ULTRASOUND EXAMINATION OF THE 2nd & 3rd TRIMESTER PREGNANCY.

Dr/ ABD ALLAH NAZEER. MD.

BASIC HARD COPY IMAGES:A morphology series should include the following minimum images: cervix lengthPlacenta and placenta to cervix distanceBPD, HC, AC, FLVentricles and choroidsCerebellum, NF, Cisterna Magnanose and lips, eyes and orbitsPalate and mandiblespine (sagittal, coronal and transverse)Pelvis, arms, hands, fingers, legs,feet,toesDiaphragm and stomach shown on left sidekidneys with PUJ measurement and bladdercord insertion and 2 umbilical arteriesHeart- 4 chamber,LVOT,RVOT,PAV,Aortic arch and ductal arch (in B mode and colour)heart rate

IMAGES TO CHECK GROWTHBiparietal Diameter and Head Circumference (BPD AND HC):The fetal head measurement must be taken in a cross sectional approach to include the skull, thalamus, septum pellucidum and it must be symmetrical. The fetus's head should be imaged laterally through the parietal bone. The measurement is from the outer edge to the inner edge of the cranium .*Note: The cerebellum must NEVER be seen in this image or the probe is too caudal which can give an inaccurate size of the fetal head.Abdominal Circumference (AC):The abdominal circumference is taken with a transverse image to include the stomach, portal vein and the spine in a true transverse plane. The ribs may or may not be seen but must be symmetrical if included. It should be a circle at 18-20 weeks and no compression by external forces. It is best taken with the baby supine or lateral because if the baby is prone then the rib shadows make it difficult to check the correct level. The measurement must be taken around the waist on the edge of the skin layer.*Note: The kidneys should not be seen in the AC image or the plane is too caudal.Femur Length (FL):The femur bone must only be imaged when it is parallel to the probe as it will not be foreshortened. The lateral edge of the shaft is measured from the greater trochanter to the lateral femoral condyle.

ULTRASOUND 18-20 WEEKS - Normal (MORPHOLOGY SCAN)

HEAD ULTRASOUND

The correct plane for the measurement of the head circumference (HC) and bi-parietal diameter (BPD)must include the cavum septum pellucidum, thalamus and choroid plexus in the atrium of the lateral ventricles.

BPD: Measure outer table of the skull to the inner table. HC: Measure around the outer table of the skull.

The correct plane for measuring the nuchal fold is to have cavum septum pellucidum (CSP) and the cerebellar hemispheres in the image.

The cerebellar diameter should approximately equal the weeks of gestation. (EG 19weeks=19mm).Normal cisterna magna is less than 10mm.A normal nuchal fold is less than 6mm (between 17-20weeks).

The LATERAL VENTRICLES should be less than 10mm in diameter (best measured at the occipital horn). The CHOROID PLEXII should be homogeneous. Small, and sometimes multiple, choroid plexus cysts are a common finding on high resolution equipment. They are of doubtful significance as an isolated finding.

PROFILE - ensure the mandible is appropriate size, nasal bone is present and there is a normal face/head shape.

FACE: Ensure there is symmetry with a normal inter-orbital distance.

NOSE & LIPS: From the 'face' image, rotate the probe to visualize the nose and lips front on.2 distinctly separate nodules and in intact hypoechoic upper lip should be seen. 2 distinctly septate nostrils and an intact hypoechoic top lip.

ABDOMINAL ULTRASOUND

AC- ABDOMINAL CIRCUMFERENCE.

The Abdominal Circumference must include the portal section from the umbilical vein, the stomach and a true cross section of the spine with 3 ossification centers. It should be circular in shape.

First, confirm that the organs are correctly sited right vs left. An axial plane through the chest and upper abdomen shows the heart and stomach on the same side (which has been proven to be the left).

In a coronal plane, confirm the presence and position of heart, stomach and bladder. Also check the diaphragm. Ensure that there is no herniation of abdominal contents into the thorax.

FETAL KIDNEYS

Confirm the presence and position of both kidneys. Be cautious not to mistake the adrenal glands which are quite large. Look for the anechoic renal pelvis. The renal pelvis TS diameter should be less than 5mm.

The kidneys must be measured in a sagittal or coronal plane. Utilize colour/power Doppler to confirm renal arteries and help identify the kidneys in a larger patient.

UMBILICAL CORD

Cord insertionEnsure the abdominal wall around the cord insertion is intact and that no bowel has herniated into the cord. Use power Doppler to confirm the presence of 2 umbilical arteries forking around the bladder. (Be careful not to slip into a more coronal plane and mistake the iliac arteries.)

There is an obvious penis identified at 18-20 weeks. Shown on the mouseover is the 3 parallel white stripes of the external genitalia of the female vulva.

FETAL SPINE

CORONAL SPINECheck for any scoliosis.Cervico-thoracic spine: Check the ribs for symmetry. Lumbar/sacral spine: In coronal, visualize the sacral taper and pelvic bones.

SAGITTAL SPINEEnsure there is a uniform, intact posterior skin edge.

TRANSVERSE SPINEThe 3 ossification centers of the spine should be visible from neck to the lumbo-sacral junction. A smooth intact skin line should be visible throughout. Beware overlying cord mimicking a meningocele.

CORONAL SPINE

FETAL LIMBS:

Femur LengthThe Femur length should only be measured when the femur is horizontal (beam is perpendicular) and shadows evenly- at least from both ends.

Lower limbsConfirm the presence and equal size of the tibia and fibula bilaterally.

The foot should be perpendicular to the tibia and fibula.

Upper limbs. 5 fingers/knuckles on each side.

The echogenic mucous plug is readily visible in the cervix. Measure the length of the cervix. It should be at least 30mm, and contain no fluid.

Uterine contractionBeware of uterine contractions mimicking a low lying placenta.

PLACENTA

Placental bed: Locate the placenta (anterior V's posterior or lateral)Ensure there is a myometrial rim of 3mm or more under the placenta (otherwise suspect placenta percreta/accreta).

The placenta tip must be greater than 3cm from the internal os.

LIQUOR and AFI

Greater than the 95th centile =Polyhydramnios. Less thanthe 5th centile =Oligohydramnios.

Amniotic Fluid index (AFI), Measure the deepest vertical pocket (with no fetal content) in each quadrant and add them together.

UMBILICAL ARTERY RESISTIVE INDEX:

Measure the Systolic-Diastolic (SD) ratio or the resistive index of the umbilical artery. Both of these are different forms of the same information. Umbilical Artery Doppler.

MIDDLE CEREBRAL ARTERY DOPPLER:

MCA Doppler

Middle cerebral artery Doppler gives an indication of the "Brain sparing effect“. Measure the pulsatility index. Another useful ratio is: MCA RI / UA RI < 1 (normally > 1).

DUCTUS VENOSUS:

Ductus venosus Doppler: Oxygen rich blood from the maternal circulation enters to the fetus via the Umbilical vein. The umbilical vein ascends the fetal abdomen and drains into the left portal vein and the IVC via Ductus venosus. DV is being flagged as a potentially earlier predictor of adverse pregnancy outcome than Umbilical artery Doppler's.

Ductus venosus Doppler is recognizable as a small high velocity structure laying superiorly in the liver, adjacent to the IVC. Should be constant forward flow throughout the cardiac cycle.

MOST COMMON ABNORMALITIES TO LOOK FOR WHEN IMAGING THE FOLLOWING STRUCTURES

Profile, nasal bone, nose/lips, mandible, palate, orbits.Cleft lip and palate, Cystic hygroma, Exophthalmos, Proptosis, Prominent eyes, Hypotelorism, Microphthalmia, Anophthalmia, Facial asymmetry, Macroglossia, MicrognathiaNasal bone absence or hypoplasticHead, BPD, HC, CBM, NSF, CM, VentriclesChoroids plexus cysts(CPC)Agenesis of the corpus callosum:Dandy-Walker cystEchogenic brain focus or fociEncephalocele, Holoprosencephaly, Intracranial cyst, Clover leaf skull, Macrocephaly, MicrocephalyVentriculomegalyArnold Chiari malformationDandy-Walker malformation, Arachnoid cysts, Intracranial bleed, Posterior fossa cystVein of Galen aneurysmAnencephaly, Aqueductal stenosis, Intracranial teratomas

Heart,4chamber,LVOT,RVOT,heart beatBradycardia, TachycardiaHeart axis towards the leftEnlarged heart, Ventricular septal defect (VSD), Atrial septal defect (ASD), Coarctation of the aorta, Double outlet right ventricleHypoplastic left heart syndrome, Hypoplastic right heart syndromeSingle ventricle, Tetralogy of FallotCardiac rhabdomyoma, Ebstein's anomalyEndocardial cushion defect (atrioventricular canal)Ectopia cordis (pentralogy of Cantrell)Common arterial truncusPremature atrial contractions Transposition of the great arteriesBright echoes in the heartLeft/right heart enlargementRight atrial enlargementPericardial effusionSmall chest, Pleural effusion

Chest cavityPericardial effusion, Small chest, Enlarged heart, Pleural effusion, Cystic massesCystadenomatoid malformations, Diaphragmatic hernia, Chest wall hematomaPericardial cyst, Tracheal atresia, Mediastinal teratoma, hemothoraxDiaphragm,liver,GB,bowelDiaphragmatic herniaAnal atresia, Duodenal atresiaGastrointestinal atresia or stenosisGastroschisis, Omphalocele, Meconium cyst, Meconium ileus, Umbilical herniaTracheoesophageal atresia or fistula/esophageal atresiaAscites, Midgut volvulus, Small bowel atresia, Meconium peritonitisDilated stomach, Dilated duodenum, Dilated bowelEchogenic massAdrenal hemorrhageHepatic tumourNeuroblastomaOvarian cyst with hemorrhageEchogenic bowelCystic fibrosisIntragut or intrabdominal bleedCalcification, Gallstones, Teratoma

Kidneys and AdrenalsHydronephrosisEctopic ureterInfantile polycystic kidney diseaseMulticystic dysplastic kidneyPosterior urethral valvesReflux (<6mm PUJ)Ureterocele, Ectopic ureterPelvo-uretero junction obstructionUreterovesical junction obstructionHorseshoe kidney, Pelvic kidney, Renal agenesisUreteroceleAdrenal hematoma, Adrenal massCord and insertion, Omphalocele, GastroschisisUmbilical herniaOne umbilical artery

Bladder and GenderAbsent bladder, Renal agenesis, Bladder exostrophy, Dilated bladderSpine coronal, trans Spina bifidaMyelomeningocele, Myeloschisis, MeningoceleCystic massesSolid masses-Sacrococcygeal teratomaLower limbs Rocker-bottom feetPolydactylyAchondroplasia, AchondrogemesisAbsent digits, Absent limbsBowingClinodactyly, Club footFracturesJoint contracturesMesomelic shortnessMuscle wastingRhizomelic shortening, Limb shortening.

Upper limbPolydactylyAchondroplasiaAchondrogemesisAbsent digitsAbsent limbsAbnormal thumbBowingClenched handsClinodactylyFracturesJoint contracturesMesomelic shortnessMuscle wastingRadial hypoplasiaRhizomelic shorteningShort limbsLimb shortening

Vein of Galen aneurysm.

MICROCEPHALY.

Anencephaly.

Anencephaly

Fetal Hydrocephalus Ultrasound.

Ultrasound image choroid plexus papilloma.

Color Doppler imagechoroid plexus papilloma.

Congenital cardiac disease is seen in 2–6.5 of 1000 live births and

is a major cause of morbidity and mortality, with half of these cases being lethal or requiring surgical correction. Environmental, genetic, and chromosomal abnormalities are believed to be causes of congenital cardiac defects, with a higher incidence among infants with affected siblings or mother. Extra-cardiac abnormalities are associated with 25% of these cases.Detection of cardiac anomalies can be challenging and is typically doneby fetal cardiac ultrasound performed between 18 and 22 weeks.

Transvaginal scan can detect anomalies even at 12–13 weeks. Detailed fetal echocardiography is performed in high-risk cases, which could be a result of fetal (extra-cardiac anomalies, increased nuchal translucency, hydrops, or polyhydramnios), maternal (teratogen exposure, metabolic disorders, congenital heart defect, folic acid deficiency, or autoantibodies), or familial (sibling or father with congenital heart defect and Mendelian syndromes) factors. Detection of anomalies alters the obstetric course and outcome, including reassurance, termination, fetal therapy, mode of delivery, and postnatal referral to a tertiary care center with advanced expertise in management of these patients.

Standard cardiac view. A, Basic four-chamber view, which shows right ventricle (RV), left ventricle (LV), right atrium (RA), and left atrium (LA). Interventricular septum (arrow) is also seen in this view that is acquired perpendicular to ultrasound beam. Interatrial septum (arrowhead) is visualized.

Extended cardiac views. A, Left ventricular outflow tract view shows left ventricle (LV), which gives origin to ascending aorta (AO). Right ventricular (RV) outflow tract and left atrium (LA) are also seen.

Extended cardiac view.B, Right ventricular outflow tract view shows RV, giving origin to main pulmonary artery (PA). AO is seen as circular structure and is perpendicular to PA.

Extended cardiac view.C, Further superiorly, right pulmonary artery (RPA) and left pulmonary artery (LPA) are seen.

A, Aortic arch can be seen giving off branches to head and neck and continuing as descending thoracic aorta (DTA). DA = ductus arteriosus.

B, DA connects pulmonary artery (PA) to DTA.

C, Superior vena cava (SVC) and inferior vena cava (IVC) open into morphologic right atrium (RA). RV = right ventricle.

D, Pulmonary veins (arrows) open into morphologic left atrium (LA). LV = left ventricle

Ventricular septal defect. Four-chamber view shows small defect (arrow) in inlet portion of interventricular septum (arrowhead). LA = left atrium, LV = left ventricle, RA = right atrium, RV = right ventricle.

Atrioventricular canal defect. Four-chamber view shows large defect in inlet part of interventricular septum (arrows) and complete absence of inter-atrial septum (arrowheads), with free communication of all cardiac chambers, consistent with atrioventricular septal defect. LA = left atrium, LV = left ventricle, RA = right atrium, RV = right ventricle.

Tetralogy of Fallot. Outflow tract view shows aorta (AO) overriding ventricular septal defect (arrows). Pulmonary artery was visualized separately (not shown). These findings are consistent with tetralogy of Fallot. LV = left ventricle, RV = right ventricle.

Truncus arteriosus. A, Outflow tract view shows common arterial trunk (straight arrow) originating from left ventricle (LV) and right ventricle (RV), overlying small ventricular septal defect (arrowhead). In addition, there is small pericardial effusion (curved arrow).

Truncus arteriosus. B, Doppler in outflow tract shows common arterial trunk (straight arrow) originating from ventricles. Admixture of flow is seen in ventricular septal defect (arrowhead). Curved arrow indicates small pericardial effusion.

D-transposition of great arteries. Outflow view shows aorta (AO) and pulmonary artery (PA) parallel to each other, with AO originating from right ventricle (RV) and PA from left ventricle (LV).

Double outlet right ventricle. Right ventricular outlet view shows aorta (AO) and pulmonary artery (PA) originating from right ventricle (RV). LV = left ventricle.

Right-sided abnormalities. A, Four-chamber view shows small right ventricle (RV), with normal sized left ventricle (LV), consistent with hypoplastic right heart syndrome. LA = left atrium, RA = right atrium.

Right-sided abnormalities. B, Four-chamber view show thickened leaflets of tricuspid valve (arrows), with restricted opening, consistent with tricuspid stenosis.

Hypoplastic left heart syndrome. Four-chamber view shows small left ventricle (LV) and left atrium (LA), associated with ventricular septal defect (VSD) consistent with hypoplastic left heart syndrome. RA = right atrium, RV = right ventricle.

Hypoplastic aorta. A, Axial image shows normal size of pulmonary artery (arrow) with severe hypoplasia of aorta (arrowhead). DA = ductus arteriosus, RV = right ventricle.

Hypoplastic aorta. B, Another axial image shows severe hypoplasia of aorta (arrowhead). In addition, there is ventricular septal defect (arrows) that allows flow from left ventricle (LV) to RV.

Aortic stenosis. Doppler through aortic valve reveals increased systolic velocity (arrow), with maximal velocity of 218 cm/s, indicative of severe aortic stenosis. LV = left ventricle.

Pulmonary stenosis. Color Doppler through pulmonary valve reveals increased systolic velocity, with maximal velocity of 240 cm/s, indicative of severe pulmonary stenosis.

Ebstein anomaly. Four-chamber view shows apical displacement of tricuspid valve (arrow) from level of annulus (arrowhead) with severe dilation of right atrium (RA), consistent with Ebstein anomaly. A and B indicate measurement of right atrium, LA = left atrium, LV = left ventricle, RV = right ventricle.

Pentalogy of Cantrell. A, Sagittal ultrasound through uterus shows defect in chest wall (curved arrows) with heart lying outside thoracic cavity (arrow).

Pentalogy of Cantrell. B, Patient also had omphalocele (arrow) and diaphragmatic hernia (arrowhead) consistent with pentalogy of Cantrell.

Cardiac rhabdomyoma. Four-chamber view shows echogenic mass (arrow) attached to interventricular septum, in patient with tuberous sclerosis, consistent with rhabdomyoma. LA = left atrium, LV = left ventricle, RA = right atrium, RV = right ventricle.

Dilated cardiomyopathy. Axial view through fetal thorax shows severely dilated heart with dilation of all chambers. In addition, there is pleural effusion (arrowhead) and diaphragmatic hernia (curved arrow). LA = left atrium, LV = left ventricle, RA = right atrium, RV = right ventricle.

Hypertrophic cardiomyopathy. Four-chamber view shows severe hypertrophy (arrows) of left ventricle (LV) and right ventricle (RV). There is also moderate pericardial effusion (arrowhead).

Endocardial fibroelastosis. Four-chamber views show increased echogenicity (arrows) within myocardium of left ventricle (LV) and right ventricle (RV) in patient with endocardial fibroelastosis. LA = left atrium, RA = right atrium.

Echogenic intracardiac foci. Four-chamber view shows echogenic focus (arrow) within myocardium. LA = left atrium, LV = left ventricle, RA = right atrium, RV = right ventricle.

Fetal arrhythmia. A, M-mode Doppler images show premature atrial contraction (arrow) with subsequent early ventricular contraction (arrowhead).

Fetal arrhythmia. B, M-Mode Doppler images show supraventricular tachycardia–atrial heart rate (arrowhead) is fast as well as ventricular heart rate (arrow).

Abdominal wall defects.

URINARY TRACT ABNORMALITIESThe frequency of urinary abnormalities is approximately 7:1000 newborns, and the recurrence risk is 8% to 10%. The etiology of urinary tract abnormalities should extend beyond the apparent site of the lesion. For example, dilation of the ureteropelvic junction (UPJ) may result either from obstruction at the upper ureter or from pathology at a more caudad level. This includes increased intraluminal pressure secondary to reflux at the level of the vesicoureteral junction resulting in dilation of the UPJ. Similarly, a posterior urethral valve (PUV) will dilate the UPJ and even produce hydronephrosis. Thus, in discussing urinary tract abnormalities, it is reasonable to start with the urethra and proceed cephalad.

Posterior Urethral ValveMost PUVs are partial, such that the resulting bladder dilation is not severe. The ureters may only be slightly dilated, and if present, hydronephrosis is moderate. In the severe form, however, the pathophysiology is severe and may resemble the findings in agenesis of the urethra. In complete PUV, the bladder is markedly dilated. The ureters also are convoluted and large. Hydronephrosis is severe. Oligohydramnios prevents appropriate pulmonary development and leads to pulmonary hypoplasia.

Longitudinal echogram showing some enlargement of the bladder ( arrow) in a fetus with a partial posterior urethral valve. Ureters are not dilated, and there is no evidence of hydronephrosis.

Cross-section of fetal abdomen at level of kidneys ( spine anterior ) show both kidneys. The left (LT) kidney shows dilation of the ureteropelvic junction (UPJ), but no hydronephrosis is present. B. The fetal spine is tot he left of the echogram and the kidney above the spine also shows dilation of the UPJ, the anteroposterior diameter (calipers) measuring 8 mm. C. The fetal spine is on the right lower side of the echogram. The kidney above the spine shows more severe UPJ (calipers) , with extension to the calyces.

Longitudinal echogram of fetus, showing kidney (within tracing) with extensive hydronephrosis. Many dilated calyces are communicating with the renal pelvis, a finding that differentiates hydronephrosis from multicystic kidney.

Infantile polycystic renal disease, Cross-section of fetal abdomen at level of kidneys (spine anterior, arrow) shows both kidneys. The areas on each side of the spine are filled with a uniform echopattern, and no kidneys are seen. B. Color Doppler of aorta in a fetus with renal agenesis fails to outline renal arteries

Cross-section of fetal abdomen at level of kidneys (spine anterior) shows both kidneys. Note pyelectasis of right kidney (anteroposterior diameter = 6.4 mm). The left kidney is enlarged and uniformly cystic, with no apparent renal cortical tissue, which is characteristic of multicystic kidney.

EXTERNALLY VISIBLE BODY DEFECTS AND SKELETAL ABNORMALITIESCleft Lip and PalateIt is now possible to image the fetal nose area and upper lip to rule out cleft lip. Cleft lip alone is genetically different from the combination of a cleft lip and palate and is more likely to occur in female infants (sex ratio, 2:1). Importantly, both conditions may be components of genetic, chromosomal, or other syndromes.

Cystic hygroma. Echogram of nostrils (single arrow shows left) nostril and upper lip (double arrows).

Fetal hydrops. Cross-section of fetal neck, showing very large cystic hygromas extending toward the right side of the echogram.

Small sacrococcygeal teratoma (+,X) noted anterior to the fetal spine. This could be readily palpated in a rectal examination in the neonate.

Fetal limb abnormalities can be detected on sonography before 15

weeks’ gestational age and are often associated with serious congenital conditions, especially trisomy 18. Transabdominal sonography alone can show most of these abnormalities, although transvaginal and 3-dimensional sonography can provide additional information. Targeted evaluation of fetal limbs during sonography before 15 weeks should be considered in high-risk populations.

Club hand on transabdominal 2- and 3-dimensional sonography in a fetus with suspected trisomy 18 at a gestational age of 13 weeks 1 day. A, Two-dimensional sonogram showing the shortened forearm (short arrow) and abnormal hand positioning (long arrow). B, Three-dimensional sonogram showing the club hand and its structural relationship to the entire fetus, which may be important for the patient to understand the anomaly.

Transabdominal 2-dimensional sonogram showing a single lower extremity witha single femur (long arrow) in the proximal portion of the lower extremity and 2 bones in the lower limb (short arrows). Note that the foot is absent

Absent right lower extremity with the membrane attached to an otherwise normal left leg in a fetus with suspected amniotic band syndrome at a gestational age of 13 weeks 5 days. Membrane attachment to an isolated or unilaterally missing extremity, in the absence of any other congenital anomaly, serves as criterion for suspicion of amniotic band syndrome. A, Transabdominal 2-dimensional sonogram showing the normal left (LT) leg for comparison. B, Transabdominal 2-dimensional sonogram showing the absent right leg (RT LE) bud. Only the iliac bones (arrows) are seen. C, Two-dimensional sonogram showing the membrane (arrow) wrapped around the otherwise normal-appearing left leg.

Abnormal left hand with a normal ulna and absent radius in a fetus with an unknown diagnosis at a gestational age of 12 weeks 4 days. A, Transvaginal 2-dimensional sonogram showing the normal right hand for comparison. B, The abnormal left hand (arrow) is more apparent on a transvaginal 2-dimensional sonogram when seen in comparison to the opposite normal hand. Notice that only 1 bone is seen in the forearm.

Overlapping fingers and clenched hands in a fetus with trisomy 18 at a gestational age of 14 weeks 4 days. A, Transvaginal 2-dimensional sonogram showing a clenched hand (arrow). L indicates left. B, Transvaginal 2-dimensional sonogram of the fetal hand showing the overlapping first digit (arrows).

Abnormal findings of fetal bones: (A and B) Bowed femur in the case of campomelic dysplasia, (C and D) fractured femur in the case of osteogenesis imperfecta type IV. Fracture and reossification affect the sonographic penetration, and the deformity is observed in radiograph

Thanatophoric dysplasia: (A to C) Micromelic shortening of femur, humerus with mild angulation and lower limbs, (D) undersized thorax compared with the abdomen, (E and F) micromelic shortening of upper and lower limbs with normal ossification, no fracture and puppet posture in 3D ultrasound and 3D-CT scan

Thank You.