Ultrasonagraphy - B-scan

Question 1

imaging tests provide a

Answer 1

picture of the bodys internal structure. - can be used to diagnose a disorder, determine how severe a disorder is, and monitor people after dx

Question 2

an imaging test that uses soundwaves is called

Answer 2

ultrasonography

Question 3

ultrasonography uses what type of soundwaves and how is it transmitted?

Answer 3

uses HIGH frequency soundwaves and is transmitted from probe/transducer into the eye

Question 4

how does an ultrasongraphy work?

Answer 4

• high Hz soundwaves hit intraocular structures, -echo is reflected back to the probe -echo converted to electrical system, -electrical signal is turned into a 2D IMAGE on a monitor

Question 5

t/f the weaker the echo, the brighter the display

Answer 5

false. THE STRONGER

Question 6

what is the most common frequency used in ophthalmic ultrasound? A. 15 MHZ, B. 25 hz c. 11 hz, d. 10MHz

Answer 6

D. 10MHZ, becaust it provides the best combo of tissue penetration AND image resolution

Question 7

ultrasound information can be displayed on a monitor In various ways . What are the different ways an ultrasound can be displayed in ophthalmic ultrasound?

Answer 7

A- scan or B-scan

Question 8

what is a A-Scan? Or how do you know you are viewing the A-scan?

Answer 8

it would be displayed as spikes on a graph

Question 9

what is a B-scan? How do you know you are viewing a B-scan vs A-scan?

Answer 9

a B-scan is the actual 2D anatomical image. A-scan are the electical spikes

Question 10

an A scan is most commonly used for ?

Answer 10

measuring axial length AND tumor differentiation

Question 11

why would we need to know axial length and what scan are we going to use?

Answer 11

we need to know for determing DIOPTRIC power for an IOL, and get a Ascan done

Question 12

which scan is the best scan to use for determining the difference between tumors inside the eye?

Answer 12

a scan

Question 13

what do the spikes on a scan represent?

Answer 13

an ultrasonic echo from a SPECIFIC ocular structure

Question 14

Figure 1: The five primary amplitude spikes in A-scan ultrasound

Answer 14

1. cornea 2. ANTERIOR Lens 3. POSTERIOR lens, 4. retina, 5. sclera/orbital fat

Question 15

what equipment piece is more reliable for IOL dioptric power?

Answer 15

lenstar

Question 16

pic of normal healthy patient B SCAN. Label each

Answer 16

a cornea/probe b. iris c. anterior lens d. posterior lens e. viterous d. optic nerve

Question 17

on the probe. There is an arrow/marker. The position of the marker is held

Answer 17

relative to the eye based on the TYPE OF CUT/SCAN desired.

Question 18

the position of the probe in relation to the EYE GAZE!!! Tells you ___________

Answer 18

type of scan you are doing

Question 19

what coupling agent is needed for trans-lid method ON B scan

Answer 19

ultrasound gel ONLY!!! No anesthetic or tear gel. The lid is closed for this method

Question 20

what coupling agent is needed for TRANS-CONJUNCTIVA method on B SCAN

Answer 20

artificial tear gel (celluvisc, genteal gel) ….the more gel the better resolution. ANESTHETIC IS REQUIRED!!!!

Question 21

define decibels

Answer 21

a measure of sound INTENSITY . 1/10 of bell

Question 22

mHz is a

Answer 22

unit for frequency in ultrasonography

Question 23

sound impedance ** EXAM QUESTION . Why is sound impedance crucial?

Answer 23

it gives us information on the difference in the echo reflectivity from one structure to another. This where get the information on data anaylsis and difference in pathology.

Question 24

Homogeneous sound impedance structure is

Answer 24

means theres not much sound impedance.

Question 25

if a sound impedance is heterogenous, what does this indicate?

Answer 25

it’s a difference between one echo reflectivity to another.

Question 26

homogeneous sound impedance means sound passes

Answer 26

through with NO signal coming back. ESP. viterous and optic nerve. Sound traveling fast through optic nere

Question 27

hetergenous sound impedences means sound passes through

Answer 27

but SENDS AN ECHO BACK (Echo reflectivity) . Represented by white.