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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