OBS.GYN.pdf

Radiology Review Manual 6th Edition

2007 Lippincott Williams & Wilkins

Obstetrics and Gynecology Differential Diagnosis of Obstetric and

Gynecologic Disorders

2 obstetrics Parity Nomenclature (for pregnancies

Outcome: no cause identified in 5080%

Recommendation if level I ultrasound is unrevealing:

1. amniocentesis for AF-AFP (with normal results in >90%) 2. level II obstetric ultrasound (skipping amniocentesis)

Level II Obstetric Ultrasound

Indication: AF-AFP 2 MoM

Accuracy: identification of abnormal fetuses in 99%

Examination targeted for:

1. Open neural tube defect:

anencephaly, encephalocele, open spina bifida,

amniotic band syndrome resulting in open neural

tube defect

2. Closed neural axis anomaly:

hydrocephalus, Dandy-Walker malformation

3. Abdominal wall defect:

gastroschisis, omphalocele, gastropleuroschisis from

amniotic band syndrome

4. Upper GI obstruction:

esophageal atresia tracheoesophageal fistula,

duodenal obstruction

5. Cystic hygroma

6. Teratoma:

sacrococcygeal, lingual, retropharyngeal 7. Renal anomalies:

Alpha-fetoprotein Levels

Sample Site Approximate Level (ng/mL) Peak

Maternal serum 30 30th32nd week

Amniotic fluid 20,000 2nd trimester

Fetal plasma 3,000,000 14th15th week

obstructive uropathy, renal agenesis, multicystic

dysplastic kidney, congenital Finnish nephrosis

Risk of fetal chromosomal anomaly is only 0.61.1% with normal level II sonogram!

Maternal serum screening Alpha-fetoprotein

= glycoprotein as major circulatory protein of early fetus

Origin: formed initially by yolk sac + fetal gut (48 weeks), later by fetal liver

Detectable in

a. fetal serum

concentration peaks at 1415 weeks followed by progressive decline

b. amniotic fluid (AF-AFP) is a result of

fetal urination fetal gastrointestinal secretions transudation across fetal membranes (amnion,

placenta)

transudation across immature fetal epithelium concentration peaks early in 2nd trimester

followed by progressive decline

c. maternal circulation (MS-AFP) secondary to leakage from

amniotic fluid across the placenta

levels start to rise at 7th week, peak at 32nd week, and decline toward end of pregnancy

Either high / low MS-AFP is

associated with 34% of all major congenital defect At the end of the 1st trimester AFP is present:

in fetal plasma in milligram quantities

in amniotic fluid in microgram quantities

in maternal serum in nanogram quantities

Reported in

MoM =

multiples of mean to standardize interpretation

among laboratories

Elevated Alpha-fetoprotein

screening at 1618 weeks GA Values must be corrected for dates, maternal weight,

race, presence of diabetes (diabetes has depressing effect on

MS-AFP so that lower levels may be associated with NTDs)

Associated with:

A. LABORATORY ERROR

B. ERRONEOUS DATES (18%):

GA 2 weeks more advanced sonographically than by clinical estimate (AFP levels rise 15% per week

during 1618-week window) C. MULTIPLE GESTATIONS (14%)

D. FETAL DEMISE (7%) / fetal distress / threatened abortion

E. FETAL ANOMALIES (61%)

1. Neural tube defects (51%):

[anencephaly (30%), myelomeningocele

(18%), encephalocele (3%), forebrain malformation]

P.996

Prevalence: 1.6:1,000 births in USA; 6:1,000

births in Great Britain

In 90% as 1st time

event!

Risk of

recurrence:

3% after one affected child; 6%

after 2 affected children

2. Ventral wall defects (21%)

(gastroschisis, omphalocele): sensitivity of

50%

3. Proximal fetal gut obstruction

(esophageal / duodenal atresia)

= diminished AFP degradation in small bowel

4. Cystic hygroma, teratoma (pharyngeal, sacral)

5. Amniotic band syndrome

(asymmetric cephalocele, gastropleuroschisis)

6. Renal abnormalities:

multicystic dysplastic kidney, renal agenesis,

pelviectasis, congenital Finnish nephrosis

(typically 10 MoM + negative amniotic fluid acetylcholinesterase)

7. Oligohydramnios

F. PLACENTAL LESION

altering the placentomaternal barrier

1. Chorioangioma

2. Peri- and intraplacental hematoma

resulting in fetomaternal hemorrhage

3. Placental lakes, infarct, intervillous thrombosis

G. LOW BIRTH WEIGHT

H. Normal pregnancy + MATERNAL DISORDER

0. Hepatitis

1. Hepatoma

I. Fetal-maternal blood mixing: collection of MS-AFP samples after amniocentesis

mnemonic: GEM MINER CO

Gastroschisis

Esophageal atresia

Multiple gestations

Mole

Incorrect menstrual dates

Neural tube defects

Error (laboratory)

Renal disease in fetus (autosomal recessive

polycystic kidney disease, renal dysplasia,

obstructive uropathy, congenital Finnish nephrosis)

Chorioangioma Omphalocele

Elevated Maternal Serum AFP (MS-AFP)

= defined as 2.5 MoM / equivalent to the 5th percentile; 4.5 MoM for multiple gestations

Power of detection at 2.5 MoM cutoff: o 98% of gastroschisis

o 90% of anencephalic fetuses

o 7580% of open spinal defects o 70% of omphaloceles

Incidence: 25% screen-positive rate (in 16% normal MS-AFP on retesting); 615% of fetuses have some type of major congenital defect; in 1.3:1,000 tests fetal anomaly

detected

The higher the AFP elevation the higher the probability

of fetal anomalies

2038% of women with unexplained high MS-AFP (ie, in absence of fetal abnormality) suffer adverse pregnancy

outcomes (premature birth, preeclampsia, 24 IUGR, 10 perinatal mortality, 10 placental abruption)!

Elevated Amniotic Fluid AFP (AF-AFP)

= defined as 2 MoM (

anomalies in 33%!

Low Alpha-fetoprotein

= MS-AFP 0.5 / AF-AFP 0.72 MoM

Incidence: 3%

1. Autosomal trisomy syndromes (trisomy 21, 18, 13)

o 20% of trisomy 21 fetuses are found in

women with low MS-AFP after adjustment for age!

2. Absence of fetal tissues (eg, hydatidiform mole)

3. Fetal demise

4. Misdated pregnancy

5. Normal pregnancy 6. Patient not pregnant

Use of Karyotyping

Frequency: 1135% of fetuses with sonographically identified abnormalities have chromosomal abnormalities

A. FETAL ANOMALIES

1. CNS anomalies: holoprosencephaly (4359%), Dandy-Walker malformation (2950%), cerebellar hypoplasia, agenesis of corpus callosum, myelomeningocele (3350%)

2. Cystic hygroma (72%): Turner syndrome

3. Omphalocele (3040%) 4. Cardiac malformations

5. Nonimmune hydrops

6. Duodenal atresia

7. Severe early-onset IUGR: trisomy 18, 13, triploidy

8. Diaphragmatic hernia

9. Bone-echodense bowel (20%): trisomy 21

B. MATERNAL RISK FACTORS

1. Advanced age

2. Low serum alpha-fetoprotein

3. Abnormal triple screen of maternal serum

4. History of previous chromosomally abnormal pregnancy

(1% risk of recurrence)

C. PLANNED INTENSE INTRAUTERINE MANAGEMENT

Fetal anomalies not associated with chromosomal anomalies:

1. Gastroschisis

2. Unilateral renal anomaly

3. Intestinal obstruction distal to duodenal bulb 4. Off-midline unilateral cleft lip

P.997

5. Fetal teratoma (sacrococcygeal / anterior cervical) 6. Isolated single umbilical artery

Amniotic fluid volume

Production:

a. 1st trimester: dialysate of maternal + fetal serum across

the noncornified fetal skin

b. 2nd + 3rd trimester: fetal urine (600800 cm3/day near term), fetal lungs (600800 cm3/day near term), amniotic membrane

Absorption:

o fetal swallowing + GI absorption, fetal lung absorption,

clearance by placenta

Assessment of amniotic fluid volume by:

0. Subjective assessment (Gestalt method): quick + efficient, accounts for GA-related variations

in fluid volume, considered the most accurate if

performed by experienced operator, operator +

interpreter must be identical, no documentation,

variations on serial scans difficult to appreciate

1. Depth of largest vertical pocket:

simple + quick (used in BPP), pockets >2 cm may

be found in crevices between fetal parts with

moderately severe oligohydramnios, does not

account for GA-related variations

2. Four-quadrant Amniotic Fluid Index (AFI):

fairly quick, probably correlates better with fluid

volume than any single measurement, may not

accurately reflect overall fluid volume, may be affected by fetal movement during measurements

Structural Defect

Incidence Aneuploidy

Risk Most common

Cystic hygroma 1:6,000 60-

75%

45X,21,18,13,

XXY

Hydrops 1:4,000 3080%

13,21,18,45X

Holoprosencephaly 1:16,000 4060%

13,18,18p

Cardiac defects 1:125 530% 21,18,13,22

AV canal 4070% 21

Omphalocele 1:5,800 3040%

13,18

Duodenal atresia 1:10,000 2030%

21

Diaphragmatic hernia

1:4,000 2025%

13,18,21,45X

Bladder outlet obstruction

1:1,000 2025%

13,18

Limb reduction 1:2,000 8% 18

Clubfoot 1:830 6% 18,13,4p-

,18q-

Hydrocephalus 1:1,250 38% 13,18, triploidy

Facial cleft 1:700 1% 13,18,

deletions

Prune belly 1:40,000 low 18,13,45X

Single umbilical

artery

1:100 minimal

Bowel obstruction 1:4,000 minimal

Gastroschisis 1:12,000 minimal

3. Planimetric measurement of total intrauterine volume

4. Dye / para-amino hippurate dilution technique: 800 cm3 at 34 weeks, 500 cm3 >34 weeks

Polyhydramnios

= amniotic fluid volume >1,5002,000 cm3 at term

Incidence: 1.123.5%

fetus does not fill the AP diameter of uterus

single largest pocket devoid of fetal parts / cord >8 cm in

vertical direction

AFI 2024 cm

Prognosis: 64% perinatal mortality with severe polyhydramnios

Etiology:

A. IDIOPATHIC (35%)

Associated with: macrosomia in 1937%

Suggested cause:

1. increased renal vascular flow

2. bulk flow of water across surface of fetus +

umbilical cord + placenta + membranes

B. MATERNAL CAUSES (36%)

1. Diabetes (25%)

2. Isoimmunization [Rh incompatibility (11%)]

3. Placental tumors: chorioangioma

C. FETAL ANOMALIES (20%)

a. gastrointestinal anomalies (616%): impairment of fetal swallowing (esophageal

atresia in 3%); high intestinal atresias /

obstruction of duodenum / proximal small

bowel (1.21.8%), omphalocele, meconium peritonitis

b. nonimmune hydrops (16%)

c. neural tube defects (916%): anencephaly, hydranencephaly,

holoprosencephaly, myelomeningocele,

ventriculomegaly, agenesis of corpus callosum,

encephalocele, microcephaly

d. chest anomalies (12%):

diaphragmatic hernia, cystic adenomatoid

malformation, tracheal atresia, mediastinal

teratoma, primary pulmonary hypoplasia,

extralobar sequestration, congenital

chylothorax

e. skeletal dysplasias (11%):

dwarfism (thanatophoric dysplasia,

achondroplasia), kyphoscoliosis, platyspondyly

f. chromosomal abnormalities (9%):

trisomy 21, 18, 13

g. cardiac anomalies (5%):

VSD, truncus arteriosus, ectopia cordis, septal

rhabdomyoma, arrhythmia

h. genitourinary malformations:

unilateral UPJ obstruction, unilateral

multicystic dysplastic kidney, mesoblastic nephroma

Cause: ? hormonally mediated polyuria

i. miscellaneous (8%):

cystic hygroma, facial tumors, cleft lip /

palate, teratoma, amniotic band syndrome,

congenital pancreatic cyst

In polyhydramnios efforts to

detect fetal anomalies should be directed at SGA fetuses!

mnemonic: TARDI

Twins

P.998

Anomalies, fetal

Rh incompatibility

Diabetes Idiopathic

Oligohydramnios

= amniotic fluid volume

o Demise of fetus / Drugs (Motrin therapy for tocolysis of

preterm labor)

o Renal anomalies, bilateral (= inadequate urine

production): renal agenesis / dysgenesis, infantile

polycystic kidney disease, prune belly syndrome,

posterior urethral valves, urethral atresia, cloacal

anomalies

20-fold increase in incidence of fetal anomalies with oligohydramnios!

N.B.: bilateral renal obstruction, if combined with intestinal obstruction, may be associated with

polyhydramnios

o IUGR (reduced renal perfusion)

o Premature rupture of membranes (most common) o Postmaturity

Cx: pulmonary hypoplasia, cord compression

Prognosis: 77100% perinatal mortality with 2nd trimester oligohydramnios

Abnormal first trimester findings

Time of onset: prior to 810 weeks

First Trimester Bleeding

= VAGINAL BLEEDING IN FIRST TRIMESTER

Frequency: 1525% of all pregnancies, of which 50% terminate in abortion

A. INTRAUTERINE conceptus IDENTIFIED

1. Threatened abortion

2. Embryonic demise

3. Blighted ovum

4. Gestational trophoblastic disease

5. Implantation bleed (34 weeks after last menstrual period)

6. Subchorionic hemorrhage

7. Low-lying placenta previa

8. Twin loss

B. NORMAL ENDOMETRIAL CAVITY

a. with -hCG level >1,800 mlU/mL 1. Recent spontaneous abortion

2. Ectopic pregnancy

b. with -hCG level

2. Retained products of conception following an incomplete

spontaneous abortion

3. Early intrauterine not yet visible pregnancy 4. Decidual reaction secondary to ectopic pregnancy

Uterus Large for Dates

1. Multiple gestation pregnancy

2. Inaccurate menstrual history

3. Fibroids

4. Polyhydramnios

5. Hydatidiform mole 6. Fetal macrosomia

Intrauterine membrane in pregnancy

A. MEMBRANE OF MATERNAL ORIGIN

1. Uterine septum

= incomplete resorption of sagittal septum between

the fused two mllerian ducts

2. Amniotic sheet / shelf

= folding of amniochorionic membrane around

uterine synechia

synechia often thins during

uterine stretching + disappears as pregnancy

progresses

B. MEMBRANE OF FETAL ORIGIN

1. Intertwin membrane

= apposing membrane of multiple pregnancy

2. Amniotic band

= rent within amnion

3. Chorioamnionic separation

= incomplete fusion / hemorrhagic separation of

amnion (= inner membrane) and chorion (= outer

membrane)

4. Subchorionic hemorrhage = chorioamnionic elevation

= separation of chorionic membrane from decidua implantation bleed of early pregnancy

P.999

C. FIBRIN STRAND

Cause: hemorrhage during transplacental amniocentesis

mnemonic: STABS

o Separation (chorioamnionic)

o Twins (intertwin membrane)

o Abruption

o Bands (amniotic band syndrome) o Synechia

Dilated Cervix

1. Inevitable abortion

2. Premature labor

o = spontaneous onset of palpable, regularly occurring

uterine contractions between 20 and 37 weeks MA 3. Incompetent cervix

Placenta Abnormal Placental Size

Placental mass tends to reflect fetal mass!

A. ENLARGEMENT OF PLACENTA = Placentomegaly

o = >5 cm thick in sections obtained at right angles to long

axis of placenta

1. maternal disease

1. Maternal diabetes (= villous edema)

2. Chronic intrauterine infections (eg, syphilis)

3. Maternal anemia (= normal histology)

4. Alpha-thalassemia

2. fetal disease

1. Hemolytic disease of the newborn (= villous

edema + hyperplasia) due to immunologic

incompatibility including Rh sensitization

2. Umbilical vein obstruction

3. Fetal high-output failure:

large chorioangioma, arteriovenous

fistula

4. Fetal malformation:

Beckwith-Wiedemann syndrome,

sacrococcygeal teratoma, chromosomal

abnormality, fetal hydrops

5. Twin-twin transfusion syndrome

3. fetomaternal hemorrhage

4. placental abnormalities

1. Molar pregnancy

2. Chorioangioma 3. Intraplacental hemorrhage

mnemonic: HAD IT

Hydrops

Abruption

Diabetes mellitus

Infection

Triploidy

B. DECREASE IN PLACENTAL SIZE

1. Preeclampsia

associated with placental infarcts in 3360% 2. IUGR

3. Chromosomal abnormality 4. Intrauterine infection

Vascular Spaces of the Placenta

1. Placental cysts o = large fetal veins located between amnion + chorion

anastomosing with umbilical vein

o sluggish blood flow (detectable by real-time

observation)

2. Basal veins

o = decidual + uterine veins

o lacy appearing network of veins underneath placenta

DDx: placental abruption

3. Intraplacental venous lakes

o intraplacental sonolucent spaces

o whirlpool motion pattern of flowing blood

Macroscopic Lesions of the Placenta

1. Intervillous thrombosis (36%) o = intraplacental areas of hemorrhage

Etiology: breaks in villous capillaries with bleeding from fetal vessels

o irregular sonolucent intraplacental lesions

(mm to cm range) o blood flow may be observed within lesion

Significance: fetal-maternal hemorrhage (Rh sensitization,

elevated AFP levels)

2. Perivillous fibrin deposition (22%) o = nonlaminated collection of fibrin deposition

Etiology: thrombosis of intervillous space

Significance: none

3. Septal cyst (19%)

Etiology: obstruction of septal venous drainage by edematous villi

o 510-mm cyst within septum

Si

gnifi

canc

e:

n

on

e

4. Placental infarct (25%)

o = coagulation necrosis of villi

Etiology: disorder of maternal vessels, retroplacental hemorrhage

o not visualized unless hemorrhagic

o well-circumscribed mass with hyperechoic / mixed echo pattern

Significance: dependent on extent + associated maternal

condition

5. Subchorionic fibrin deposition (20%)

o = laminated collection of fibrin deposition

Etiology: thrombosis of maternal blood in subchorionic space

o subchorionic sonolucent area

Significance: none

6. Massive subchorial thrombus

o = Breus MOLE = preplacental HEMORRHAGE

Placental Tumor

A. TROPHOBLASTIC

1. Complete hydatidiform mole

2. Partial hydatidiform mole

3. Invasive mole

4. Choriocarcinoma

B. Nontrophoblastic

1. Chorioangioma (in up to 1% of placentas) 2. Teratoma (rare)

P.1000

3. Metastatic lesion (rare): melanoma, breast carcinoma, bronchial carcinoma

Unbalanced Intertwin Transfusion

= unbalanced intertwin transfusion through vascular

anastomoses between the two circulations of monochorionic

twins

A. ACUTE = Twin-embolization syndrome

B. CHRONIC = Twin-twin transfusion syndrome C. REVERSE = Acardiac twinning

Umbilical cord Abnormal Cord Attachment

1. Marginal cord attachment (7%)

o = battledore placenta (flat wooden paddle used in an

early form of badminton)

o no clinical significance 2. Velamentous insertion of cord (1%) 3. Vasa previa

Umbilical Cord Lesions

Umbilical cord cysts persisting into 2nd + 3rd trimester

are frequently accompanied by fetal anomalies (hernia,

intestinal obstruction, urinary tract obstruction, urachal anomalies, omphalocele, cardiac defect, trisomy 18)!

A. DEVELOPMENTAL CORD LESION

1. Umbilical hernia

= protrusion from anterior abdominal wall with

normal insertion of umbilical vessels

Predisposed:

Blacks, low-birth-weight infants, trisomy 21,

congenital hypothyroidism, Beckwith-Wiedemann syndrome, mucopolysaccharidoses

Prognosis: spontaneous closure in first 3 years of

life

2. Omphalomesenteric duct cyst

near fetal end of cord + eccentric

in cord

3. Allantoic cyst

= remnant of umbilical vesicle / allantois; usually degenerates by 6 weeks

Histo: lined by single layer of flattened epithelium

near fetal end of cord + in center

of cord

4. Amniotic inclusion cyst

= amniotic epithelium trapped within umbilical cord

5. Mucoid degeneration of umbilical cord

= umbilical cord pseudocyst

= liquefaction of Wharton jelly / edema

focal thickening of Wharton jelly,

usually near umbilicus

usually resolved by 12 weeks MA

Associated commonly with

omphalocele

6. Noncoiled straight cord counterclockwise:clockwise umbilical cords = 7:1 right-handed:left-handed persons = 7:1

Incidence: 3.75%

absent vascular coiling for entire

length of visible cord

At

risk

for:

intrauterine death (8%), stillbirth, fetal anomalies

(24%), prematurity, intrapartum heart rate

decelerations, fetal distress, meconium staining

B. ACQUIRED CORD LESION

1. False knot

a. exaggerated looping of cord vessels causing focal

dilatation of cord

b. focal accumulation of Wharton jelly

c. varix of umbilical vessel

knoblike protrusion / bulge of

cord 2. True knot

Incidence: 1% of pregnancies

Cause: excessive fetal movements

Predisposed: long cord, polyhydramnios, small fetus,

monoamniotic twins

local distension / thrombosis of

umbilical vein near cord knot resembling an

umbilical cyst tortuosity of cord at level of knot

Cx: vascular occlusion + fetal death in

utero

OB management:

expectant

3. Umbilical cord hematoma

= rupture of the wall of the umbilical vein

secondary to mechanical trauma (torsion, loops, knots, traction) / congenital weakness of vessel wall

Incidence: 1:5,505 to 1:12,699 deliveries

Location: near fetal insertion of umbilical cord (most common)

hyper- / hypoechoic mass 12 cm in size, multiple (in 18%)

Cx: rupture into amniotic cavity with

exsanguination

Prognosis: 52% overall perinatal fetal mortality

4. Neoplasm

. Angiomyxoma / hemangioma of cord

Incidence: 22 cases in literature

Histo: multiple vascular channels lined by benign

endothelium surrounded by edema + myxomatous degeneration of Wharton jelly

Associated with:

elevated -fetoprotein level

Location: more frequently near placental end of

umbilical cord

hyperechoic /

multicystic mass within cord

may be associated with

pseudocyst

(= localized collection of edema)

Cx: premature delivery, stillbirth,

hydramnios, nonimmune hydrops, massive hemorrhage due to rupture

a. Other tumors: myxosarcoma, dermoid, teratoma

5. Umbilical vein varix

Incidence:

Small-for-gestational age fetus (SGA)

= generic clinical term describing a group of perinates at /

below the 10th percentile for gestational age without reference to etiology

1. Fetus of appropriate growth (misdiagnosed as small)

2. Small normal fetus = constitutionally small fetus (8085%) o No indication for surveillance / intervention!

3. Small abnormal fetus = primary growth failure

associated with karyotype anomaly / fetal infection (510%) o Active intervention is of no benefit!

4. Dysmature fetus = IUGR = growth failure as a

result of uteroplacental insufficiency (1015%) o Intensive management is likely of benefit!

Fetal Overgrowth Disorder

1. Beckwith-Wiedemann syndrome

2. Simpson-Golabi-Behmenl syndrome 3. Perlmann syndrome

Fetal skeletal dysplasia

= DWARFISM

= heterogeneous group of bone growth disorders resulting in

abnormal shape + size of the skeleton

More than 200 skeletal dysplasias are known, but only a

few are frequent:

thanatophoric dysplasia

osteogenesis imperfecta type II

achondrogenesis

heterozygous achondroplasia

Birth prevalence:

3:10,0007.6:10,000 births for all skeletal dysplasias; 5:10,000 births for lethal skeletal dysplasias

Finding Perlman BWS SGBS

Macrosomia X X X

Polyhydramnios X X X

Hepatomegaly X X X

Nephromegaly X X X

Hydronephrosis X X X

Cystic hygroma X

Choroid plexus cyst X

Agenesis of corpus callosum X

Ascites X

Macrocephaly X X

Cardiomegaly X X

Cardiac defects X X

Macroglossia X X

Cleft lip / palate X X

Hydrops X X

Placentomegaly X

Omphalocele / umbilical hernia X

Polydactyly / syndactyly X

BWS = Beckwith-Wiedemann syndrome;

SGBS =Simpson-Golabi-Behmenl syndrome

Birth Prevalence Perinatal

Deaths

Thanatophoric dysplasia 0.69:10,000* 1:246

Achondroplasia 0.37:10,000* none

Achondrogenesis, type I 0.23:10,000* 1:639

Achondrogenesis, type II 0.25:10,000*

Osteogenesis imperf. type II

0.18:10,000* 1:799

Osteogenesis imperf., others

0.18:10,000* none

Asphyxiating thoracic dysplasia

0.14:10,000*

Hypophosphatasia 0.10:10,000*

Chondrodysplasia

punctata, rhizo

0.09:10,000* none

Camptomelic dysplasia 0.05:10,000* 1:3,196

Chondroectodermal dysplasia

0.05:10,000* 1:3,196

Cleidocranial dysplasia 0.05:10,000*

Diastrophic dysplasia 0.02:10,000*

* = lethal dysplasias

Prognosis: 51% lethal due to hypoplastic lungs:

23% stillbirths, 32% death in 1st week of life

Associated with:

polyhydramnios

small thorax

morphologically abnormal bones

shortening of long bones (common

characteristic)

Femur length >5 mm below 2 standard

deviations suggests skeletal dysplasia!

femur length / foot length ratio 30% of the mean in achondrogenesis

DDx features:

mineralization, bowing, fractures, number of digits, fetal movement, thoracic measurement, associated anomalies,

age of onset

DDx: constitutionally short limbs, severe IUGR

see also DWARFISM

Fetal Hand Malformation Polydactyly

trisomy 13, short-rib-polydactyly syndrome, asphyxiating

thoracic dystrophy (Jeune syndrome), Smith-Lemli-Opitz

syndrome

a. Postaxial polydactyly

chondroectodermal dysplasia (Ellis-van Creveld

syndrome), Meckel-Gruber syndrome, hydrolethalus

syndrome

b. Preaxial polydactyly

orofaciodigital syndrome

Syndactyly

Apert syndrome, triploidy, Roberts syndrome

Clinodactyly

trisomy 21, triploidy

Overlapping Digit

trisomy 18

P.1002

Hitchhikers Thumb

diastrophic dysplasia

Flexion Contractures

trisomy 13 + 18, fetal akinesia deformation sequence

Limb Reduction

congenital varicella, hypoglossia-hyperdactyly syndrome

Amputation

amniotic band syndrome

Fetal CNS anomalies

Incidence: 2:1,000 births in USA; 90% as 1st time occurrence

Recurrence: 23% after 1st, 6% after 2nd occurrence

ventricular atrium + cisterna magna are two sensitive

anatomic markers for normal brain development!

A. HYDROCEPHALUS

1. Aqueductal stenosis

2. Communicating hydrocephalus

3. Dandy-Walker malformation

4. Choroid plexus papilloma B. NEURAL TUBE DEFECT

Incidence: 1:500600 live births

Risk of recurrence: 34%

1. Spina bifida

2. Anencephaly

3. Acrania

4. Encephalocele (815%) 5. Porencephaly

6. Hydranencephaly

7. Holoprosencephaly

8. Iniencephaly

9. Microcephaly

10. Agenesis of corpus callosum

11. Lissencephaly

12. Arachnoid cyst

13. Choroid plexus cyst 14. Vein of Galen aneurysm

Associated

with:

trisomy 13 and 18

Increased

risk:

low parity, low socioeconomic status, relative infertility,

diabetes, obesity, anticonvulsants, folate deficiency

C. INTRACRANIAL NEOPLASM 1. Teratoma (>50%): benign / malignant

Location: originate from base of skull

2. Glioblastoma 3. Astrocytoma

Fetal Ventriculomegaly

Cause:

A. Morphologic anomaly (7080%): 1. Spina bifida (3065%) 2. Dandy-Walker malformation

3. Encephalocele



B. Abnormal karyotype (1020%) C. Viral infection

o 2040% of concurrent anomalies are missed by ultrasound!

dangling choroid plexus

width of ventricular atrium >10 mm

Prognosis: 21% survival rate; 50% with intellectual impairment

Isolated Mild Ventriculomegaly

= atrial width of 1015 mm

Prevalence: 1:700 in low-risk population

Most common brain anomaly on prenatal sonograms

Associated structural anomalies (9%):

o periventricular leukomalacia, subependymal / germinal

matrix hemorrhage, partial agenesis of corpus callosum, heterotopia, parenchymal dysplasia

Associated chromosomal

anomalies:

in 4%

Recommendation: MRI to diagnose associated structural

anomalies

Prognosis: 80% with isolated mild ventriculomegaly have normal motor +

intellectual function at 12 months of age

Lemon Sign

= flat / inwardly scalloped contour of both frontal bones

1. Spina bifida

Prevalence for fetuses 24 weeks: 98%

o (9093% sensitive, 9899% specific, 84% PPV for high-risk population, 6% PPV for low-risk population)

Prevalence for fetuses >24 weeks: 13%

o (disappears in 3rd trimester)

2. Encephalocele


4. Thanatophoric dysplasia

5. Cystic hygroma


7. Fetal hydronephrosis

8. Umbilical vein varix 9. Normal fetus (in 0.71.3%)

Prenatal Intracranial Calcifications

1. Toxoplasmosis

2. CMV infection

3. Tuberous sclerosis

4. Sturge-Weber syndrome

5. Venous sinus thrombosis 6. Teratoma

Cystic Intracranial Lesion

mnemonic: CHAP VAN

Choroid plexus cyst

Hydrocephalus, Holoprosencephaly, Hydranencephaly

Agenesis of corpus callosum + cystic dilatation of 3rd ventricle

Porencephaly

Vein of Galen aneurysm

Arachnoid cyst

Neoplasm (cystic teratoma)

Abnormal Cisterna Magna

Normal size between 15 and 25 weeks MA:

o >2 to

3. Severe hydrocephalus

B. LARGE CISTERNA MAGNA

1. Megacisterna magna

cerebellum + vermis remain

intact

2. Arachnoid cyst

en bloc displacement of

cerebellum + vermis

3. Cerebellar hypoplasia 4. Dandy-Walker syndrome (with vermian agenesis)

Fetal orbital anomalies Hypotelorism


2. Chromosomal abnormalities: trisomy 13

3. Microcephaly, trigonocephaly

4. Maternal phenylketonuria

5. Meckel-Gruber syndrome

6. Myotonic dystrophy

7. Williams syndrome 8. Oculodental dysplasia

Hypertelorism

1. Median cleft syndrome: cleft lip / palate

2. Craniosynostosis: Apert /Crouzon syndrome

3. Pena-Shokeir syndrome

4. Frontal / ethmoidal, sphenoidal encephalocele 5. Dilantin / phenytoin effect

Orbital and Periorbital Masses

1. Dacryocystocele

2. Anterior encephalocele

3. Glioma

4. Hemangioma

5. Teratoma

Fetal neck anomalies

1. Cervical myelomeningocele

2. Occipital cephalocele

3. Cystic hygroma / lymphangioma

4. Teratoma

5. Branchial cleft cyst

6. Enlarged thyroid 7. Sarcoma

Nuchal Skin Thickening

= NUCHAL SONOLUCENCY / FULLNESS / EDEMA

= skin thickening of posterior neck measured between

calvarium + dorsal skin margin

a. 3 mm during 913 weeks MA b. 5 mm during 1421 weeks MA

c. 6 mm during 1924 weeks MA o The smallest measurement should be used!

Image

plane:

axial / transverse image (slightly craniad to that of the

BPD measurement) that includes cavum septi pellucidi, cerebellar hemisphere and cisterna magna

(transcerebellar diameter view)

Incidence: among the most common anomaly in 1st trimester +

early 2nd trimester

Cause:

. NORMAL VARIANT (0.06%)

A. CHROMOSOMAL DISORDERS

trisomy 21 (in 4580%), Turner syndrome (45 X0), Noonan syndrome, trisomy 18, XXX syndrome, XYY

syndrome, XXXX syndrome, XXXXY syndrome, 18p-

syndrome, 13q-syndrome

3040% of fetuses with Down syndrome have nuchal skin thickening!

B. nonchromosomal DISORDERS

1. Multiple pterygium syndrome = Escobar syndrome

2. Klippel-Feil syndrome (fusion of cervical vertebrae,

CHD, deafness (30%), cleft palate

3. Zellweger syndrome = cerebrohepatorenal

syndrome (large forehead, flat facies, macrogyria,

hepatomegaly, cystic kidney disease, contractures

of extremities)

4. Robert syndrome

5. Cumming syndrome

larger lymphangiomas with radiating septations are

usually found with trisomy 18

nuchal fullness 3 mm during 1st trimester is seen in trisomy 21 / 18 / 13 (3050% PPV)

often reverting to normal by 1618 weeks

septations within nuchal translucency carries a

20- to 200-fold risk for chromosomal anomalies compared with normal

Sensitivity: 24475% for detection of trisomy 21

Specificity: 99% for detection of trisomy 21

PPV: 69%

Positive screen: 1.23% in general population (exceeding 0.5% risk of amniocentesis)

False positives: 0.528.5%

OB management:

thorough sonographic evaluation at 1820 weeks MA

DDx: chorioamnionic separation

Protruding Tongue

1. Macroglossia

2. Lymphangioma of the tongue

Macroglossia

1. Beckwith-Wiedemann syndrome

2. Down syndrome

3. Hypothyroidism 4. Mental retardation

Fetal chest anomalies Pulmonary Hypoplasia

Path: absolute decrease in lung volume / weight for gestational age

Cause:

1. Prolonged oligohydramnios (2025%) 2. Skeletal dysplasia (small thorax)

3. Intrathoracic mass (lung compression)

4. Large hydrothorax (lung compression)

5. Neurologic condition (reduced breathing activity)

6. Chromosomal abnormality 7. CHD with R-sided cardiac obstructing lesion

P.1004

thoracic circumference (TC) 0.80 (75% sensitive, 8090% specific); not applicable for intrathoracic masses

Intrathoracic Mass

in order of frequency:

1. Diaphragmatic hernia / eventration

2. Cystic adenomatoid malformation

3. Bronchopulmonary sequestration

4. Bronchogenic cyst with bronchial compression 5. Bronchial atresia

Unilateral Chest Mass

1. Congenital diaphragmatic hernia

2. Cystic adenomatoid malformation

3. Bronchopulmonary sequestration

4. Bronchogenic cyst 5. Unilateral bronchial atresia / stenosis

Bilateral Chest Masses

1. Laryngeal / tracheal atresia

2. Bilateral cystic adenomatoid malformation 3. Bilateral congenital diaphragmatic herniae

Mediastinal Mass

1. Goiter

2. Cystic hygroma

3. Pericardial teratoma

4. Neuroblastoma

Cystic Chest Mass

1. Bronchogenic cyst

2. Enteric cyst

3. Neurenteric cyst

4. Cystic adenomatoid malformation (type I)


6. Pericardial cyst 7. Mediastinal meningocele

Complex Chest Mass


2. Cystic adenomatoid malformation (type I, II, III)

3. Pulmonary sequestration

4. Complex enteric cyst 5. Pericardial teratoma

Solid Chest Mass

1. Congenital diaphragmatic hernia (bowel liver)

2. Cystic adenomatoid malformation type III

3. Pulmonary sequestration

4. Obstructed lung from bronchial atresia, laryngeal atresia,

bronchogenic cyst

5. Bronchopulmonary foregut malformation

6. Pericardial tumor 7. Heterotopic brain tissue

Regressing Fetal Chest Mass

1. Cystic adenomatoid malformation 2. Bronchopulmonary sequestration

Chest Wall Mass

1. Hemangioma

2. Cystic hygroma

3. Teratoma

4. Hamartoma 5. Thoracic myelomeningocele

Pleural Effusion

1. Primary idiopathic chylothorax (most common)

2. Hydrops fetalis (multiple causes)

3. Chromosome anomaly: trisomy 21, 45 XO (mostly)

4. Pulmonary lymphangiectasia / cystic hygroma

5. Lung mass: cystic adenomatoid malformation,

bronchopulmonary sequestration, congenital diaphragmatic

hernia, chest wall hamartoma (uncommon)

6. Pulmonary vein atresia 7. Idiopathic

Fetal cardiac anomalies

Incidence: 1:125 births = 0.8% of population; most common of all

congenital malformations (40%)

90% occur as isolated multifactorial traits with a

recurrence risk of 24% 10% are associated with multiple birth defects

responsible for 50% of childhood deaths

from congenital malformations

Antenatal sonographic diagnosis to prompt cardiac evaluation:

A. ABNORMALITIES IN CARDIAC POSITION

B. CNS

1. Hydrocephalus

2. Microcephaly


4. Encephalocele (Meckel-Gruber syndrome)

C. GASTROINTESTINAL

1. Esophageal atresia

2. Duodenal atresia

3. Situs abnormalities


D. VENTRAL WALL DEFECT

1. Omphalocele

2. Ectopia cordis

E. RENAL

1. Bilateral renal agenesis

2. Dysplastic kidneys

F. TWINS 1. Conjoined twins

Prenatal Risk Factors for Congenital Heart Disease

A. FETAL RISK FACTORS

1. Symmetric IUGR

2. Arrhythmias

a. fixed fetal bradycardia (50%) 110 bpm b. tachycardia (low risk)

c. irregular: PACs, PVCs (low risk)

3. Abnormal fetal karyotype

(CHD in Down syndrome in 40%; in trisomy 18 / 13

in >90%; in Turner syndrome in 35%)

4. Extracardiac somatic anomalies by US

omphaloceles (20%), duodenal atresia,

hydrocephaly, spina bifida, VACTERL

5. Nonimmune hydrops (3035%) 6. Oligo- / polyhydramnios

P.1005

B. MATERNAL RISK FACTORS

1. Maternal heart disease (10%)

2. Insulin-dependent diabetes mellitus (45%) 3. Phenylketonuria (in 15% if maternal phenylalanine

>15%)

4. Collagen vascular disease: SLE

5. Viral infection: rubella

6. Drugs

. phenytoin (in 2% PS, AS, coarctation, PDA)

a. trimethadione (in 20% transposition, tetralogy,

hypoplastic left heart)

b. sex hormones (in 3%)

c. lithium (7%): Ebstein anomaly, tricuspid atresia

d. alcohol (25% of fetal alcohol syndrome): VSD, ASD

e. retinoic acid = isotretinoin (?15%)

7. Paternal CHD (risk uncertain)

C. MENDELIAN SYNDROMES

1. Tuberous sclerosis

2. Ellis-van Creveld syndrome

3. Noonan syndrome

D. FAMILIAL RISK FACTORS FOR RECURRENCE OF HEART DISEASE

overall incidence : 68:1,000 live births

affected sibling : 14% (risk doubled)

affected parent : 2.54%

In 50% of neonates with CHD there is no identifiable

risk factor!

Poor prognostic features:

1. Intrauterine cardiac failure (hydrops)

2. Severe trisomy (18, 13)

3. Hypoplastic left heart + endocardial fibroelastosis 4. Delivery in center without pediatric cardiology

In Utero Detection of Cardiac Anomalies

A. ABNORMAL HEART POSITION


2. Lung anomaly

3. Pleural effusion

4. Cardiac defect B. CHAMBER ENLARGEMENT

RA: LA:

1. Tricuspid regurgitation 1. Mitral stenosis

2. Tricuspid valve dysplasia 2. Aortic stenosis

3. Ebstein anomaly

RV: LV:

1. Coarctation 1. Aortic stenosis

2. Normal in 3rd trimester 2. Cardiomyopathy

C. ABNORMAL FOUR-CHAMBER VIEW

1. Septal rhabdomyoma

2. Endocardial cushion defect

3. Ventricular septal defect

4. Ebstein anomaly

5. Single ventricle

D. VENTRICULAR DISPROPORTION

1. Hypoplastic right / left ventricle

2. Hypoplastic aortic arch

3. Aortic / subaortic stenosis

4. Coarctation of aorta

5. Ostium primum defect

E. INCREASED AORTIC ROOT DIMENSION

1. Tetralogy of Fallot

2. Truncus arteriosus

3. Hypoplastic left ventricle with transposition

F. DECREASED AORTIC ROOT DIMENSION

1. Coarctation of aorta 2. Hypoplastic left ventricle

2680% of serious cardiac anomalies can be detected on four-chamber view!

Increased sensitivity >20 weeks + by including outflow views!

Structural Cardiac Abnormalities & Fetal Hydrops

1. Atrioventricular septal defect + complete heart block

2. Hypoplastic left heart

3. Critical aortic stenosis

4. Cardiac tumor

5. Ectopia cordis

6. Dilated cardiomyopathy

7. Ebstein anomaly 8. Pulmonary atresia

Fetal Echocardiographic Views

A. FOUR-CHAMBER VIEW

1. Position of heart within thorax

2. Number of cardiac chambers

3. Ventricular proportion

4. Integrity of atrial + ventricular septa

5. Position + size + excursion of AV valves

B. PARASTERNAL LONG-AXIS VIEW

o = LEFT VENTRICULAR OUTFLOW TRACT VIEW

2. Continuity between ventricular septum + anterior aortic

wall

3. Caliber of aortic outflow tract

4. Excursion of aortic valve leaflets

C. SHORT-AXIS VIEW OF OUTFLOW TRACTS

0. Spatial relationship between aorta + pulmonary artery

1. Caliber of aortic + pulmonary outflow tracts D. AORTIC ARCH VIEW

Identification of fetal RV:

o RV lies closest to anterior chest wall

o foramen ovale flap seen within

LA

o prominent moderator band + papillary

muscles in RV

Echogenic Intracardiac Focus

Cause: mineralization of a papillary muscle

Isolated anomaly in 90%!

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P.1006

1. Trisomy 21 (in 30% of affected fetuses)

2. Trisomy 13 (in 50% of affected fetuses)

3. Normal pregnancy (4% in a population at high risk for fetal anomalies)

Fetal gastrointestinal anomalies

1. Esophageal atresia TE fistula

2. Duodenal atresia

3. Meconium peritonitis

4. Hirschsprung disease

5. Choledochal cyst 6. Mesenteric cyst

Fetal Abdominal Wall Defect

Prevalence: 1:2,000 pregnancies

1. Gastroschisis

2. Omphalocele spectrum:

upper abdominal wall defect

3. Ectopia cordis

4. Pentalogy of Cantrell

midabdominal wall defect: classic omphalocele

lower abdominal wall defect

5. Bladder exstrophy

6. Cloacal exstrophy

7.Amniotic band syndrome

8. Limb-body wall complex

Fetal Hepatomegaly

A. CONGENITAL INFECTIONS

1. CMV

B. SEVERE HEMOLYTIC DISEASE

C. SYNDROMES

1. Beckwith-Wiedemann syndrome 2. Zellweger syndrome

Intraabdominal Echogenic Mass in Fetus

A. Abdomen

1. Echogenic bowel

2. Enteric duplication cyst (rarely echogenic)

3. Subdiaphragmatic extralobar pulmonary sequestration

(4:1 left-sided predominance)

B. Liver

1. Hepatic hemangioma

2. Hepatic mesenchymal hamartoma composed of multiple

microcysts

C. Adrenal / renal

1. Neuroblastoma

2. Adrenal hemorrhage 3. Mesoblastic nephroma

Nonvisualization of Fetal Stomach

Fetal swallowing begins at 11 weeks MA

Normal: stomach is visualized in almost all normal fetuses by 1314 weeks (definitely by 19 weeks)

Incidence: 2%

Cause:

1. Physiologic gastric emptying /

intermittent swallowing

Repeat scan after 30 minutes!

2. Oligohydramnios

3. CNS depression / abnormalities impairing swallowing

4. Abnormal position of stomach:

a. stomach on contralateral side (situs inversus)

b. congenital diaphragmatic hernia

5. Esophageal atresia TE fistula

Nonvisualization of fetal stomach

and polyhydramnios in 33% fetuses with

esophageal atresia after 24 weeks MA! 6. Cleft lip / palate (impairing normal swallowing)

Rx: repeat ultrasound scan

Double Bubble Sign

= fluid-filled stomach + proximal duodenum

A persistently fluid-filled duodenum is always abnormal!

A. DUODENAL OBSTRUCTION 1. Duodenal atresia (usually not seen

Incidence: imperforate anus 1:3,000;

small bowel 1:5,000; colon 1:20,000

Pathologic types:

I. one / more transverse diaphragms

II. blind-ending loops connected by fibrous string

III. complete separation of blind-ending loops

IV. apple-peel atresia of small bowel (occlusion of SMA branch)

Associated

with:

GI anomalies in 45% (malrotation, duplication,

microcolon, esophageal atresia)

P.1007

multiple distended bowel loops >7 mm in diameter

increased peristalsis

polyhydramnios (if obstruction above level of

mid jejunum; exceptions are esophageal atresia + TE fistula) due to fetal inability to cycle amniotic fluid through gut

Cx: Meconium peritonitis (50%)

DDx: (1) Other cystic masses: duodenal atresia, hydronephrosis, ovarian

cyst, mesenteric cyst

(2) Chronic chloride diarrhea

Hyperechoic Fetal Bowel

Most common echogenic mass in fetal abdomen

Definition: bowel echogenicity bone

Incidence: 0.21.0% of 2nd trimester fetuses

Cause: (?) constipation in utero due to decreased swallowing, hypoperistalsis, bowel obstruction + increased fluid absorption,

ingestion of blood

1. Normal small bowel variant (especially

A. TUMOR

1. Hepatoblastoma

2. Metastatic neuroblastoma

3. Hemangioma / hemangioendothelioma

4. Teratoma

5. Ovarian dermoid

B. OTHERS

1. Fetal gallstones (>28 weeks EGA)

Cause: hemolytic disease, cholestasis, maternal drug use

Prognosis: resolution before / after delivery

Cystic Mass in Fetal Abdomen

A. POSTERIOR MID ABDOMEN

1. Cysts of renal origin

2. Hydroureteronephrosis

3. Multicystic dysplastic kidney

4. Paranephric collection

B. RIGHT UPPER QUADRANT

1. Liver cyst

2. Choledochal cyst

C. LEFT UPPER QUADRANT

1. Splenic cyst

D. ANTERIOR MID ABDOMEN

1. Gastrointestinal duplication cyst

2. Mesenteric cyst

3. Meconium pseudocyst

4. Dilated bowel

5. Urachal cyst

E. LOWER ABDOMEN

1. Adnexal cyst: follicular cyst (most), corpus luteum cyst,

theca lutein cyst, paraovarian cyst, teratoma, cystadenoma

Cx of large cysts:

polyhydramnios, dystocia, torsion, respiratory distress

Prognosis: 60% resolve within first 6 months of life

2. Hydrometrocolpos

3. Meningocele

4. Sacrococcygeal teratoma

Fetal Ascites

A. ASCITES + FETAL HYDROPS

1. Immune hydrops

2. Nonimmune hydrops

B. ISOLATED ASCITES

1. Urinary ascites

2. Meconium peritonitis

3. Bowel rupture

4. Ruptured ovarian cyst

5. Hydrometrocolpos 6. Glycogen storage disease

Fetal urinary tract anomalies

Incidence: 0.25%1% liveborn infants (OB-US);

1:1001:200 neonates (pediatrics)

Types:

1. Bilateral renal agenesis

2. Infantile polycystic kidney disease

3. Adult polycystic kidney disease

4. Multicystic dysplastic kidney

5. Ureteropelvic junction obstruction

6. Megaureter

7. Posterior urethral valves

8. Prune belly syndrome

9. Megacystis-microcolon-intestinal hypoperistalsis syndrome

P.1008

10. Mesoblastic nephroma

11. Wilms tumor 12. Neuroblastoma

Associated chromosome abnormalities in 12% (74%

with: trisomy, 10% deletion, 9% sex chromosome aneuploidy, 6% triploidy)

fetal urine production:

5 mL/hr at 20 weeks MA;

56 mL/hr at 40 weeks MA

bladder

volume:

1 mL at 20 weeks MA;

36 mL at 40 weeks MA

filling + emptying of fetal urinary bladder occurs every

1030 (range 743) minutes increased renal parenchymal echogenicity indicates

renal abnormality in 80%

fetal hydronephrosis

o = AP diameter of renal pelvis >5 mm at 1520 weeks, 8 mm at 2030 weeks, 10 mm at >30 weeks

General gynecology Pelvic Features of Estrogen Stimulation

increased thickness + volume of uterus

fundocervical ratio >2

echogenic endometrium

appearance of ovaries NOT USEFUL (because of widely

varying ovarian volumes + normal visualization of follicles at all ages)

Precocious Puberty

= complete sexual development with secondary sex

characteristics appearing

virilization in girls

feminization in boys

c. gonadotropin-dependent = true precocious puberty d. gonadotropin-independent = pseudoprecocious puberty

Isolated Premature Adrenarche

= pubic hair development due to action of adrenal androgens

increased levels of adrenal androgens prepubertal uterus + ovaries (0.11 cm3)

Isolated Premature Thelarche

= breast enlargement

May occur without endocrine abnormalities

prepubertal uterus + ovaries

Pseudoprecocious Puberty

= pseudosexual PRECOCITY = PERIPHERAL PRECOCIOUS

PUBERTY= incomplete precocious puberty

= pubertal changes occurring independently of the action of

pituitary gonadotropins, ie, early development of secondary

sex characteristics without ovulation

Cause:

1. Autonomous ovarian follicular cyst (most common cause)

2. Estrogen-secreting ovarian tumor:

eg, granulosa theca-cell tumor, gonadoblastoma,

thecoma, choriocarcinoma

3. McCune-Albright syndrome

4. Adrenocortical neoplasm

5. Hypothyroidism

6. Neurofibromatosis

7. Hepatoblastoma

8. Estrogen ingestion

low gonadotropin levels after LHRH stimulation high estradiol level low levels of FSH and LH

normal bone age prepubertal uterus + ovaries

asymmetric ovarian enlargement (one ovary

2.47 cm3) with macrocysts (>9 mm)

unilateral follicular ovarian cyst characterized by internal daughter cyst

True Precocious Puberty

= CENTRAL PRECOCIOUS PUBERTY = TRUE ISOSEXUAL

PRECOCITY = complete precocious puberty

= gonadotropin-dependent early development of gonads +

secondary sex characteristics with ovulation before 8 years of

age

Cause:

1. Idiopathic activation of hypothalamic-pituitary-gonadal

axis (6680%) 2. Lesion of pituitary gland / hypothalamus:

eg, tuber cinereum hamartoma

3. Increased intracranial pressure:

eg, postmeningitis hydrocephalus

increased levels of estrogen increased gonadotropin levels after LHRH stimulation

advanced bone age adult-sized ovaries (1.212 cm3) dominance of corpus over cervix length

Rx: long-acting gonadotropin-releasing hormone analogue

Amenorrhea Primary Amenorrhea

Definition:

a. no menarche by 16 years of age

b. no thelarche / adrenarche by 14 years of age

c. no menarche >3 years after adrenarche + thelarche

Cause:

A. FEMALE ANATOMIC ANOMALIES

= Mllerian (uterovaginal) anomalies (20%)

B. CONGENITAL DISORDERS OF SEXUAL DIFFERENTIATION

a. pure gonadal dysgenesis = Turner syndrome (33%)

bilateral dysfunctional /

streak gonads

b. mixed gonadal dysgenesis testis + streak gonad

P.1009

Risk: in 25% development of dysgerminoma / gonadoblastoma

in dysgenetic gonads with Y chromosome

C. OVARIAN FAILURE / DYSFUNCTION

D. HYPOTHALAMIC / PITUITARY CAUSES (15%)

E. CONSTITUTIONAL DELAY (10%)

F. OTHERS: eg, systemic, psychiatric illness (22%)

absent / streak gonads + infantile uterus:

0. Hypogonadotrophic hypogonadism

low / normal LH + FSH levels

a. hypothalamic dysfunction: hypothalamic

tumor, Kallmann disease (= lack of pulsatile

GnRH release), systemic illness, constitutional

growth delay, extreme physical / psychological

/ nutritional stress (cystic fibrosis, sickle cell

disease, Crohn disease), irradiation

b. pituitary dysfunction: disruption of pituitary

stalk from child abuse, head trauma

1. Hypergonadotropic hypogonadism

= ovarian tissue fails to respond to endogenous

gonadotropins

high LH + FSH levels b. abnormal karyotype: Turner syndrome, XY gonadal

dysgenesis

c. irradiation, chemotherapy, autoimmune disease (eg,

autoimmune oophoritis)

absent uterus:

0. Testicular feminization = male intersex = male

pseudohermaphroditism (end-organ insensitivity to

testosterone)

1. Mllerian dysgenesis (= Mayer-Rokitansky-Kster-Hauser

syndrome) normal fallopian tubes + ovaries

associated

with:

unilateral renal abnormality (50%), skeletal

abnormality (12%)

small infantile uterus:

0. Androgen-producing virilizing tumors of adolescent ovary

(usually Sertoli-Leydig cell tumor)

unilateral adnexal mass

1. Turner syndrome

2. In utero exposure to diethylstilbestrol

normal uterus + unilateral ovarian tumor:

0. Estrogen-producing ovarian tumor with disruption

of menstrual cycle:

granulosa cell tumor, thecoma

hematometrocolpos:

. neonate = congenital uterovaginal obstruction

0. Urogenital sinus / cloacal malformation

pelviabdominal cystic

mass with fluid-debris level in fetal US

during 3rd trimester

renal dysplasia /

obstruction

a. teenager

0. Imperforate hymen

1. Transverse vaginal septum

in upper vagina (45%)

in mid vagina (40%)

in lower vagina (15%)

hematometra

0. Cervical dysgenesis

bilateral ovarian enlargement:

0. Polycystic ovary syndrome

(= Stein-Leventhal syndrome): most common cause of secondary amenorrhea

Secondary Amenorrhea

1. Pregnancy: most common cause in girls >9 years of age

2. Polycystic ovary syndrome (main pathologic cause)

3. Asherman syndrome 4. All causes of primary amenorrhea

Calcifications of Female Genital Tract

A. UTERUS

1. Uterine fibroid

2. Arcuate arteries

B. OVARIES

1. Dermoid cyst (50%)

2. Papillary cystadenoma (psammomatous bodies)

3. Cystadenocarcinoma

4. Hemangiopericytoma

5. Gonadoblastoma

6. Chronic ovarian torsion

7. Pseudomyxoma peritonei

C. FALLOPIAN TUBES

1. Tuberculous salpingitis

D. PLACENTA E. LITHOPEDION

Psammoma Bodies in Tumors

1. Papillary serous cystadenoma / cystadenocarcinoma

2. Mucinous carcinoma of colon

3. Papillary thyroid cancer 4. Meningioma

Free Fluid in Cul-de-sac

1. Follicular rupture

2. Ovulation

3. Ectopic pregnancy

4. S/P culdocentesis

5. Ovarian neoplasm 6. Pelvic inflammatory disease

Pelvic mass Frequency of Pelvic Masses

1. Benign adnexal cyst 34%

2. Leiomyoma 14%

3. Cancers 14%

4. Dermoid 13%

5. Endometriosis 10%

6. Pelvic inflammatory disease 8%

Cystic Pelvic Masses

A. CYSTIC ADNEXAL MASS

B. EXTRAADNEXAL CYSTIC MASS

1. Peritoneal inclusion cyst

2. Mesenteric cyst

3. Lymphocele 4. Bladder diverticulum

P.1010

5. Ectopic gestation

6. Fluid-distended bowel

7. Loculated pelvic abscess: appendiceal, diverticular,

postoperative, Crohn disease, tuberculous, pelvic actinomycosis

Complex Pelvic Mass

mnemonic: CHEETAH

Cystadenoma / cystadenocarcinoma

Hemorrhagic cyst

Endometrioma

Ectopic pregnancy

Teratoma (dermoid)

Abscess (from adjacent appendicitis, etc.) Hematoma in pelvis

Solid Pelvic Masses

1. Pedunculated myoma (most common)

2. Fibroma

3. Adenofibroma

4. Thecoma 5. Brenner tumor

Fatty Pelvic Mass

A. UTERUS

1. Lipoleiomyoma

2. Fibromyolipoma

B. OVARY

1. Benign cystic ovarian teratoma

2. Malignant degeneration of cystic teratoma

3. Nonteratomatous lipomatous ovarian tumor

C. PELVIS

1. Benign pelvic lipoma

2. Liposarcoma 3. Lipoblastic lymphadenopathy

Extrauterine Pelvic Masses

1. Solid adnexal mass

2. Metastatic disease

3. Lymphoma

4. Pelvic kidney

5. Rectosigmoid carcinoma

6. Bladder carcinoma

7. Retroperitoneal tumor / fibrosis

8. Intraperitoneal fat

9. Vascular mass / malformation

10. Hematoma

11. Bowel

Pelvic Pain in Pediatric Age Group

1. Ovarian torsion

a. of normal ovary

Cause: excessive mobility of ovary in childhood

b. with ovarian mass:

functional cyst (60%)

neoplasm (40%):

benign mature teratoma (66%) malignancy (33%): germ cell t

Radiology Review Manual

6th Edition

2007 Lippincott Williams & Wilkins

Statistics Terminology

Incidence = number of diseased people per 100,000

population per year

Prevalence = number of existing cases per 100,000 population

at a target date

Mortality = number of deaths per 100,000 population per year Fatality = number of deaths per number of diseased

GOLD STANDARD

normal abnormal subtotal

T

E S

T

normal TN FN T- NPV

abnormal FP TP T+ PPV

subtotal D- D+ total preval

specificity sensitivity acc

TP = test positive in diseased subject

FP = test positive in nondiseased subject

FN = test negative in diseased subject

TN = test negative in nondiseased subject

T+ = abnormal test result

T- = normal test result

D+ = diseased subjects D- = nondiseased subjects

Sensitivity

= ability to detect disease

= probability of having an abnormal test given disease

= number of correct positive tests / number with disease

= true positive ratio = TP / (TP + FN) = TP / D+

D+ column in decision matrix Independent of prevalence

Specificity

= ability to identify absence of disease

= probability of having a negative test given no disease

= number of correct negative tests / number without disease

= true negative ratio = TN / (TN + FP) = TN / D-

D- column in decision matrix Independent of prevalence

Accuracy

= number of correct results in all tests

= number of correct tests / total number of tests

= (TP + TN) / (TP + TN + FP + FN) = (TP + TN) / tota l

Depends much on the proportion of diseased +

nondiseased subjects in studied population

Not valuable for comparison of tests Example: same test accuracy of 90% for two tests A and B

Positive Predictive Value

= positive test accuracy

= likelihood that a positive test result actually identifies

presence of disease

= number of correct positive tests / number of positive tests = TP / (TP + FP) = TP / T+ Test A: 90% accuracy

GOLD STANDARD


T

E S

T

normal 90 10 100 90%

abnormal 10 90 100 90%

subtotal 100 100 200 50%

90% 90% 90%

GOLD STANDARD


T

E S

T

normal 170 20 190 89%

abnorma 0 10 10 100%

subtotal 170 30 200 15%

100% 33% 90%

T+ row in decision matrix Dependent on prevalence

PPV increases with increasing prevalence for

given sensitivity + specificity

PPV increases with increasing specificity for given prevalence

Negative Predictive Value

= negative test accuracy

= likelihood that a negative test result actually identifies

absence of disease

= number of correct negative tests / number of negative tests

= TN / (TN + FN) = TN / T-

T- row in decision matrix Dependent on prevalence

NPV increases with decreasing prevalence for given

sensitivity + specificity

NPV increases with increasing sensitivity for given prevalence

False-positive Ratio

= proportion of nondiseased patients with an abnormal test

result

D- column in decision matrix = FP / (FP + TN) = FP / D- = 1 - specificity = (TN + FP - TN) / (TN + FP)

False-negative Ratio

= proportion of diseased patients with a normal test result

D+ column in decision matrix = FN / (TP + FN) = FN / D+ = 1 - sensitivity = (TP + FN - TP) / (TP + FN)

Disease Prevalence

= proportion of diseased subjects to total population

= (TP + FN) / (TP + TN + FP + FN) = D+ / total

P.1127

GOLD STANDARD

T E

S

T


normal 162 2 164 99%

abnormal 18 18 36 50%

subtotal 180 20 200 10%

90% 90% 90%

GOLD STANDARD

T E

S T


normal 18 18 36 50%

abnorma 2 162 164 99%

subtotal 20 180 200 90%

90% 90% 90%

Sensitivity + specificity are independent of prevalence

Affects predictive values + accuracy of a test result

Example:

Test A, C, D: 90% sensitivity + 90% specificity

Bayes Theorem

= the predictive accuracy of any test outcome that is less than

a perfect diagnostic test is in. uenced by

a. pretest likelihood of diseaseReceiver Operating

Characteristics b. criteria used to de.ne a test result for 3 Different Tests

Receiver Operating Characteristics (ROC)

= degree of discrimination between diseased + nondiseased

patients using varying diagnostic criteria instead of a single

value for the TP + TN fraction

= curvilinear graph gen er at ed by plotting TP ratio as a

function of FP ratio for a number of different diagnostic

criteria (ranging from de.nitely normal to definitely abnormal)

Y-axis: true-positive ratio = sensitivity

X-axis: false-positive ratio = 1 - specificity; reversing the

values on the X-axis results in an identical sensitivity-specificity curve

Use: variations in diagnostic criteria are reported as a

continuum of responses ranging from de. nitely abnormal to

equivocal to de.nitely normal due to 0.2 subjectivity + bias of

individual radiologist

A minimum of 4-5 data points of diagnostic criteria are

needed!

Difficulty: subjective evaluation of image features; subjective

diagnostic interpretation; data must be ordinal (= Specificity

discrete rating scale from definitely negative to definitely

positive)

Interpretation:

o Increase in sensitivity leads to decrease in

specificity!

o Increase in specificity leads to decrease in

sensitivity!

o The most sensitive point is the point with the

highest TP ratio

o - equivalent to overreading by using less stringent diagnostic criteria (all findings read as abnormal)

o The most specific point is the point with the

lowest FP ratio

o - equivalent to underreading by using more strict diagnostic criteria (all findings read as normal)

o The ROC curve closest to the Y-axis

represents the best diagnostic test

o Does not consider disease prevalence in the population

Receiver Operating Characteristics for 3 Different Tests

Interpretation of Receiver Operating Characteristics

P.1128

Receiver Operating Characteristics for Positive Predictive Value of

Various Tests with Different Sensitivities and Specificities

Confidence Limit

= degree of certainty that the proportion calculated from a

sample of a particular size lies within a specific range

(binomial theorem) Analogous to the mean 2 SD

Clinical Epidemiology

= application of epidemiologic principles + methods to

problems encountered in clinical medicine with the purpose of

developing + applying methods of clinical observation that will

lead to valid clinical conclusions

Epidemiology = branch of medical science dealing with

incidence, distribution, determinants in control of disease within a de. ned population

Screening Techniques

Principle question: can early detection in. uence the natural

history of the disease in a positive manner?

Outcome measure: early detection + effective therapy should

reduce morbidity + mortality, ie, increase survival rates

(observational study)!

Biases:

o Lead time = interval between disease detection at

screening + the usual time of clinical manifestation;

early diagnosis always appears to improve survival by at

least this interval, even when treatment is ineffective

o Length time = differences in growth rates of tumors:

a. slow-growing tumors exist for a long time before

manifestation thus enhancing the opportunity for

detection

b. fast-growing tumors exist for a short time before

manifestation thus providing less opportunity for

detection at screening interval cancers = clinically detected between scheduled screening exams are

likely fast-growing tumors; patients with tumors

detected by means of screening tests will have a better prognosis than those with interval cancers

Receiver Operating Characteristics for Negative Predictive Value of Various Tests with Different Sensitivities and

Specificities

o Self-selection = decision to participate in screening

program; usually made by patients better educated +

more knowledgeable + more health-conscious; mortality

rates from noncancerous causes can be expected to be

lower than in general population

o Overdiagnosis = detection of lesions of questionable

malignancy, eg, in situ cancers, which might never have

been diagnosed without screening + have an excellent prognosis

Randomized Trials

Design: two arms consisting of (a) study group and (b) control

group with patients assigned to each arm on randomized basis

Endpoint: difference in mortality rates of both groups

Power: study must be of suf.cient size + duration to detect a

difference, if one exists; analogous to sensitivity of a

diagnostic test

Impact on effective size of groups:

o Compliance = proportion of women allocated to

screening arm of trial who undergo screening

o Contamination = proportion of women allocated to control group of trial who do undergo screening

Case-control Studies

Retrospective inquiry, which is less expensive, takes less time,

is easier to perform:

a. determine the number of women who died from breast

cancer

b. chose same number of women of comparable age who

have not died from breast cancer

c. ascertain the number of women who were screened +

who were not screened in both arms Calculation of odds ratio = ad / bc

Kappa (K)

measures concordance between test results and gold

standard

Analogous to Pearson correlation coef.cient (r) for continuous data!

P.1129

Example: = 0.743 Predictive value of :

0.00 - 0.20 little or none

0.20 - 0.40 slight

0.40 - 0.60 group

0.60 - 0.80 some individual

0.80 - 1.00 individual

cases of deaths from breast cancer

controls not died from breast cancer

screened a b

not

screened

c d

GOLD STANDARD

T

E 18 3 0 0 21

S T

2 20 5 2 29

1 4 2 3 28

0 0 5 17 22

21 27 30 22 100

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Documents

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