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- 3. Intra-decidual sac sign • Tiny cystic structure embedded within thickened decidua. • Detected by TVUS at 3.5 – 4 weeks. • Non-specific
- 5. Gestational sac • After 5 weeks • Well defined rounded or oval anechoic sac • Site: within the endometrial cavity near the uterine fundus • Surrounded by chorio-decidual reaction > 2 mm. • Double decidual sac sign (specific) • MSD by > 1.2 mm /day
- 7. Yolk Sac • Spherical cystic structure that within the gestational sac. • Should be visualized : - MSD > 20 mm by TA U/S - MSD> 8 mm by TV U/S
- 9. Embryo • Double bleb sign is the earliest presentation • Detected earlier by TVUS • Should be visualized : - MSD > 25 mm by TA U/S - MSD> 16 mm by TV U/S • Measured by Crown rump length (CRL)
- 12. Cardiac activity • Should be seen by TVUS when CRL > 5 mm
- 14. Fetal measurements • Mean sac diameter (MSD): - Used when no embryo - Average of 3 orthogonal planes • Crown rump length (CRL): - Most accurate in 1st trimester (till 12th week). - Used as a baseline for assessment of fetal growth for the rest of the pregnancy.
- 18. •Anembryonic sac •Abortion •Subchorionic hemorrhage •Ectopic pregnancy •Gestational trophoblastic disease
- 19. Anembryonic sac - Distorted sac shape with low position. - Poor chorio-decidual reaction (< 2mm) with absence of double decidual sac sign. - Growth < 1 mm/day - Absence of yolk sac when MSD > 20 mm by TA U/S or MSD> 8 mm by TV U/S - Absence of fetal pole when MSD > 25 mm by TA U/S or MSD> 16 mm by TV U/S
- 22. Abortion • Threatened vaginal bleeding yet with live embryo and closed cervix • Inevitable open cervix with fetal tissue within the cervical canal • Missed GS within the uterus absent cardiac activity • Complete No retained products of conception. • Incomplete retained products of conception.
- 23. Missed Abortion • Absent cardiac activity when CRL > 5 mm by TVUS • GS within the endometrial cavity • Closed cervix
- 25. Complete abortion • No visible products of conception within the endometrial cavity.
- 27. Incomplete abortion • Retained products of conception within the endometrial cavity. • Thickened endometrium of mixed echogenicity.
- 29. Inevitable abortion • Open Cervix • Fetal tissue within the cervical canal
- 31. Sub-chorionic hemorrhage • Part of the picture of threatened abortion. • Due to separation of chorion from the myometrium. • Before 20 wks • US appearance varies with age: - Acute hyper to isoechoic - Subacute (clotted) hypoechoic - Chronic (lysis) anechoic
- 33. Ectopic Pregnancy • Risk factors PID, IUCD , tubal surgery , endometriosis or previous ectopic pregnancy. • Most common site isthmus of tube • Other sites ovary , cervix , abdominal cavity • Presence of intra-uterine pregnancy almost excludes ectopic pregnancy (1 in 30000)
- 34. Ectopic Pregnancy • Sure Signs of ectopic pregnancy: - Live fetus outside the uterus - GS with yolk sac outside the uterus - GS outside the uterus with an echogenic ring (tubal ring sign) DD corpus luteum cyst : - Thin walled - Within ovary
- 37. Ectopic pregnancy • Relative Signs of ectopic pregnancy: Positive B-HCG + - No intra-uterine pregnancy (43%) - Pseudo-gestational sac (no double decidual sac sign) - Complex adnexal lesion (other than CL cyst)(83%) - Pelvic fluid collection (94 %)
- 40. Gestational trophoblastic disease • Associated with markedly elevated B-HCG • Associated with bilateral ovarian theca lutein cysts. Forms: - Vesicular (hydatiform) mole. - Invasive mole - Choriocarcinoma
- 42. Vesicular mole • Benign form (no myometrial invasion) • Complete mole no fetus • Partial mole abnormal triploid fetus • Classic US appearance (seen in second trimester): Uterus filled with innumerable variable sized cysts (snow-storm appearance) • Early appearance: Solid echogenic mass Anechoic fluid collection ( DD blighted ovum)
- 45. Invasive Mole Choriocarcinoma • Persistent or elevated B-HCG level following molar evacuation. • Invasion of myometrium (invasive mole) • Invasion of myometrium , parametrium and distant metasteses ( choriocarcionoma) • US nodules in myometrium (insensitive) • MRI more sensitive in detection of myometrial invasion
- 48. Second and Third Trimester
- 49. • Fetal Measurements • Fetal Doppler • Cervical Competence • Placenta • Amniotic fluid • Fetal anomaly scan
- 50. Fetal Measurements 1) Biparietal diameter • Measured at the level of thalamus • From outer table of near cranium to the inner table of far cranium • Affected by head shape
- 51. Fetal Measurements 2) Head Circumference • Measured at same level as BPD • Outer circumference of the cranium • Independent of head shape
- 53. Fetal Measurements 3) Abdominal Circumference • Measured at the level of intra-hepatic portion of umblical vein (portal vein) • Outer circumference of the abdomen
- 55. Fetal Measurements 4) Femoral Length • Measures the length of the ossified part of femoral diaphysis.
- 57. Fetal Measurements • Composite age (average of all parameters) and estimated fetal weight (EFW) is more accurate than any single parameter. • Much more accurate in early pregnancy. • All subsequent fetal examinations are compared with 1st examination to assess fetal growth.
- 58. IUGR • Diagnosed when EFW is less than the 6th percentile for gestational age • Or between 6th and 20th percentile + oligohydraminos and maternal hypertension • Normal fetal weigt gain in 3rd trimester is 100- 200 gm week
- 59. Fetal Macrosomia • EFW above the 90th percentile for GA • OR EFW > 4000 gms
- 60. Fetal Doppler 1) Fetal Heart Rate • 120-160 bpm • Regular
- 62. Fetal Doppler 2) Umblical Artery RI • RI < 0.7 • If > 0.7 impaired feto-placental circulation • Two arteries + one vein • Single artery umblical artery ass. with congenital anomalies
- 66. Fetal Doppler 3) MCA RI • RI > 0.7 • If < 0.7 brain hypoxia
- 68. Cervical Competence • Assessed in the beginning of 2nd trimester • Best assessed by trans-vaginal or trans-labial US on empty bladder. • Full bladder falsely elongated the cervical canal. • Cervical length > 3 cm
- 71. Cervical Incompetence • Cervical length < 25 mm • Cervical canal diameter > 8 mm • Funneling of internal os • Bulging of membranes
- 73. Placenta • Thickness (N= 2- 4 cm) • Grading • Placenta previa • Placental Abruption • Placental anomalies
- 75. Placental Grading (Grade 0) • Early 2nd trimester • Uniform moderate echogenicity • Smooth chorionic plate without indentations
- 77. Placental Grading (Grade I ) • Mid 2nd trimester – early 3rd trimester • Subtle indentations of chorionic plate • Small, diffuse calcifications randomly dispersed in placenta
- 79. Placental Grading (Grade II ) • Late 3rd trimester • Larger indentations along chorionic plate • Larger calcifications
- 81. Placental Grading (Grade III ) • 39 wks – post dates • Complete indentations of chorionic plate through to the basilar plate creating “cotyledons” (portions of placenta separated by the indentations) • More irregular calcifications with significant shadowing
- 83. Placenta Previa • The placenta covers all or part of the internal os. • Low lying within 2 cm of os • 45 % in 1st and 2nd trimester then most of them resolves. • Diagnosed in 3rd trimester • Diagnosed by TVUS or trans-perineal US on an empty bladder.
- 86. Placental Abruption • Ass. With maternal hypertension • Separation of the placenta from underlying myometrium retro-placental hematoma • US appearance varies with age: - Acute hyper to isoechoic (identified by placental thickening and disruption of retro- placental complex) - Subacute (clotted) hypoechoic - Chronic (lysis) anechoic
- 89. Placental Anomalies • Adherent placenta (acreta): - If infiltrates myometrium (increta) and serosa (percreta) - US loss of retroplacental complex retroplacental complex within bladder wall - Best diagnosed by MRI Uterine bulge- heterogenous placental signal- intraplacental dark band -focal interruption of myometrial wall – UB tenting
- 93. Placental anomalies • Circumvallate placenta : rolled placental edges due to smaller chorionic plate (placental shelf) • Succenturiate placenta : small accessory lobe • Bilobed placenta: two equal sized lobes • Placenta membranacea: thin placenta covering nearly all the uterine wall • Chorioangioma: Benign vascular placental mass… If large high cardiac output HF
- 99. Amniotic fluid • AFI (N= 5-20) = Sum of vertical diameters of the deepest pockets in the 4 quadrants ( not containing fetal parts or umblical cord) • Polyhydraminos : AFI > 20 , single pocket > 8 , fetus not touching any uterine wall after 24 wks • Oligohydraminos: AFI < 5 , largest pocket < 1 , crowded fetal parts
- 102. Twin Pregnancy • Amniocity : no of amniotic sacs • Chorionicity: no of placentas • Risk of anomalies: Monoamniotic > diamniotic monochorionic > diamniotic dichorionic • Features of diamniocity: - Separate placenta - Different sex - Chorion extending into the inter-twin membrane (lambda sign)
- 106. Twin Transfusion Syndrome • Shunting through vascular connection in placenta • Only if monochorionic • One fetus IUGR + oligohydraminos • Other hydrops + polyhdraminos
- 108. Twin Embolisation syndrome • Demised Twin Blood products from dead fetus shunted through placenta to live fetus DIC
- 109. Conjoined Twins • Only in monoamniotic monochorionic • Thoracopagus (most common) • Omphalopagus (anterior abdomen) • Pyopagus (sacral) • Craniopagus
- 111. Fetal anomalies
- 112. • Immune or non- immune • Pleural effusion + Pericardial effusion + ascitis + SC edema Fetal Hydrops
- 113. Down Syndrome • Nuchal thickness > 6 mm. • Endocardial Cushion Defect • Duodenal atresia • Hydrocephalus • Pyelectasis • Short humerus, femur
- 114. CNS anomalies 1) Presence of skull : If absent anencephaly
- 116. CNS anomalies 2) Presence of Falx: If absent absent cortical mantle hydrancepaly present cortical mantle holoprosencephaly
- 120. CNS anomalies 3) Trans-thalamic plane: - Measure BPD , HC - Detect microcephaly , macrocephaly and other structural abnormalities
- 123. CNS anomalies 4) Trans-ventricular plane: - Dominant feature is choroid plexus within the ventricular atrium. - Ventriculomegaly atrial diameter > 10 mm and separation of corid plexus from ventricular wall by > 3 mm . - Most common causes are Chiari II and aqueductal stenosis.
- 126. CNS anomalies 5) Trans-cerebellar plane: - Assess cerebellar hemispheres (hypoplastic in Dandy Walker) - Assess Cisterna Magna (N= 2-11mm) If < 2 mm Chiari II (+ small posterior fossa with banana shaped cerebellum + frontal bossing “ lemon sign” + hydrocephalus + myelomengiocele) If > 11mm a)communicating with fourth ventricle Dandy Walker b)not communicating with fourth ventricle Arachnoid cyst or mega cisterna magna
- 131. CNS anomalies 6) Cystic Lesions: Intra-cranial : - Arachnoid cyst - Porencephalic cyst - Choroid plexus cyst - Vein of Galen Aneurysm 6) Cystic Lesions: Extra-cranial : -Encephalocele -Meningiocele -Cystic Hygroma
- 137. CNS anomalies 7) Spina Bifida: - Outward convergence of vertebral laminae - Defect in overlying soft tissues - Protruding sac contain fluid and other neural structures (menigocele , myelomenigocele) - Associated with other anomalies e.g. Chiari II
- 141. Normal Lung
- 142. Chest Anomalies ( Congenital Diaphragmatic hernia) • Abdominal contents within the chest • Either postero-lateral (Bochdalek) or antro- medial (Morgagni) • US fluid filled multicystic mass displacing the heart + absence of stomach in abdomen
- 143. Chest Anomalies ( Cystic adenomatoid malformation) • Multi-cystic lesion • Cysts vary fro microscopic to 2 cm
- 144. Chest Anomalies ( Pulmonary Sequestration) • Mass of sequestrated lung tissue. • Extra-lobar type more frequently detected by fetal US • US Homogenous echogenic solid lung mass displacing the mediastinum
- 145. Fetal Heart Assessment • Assessed in four chamber view on axial scan • Ventricles are nearly equal in size • Ventricles smaller than atria • Apex is directed to the left at 45 • Any abnormality fetal echo is requested
- 147. Abdominal and Pelvic Anomalies • Stomach • Bowel • Kidneys • Urinary Bladder • Herniations
- 148. Stomach • Should be visualized by 18 weeks • Absent stomach on repeated scans - Esophageal atresia - Impaired swallowing (neuromuscular disorder , facial cleft) - Low AFI - Diaphragmatic hernia • Double bubble sign Duodenal atresia
- 150. Bowel • Small bowel < 6 mm • Large bowel < 23 mm • Anechoic to moderately echogenic (meconium) • Meconium ileus (ass. with cystic fibrosis) dilated bowel loops + echogenic bowel (equal to bone) • Meconium peritonitis Peritoneal cavity calcified mass + bowel dilatation + ascitis
- 152. Kidneys • Paired slightly hypoechoic structures adjacent to spine. • Lobulated • Renal pelvis < 3mm
- 153. Hydronephrosis • Renal pelvis > 10 mm or > 50% of the AP diameter of kidney • Renal pelvis 0f 3-10 mm follow up and post- natal ultrasound
- 154. Cystic renal diseases • Multicystic dysplastic kidney multiple variable sized cysts with non-functioning kidney tissue. • ARPKD Enlarged echogenic kidneys
- 155. Bladder • Should be observed to fill and empty. • Related to the amniotic fluid index • PUV keyhole sign + hydronephrosis
- 156. Abdominal Herniations Gastroschisis - On the side of umblical cord - No covering membranes - Normal cord insertion - Isolated Omphalocele - Midline (at umblicus) - Covered by membranes - The cord inserts in it. - Associated anomalies are common
- 159. Skeletal Anomalies US findings ass. with skeletal dysplasia: - Extremity bone shortening (short femur) - Fractures - Bowing - Demineralization - Small thorax
- 160. Achondroplasia • Proximal limb shortening • Positive family history
- 161. Osteogenesis Imperfecta • Diminished bone echogenicity • Bone bowing • Fractures
- 162. Hands • Polydactyly • Hypoplastic middle phalynx 5th digit Down Syndrome
- 163. THE END