Ultrasound: Difference between revisions
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# Soft markers identify a significant increase in fetal risk for genetic disease. Timely referral for confirmation, counselling, and investigation is required to maximize management options (III-B). | # Soft markers identify a significant increase in fetal risk for genetic disease. Timely referral for confirmation, counselling, and investigation is required to maximize management options (III-B). | ||
==Ultrasound | ==Doppler Ultrasound == | ||
Doppler ultrasound is a noninvasive measure of blood flow and blood pressure by bouncing ultrasound off circulating red blood cells. Originally used for fetal heart beat detection, more recently used diagnostically in uterine, placental, ductus venosus and other fetal blood vessels. | Doppler ultrasound is a noninvasive measure of blood flow and blood pressure by bouncing ultrasound off circulating red blood cells. Originally used for fetal heart beat detection, more recently used diagnostically in uterine, placental, ductus venosus and other fetal blood vessels. | ||
Doppler effect is due to the movement of blood cells causing a change in pitch of the reflected sound waves. | |||
== Ultrasound Research == | == Ultrasound Research == |
Revision as of 13:43, 7 February 2013
Introduction
This page links to all ultrasound movies of live normal human embryos. Ultrasound imaging began in the 1950's but it was only with the application of computer analysis beginning in the 1980's that more detailed images could be generated.
Parents now commonly see ultrasound movies or images in the first trimester and clinically this is a non-invasive prenatal diagnostic tool for detection of abnormalities as well as a method of staging (ageing) and checking growth. There are several different standards available[1] for calculating age based upon several measurements, including embryo or fetal crown rump length (CRL).[2]
Ultrasound can also be used in combination with other techniques to locate both embryo and placenta for other prenatal tests (More? prenatal diagnosis).
The ultrasound technique can be used at any stage during pregnancy for embryo and placenta monitoring.
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Movie shows a 12 week fetus in 3d in realtime (hence 4D). Quicktime | Flash |
The ultrasound movies can be viewed in two ways. Firstly, click the image or text link opens a new page with both the movie and a more detailed text description of features. Secondly, clicking on the quicktime link will open the movie alone on a new page. At the bottom of this current page is further ultrasound information and links to internet ultrasound sites.
Abnormal developmental ultrasound and features are listed on a separate page (More? abnormal ultrasound) all content is for educational use only.
Special thanks to Dr Andrew McLennan, Foetal Medicine Unit, Royal North Shore Hospital for the original video materials.
| Abnormal Ultrasound | original Ultrasound page
Some Recent Findings
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Ultrasound Movies
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Additional Ultrasounds
4D Ultrasound
Fetal Face
(a) 24 weeks (b) 27.5 weeks (c - d) 32 weeks. [6] | (a) 28 weeks neutral face (b) 33 weeks (c) 32.5 weeks (d) 33 weeks.[6] |
3D Ultrasound
Three dimensional (3D) ultrasound scan images are generated from a series of images in 3 different planes. The image shows a 12 week fetal ultrasound images in the sagittal, axial and coronal planes that are used by the computer to generate the final 3D image in the lower right. Computers are able to generate these images in realtime, therefore in addition to static pictures, realtime 4D movies can be generated.
Heart
The heart is the first organ in the embryo that can be easily ultrasound visualised by its contractility. The absence of contractility also being a early diagnosis of embryo/fetal demise or trophoblastic disease.
The use of ultrasound at later stages of heart development in the mid-1980's began to be used as a diagnostic tool for congenital cardiac abnormalities.[7]
Soft Markers
The term "soft markers" refers to ultrasound measurements which may not be diagnostic by themselves, but can have an indicative role for further diagnostic analysis of the pregnancy.
The Diagnostic Imaging Committee of the Society of Obstetricians and Gynaecologists of Canada in 2005[8] made the following recommendations:
- The screening ultrasound at 16 to 20 weeks should evaluate 8 markers, 5 of which (thickened nuchal fold, echogenic bowel, mild ventriculomegaly, echogenic focus in the heart, and choroid plexus cyst) are associated with an increased risk of fetal aneuploidy, and in some cases with nonchromosomal problems, while 3 (single umbilical artery, enlarged cisterna magna, and pyelectasis) are only associated with an increased risk of nonchromosomal abnormalities when seen in isolation (II-2 B).
- Identification of soft markers for fetal aneuploidy requires correlation with other risk factors, including history, maternal age, and maternal serum testing results (II-1 A).
- Soft markers identify a significant increase in fetal risk for genetic disease. Timely referral for confirmation, counselling, and investigation is required to maximize management options (III-B).
Doppler Ultrasound
Doppler ultrasound is a noninvasive measure of blood flow and blood pressure by bouncing ultrasound off circulating red blood cells. Originally used for fetal heart beat detection, more recently used diagnostically in uterine, placental, ductus venosus and other fetal blood vessels.
Doppler effect is due to the movement of blood cells causing a change in pitch of the reflected sound waves.
Ultrasound Research
Ultrasound imaging began in the 1950's but it was only with the application of computer analysis beginning in the 1980's that more detailed images could be generated. The increasing quality of ultrasonic equipment and computing allows today realtime 3D scans and calculations of fetal measurements as well as doppler measurement of heart rates.
In medical research there have been recent developments that allow spatial high resolution down to 30 microns in real-time.
Other Imaging Techniques
There are a range of other imaging techniques to study development and used in developmental research.
Other developmental research imaging techniques include:
- Magnetic Resonance Imaging
- Computed Tomography
- high frequency ultrasound or High Intensity Focused Ultrasound (HIFU)
- positron emission tomography (PET)
- single photon emission computed tomography
- optical bioluminescence
- fluorescence
Additional Images
References
- ↑ <pubmed>11065037</pubmed>
- ↑ <pubmed>20350241</pubmed>
- ↑ <pubmed>20205205</pubmed>
- ↑ <pubmed>18551722</pubmed>
- ↑ <pubmed>16903253</pubmed>
- ↑ 6.0 6.1 Reissland N, Francis B, Mason J, Lincoln K (2011) Do Facial Expressions Develop before Birth? PLoS ONE 6(8): e24081. doi:10.1371/journal.pone.0024081 PLoS One
- ↑ <pubmed>3923046</pubmed>
- ↑ <pubmed>16100637</pubmed>
Books
Molecular Imaging and Contrast Agent Database (MICAD) NBK5330 | PMID:20641179
Search PubMed
Search PubMed: Ultrasound prenatal diagnosis | Ultrasound
- ART - Assisted Reproductive Technology a general term to describe all the clinical techniques used to aid fertility.
- blastomere biopsy - An ART preimplantation genetic diagnosis technique carried out at cleavage stage (day 3), excluding poor quality embryos, detects chromosomal abnormalities of both maternal and paternal origin. May not detect cellular mosaicism in the embryo.
- blastocyst biopsy - An ART preimplantation genetic diagnosis technique carried out at blastocyst stage (day 4-5), removes several trophoblast (trophoderm) cells, detects chromosomal abnormalities of both maternal and paternal origin and may detect cellular mosaicism.
- cell-free fetal deoxyribonucleic acid - (cfDNA) refers to fetal DNA circulating and isolated from the plasma portion of maternal blood. Can be performed from GA 10 weeks as a first-tier test or as a second-tier test, with women with increased probability on combined first trimester screening offered cfDNA or diagnostic testing.
- false negative rate - The proportion of pregnancies that will test negative given that the congenital anomaly is present.
- false positive rate - The proportion of pregnancies that will test positive given that the congenital anomaly is absent.
- free β human chorionic gonadotrophin - beta-hCG subunit of hCG used as a diagnostic marker for: early detection of pregnancy, Trisomy 21, spontaneous abortion, ectopic pregnancy, hydatidiform mole or choriocarcinoma.
- multiples of the median - (MoM) A multiple of the median is a measure of how far an individual test result deviates from the median and is used to report the results of medical screening tests, particularly where the results of the individual tests are highly variable.
- negative predictive value - The probability that a congenital anomaly is absent given that the prenatal screening test is negative.
- Non-Invasive Prenatal Testing - (NIPT) could refer to ultrasound or other imaging techniques, but more frequently used to describe analysis of cell-free fetal DNA circulating in maternal blood.
- polar body biopsy - (PB biopsy) An ART preimplantation genetic diagnosis technique that removes either the first or second polar body from the zygote. As these are generated by oocyte meiosis they detects chromosomal abnormalities only on the female genetics.
- positive predictive value - The probability that a congenital anomaly is present given that the prenatal screening test is positive.
- pre-implantation genetic diagnosis - (PGD, pre-implantation genetic screening) a diagnostic procedure for embryos produced through Assisted Reproductive Technology (ART, in vitro fertilisation, IVF) for genetic diseases that would generate developmental abnormalities or serious postnatal diseases.
- prenatal screening sensitivity - (detection rate) The probability of testing positive on a prenatal screening test if the congenital anomaly is present.
- prenatal screening specificity - The probability of testing negative on a prenatal screening test if the congenital anomaly is absent.
- quadruple test (maternal serum testing of a-fetoprotein Template:AFP, free B-hCG or total hCG, unconjugated estriol, and inhibin A) is a fetal chromosomal anomaly test usually carried out later in pregnancy (GA 14 to 20 weeks).
- single nucleotide polymorphisms - (SNPs) the variation in a single DNA nucleotide that occurs at a specific position in the genome.
- triple test - (maternal serum testing of a-fetoprotein Template:AFP, free B-hCG or total hCG, and unconjugated estriol) is a fetal chromosomal anomaly test usually carried out later in pregnancy (GA 14 to 20 weeks).
Other Terms Lists |
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Terms Lists: ART | Birth | Bone | Cardiovascular | Cell Division | Endocrine | Gastrointestinal | Genital | Genetic | Head | Hearing | Heart | Immune | Integumentary | Neonatal | Neural | Oocyte | Palate | Placenta | Radiation | Renal | Respiratory | Spermatozoa | Statistics | Tooth | Ultrasound | Vision | Historic | Drugs | Glossary |
Terms
- Biparietal diameter (BPD)
- Crown-Rump Length (CRL)
- Femur length - (FL) is used to determine fetal age and normal development (small/large/abnormal) parameters. The femur is the longest bone in the body and measurements and reflects the longitudinal growth of the fetus (approximately 14 weeks 1.5 cm - term 7.8 cm). It is one of the four typical ultrasound assessments of fetal size and age: Biparietal Diameter (BPD), Head Circumference (HC), Abdominal Circumference (AC), and Femur Length (FL).
- Functional linear discriminant analysis (FLDA) - new growth assessment technique using serial measurements to discriminate between normal and abnormal fetal growth.
- Head Circumference (HC)
- Gestational sac (GS) size
- inversion mode - an ultrasound processing method of volume analysis for the visualization of fluid-filled fetal structures such as; heart chambers, vessel lumen, stomach, gallbladder, renal pelvis, and the bladder. Post-processing inverts the gray scale of the volume voxels showing the normally anechoic structures in 3D or 4D renderings. This technique has been used to identify cardiac anomalies.
- Linear discriminant analysis (LDA) to longitudinal data (James and Hastie, 2001)
- Mean gestation sac diameter (MSD)
- Mean yolk sac diameter (MYD)
- Spatiotemporal image correlation (STIC) - an image acquisition method used mainly for fetal heart analysis. Requires two steps; an automatic volume sweep, then image data analysis according to spatial and temporal domain generating an online dynamic 3D image sequence.
- Transvaginal scan (TVS)
- Termination of pregnancy (TOP)
External Links
External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.
- Australian Society for Ultrasound Medicine - Guidelines For The Mid Trimester Obstetric Scan PDF (2005)
Glossary Links
- Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link
Cite this page: Hill, M.A. (2024, May 2) Embryology Ultrasound. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Ultrasound
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G