Volume Ultrasound Imagingof

Neonatal Hip Joints

declarations

declarations?

The project

The Project

The problem

• Late-presenting DDH a continuing problem

• Argument for population ultrasound screening has not been carried

• Logistic difficulty –

• technically demanding specialist examination delivered to every baby within short timeframe

The Plan

The Scan

• Matrix probe located over greater trochanter

• Press “Go”

• Volume image acquired in around 0.6 second

The Plan

The Study

The study

• 10 babies. 20 hips

• Conventional 2D diagnostic scan by senior ultrasonographer

• Volume Scan acquired by senior ultrasonographer

• Volume Scan acquired by untrained examiner

• Offline manipulation of 3D image - ‘standard plane’ identified

Results

• Volume scan successfully acquired in all hips by sonographer

• Alpha angles from 2D and volume images are equivalent

• Untrained examiner acquired volume images in 16 / 20 hips

Results

• Volume scan successfully acquired in all hips by sonographer

• Alpha angles from 2D and volume images are equivalent

• Untrained examiner acquired volume images in 16 / 20 hips

• No statistically significant difference between the alpha angles

Summary

• Fast

• Robust

• Shifts expertise from the acquisition to interpretation

Implications

• Remote area screening

• Automated image analysis – key to mass screening

• Better understanding of 3 dimensional morphology of the growing hip

Remote area screening

Image analysis

• Pattern-recognition software

• Assist examiner to find Standard Plane image

• The easier it is to obtain an accurate image, the closer we are to population screening.

3D morphology

Conclusion

• Available technology and expertise

• Immediate applications

• Population Screening a step closer

Average measurements of hip

55

60

65

70

75

80

0 1 2 3 4 5 6 7 8 9 10

Avg

. mea

sure

men

t

Anova: Single Factor

SUMMARY

Groups Count Sum Average Variance standard error

64.8 9 594.8 66.08889 6.551111 0.853171281

62.8 9 584.2 64.91111 15.36611 1.306654384

65.9 9 597 66.33333 37.405 2.03865424

52.2 9 602.4 66.93333 37.3 2.035790865

64.7 7 424.2 60.6 73.65667 3.243821967

70.4 5 299 59.8 38.71 2.782444968

ANOVA

Source of Variation SS df MS F P-value F crit

Between Groups 324.0489 5 64.80978 1.98722 0.100342228 2.437693

Within Groups 1369.758 42 32.61328

Total 1693.807 47

Comparison of modality

54

56

58

60

62

64

66

68

70

USS v's 3D USS v's Lupu 3D v's Lupu

t-Test: Paired Two Sample for Means

USS v's 3D USS v's Lupu 3D v's Lupu

USS 3D USS Lupu 3D Lupu

Mean 65.33 65.875 65 61.30714 66.10714 61.30714

Variance 9.935895 41.92724 9.096923 54.29456 38.25148 54.29456

Observations 20 20 14 14 14 14

standard error 0.704837 1.447882 0.806089 1.96931 1.652952 1.96931

Pearson Correlation 0.416029 -0.12004 -0.23891

Hypothesized Mean Difference 0 0 0

df 19 13 13

t Stat -0.41269 1.666722 1.679737

P(T<=t) one-tail 0.342228 0.059733 0.058433

t Critical one-tail 1.729133 1.770933 1.770933

P(T<=t) two-tail 0.684456 0.119467 0.116866

t Critical two-tail 2.093024 2.160369 2.160369

Aim

• Electronically steered 3D probe (Matrix probe) used to measure baby hip angles to derive standard plane 2D images

• Hip screening: no change in last 25 years, population scanning has not been effective enough

• Expand our knowledge of the developing hip

• Use

• USS 2D requires highly trained personnel

• Difficult to offer all patients in all regions timely screening

• Offer remote areas screening

Methods• Ethical approval and parental consent

• Acquired a 3D volume dataset

• Offline manipulation using MPR (multi planar reconstruction)• 3D scanner used as an MPR to gain 2D

• Prospective pilot study

• Angles measured by two clinicians:• Senior sonographer: 2D and 3D scan measurements• Untrained person (blinded): 3D scan measurements

• 4 clinics

• Data analysis:

Results

• 10 patients

• 20 hips

• M:F hips 6:14

• Age: 36.6 days (7-48 days)

• Sonographer: 2D angles vs 3D angles

• Sonographer vs Untrained person 3D angles