OBSTETRIC ULTRASOUND

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OBSTETRICULTRASOUND : 

10/21/2009 1 OBSTETRICULTRASOUND Bambang Widjanarko

Slide 2: 

10/21/2009 2 Ultrasound in obstetrics can provide good information about the fetus and its environment With ultrasound , can be determined an early intervention or conservative management in pregnancy Latest developments in ultrasound examination is a transvaginal ultrasound discovery - the observation of "FLOW DOPLLER" and the most sophisticated ultrasound 3 D and 4D which has a high ability to determine fetal condition

Utrasound Technology : 

10/21/2009 3 Utrasound Technology Intermittent high-frequency sound waves are generated by applying an alternating current to a transducer made of piezoelectric material. The transducer is “connected” to the abdominal or vaginal wall by placing a coupling agent to diminished the loss of ultrasound wave A pulse sound waves passes through soft tissues until an interface between the structures of different tissues densities is reached Some of the energy is reflected or echoed back to the transducer and amplified and displayed on a screen With real-time ultrasonography , the movement including breathing, cardiac actions and vessel pulsations can be detected

Patient Preparation : 

10/21/2009 4 Patient Preparation Prerequisite for an abdominal ultrasound examination is a full bladder for three important reasons : Full bladder pushes the uterus out of the pelvic → removing it from acoustic shadow of symphisis pubis Full bladder provides an acoustic windows → pelvic organ can be visualized Displayed bowels superiorly, → preventing the gas from scattering the ultrasound beam For an vaginal ultrasound, the bladder must be empty → small amount of urine can pushed uterus posteriorly out of the field of view of the transducer

Clinical Applications : : 

10/21/2009 5 Clinical Applications : Very early identification of intrauterine pregnancy Demonstration of the size and the rate of growth of the amnionic sac and the embryo and, at times, resorbtion or expulsion of the embryo Identification of multiple fetuses including conjoined twins Measurements of the fetal head, abdominal circumference,femur and other anatomical landmarks to help identify the duration of gestation and identify growth retarded fetus Identify hydrocephaly – microcephaly , or anencephaly → comparison of the fetal head and chest or abdominal circumference

Slide 6: 

10/21/2009 6 Detection of fetal anomalies Distension of fetal bladder Ascites Polycyctic kidney Renal Agenesis Ovarian cyst Intestinal obstruction Diafragmatic hernia Meningomyelocel Intracranial, cardiac or limb defect Demonstration of hydramnion or oligohydramnion Identification of the location and size of the placenta Demonstration of placental abnormalities : Hydatidiform mole Molar degeneration Chorioangioma Identification of uterine tumors or anomalous development Detection of foreign body → IUD, blood clot or retained placental fragments

Obstetric Sonography( 1st trimester ) : 

10/21/2009 7 Obstetric Sonography( 1st trimester ) Establishment of an intrauterine pregnancy Identification of the number of gestation Detection of embryonic and fetal viability Evaluation of complicated early pregnancy : Retrochorionic hemorrhage Anembryonic pregnancy Incomplete or complete abortion Molar pregnancy Early dating of the pregnancy : Gestational sac diameter Crown-rump length Biparietal diameter Evaluation of the uterus and adnexae

Slide 8: 

10/21/2009 8 Transabdominal ultrasound : Gestational sac usually established by 5 weeks of amenorrhea HCG 1800 – 3600 mIU / ml Transvaginal ultrasound : Gestational sac usually established by 4 weeks of amenorhea Serum level of HCG 800 mIU/ml Absence of an intrauterine gestational sac in conjuction with HCG value → ectopic pregnancy ?? Using the M-mode, fetal heart motion can usually established by 7 weeks of gestation

Early dating of pregancy : 

10/21/2009 9 Early dating of pregancy 4 – 6 weeks : use of GS diameter 8 – 10 weeks : use of CRL (most acurate dating of early pregnancy) 10 – 12 weeks : use of BPD

Gross malformation may be detected in 1st trimester sonogram : : 

10/21/2009 10 Gross malformation may be detected in 1st trimester sonogram : Anencephalus Acrania Hydrancephaly Cystic Hygroma Fused twins Omphalocele Gastroschisis

Central Nervous System Abnormalities : 

10/21/2009 11 Central Nervous System Abnormalities Three routine tranverse ( axial ) to depict the fetal brain and cranium Transthalamic view : Measure the BPD & Head circumference Transventricular view : Ventrikel cerebri lateralis Pleksus choroideus Cranial contour Transcerebellar view : Cerebellum Cysterna Magna

Slide 12: 

10/21/2009 12 a cross section through the fetal head at the level of the thalamus. The skull is represented by the thick white lines which surround the brain. This view is used to measure the biparietal diameter (line) and the circumference of the head (dots). Trans thalamic view

Slide 13: 

10/21/2009 13 Transcerebellar View

Nuchal Translucency : 

10/21/2009 14 Nuchal Translucency The maximum thickness of the subcutaneus translucent area between the skin and the soft tissues overlying the posterior aspect of the cervical spine in sagital scane plane. A thickness > 3 mm ( sagital plane ) : 90% trisomy 18 and 13 80% trisomy 21 5% normal

Slide 15: 

10/21/2009 15 This is a view obtained through the lower portion of the fetal head. The skull is represented by a thick white line which surrounds the developing brain. The yellow square illustrates the area in the fetal head where the nuchal skin fold is identified. The nuchal skin fold is the thickness of the skin in the neck region. If the thickness is increased, it could indicate a high-risk for Down syndrome, or other chromosomal abnormalities. The inset illustrates the location of the nuchal skin fold.

Uterus and Adneksa : 

10/21/2009 16 Uterus and Adneksa Cervical incompetence : Funeling of the internal ( dilatation ) Cervical length < 3 cm Bulging membranes ( with or without prolaps of the cord or fetal parts ) Adnexal mass : Physiological : Diameter corpus luteum at pregnancy about 2 cm 30 weeks of gestational age : length of cervix more than 3 cm

Slide 17: 

10/21/2009 17 Uterus and cervical plug

Slide 18: 

10/21/2009 18 First trimester fetus and yolk sac

Slide 19: 

10/21/2009 19 10 weeks fetus & yolk sac

Slide 20: 

10/21/2009 20 Embryo 4 weeks

Slide 21: 

10/21/2009 21 Uterine texture subtleitis and 1st trimester fetus

Slide 22: 

10/21/2009 22 Biparietal Diameter

Slide 23: 

10/21/2009 23 28 mm CRL in 10 weeks twin pregnancy

Slide 24: 

10/21/2009 24 Pregnant uterus - longitudinal

Slide 25: 

10/21/2009 25 Triplet with subchorionic bleeding

Slide 26: 

10/21/2009 26 Early intracranial structure and cord

Slide 27: 

10/21/2009 27 Fetal : intracranial structure and ekstrimity

Slide 28: 

10/21/2009 28 Fetal intracranial structure

Slide 29: 

10/21/2009 29 Fetal intracranial structure

Slide 30: 

10/21/2009 30 Fetal Intracranial structure ( color Doppler )

Obstetric Sonography ( 2nd and 3rd trimester ) : 

10/21/2009 31 Obstetric Sonography ( 2nd and 3rd trimester ) Fetal viability , number and presentation Amount of amniotic fluid Placental localization Establishment of fetal age and growth by fetal biometry including : BPD ~ biparietal diameter FL ~ femur length AC ~ Abdominal circumference Evaluation of fetal anatomic structures : Cerebral lateral ventricles Spine Four chamber view of the heart Stomach-bowel,abdominal wall at the area of the umbilical cord insertion Bladder and kidney Limbs and umbilical cord Evaluation of the cervix and adnexae

Prefereda fetal dimension for estimation of gestational age at various stage of pregnancy : 

10/21/2009 32 Prefereda fetal dimension for estimation of gestational age at various stage of pregnancy a In decreasing order b Only if cephalic index ( BPD divided by occipital-frontal diameter ) is normal ( 76-84%) ; otherwise , the fetal head may be dolichocephalic or brachycephalic

Fetal viability : 

10/21/2009 33 Fetal viability Fetal cardiac activity Fetal movement Breathing movement

Fetal Breathing Movement : 

10/21/2009 34 Fetal Breathing Movement

Slide 35: 

10/21/2009 35 FETAL CIRCULATION 14 weeks

Slide 36: 

10/21/2009 36 Fetal Aorta

Slide 37: 

10/21/2009 37 Aortic Arch

Slide 38: 

10/21/2009 38 Fetal Cardiac Structure

Slide 39: 

10/21/2009 39 Fetal Face

Fetal Face14 weeks : 

10/21/2009 40 Fetal Face14 weeks

Slide 41: 

TRYING TO THINK

Slide 42: 

10/21/2009 42 Fetal Femur

Slide 43: 

10/21/2009 43 Trisomi 18

Slide 44: 

10/21/2009 44 Fetal Hand

Slide 45: 

BOXING

Slide 46: 

CLUB FEET

Slide 47: 

10/21/2009 47 CLUB FEET

Slide 48: 

10/21/2009 48 Fetal Lenses

Slide 49: 

10/21/2009 49 Fetal Knee ( 3rd Trimester )

Slide 50: 

10/21/2009 50 Fetal Liver 3rd Trimester

Slide 51: 

10/21/2009 51 Fetal Liver and Lung interface

Slide 52: 

10/21/2009 52 Fetal Umbilical arteri and Bladder

Spine3 D : 

10/21/2009 53 Spine3 D

Sonographic assesment of the amniotic fluid : 

10/21/2009 54 Sonographic assesment of the amniotic fluid Normal : at 2nd and 3rd trimester vertical pocket about 2 cm AFI ( amniotic fluid index ) : sum of the depth of the largest pocket of fluid in the four quadrants of abdomen AFI < 5 cm : strongly asociated with oligohidramnions postmaturity

Slide 55: 

10/21/2009 55 Amniotic Fluid Index

Slide 56: 

10/21/2009 56 BPD, FL and AC the most important parameters for determination of gestational age Determination of gestational age should be performed prior to 26 weeks gestational age 3rd trimester determination of gestational age does not acurately reflect gestational age BPD at a standard reference level measurement should include the cavum septi pellucidi, the thalamus or the cerebral peduncles. When the shape is not oval the BPD measurement is not acurate

HYDROCEPHALUS : 

10/21/2009 57 HYDROCEPHALUS 85% have other intracranial or extracranial mallformation Early determination with lateral ventricular ratio ( lateral ventricular width divided by hemispheric width ) At 15 weeks : LVR 71% At 24 weeks : LVR 33% After 24 weeks, LVR > 50% is considered abnormal

Neural tube defects : 

10/21/2009 58 Neural tube defects NTD’s result from failure of tube closure by the 6th weeks gestational age ( embryonic age 26 – 28 days ) Various NTD’s anomalies : Anencephaly Encephalocele Spina Bifida

Spina Bifida : 

10/21/2009 59 Spina Bifida Consist of a hiatus, usually in the lumbosacral vertebrae, through which a meningeal sac may protruded → meningocele 90% of cases, the sac contains neural elements → meningomyelocele The fetal spine should be examined by sonography with : sagittal, tranverse and coronal views

Slide 60: 

10/21/2009 60 Fetal Spine

Slide 61: 

10/21/2009 61 Fetal Spine

Slide 62: 

10/21/2009 62 Spina Bifida

Slide 63: 

10/21/2009 63 NEURAL TUBE DEFECTS

Slide 64: 

10/21/2009 64 NEURAL TUBE DEFECTS

Slide 65: 

10/21/2009 65 VARIANT NEURAL TUBE DEFECTS

anencephaly : 

10/21/2009 66 anencephaly The first fetal malformation to be diagnosed prenatally by using sonography In the second trimester, anencephaly is diagnosed with virtually 100% acuracy Sonographically, anencephaly is characterized by absence of the cranial vault and brain above the base of the skull and orbits Hydramnion, secondary to impaired fetal swallowing, commonly accompanies anencephaly but typically is a late finding

Slide 67: 

10/21/2009 67

Encephalocele : 

10/21/2009 68 Encephalocele Condition in which the meninges and cerebrospinal fluid, usually in association with brain tissue, herniate through a cranial defect Sonographycally, Encephalocele vary in size and are characterized by either a cystic or solid appearance Commonly associated with either hydrocephaly or microcephaly Occipital encephalocele can be detected utilizing transthalamic and transcerebellar view

Choroid plexus cyst : 

10/21/2009 69 Choroid plexus cyst CPC have been identified 1 – 3% of 2nd trimester fetuses Usually are transient and no clinical significance In some situations, have been associated with trisomy 18

Slide 70: 

10/21/2009 70 Pleksus Choroideus and Cyste

GASTROINTESTINALAbnormalities : 

10/21/2009 71 GASTROINTESTINALAbnormalities The intergrity of the abdominal wall, umbilical cord insertion and intra abdominal anomalies can be assessed with confidence by using high-resolution diagnostic sonography In most pregnancies, the liver, spleen, gallbladder and bowel can be identified Normally, the appearance of the fetal bowel changes with gestational age and considerable overlap exist between normal and pathological condition

umbilicus : 

10/21/2009 72 umbilicus

Slide 73: 

UMBILICAL CORD INSERTION

Diafragmatic Hernia : 

10/21/2009 74 Diafragmatic Hernia Result from incomplete fusion of the pleuroperitoneal membrane More frequently on the left side Ultrasonografi examination : Cystic structure, usually behind the left atrium , seen on an axial image at the level four-chamber cardiac view Absence of an intra-abdominal stomach bubble Mediastinal shift with normal cardiac axis Small abdominal circumference Peristalsis in the fetal chest Half of cases associated with other major anomalies Chromosomal abnormalities are found in up to 20% affected infants

Slide 75: 

10/21/2009 75 Physiologic Midgut Hernia

Abdominal Wall Defects : 

10/21/2009 76 Abdominal Wall Defects The two most common are : Omphalocele Gastroschisis Can be ascertained early in pregnancy by maternal serum alphafetoprotein screening programs

Omphalocele : 

10/21/2009 77 Omphalocele Congenital midline defect in the anterior abdominal wall when the lateral abdominal fold fail to fuse Can be diagnosed accurately as early as 12 weeks Herniation of intra-abdominal structures into the base of the umbilical cord Must be differentiated from the physiological herniation that apparent normally until 14 weeks Associated major malformations are found in about half of fetuses with an omphalocele Diagnosis : A sac containing intra-abdominal structures is image outside the abdomen Umbilical cord inserting into the hernia sac

Slide 78: 

OMPHALOCELE

Gastroschisis : 

10/21/2009 79 Gastroschisis Intra-abdominal organs herniate through a defect in the anterior abdominal wall The defect caused by interruption of the right omphalomesenteric artery and is located usually to the right of the umbilicus and spares the rectus muscle Has been diagnosed as early 13 weeks using transvaginal sonography Sonographyically : Extracorporeal bowel has typical cauliflower appearance. Herniated organs float freely in the amniotic fluid with no covering membrane Umbilical cord insertion is normal

Slide 80: 

10/21/2009 80 GASTROSCHISIS

Gastrointestinal Atresia : 

10/21/2009 81 Gastrointestinal Atresia Most of these anomalies are caused by obstruction with subsequent proximal bowel dilatation The more proximal the obstruction, the more likely it will associated with hydramnions Esophagel atresia and tracheo-esophagel fistula : Cannot be diagnosed realibly in -utero Suspected when hydramnions is found in the absence of fluid-filled stomach

Duodenal atresia : 

10/21/2009 82 Duodenal atresia Diagnosed prenatally by the demonstration of the double bubble sign ( distension of the stomach and first part of the duodenum ) Must be differentiated from other cystic structures in the upper abdomen Diagnosis generally is not possible before 24 weeks 30% of cases has been associated with trisomy 21

Genitourinary Tract : 

10/21/2009 83 Genitourinary Tract The fetal kidneys are visualized as paraspinous mass as early as 14 weeks Appear elliptical in parasagital plane and circular in tranverse plane Renal cortex is echogenic, surrounds the hypoechoic medullary pyramids and outlined by perinephric fat and the renal capsule The renal pelvic is centrally located an anechoic Urine production normally begins late in the 1st trimester so the fetal bladder can be observed as an anechoic area in the pelvis early in 2nd trimester Assesment of amniotic fluid volume provides important information regarding fetal renal function ; often significant fetal urinary tract abnormalities result in oligohydramnions

Slide 84: 

10/21/2009 84 Four-chamber view of the heart DOPPLER

Slide 85: 

10/21/2009 85 Four chamber view of the heart

Slide 86: 

10/21/2009 86 The Arm

Slide 87: 

10/21/2009 87 BLADDER

Slide 88: 

10/21/2009 88 CP = plexus choroideus

Slide 89: 

The skull is represented by thick white lines which surround the brain. The area of brain which is of interest is outlined by the yellow box. The insert is an enlarged image of this area illustrating the choroid plexus (CP), which floats within the ventricles. The ventricle size can be measured (yellow lines). If the dimension of the ventricle is more than 10 mm, this could represent an early manifestation of an abnormal accumulation of fluid within the ventricles. In severe cases, hydrocephaly could result from progressive enlargement of the ventricles.

Slide 90: 

10/21/2009 90

Slide 91: 

This is a view obtained through the lower portion of the fetal head. The skull is represented by a thick white line which surrounds the developing brain. The yellow square illustrates the area in the fetal head where the cerebellum is identified. The shape of the cerebellum is important. It normally appears as a "dumb bell", as outlined in the inset picture in the upper right of the screen. However, if it should change shape, this could indicate that a spinal cord defect is present.

Location of the Eye : 

Location of the Eye This is a view obtained through front of the fetal head. The yellow box illustrates the area of the mid face. The inset demonstrates the bony structures of the face with the dots representing the area where the eyes are located.

Slide 93: 

10/21/2009 93

Kidneys : 

Kidneys A cross section through the fetal abdomen at the level of the kidneys. The yellow box illustrates where the kidneys should be located. The inset in the upper right of the picture demonstrates the kidney (dots) on one side of the spine (Sp). The other kidney is not clearly identified (?). If this occurs the kidneys can be examined using color Doppler ultrasound. If the kidneys are dilated, this may suggest an increased risk for Down syndrome, or be an early indication of blockage. If blockage is identified before birth, it can often be successfully corrected after birth.

Measurement of the abdomen : 

Measurement of the abdomen This is a cross section through the fetal abdomen at the level of the stomach and liver. This view is used to measure the circumference of the abdomen (dots). This measurement is used to determine the age and growth of the fetus. Inadequate growth of the abdomen may be an indication of placental dysfunction which can lead to an increase risk for a small baby. In severe cases, this may increase the risk for stillbirths as well as neurological damage.

Measuring the leg : 

10/21/2009 96 Measuring the leg This is the femur, which is the bone from the hip to the knee. Measurement of this bone is useful to determine if the skeletal system is developing properly.

Slide 97: 

This is the humerus, which is the bone from the shoulder to the elbow. Measurement of this bone is not done by most physicians unless the patient is at increased risk for Down syndrome. The reason this measurement is important is because fetuses with Down syndrome may have a short upper arm.

Spine : 

Spine This image was obtained by directing the ultrasound beam along the back of the fetus. In this plane, the back of the head can be identified as well as the spine and ribs.

Slide 99: 

10/21/2009 99 Male

Renal agenesis : 

10/21/2009 100 Renal agenesis Incidence of bilateral renal agenesis of about 1 : 4000 births Severe oligohydramnion is developed Fetal adrenal glands appear to enlarged and care must be taken to avoid mistaking them for kidneys Death follows, either in utero or shortly after birth and the infants exhibits pulmonary hypoplasdia, limb deformities, loose skin and typical facies of the Potter Syndrome Associated anomalies especially cardiac are common

CYSTIC RENAL DISEASE : 

10/21/2009 101 CYSTIC RENAL DISEASE Secondary cystic changes may developed in the fetal kidneys cause by urinary obstruction Ultrasonographycally : the kidney replaced by randomly oriented cysts of varying size and normal renal contour is lost

DOPPLER VELOCIMETRY : 

10/21/2009 102 DOPPLER VELOCIMETRY The primary use of Doppler echo shifts in obstetrics have been to detect and measured blood flow Basis of Doppler Velocimetry : The sound of moving blood cells within vasculature generates an effective Doppler Shift There are 2 methods of estimating circulatory hemodynamics : Direct measurement of the volume of blood flow Indirect estimation of flow velocity using wave form analysis

DETERMINATION OF BLOOD VOLUME FLOW : 

10/21/2009 103 Doppler-shifted sound frequencies depend on a number of factors and summarized in the following equation : Frequency deviation ( fd ) or shift = 2 fo fo is original frequency of the ultrasound beam ( in obstetrics usually 3 – 5 mHz) v is the velocity of blood cells in the vessel θ is the incident angle between ultrasound beam and the vessel c is speed of sound ( in tissue is equal to 1540 m/sec ) The velocity : DETERMINATION OF BLOOD VOLUME FLOW v cos θ c Velocity = ( fd x c ) 2 fo x cos θ

Slide 104: 

10/21/2009 104 θ artery Fd = 2 f0 V cos θ c Doppler equiation : Ultrasound emanating from transducer with initial frequency f0 strikes blood moving at velocity. Reflected frequency fd is dependent on angle θ beetween beam of sound and vessel ( From Copel and associates, 1988 ) DETERMINATION OF BLOOD VOLUME FLOW

Estimasi velocity of red blood cell : 

10/21/2009 105 Estimasi velocity of red blood cell Velocity = ( fd x c ) 2 f0 x cos θ Because of methodological problems, blood volume flow measurements have been largely abandoned in clinical application

Waveform analysis of blood velocimetry : 

10/21/2009 106 Waveform analysis of blood velocimetry S D D S MEAN = S/D ratio = Resistance index = Pulsatility index Doppler systolic-diastolic waveform indices of blood flow velocity. S = Systole ; D = Diastole Mean is calculated from computer digitized waveform S S - D S - D

Slide 107: 

10/21/2009 107 Fetal Umbilical Cord Doppler

Slide 108: 

10/21/2009 108 Waveform with high flow in diastole accompany low downstream vessel impedance. In contrast, waveform with little diastolic flow or reversed flow, are seen when vascular impedance downstream is abnormally high ( placental insufficiency )

Continous Wave Doppler Sonography of uterine and umbilical artery : 

10/21/2009 109 Continous Wave Doppler Sonography of uterine and umbilical artery Assesment of utero-placental blood flow : Hypertension IUGR Twin-to-twin tranfusion Reversal of Fetal Diastolic blood flow in the umbilical artery → severely compromised fetus

Thank You : 

10/21/2009 110 Thank You Bambang Widjanarko Departement of Obstetrics and Gynecology School of Medicine Atmajaya University Indonesia 2005