Imaging techniques (lil more physics)

Harmonics

Improves image resolution for lower frequency transducers needed for penetration; improved lateral and contrast resolution

Improved S to N ratio

Spatial compounding

Scan lines are electronically steered by the transducer in different directions to evaluate structures using multiple pulses from several different angles

Spatial resolution improved

Increased power output increases…

Amplitude of voltage spike applied to the transducer and the intensity of the beam produced

If the entire image is too bright, decrease _________ first

Power

Biplane imaging

A matrix transducer offers new technology that can steer beam electronically to perform the anatomy sweep and obtain the volume data set for 3D

Used for heart, spine and brain

Multiplanar reconstruction

Allows for viewing anatomy in 3 different planes simultaneously

Tomographic display

Allows for display of a series of parallel slices obtained in data set

Maximum rendering

X-ray or skeletal mode, used for bony structures or fetal bladder

Minimum rendering

Used to evaluate fluid-filled or hypoechoic structures

Inversion mode

Displays fluid filled or hypoechoic structures as solid objects

Useful for evaluating hydrocephalus and dilated urinary system in a fetus

Transparency or glass body mode

Used with color or power Doppler to highlight vascular structures

Tissue is partially or completely transparent

Virtual organ computer aided analysis

Used to calculate volume of a structure

For fetal lungs, cranial ventricles or bladder

Spatiotemporal image correlation

Used to evaluate moving structures (fetal heart)

Cine loop of one full cardiac cycle

We use 3D/4D in US in gym for

Congenital anomalies, IUD position, Eval pelvic floor, eval endo

When evaluating fetal bones for appropriate ossification, it may be necessary to turn off:

Spatial compounding

If the entire image is too dark, ___________ first

Overall gain

Adjusting the dynamic range affects the:

Contrast resolution

What are techniques used to evaluate large areas of masses?

Panoramic view, trapezoidal view or dual screen

How is biplane imaging used in OB

For comparison views of structures in two different imaging planes; typically for spine, heart and brain

First step in 3D imaging

Optimize 2D image

When performing a 3D volume data acquisition sweep, adjusting the __________ adjusts the distance covered during the sweep

Z axis

What 3 planes are demonstrated in multiplanar reconstruction

1st image is plane date was acquired in

2nd image is reconstructed plane 90 degrees to 1st

3rd image is a reconstructed plane 90 degrees to 2nd

Uses of 3D in OB

Evaluate facial anomalies

Eval spine and extremity anomalies

Eval hear and lungs

Needle guidance