Basic Training

ISUOG Basic TrainingQuality Control Processes for Operators &

Programmes

Basic Training

Learning objectives:

At the end of this lecture you will be able to:

• List the quality control processes that are required to ensure ultrasound operators perform obstetric and/or gynaecological examinations safely and to the required standard

• List the quality control processes that are required to ensure obstetric and/or gynaecological ultrasound programmes are delivered safely and to the required standard

Basic Training

Key questions

1. What are quality control processes?

2. What QC processes should be in place to ensure a

high quality ultrasound service is being delivered?

3. What contribution does the ultrasound trainee and

his/her mentor make to the QC process?

Basic Training

Primum non nocereHippocrates ‘Of the Epidemics’

400BC

Basic Training

Establishing QA at a program level The audit cycle

What is the

program aiming to

achieve?

Audit

performance

Define SOP to

effect this aim

Re-audit

performance

Improve SOP

to effect

change

What standard should

be measured?

Basic Training

Defining local standards of care

Basic Training

“The Register”, 14 Sept 2001

Basic Training

Providing QA for Down Syndrome screening

Aims of the program:• All women should be offered a screening test

• This should be available in a timely fashion

• Results should be calculated and reported in a timely fashion

• The efficacy of the test should:

– Limit the FPR (5%)

– Detect 90% of cases

Basic Training

Nuchal translucency & Trisomy 21

Crown-rump length (mm)

45 55 65 75 85

NT (mm)

0

2

4

6

8

Trisomy 21

Basic Training

How is NT used to adjust risk?- Have a clear understanding of how the test works

NT (MoM) value

531 2 40.5

Euploid

Trisomy 21

Likelihood ratio

Basic Training

The concept of standardised measurement

• Gestation 11+0 to 13+6 weeks

• CRL 45-84 mm

• Mid-sagittal view

• Large image

• Neutral position

• Away from amnion

• Maximum nuchal lucency

• Callipers ‘on-to-on’

Basic Training

Basic Training

Assessing NT distributions- Auditing operator measurements

0.0

1.0

2.0

3.0

4.0

5.0

6.0

45 50 55 60 65 70 75 80 85

Crown- rump length (mm)

Nu

cha

l tr

an

slu

cen

cy (

mm

)

Basic Training

0

10

20

30

40

50

60

70

80

90

100

2002 2003 2004 2005 2006 2007 2008

Nisbet et al. ANZJOG 2010

Assessing NT distributions- All Australian operators

Basic Training

51%

49%

Spread = 1

Crown-rump length (mm)

40 45 50 55 60 65 70 75 80 85 90

Nu

ch

al T

ran

slu

ce

ncy (m

m)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Pass: Spread >0.7 & <1.3

Crown-rump length (mm)

40 45 50 55 60 65 70 75 80 85 90N

uch

al T

ran

slu

ce

ncy (m

m)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

51%

49%

Spread = 1.85

Fail: more than 1.3

51%

49%

Crown-rump length (mm)

40 45 50 55 60 65 70 75 80 85 90

Nu

ch

al T

ran

slu

ce

ncy (m

m)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Spread = 0.43

Fail: less than 0.7

Wright et al. DQASS 2010

Assessing NT distributions- Current FMF technique

Basic Training

Effect of under measuring or over measuring NT

comb

NT / MAcomb

NT / MA

Kagan et al. UOG 2009

Basic Training

What is the effect of bias?Bias (mm) FPR DR

-0.4 1.8% 79%

-0.3 1.9% 80%

-0.2 2.0% 82%

-0.1 2.2% 83%

0 2.6% 85%

0.1 3.1% 86%

0.2 3.7% 87%

0.3 4.6% 88%

0.4 5.7% 90%

Basic Training

Basic Training

1 2 3 4 5 6 7

n

0

1

2

3

4

5

Groups of 20 scans

Failed exams per group of 20 scans

120 scans

Nasal bone:

Importance of operator experience

Basic Training

Absent NB

NormalTrisomy 21 LR

Total67% 2.8% 24

Caucasian 66% 2.5% 27

African 78% 10.4% 7

Asian 73% 6.8% 11

CRL 45-54 79% 4.6% 17

CRL 55-64 66% 3.9% 17

CRL 65-84 64% 1.4% 47

NT <95th61% 1.8% 34

95th – 4.4mm 65% 3.7% 18

>4.5 mm 52% 11.8% 4Cicero et al. 2003

Quality assurance of subjective measures

Basic Training

FMF UK: Prospective screening study at 11-13 wks

Total: 64,647; PE: 1,482 (2.3%) Detection rate for FPR 10%%

0

10

20

30

40

50

60

70

80

90

100

PE: Gestation at delivery (wks)<30 <32 <34 <36 <38 All

56%

37%

Improved DR 30%86%

42%

81% 79%

68%

57%

0.8 0.9 1.0 1.1

Weight 70 kg

90 kg110 kg

11 wks

12 wks

13 wks

Odds ratio (95% CI)

White

Black

Screening for ePET: Uterine Artery Pulsatility Index

Basic Training

Ridding et al. FDT 2014

Screening for ePET: Uterine Artery Pulsatility

Index

Basic Training

0.92

0.13

Overall Median:

Overall Log10 SD:

RPA # 7

Pulsatility Index Quality Assurance Assessment

Sonographer :

Date of Assessment: 25-Apr-13

2011-04-21

22-Nov-10

Period Start:

Period End:

Lowest Pulsatility Index MoM

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

2.2

2.4

40 45 50 55 60 65 70 75 80 85 90

Low

est

Pu

lsat

ility

In

de

x (P

I)

Crown Rump Length (CRL) in mm

M

95th Percentile

5th Percentile

-20

-15

-10

-5

0

5

10

15

0 50 100 150 200 250

CU

SUM

Pulsatility Index Measurements (n)

1.1 MoM 1.05 MoM 0.95 MoM 0.9 MoM

0.06

0.07

0.08

0.09

0.10

0.11

0.12

0.13

0.14

0.15

0.16

0.17

0.18

0.85 0.90 0.95 1.00 1.05 1.10 1.15

Dis

ple

rsio

n

(Lo

g10

Lo

we

st P

uls

atili

ty In

de

x M

oM

)

Central Tendency (Median Pulsatility Index MoM)

DSSahota/ AMcLennan 18/3/2013

Screening for ePET: Uterine Artery Pulsatility Index

Basic TrainingBasic Training

Basic Training

National audit of screening performance

• Collation of outcome data

• Conceal identity of centres

• Define median

• Include confidence intervals

Bull; Lancet 1999

Basic Training

Assessing the fetal heart:

sequential exam / fixed views

http://www.biomecsrl.it/evaluation-of-the-fetal-heart-using-fetal-echocardiography/

Basic Training

J Ultrasound Med 2016; 35:679-681

Basic Training

Methods of assessing quality

• Qualitative

• Quantitative

• Single Operator

• Local group

• National comparisons

• Training implications

• Frequency / Automation of process

Basic Training

FAS assessment (SPSZN criteria)

Upload images: 5 cases | 25 images

Examine Based on best of three cases

Criteria: Image magnification

Correct plane

Correct calliper placement

Score: 56 points: excellent

50-55 points: good

42-50 points: pass

<42 points: failUrsem et al. JUM 2017

Basic Training

Results: QA 20 week anomaly scan audit

85 ultrasonographers:

Qualitative audit anomaly scan

Perfect Good Pass Failed

N sonographers 2 (2.3%) 46 (54%) 25 (29%) 12 (14%)

Ursem et al. JUM 2017

Basic Training

Conclusion: FAS audit

• 1. Fetal structures

– Best: Bladder, umbilical cord vessels, femur

• 2. Fetal structures

– Least: Sagittal profile, placenta –cervix, diaphragm

• 3. Magnification

– Best: HC

– Least: 4-chamber view

• 4. Callipers

– Best: TCD (97% correct)

– Least: measurement renal pelvis (66% R & 61 % L)

Ursem et al. JUM 2017

Basic Training

“Study the past if you

would define the future.”

Confucius 551 – 479 BC

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