How To get A Good 3D / 4D Image

1. How to Get a Good 3D/4D Image
Conception and classification
Static 3D
Use volume probe
Automatic scanning by probe
Single frame image
4D / Real-time 3D
Use volume probe
Automatic scanning by probe
Dynamic video
This guideline only refers to Static 3D and 4D

2. Factors affecting image quality
Fetal condition
Gestational age ： fetuses of 22~26 weeks old are the most
appropriate for 3D/4D imaging
Fetal body postureRecommended ： cephalic face up (figure
A) or face aside (figure B) ； not recommended: cephalic face
down (figure C)
How to Get a Good 3D/4D Image
A B C

3. Factors affecting image quality
Fetal condition
Amniotic fluid isolatio ： the region desired should be isolated
by amniotic fluid adequately
How to Get a Good 3D/4D Image
Inadequate Amniotic Fluid around Fetal Face

4. Factors affecting image quality
Fetal condition
Covering condition ： the region desired should not be covered
by placenta ， limbs or umbilical cord
How to Get a Good 3D/4D Image
Fetal Face Covered by Hands

5. Factors affecting image quality
2D image quality
Scanning planes ： the ideal scanning planes are sagittal
plane ， oblique coronal plane and coronal plane ， which
correspond to the front ， oblique lateral and lateral fetal face
How to Get a Good 3D/4D Image
Sagittal in 2D
Front in 3D/4D
Oblique Coronal in 2D
Oblique Lateral in 3D/4D
Coronal in 2D
Lateral in 3D/4D

6. Factors affecting image quality
2D image quality
Parameters ： before entering 3D/4D capture ， optimize 2D
image to assure ：
High contrast between the desired region and the amniotic
fluid surrounded ： Dynamic Range ， Gray Map
Clear boundary of the desired region ： Focus Position ，
TSI ， Gain
Low noise of the amniotic fluid area ： iClear ， Noise
Reject ， Focus Position
Proper size and position of ROI ： set ROI in the largest
section area of the fetal face ， and a little larger in size
than fetal head
How to Get a Good 3D/4D Image

7. How to Get a Good 3D/4D Image
ROI doesn’t Contain the
Largest Section
ROI Contains the Largest
Section
Too Shallow ROI
Too Deep ROI
Too Big ROI
Too Small ROI

8. How to Get a Good 3D/4D Image
ROI in Proper Position ， Depth and Size

9. Parameter adjusting in 3D/4D
Rendering mode
Surface ： for the imaging of surface of fetus ， such as
face ， arms ， hands ， legs ， feet ， etc.
Max ： for the imaging of bones
Min ： for the imaging of hollow structures ， such blood
vessels ， etc.
X Ray ： for the imaging of tumors or tissues with different
structure inside
How to Get a Good 3D/4D Image

10. How to Get a Good 3D/4D Image
Surface
Max
Min
X Ray

11. Parameter adjusting in 3D/4D
VOI
Adjusting the VOI box size and position is to select the volume
data needed to render the 3D/4D image and improve rendering
effect
How to Get a Good 3D/4D Image
Too Big VOI Too Small VOI Proper VOI

12. Parameter adjusting in 3D/4D
Angle
Set the angle that the probe covers during a fan scanning
Wide angle will decrease the frame rate
How to Get a Good 3D/4D Image
Too Narrow Angle Proper Angle

13. Parameter adjusting in 3D/4D
Threshold
3D/4D image is rendered using the signal above threshold
Signals below threshold (such as the noise) will be filtered
Only used in Surface rendering mode
How to Get a Good 3D/4D Image
Too Low Threshold Proper Threshold

14. Parameter adjusting in 3D/4D
Other parameters
Smoothness ： to set the smoothness of 3D/4D image.
Insufficient smoothness can result in a fuzzy image ； over
smoothness will lead to image distortion
Transparency ： to set the transparency value for 3D/4D
image rendering. The higher the number ， the more
transparent the gray scale information. Only used in Surface
rendering mode
Brightness ： to set the brightness of 3D/4D image
Contrast ： to set the contrast of 3D/4D image
How to Get a Good 3D/4D Image

15. Notice
A good 3D/4D image not only depends on the performance of
ultrasound system ， but also closely relates to fetal
condition and doctor’s skills
How to Get a Good 3D/4D Image