volts), PW (30 volts), color (40 volts), M-mode (60 volts), B-mode (150 volts)

Mechanical Index (MI)

measure of pressure amplitude that occurs in tissue

-MI is equal to the peak rarefactional pressure divided by the square root of the operating frequency —> MI = P_r (mPa) / f (mHz) ^½

-indicator of cavitation

FDA limit —> MI less than or equal to 1.9

ALARA Principle

obtain adequate images with the least amount of energy exposure to the patient (high gain and low output power)

-use lower power for OB/peds exams

-keep exposure time to a minimum

-benefit must outweigh risk

US Equipment Operation and Maintenance

it is the sonographer’s job to make sure the US machine/transducers are in working order

Quality Assurance (QA)

routine, periodic evaluation of performance of US system/transducers; ensures diagnostic image quality/consistency, testing devices used (tissue equivalent phantom), AIUM required

Quality Control (QC)

testing on operation and acoustic output of US system; ACR requires semiannually

Performance Measures

detail/contrast resolution, penetration and dyn/ range, TGC, accuracy of depth and distance measurements

Chi Square

comparison test vs. gold standard

Sensitivity

ability of a test to detect disease

Specificity

ability of a test to detect absence disease

Positive Predictive Value

measures how often the test is correct when positive for disease

Negative Predictive Value

measures how often the test is correct when negative for disease

Accuracy

measures the percentage of exams that agreee with the gold standard or quality of being near to the true value

QC Testing

acoustic output testing and operation testing

Acoustic Output Testing

evaluates safety, requires special equipment, performed by engineers/physicists

Hydrophone

microphone that detects sound waves under water; large piezoelectric membrane with small metallic electrodes centered on each side

Parameters Evaluated with Hydrophone

-relationship between acoustic pressure and voltage produced

-measures acoustic output

-measures pressure and intensities across the sound beam

-measures period, PRP and PD

Operation Testing

evaluates entire US instrument as a diagnostic tool; performed by service professionals/instrument operators

-requires testing devices —>

Phantom: tissue-equivalent device

Test Objects: device without tissue like properties

Tissue Mimicking Phantoms

-simulates tissue properties of soft tissue, cystic and solid structures

-attenuation is similar to ST

-small fibers (nylon) are used to evaluate axial/lateral resolutions

Parameters Evaluated of Phantoms

dead zone, penetration, compression/dyn. range, compensation, axial/lateral/contrast/slick thickness resolution, vertical/horizontal calibration, system sensitivity, registration accuracy

Dead Zone

distance between the front surface of the transducer and the first identifiable echo

-transducer cannot send/receive at same time = results of transducer tinging and reverb b/w the transducer/phantom interface

Rod Groups

V, H, A, L, HD, DZ, C, M, GS

Vertical Group (V)

measures vertical distance accuracy

Horizontal Group (H)

measures horizontal distance accuracy

AR Rod Groups (A)

measures AR; spaced at varying distances vertically, offset horizontally to prevent shadowing

LR Rod Groups (L)

measures LR; spaced at varying distances horizontally; multiple rows at various depths

High Intensity Attenuator (HD)

Dead Zone Group (DZ)

measures distance of dead zone; spaced vertically/offset horizontally; depth of rod that can be visualized closest to the surface is depth of DZ

Simulated Cysts (C)

evaluate size, accuracy of shape, posterior enhancement

Solid Masses (M)

evaluate size, accuracy of shape, posterior shadowing

Gray Scale Targets (GS)

evaluate contrast resolution; solid cylinders with different scattering properties

-shown in dB

Equipment Record Maintenance

-helps detect gradual/sporadic system changes

-documents need to replacement of equipment

-required for hospital and clinic accreditation

-files for each machine should include…

original purchase order, equipment specification, results of QA tests, documentation of problems, service/maintenance reports