role of doppler ultrasonography in...
TRANSCRIPT
ROLE OF DOPPLER ULTRASONOGRAPHY IN
OBSTETRICS
PRESENTOR:DR.Y.RAMA CONSULTANT:DR.VEENU
SENIOR RESIDENT:DR.AJAY KUMAR
BASICS OF DOPPLER
• Pitch altered with change in relative motion b/n observer & object- DOPPLER SHIFT
• FORMULA:
fD= 2fo v cos 0/v
TYPES OF DOPPLER USG
CONTINUOUS WAVE DOPPLER PULSED DOPPLER: Brief pulses of ultrasound waves Vessels visualised on gray scale and flow
velocity patterns obtained
SAMPLE VOLUME
DOPPLER GATE
COLOR DOPPLER
Stationary targets-B-mode image
Signals from moving targets-display color
Color assigned – direction of flow
RED – TOWARDS
BLUE-AWAY
DOPPLER INDICES
PSV-peak systolic velocity-A
EDV-end diastolic velocity-B
Systolic /diastolic ratio
RI-resistive index:(A-B)
A
PI-pulsatility index:(A-B)
Mean
POWER DOPPLER
• Detects energy or amplitude of doppler signals of moving blood
• Independent of direction
• Subtle amount of flow
• Velocity –not obtained
INDICATIONS IN OBSTETRICS
• LOCALISATION OF GESTATIONAL SAC
• EARLY PREGNANCY FAILURE
• FAILED TERMINATION OR RETAINED PRODUCTS OF CONCEPTION
• PREDICTION OF PREECLAMPSIA
• INTRAUTERINE GROWTH RETARDATION
• TWIN GESTATION
• FETAL HYDROPS AND ANEMIA
• PLACENTAL AND CORD ANAMOLIES
• STRUCTURAL ANAMOLIES OF FETUS
SAFETY OF DOPPLER IN PREGNANCY
• Epidemiologic studies- association of LBW, delayed speech devn
• More research
CURRENT RECOMMENDATIONS & GUIDELINES
• Initial power setting lowest to produce adequate images-ALARA(As low as reasonably achievable) principle
Operator-color flow box small, Exposure time, non stationary probe
• Preexisting temperature elevation of mother
• Sensitive tissues-head, brain, spine,eye (esp.<8w)
• Thermal and mechanical indices
VESSELS AND NORMAL WAVEFORMS
UTERINE ARTERY:
ANATOMY:
branch of anterior division of internal iliac artery-on levator ani-isthmus-upwards on lateral sides of uterus in leaves of broad ligament
NORMAL WAVEFORMS
DOPPLER MEASUREMENT AND WAVEFORM
• At the cervico corporal junction
NORMAL WAVEFORMS
NORMAL PI<1.2 NOTCH PI>1.45
PREGNANT NON PREGNANT PREGNANT
Extravillous trophoblast from anchoring villi- into decidua-spiral artery
innervated muscular
vessels of high resis- tance--- passively dilated low resistance
Vasodilatory peptides-increase in maternal blood flow
NORMAL WAVEFORMS
COILED SPIRAL ART
UNCOILED SPIRAL ART
EXTRAVILLOUS TROPHOBLASTIC CELLS
SPIRAL ART
FETO MATERNAL CIRCULATION
UMB V
DUCTUS VENOSUS
DESC.AORTA
UMB ART
IVC
UMBILICAL ARTERY Information on perfusion of fetoplacental
unit
Measured in extraabdominal portion
NORMAL WAVEFORMS
NORMAL WAVEFORMS
Growth of placenta ; increase in Cardiac output 1. increase in systolic & diastolic velocities 2.continuous forward flow 3.decrease in impedance
3rd TM PI:1-1.5
1st TM
UMBILICAL VEIN • From extra abdominal portion
• Blood flow increases as gestation progresses-Pulsations disappear
NORMAL WAVEFORMS
1st TM 3rd TM
DUCTUS VENOSUS • Oblique section of
upper abdomen or midsagittal section
• Doppler measurements- sample volume at the initial or middle portion
• Distal portion-contaminates IVC, HV
NORMAL WAVEFORMS
Continuous forward flow throughout cardiac cycle
BIPHASIC
S wave---ventricular systole
D wave---diastole
A wave---forward flow at atrial
contraction
NORMAL WAVEFORMS
D A
S
THORACIC AORTA • Descending thoracic
aorta flow throughout cardiac cycle
NORMAL WAVEFORMS
MIDDLE CEREBRAL ARTERY
Easier to detect
Sensitive to detect IUGR
Transverse axial view- slightly caudal than for BPD measurements
Sample volume at the proximal part and the flow towards probe
High systolic and low diastolic velocities– auto regulation
NORMAL WAVEFORMS
PI>1.45
LOCALISATION OF GESTATIONAL SAC
TO DIAGNOSE ECTOPIC:
TRUE GESTATIONAL SAC
Double decidual sign-
•Oval & eccentric
PSEUDOGESTATIONAL SAC
Single echogenic layer
•central
ENDOMETRIUM
ENDOMETRIUM ONLY EMBRYO & TROPHOBLAST
Ectopic: Sac - No peritrophoblastic flow
Low velocity flow(<21cm/sec)
TO DIAGNOSE ECTOPIC:
Ectopic: Adnexa- RING OF FIRE
DD:Corpus luteal cyst-low resistance ;low vel flow
Ectopic – Low resistance ;high vel flow
Cardiac activity - M mode /color /power doppler
MASS
RING OF FIRE
TO DIAGNOSE ECTOPIC:
• Interstitial & cornual ectopic-when no significant mass seen
• CDI:increased flow
TO DIAGNOSE ECTOPIC:
MONITOR METHOTREXATE THERAPY
• To assess placental flow- absent or persistent-after treatment
CERCIVAL SCAR IMPLANTATION
• Past H/O caesarean
• Sac in LUS and local myometrial thinning
• Significance:distinguish ongoing abortion dead embryo no peritrophoblastic activity
• Catastrophic hemorrhage-even bladder involvement can occur
PREDICTION OF PREECLAMPSIA
• Insufficient invasion of maternal spiral arteries by trophoblast
impaired placental
perfusion
Increase in RI or notching-dec placental flow
NOTCH
UTERINE ART
FAILED TERMINATION
• RETAINED PRODUCTS OF CONCEPTION
• large echogenic mass filling endometrial canal extending into myometrium
• CDI- mass of vessels in the myometrium &high velocity flow
• No flow-non viable –pass spontaneously
• To plan D & C
Vessels in myometrium
INTRAUTERINE GROWTH RESTRICTION
• resistance in uteroplacental circulation
• velocity in feeding arteries esp. Diastolic
• Changes in uterine, umbilical, MCA, Aorta, ductus venosus
UTERINE ARTERY • Notch
• Mean P.I. Of both uterine arteries >1.45
• placenta on one side- ipsilateral waveform reported
NORMAL PI<1.2
NOTCH MEAN PI>1.45
UMBILICAL ARTERY-PROGRESSIVE CHANGES
ABSENT EDF
REVERSAL EDF
NORMAL
MIDDLE CEREBRAL ARTERY
• Fetal hypoxia
• Chemoreceptors sense
• Inc flow to brain for oxygen(most sensitive)
• diastolic vel(dec P.I.)--REDISTRIBUTION
NORMAL PI>1.45
THORACIC AORTA
• Absent end diastolic velocity(adaptation to inc flow to brain)
• Hypoxia,distress,IUGR impedance impedance in aorta in brain absent EDV
NORMAL
DUCTUS VENOSUS
Dec cardiac function
Dec forward flow on atrialcontraction
Reverse A wave
NORMAL
PSV>50cm/s
A WAVE REVERSAL
PSV<5cm/s
ABSENT A WAVE
UMBILICAL VEIN
• Decreased forward flow;no inc diastolic flow
• Venous pulsations
PULSATIONS
NORMAL
SIGNIFICANCE OF DOPPLER
• Not for diagnosis-positive predictive value for doppler indices is low
• Prognosis and monitoring once diagnosed
• If absent or reversed end diastolic flow in umb artery– very poor –prompt delivery
• Fetal hypoxia before acidosis (CTG- changes only if acidosis)
STEROID ADMINISTRATION
• Severe IUGR with absent EDF before 32w- no lung maturity – steroids given-improves lung maturity
• CDI- assess cardiovascular response to steroids
• Improves umbilical artery waveforms in 2/3rds
• 1/3rd-deteriorate acutely-daily monitoring is imp-needs delivery
TRANSIENT EDF PERSISTENT ARED
BASELINE
>24H
INTEGRATED FETAL TESTING
• Abnormal doppler—BPS to be done
• Timing of delivery depending only on doppler—compromise by prematurity
• BPS done if abnormal doppler --combination- safe intrauterine time
TWIN GESTATION
• Monochorionic twins-single placenta--MC complication- twin to twin transfusion syndrome;Twin embolisation syndrome
• Dichorionic twins-discordant growth
• Monoamniotic twins
TWIN TO TWIN TRANSFUSION SYNDROME:
• Predominant AV anastomoses running from donor to recipient
• Volume depletion in one twin;volume overload in the other
D R
•Suspected if polyhydramnios in recipient and oligohydramnios in donor
•To identify prognostic signs:distance b/n cord insertions, AA anastomoses, umb artery PI values
•To stage c TTTS
•To evaluate treatment
STAGING : STAGE I: donor bladder still visible
D
STAGE II:donor bladder not visibe
STAGE III:( ABNORMAL DOPPLER VALUES)
RECIPIENT TWIN:
• Inc pressure and volume overload
• RV stretches; inc end diastolic pressure
• Inc end diastolic pressure of RA
• Retrograde flow on atrial systole in DV, HV,IVC
DONOR TWIN: Volume depletion-UA changes
DONOR TWIN RECIPIENT TWIN
STAGE III:( ABNORMAL DOPPLER VALUES)
STAGE IV:HYDROPS
STAGE V:DEATH OF CO-TWIN
TO EVALUATE TREATMENT
Post amniocentesis & selective laser occlusion of AV connections-look for restoration of normal doppler indices
TWIN EMBOLISATION SYNDROME
• Death of co-twin
• Transfusion of thromboplastin rich blood or embolisation of clot &debris across vascular anastomoses
• Acute hypotensive episode-MC- Ischemic brain injury
• CDI-Normal MCA doppler within 2-3d reassures normal subsequent growth
DICHORIONIC TWINS
• Cause of discordant fetal growth
• CDI rules out placental disease- avoids frequent USG monitoring
• Differences in fetal sex, growth potential, timing of fertilisation-considered.
MONOAMNIOTIC TWINS
• identifies cord entanglement
• Common due to close insertion of cords
• Intermittent cord occlusion is detected by serial umb artery doppler
FETAL HYDROPS
• IMMUNE HYDROPS: Rh incompatibility hemolysis anemia & cardiac fail inc blood flow velocities for Oxygen inc PSV IN MCA Prevents unnecessary invasive amniocentesis or
fetal blood sampling
NON IMMUNE HYDROPS
• Causes:fetal, maternal,placental
• Monitoring for fetal welfare
• CDI- Indicates anemia, Cardiac fail
• UV pulsations or DV a wave reversal-cardiac diastolic dysfunction
• Abnormal UA &MCA waveforms
PLACENTAL & CORD ABNORMALITIES
CORD INSERTION:
Insertion if not found on placental disc-l/f velamentous insertion & marginal insertion
Marginal & velamentous cord-IUGR
MARGINAL AND VELAMENTOUS INSERTION
Vasapraevia:vessels across os
• TVS/ transperineal doppler
• to prevent inadvertent rupture of vessels in membranes at labour
• to plan caesarean
PLACENTA PERCRETA - INVASIVE PLACENTATION • >1/3rd of
Myometrium infiltrated with blood vessels-pathological
• Apparent loss of myometrial layer
• DOPPLER:Vessels in the space b/n basal plate & serosa
• TVS:Extent into bladder, pararectal & pelvic tissues
BLADDER VESSELS
SIGNIFICANCE:
• mode of delivery
• Perinatal management-By intervention radiology -uterine artery embolisation
• Goal to retain intact placenta—later sheds
SINGLE UMBILICAL ARTERY
• Umbilical cord cross section 2 Umb A
1 Umb V
Plane of transverse section of free floating loop of cord
Early diagnosis of SUA is difficult on gray scale
CDI- UAs seen around fetal bladder & cord insertion
NUCHAL CORD
• Seen as multiple echoes in nuchal region
• b/n 11-14w important to demonstrate cord in color to avoid interpretation of inc nuchal translucency
STRUCTURAL ANAMOLIES OF FETUS
OMPHALOCOELE
• Cord insertion at apex of herniated mass & course of umb vein thru defect- important
• To differentiate from gastroschisis
RENAL AGENESIS
• Oligohydramnios after 16w
• Lying down adrenal sign-discoid flattened in renal bed- mistaken
• Urachal cyst, cystic pelvic mass-mistaken for bladder
• Empty bladder may dec renal function
ROLE OF DOPPLER
• Renal arteries not seen esp on power dop
• Bladder localised by intraabd umb arteries
DIAPHRAGMATIC HERNIA
• To identify the herniated liver
• Difficult to distinguish echogenic lung lesion and herniated liver
• CDI- identifies portal vein & intrahepatic umb vein-liver
• Hydrops –compression of grave prognosis
HEART
L PORTAL V
LIVER
• Intrathoracic liver –influences prognosis
• LIVER UP-POOR PROGNOSIS
• Management differs
BRONCHOPULMONARY SEQUESTRATION:
• Abnormal lung tissue separate from rest of lung
• extralobar- congenital (intralobar-acquired-infection)
• CDI-systemic supply
• Sig- to differentiate pulmonary lesions CCAM,CDH,bronchial atresia,lobar emphysema -pulmonary blood supply-Management differs
Vessel can be occluded by USG guided laser fibre
Vessel from aorta
ANEURYSM OF VEIN OF GALEN
• single or multiple arteries/parenchymal AVM drain –single dilated midline fluid filled structure – in posterior 3rd ventricle region
• CDI- differentiates midline fluid structures- arachnoid cysts,cysts asso with agenesis of corpus callosum, porencephaly
• Heart failure
• Embolisation therapy
CDI-Confirms the diagnosis;pulsed dop-turbulent bidirectional flow, arterial flow
CONCLUSION
• Useful in screening high risk pregnancies & prevention can be given
• Diagnose conditions – differs management
• As adjunct to gray scale imaging
• Avoids unnecessary invasive procedures BASED ON SCIENTIFIC EVIDENCE OF ULTRASONICALLY
INDUCED BIOLOGICAL EFFECTS TO DATE, THERE IS NO REASON TO WITHHOLD SCANNING FOR ANY CLINICAL APPLICATION, INCLUDING ROUTINE SCANNING OF EVERY WOMAN DURING PREGNANCY-ECMUS-European committee for medical ultrasound safety