Post on 12-Dec-2015
transcript
Rationale for the Scan Menu
to provide consistency in the scan procedure
to specify measuring techniques
to define the range of anatomical structures to be assessed
to provide the minimum assessment that should be undertaken
The NHS FASP Anomaly Screening Service
population pre-screened & low risk for Down’s (or declined screening)
examination focused towards optimising perinatal management pathways
addresses 11 selected conditions
Includes target detection rates
incorporates annual audit
Key Ultrasound Features
gestational age 18+0 – 20+6 weeks - change from ~20 weeks
- no need to recall if scanned ‘early’
appointment time 30 minutes - times currently vary from 10-30 mins, 61% 20mins
- underpins clinical importance of examination
- supports extension of scanning time to incorporate additional views & measurements
Key Ultrasound Features
six specified images recorded & stored- allows audit of examination’s quantitative & qualitative components at local level
- valuable tool for confirming quality
single further scan only, at 23 weeks if first assessment incomplete- when quality compromised by ↑BMI,fibroids, abdominal scarring, fetal position ‘allows’ an incomplete screen
Key Ultrasound Features
range of normal variants extended to include previous ‘markers’, with exception of ↑nuchal fold (Tri 21)
outflow tracts & coronal lips included
fingers, toes, carrying angles, profile not screened
normal renal pelvis increases to 7.0mm
Eleven Auditable Conditions
Condition Detection rate (%)
Anencephaly 98
Open spina bifida 90
Cleft lip 75
Diaphragmatic hernia 60
Gastroschisis 98
Exomphalos 80
Serious cardiac abnormalities 50
Bilateral renal agenesis 84
Lethal skeletal dysplasia 60
Edward’s syndrome (Trisomy 18) 95
Patau’s syndrome (Trisomy 13) 95
Scan Menu – ‘tick list’
Area Views
1, 2 Head and neck HC (Chitty) + suboccipito-bregmatic
3 Face Lips coronal
4-7 Chest 4ch, both outflow tracts, lungs
8-12 Abdomen AC, cord insertion, kidneys, bladder
13-14 Spine Sagittal & transverse, skin covering
15-19 Limbs FL, metacarpals & metatarsals x 2
20-21 Uterine cavity Amniotic fluid, placenta position noted
Scan Menu – fetal biometry
HCChitty et alBr J Obstet Gynaecol 1994101:35-43
ACChitty et alBr J Obstet Gynaecol 1994101:125-131
Scan Menu – fetal biometry
FLChitty et alBr J Obstet Gynaecol 1994101:132-135
small measurements compared to dating scan
(significantly less than 5th centile on national charts)
- refer
Scan Menu – other measurements
ISUOG Guideline. Ultrasound Obstet Gynecol 2007;29:109-116 Goldstein et al. Am J Obstet Gynecol 1987:156:1065-9
atrium >10.0mm – refer
nuchal fold >6.0mm - refer
Scan Menu – tick list & referral
echogenic bowel (with density equivalent to bone) – refer
renal pelvic dilatation(AP measurement > 7.0mm) - refer
Scan Menu – tick list limbs
femur – length (one leg only)
hands – metacarpals (right & left)
feet – metatarsals (right & left)
Scan Menu – six images
measured HC & atrium
1 2
measured TCD (+ NF))
3
measured AC
4
measured FL
5
sagittal spine including sacrum & skin covering
6
coronal lips & nasal tip
Conclusions
implementation of national programme should shift emphasis of routine anomaly scan from ‘markers’ to ‘requiring referral’ and from aneuploidy to perinatal management.
adopting scan menu should extend diagnostic capability of anomaly scan rather than diminish it
the scan menu provides an exciting challenge for all health professionals involved along pathway & an opportunity for many sonographers to develop & extend their range of skills