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25 Cards in this Set
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Dandy-Walker malformation
Case findings: Large posterior fossa fluid collection with communication with the 4th ventricle Agenesis of the vermis Separation of the lateral ventricles Diagnosis: Dandy-Walker Malformation with agenesis of the corpus callosum and enlarged posterior fossa Classic triad: Vermian agenesis Communicating with an enlarged 4th ventricle Posterior fossa enlargement with upward displacement of the lateral sinuses, tentorium, and torcular Vermian agenesis cannot be diagnosed until 18 weeks gestational age DDX: Ultrasound: Dandy-Walker malformation with ACC Normal rhomboencephalic cavity (if seen on ultrasound alone before 18 weeks) Arachnoid cyst Mega cisterna magna MR: Dandy-Walker Malformation with ACC |
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Acute hydrosalpinx/salpingitis
Case findings: US: complex, cystic, septated, somewhat tubular mass in right adnexal region CT: 1.5cm x 4.0 cm fluid density, septated, tubular structure present posterior to the right ovary |
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Gastroschisis
Case findings: Moderately large gastroschisis (MC right paraumbilical location) Bowel loops seen flowing freely within amniotic fluid DDX: Gastroschisis Omphalocele Limb-body wall complex (LBWC): omphalocele, scoliosis, CV anomalies Normal (up to 14 weeks): 20% of normal pregnancies have herniated bowel at 12 weeks gestational age Umbilical cord inserts normally (in contrast, cord inserts on defect in omphalocele) No covering membrane No ascites (unlike omphalocele) Liver is never included in the defect Defect is small, in omphalocele it’s large Follow-up ultrasound useful since fetus at risk for IUGR, bowel obstruction, or perforation |
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Molar pregnancy
Case findings: Multiple, large soft tissue densities throughout an enlarged uterus Several anechoic (cystic) foci are present throughout the uterus No normal fetal anatomy is seen Old machines: snowstorm of tiny vesicles increased through transmission, expands endometrial cavity Current machines: Multiple, anechoic (cystic) spaces seen in heterogeneous echogenic mass Cystic spaces correlate to hydropic villi Types: MC complete or incomplete, invasive mole (myometrial extension), choriocarcinoma Gestational trophoblastic disease Complete mole: diploid, all paternal origin, MC 46XX Partial mole: forms within placenta, fetus is abnormal DDX: hydropic degeneration of the placenta Triploid, no malignant potential (unlike complete mole) Risk factors: advanced maternal age, prior molar pregnancy Complications: Theca-lutein cyst: increased levels of b-HCG Hemorrhage Malignant transformation Follow-up b-HCG for one year, and preventing pregnancy during this time, is important to detect malignant disease |
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Early intrauterine pregnancy
Double decidual sac sign: early sign if IUP Placenta: chorionic leave (blood supply) + decidual basalis Decidual parietalis and capsularis Double decidual sac sign Decidua parietalis: hyperechoic Hypoechoic fluid in uterine cavity Decidua capsularis: hyperechoic |
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Early intrauterine pregnancy
Amniotic cavity: Contains embryo and fuses with chorion by 14-16 weeks Yolk sac: Outside amniotic cavity but within chorionic cavity Connected to primitive gut by omphalomesenteric (vitelline) duct Umbilical cord forms and yolk sac is extruded Gestational sac (same as chorionic sac): Gestational sac should never shrink Normal growth of 1 mm per day |
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Empty gestational sac
Diagnosis: Empty gestational sac in bicornuate uterus Empty gestational sac: does not contain a yolk sac or embryo (fetal pole) DDX: Early normal IUP (if MSD < 8 mm) Blighted ovum (if MSD > 8 mm) Other names: embryonic demise, fetal demise MSD > 10 mm MUST have yolk sac (TV) MSD > 18 mm MUST have fetal pole / embryo (TV) Pseudogestational sac of ectopic pregnancy |
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Pseudogestational sac
Located centrally, unlike true gestational sac which is eccentric Does not have a yolk sac Absent double decidual sign IUP normal findings Yolk sac (TV): visible if MSD > 8 mm Fetal pole/embryo (TV): visible if MSD > 18 mm Heartbeat: MSD 16 mm, CRL 5 mm Use M mode NOT pulse wave since this will concentrate ultrasound waves between calipers and cause heating 5-6 weeks: 100-110 bpm 8-9 weeks: 150-170 bpm |
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Subchorionic hemorrhage
Subchorionic hemorrhage: MC site of placental abruption Acutely, may be hyperechoic and as the hemorrhage begins to liquify and resorb becomes more hypoechoic DDX for hypoechoic subchorionic hemorrhage: Amniotic band Synechiae DDX for acute hyperechoic subchorionic hemorrhage: Myoma Succenturiate lobe: accessory placenta lobe that is removed from but in vascular continuity with the main placenta Co-existent hyatidiform mole |
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Cornua ectopic pregnancy
Interstitial (cornua) pregnancy Eccentric, partially covered by uterus (myometrium) Catastrophic hemorrhage Symptoms present later than ectopic pregnancies in other locations Ectopic pregnancy No intra-uterine pregnancy visible Pseudogestational sac: central location Thickened endometrium MC ectopic sac with echogenic ring (presence of trophoblasts, ring of fire) Corpus luteum cyst: also seen as ring of fire (represents vascular ring however) Complex fluid in cul-de-sac (hemorrhage) Adnexal mass Location: MC tubal (95%) LC interstitial (cornua), cervix, ovary, abdominal b-hCG Doubles every 48 hours 2nd IS: > 1,000 IU/L 3rd IRP: > 2,000 IU/L |
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Holoprosencephaly
Alobar: No definable interhemispheric fissure Falx cerebri completely absent Large dorsal cyst Fused thalami Semilobar: Interhemispheric fissure partially formed posteriorly Posterior falx present Thalami partially separated Small 3rd ventricle Rudimentary temporal horns, frontal horns never formed Lobar: Interhemispheric fissure extends to frontal areas of the brain Frontal horns are present but small Posterior corpus callosum is formed in the absence of any of the callosal genu or anterior callosal body Septo-optic dysplasia (de Morsier’s syndrome): Findings: absent septum pellucidum, hypoplasia of optic nerves Hypothalamic-pituitary dysfunction: short stature secondary to diminished GH Associated with: schizencephaly DDX: Hydranencephaly: near total absence of cerebrum with intact thalami, brainstem due to occlusion of supraclinoid arteries No visible cortical mantle Maximal hydrocephalus Bilateral open-lip schizencephaly Identification of septum pellucidum excludes all types of holoprosencephaly Fused thalami excludes severe hydrocephalus Anterior cerebral mantle (horseshoe) excludes hydranencephaly |
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Ventriculomegaly
Dangling choroid plexus in lateral ventricle Lateral ventricles > 10 mm Etiology of hydrocephalus: MC spina bifida Aqueductal stenosis Dandy-Walker malformation Encephalocele Chiari malformation |
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Arachnoid cyst
DDX neonatal intracranial cystic structure: Cystic teratoma Arachnoid cyst: No communication with ventricle Choroid plexus cyst: > 10 mm may be associated with Trisomy 18 Porencephalic cyst AVM |
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Dandy-Walker syndrome
Associated with: Agenesis of the corpus callosum Encephalocele DW complex: Includes DW malformation and its variants In utero insult to the 4th ventricle, which leads to complete or partial outflow obstruction of CSF Cystic dilation of the 4th ventricle prevent fusion of the cerebellar hemispheres DW variant: Mild vermian hypoplasia Cystic dilatation of 4th ventricle without enlargement of the posterior fossa DW malformation: Communication of retrocerebrallar cyst with 4th ventricle Enlarged 4th ventricle Hypoplastic vermis and cerebellum Enlarged posterior fossa with high tentorium (tectal beaking) DDX: Normal rhomboencephalic cavity (if seen on ultrasound alone before 18 weeks) Arachnoid cyst Mega cisterna magna AP diameter > 10 mm No communication with 4th ventricle |
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Myelomeningocele
Associated with: Chiari II malformation Neural tube defects: MC anencephaly Spina bifida and myelomeningocele LC encephalocele |
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Chiari II malformation
Lemon sign: bifrontal calvarial indentation MC associated with spina bifida Banana sign: cerebellum wrapped around brainstem secondary to downward traction of spinal cord Hydrocephalus Myelomeningocele Chiari malformation Chiari I: Herniation of cerebellar tonsils (peg-like) Associated with syringohydromyelia DDX: intracranial hypotension with downward displacement of cerebellar tonsils (not as pointed or peg-like) Chiari II (MC anomaly): Small posterior fossa, enlarged foramen magnum, tectal beaking Towering cerebellum: cerebellum herniates up through tentorial incisura Lacunar (Luckenschadel) skull Associated with: myelomeningocele (MC LS), Klippel-Feil, CC dysgenesis, heterotopia Chiari III Chiari II (no myelomeningocele) and high cervical or occipital encephalocele |
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Anencephaly
Complete absence of cranial vault and cerebral hemispheres Angiomatous stroma covers base of the skull Diagnose after 14 weeks when skull is ossified |
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Encephalocele
Developmental abnormality in which part of the CNS herniates through a cranial defect MC occipital calvarium (80%) Meningocele: Contains only CSF and meninges Meningoencephalocele: Contains neural tissue and meninges Hydroencephalomeningocele: Contains neural tissue, meninges, and ventricle DDX: cystic hygroma Associated with: Meckel-Gruber syndrome: occipital encephalocele, bilateral MCDK, polydactyly Chiari III malformation: Chiari II, encephalocele Klippel Feil anomaly Walker Warburg syndrome: occipital encephalocele, eye malformation, lissencephaly, cerebellar dysgenesis |
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Cystic hygroma
MC in posterior triangle MC multiple cysts of varying sizes separated by septae DDX: occipital encephalocele Associated with: Turner’s syndrome Trisomy 21, 18, 13 Fetal alcohol syndrome |
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Ventricular septal defect
Normal fetal heart Endocardial cushion defect Aortic stenosis |
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Congenital diaphragmatic hernia
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Omphalocele
Midline anterior abdominal wall defect Herniation of intra-abdominal contents into the base of the umbilical cord Herniated contents covered by peritoneum, amnion, and Wharton’s jelly High incidence of associated anomalies Gastrochisis versus omphalocele Gastrochisis Omphalocele |
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UPJ obstruction
Enlarged renal pelvis with or without enlargement of the calyces DDX: Multicystic dysplastic kidney Renography with either DTPA or MAG: Definitive diagnosis Inadequate drainage of the kidney seen on time activity curves with images demonstrating hold up to be within the kidney with no ureteric dilatation Excretory urography: Delayed uptake of contrast Delayed opacification of the calyces and renal pelvis and usually non-opacification of the ureter Vesicoureteric reflux may be associated |
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Posterior urethral valve
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MCKD
Non-communication cysts with nonfunctional renal parenchyma DDX: Hydronephrosis Associated contralateral renal anomalies: UPJ obstruction MCKD (lethal) Renal agenesis (lethal) |
