Module 9 : 3D/4D Flashcards
what are the clinical applications of 3D/4D
- fetal portrait
- nose/lips
- NTD
- hands, feet, ankles
- heart
- mullein duct anomalies
- endometrium
- IUDS
what is method 1 of 3D/4D
- free hand 2D
- transducer manually moving over the area of interest
- no measurements, no extra equipment
what si method 2 for 3D/4D
- separate transmitter created an electromagnetic flied
- sensor attached to outside of the 2D transducer
what is method 3 for 3D/4D
- mechanical
- motor within transducer provides sweep
- steered electronically without external parts
what is method 4 for 3D/4D
- matrix transducer
- cardiac applications
- more crystals
what is ROI
- region of interest
what si MPR
- multiplayer reconstruction
what is pixel
- smallest unit of 2D image
what is a voxel
- smalles unit of 3D volume data set
what do the width height and volume angle correspond to
- x,y,z
what is the volume angle
- information acquired in the z axis
- distance the transducer covers in a sweep
what comes from a slow acquisition speed
- more slices
- better quality volume
- higher resolution
what comes from a fat acquisition speed
- active fetus
- eliminates fetal motion
how does the image quality change between 2D to 3D
- SAME
- optimal 2D = optimal 3D
what 3 factors affect image quality
- maternal size
- decreased amniotic fluid
- fetal positon
how is multiplayer reconstruction does
- A= X, B=Y, C=Z
- A and B determines ROI
- C = size of volume
- B and C have lower resolution than A
- C lowest resolution
what is the red dot
- the point where all three dots intersect
what is tomographic ultrasound
- series of tomographic images
- similar to CT or MRI
what are the purpose fo rendering modes
- allows different characteristics to be highlighted
-
what is the surface smooth rendering
- gives face the smooth surfaces of skin which is popular with parents
what si surface texture rendering
- enhances the details of a surface
what is gradient light rendering
- illuminating giving a depth of impression
- more life like
what is important to think about with threshold
- manually adjusted
- importnat info can be eliminated
what is a low threshold
- fetal face
what is a high threshold
- eliminates skin look at bony structures
what is the electronic scalpel
- removes unwanted structures from an image
- placenta from face
- uterine wall
what is maximum skeletal or X ray mode
- eliminates weaker signals like soft tissue
- used for some syndromes
what is inversion
- hypoechoci structures turned into solid structure
- digital cast
- gray scale removed
- cystic areas echogenci
what is the obstetrical application of inversion technique
- fetal ventricles
- dilated fetal urinary tract
- heart and vessels
- feal stomaach
what are the gynaecological application of inversion technique
- saline filled uterus
- PCOS
- hydrosalpinx
- follicular monitoring
what is glass body or transparent and was is it used with
- makes tissue transparent to visualize vessels better
- used with power doppler
what is VOCAL
- virtual organ computer aided analysis
- software program used to measure the volume of an irregular object
how does VOCAL allow contour mapping of a structure
- data set rotates 180º around fixed central axis
- tracing object contour
- contours outlined
- system recreates a model of all the contours
what is the 3D vs 4D
- static
- single sweep through an area
- volume is stored and viewed in many formats
what is the difference between 4D vs 3D
- liver or real time
- transducer elements continuously sweeping back and forth
what are some of the applications fo 3D/4D in gyne
- congenital uterine anomalies
- IUD location
- endo lesions
- origin of adnexal masses
- sonohysterography
- infertility evaluation
what will a bicornuate uterus look like on 3D
- two separate uterine cornea on a coronal imaging plane
- external fundal indentation >1cm needed for diagnosis
what is the purpose of a sonohysterogram
- volume of uterus obtained
- 3D reconstruction improves visualization of polyps, fibroids, adhesions
what is the best view to asses IUD location.
- coronal view in 3D
what thickness of endo is hard reconstruct
- <5mm
what is the Z technique
- obtain 3d volume of uterus in sag plane
- in A plane place reference dot in centre of endo
- using Z ration known to align endo so parallel to horizontal plane
- in B plane place reference dot in centre of endo
- using Z rotation known to straighten the trans image so end parallel to horizontal plane
- C plane should now display a coronal image of endo
- use z to rotate image so it is in normal plane
what can be assessed with 3D/4D in OB
- facial anomalies
- nasal bone
- CNS anomalies
- cranial sutures
- spine
- extremities
- fetal heart
- chromosomal anormalities
- fetal movement and behaviour
what 5 things can we look for with the fetal face using 3D
- cleft lip
- cleft palate
- forehead
- nasal bone
- mandible
what do we look for with ears with 3D
- morphology
- location
- orientation
what doe we look for with cranial bones using 3D
- sutures
- fontanels
- bones
- workman bones
- skeletal dysplasia
what can we determine in regards to the spine with 3D
- spina bifida (level of defect)
- hemivertibrae
how does 3D help with nuchal translucency scan
- measurement performed in less time
what anomalies can we look for with 3D
- club feet
- hands
- rocker bottom feet
- overlapping fingers
- polydactyly
what is spatio-temporal imaging correlation STIC
- motion gated scanning method
- demonstrates functional and anatomical information from one full cardiac cycle
what view is needed to perform STIC
- 4 chamber
