Reference Cap of Poly Vinyl Alcohol for Quantitative Elastography of the Human Uterine Cervix

TY - CONF

T1 - Reference Cap of Poly Vinyl Alcohol for Quantitative Elastography of the Human Uterine Cervix

AU - Leonhard, Anne Katrine

AU - Sandager, Puk

AU - Rasmussen, Christina Kjærgaard

AU - Hee, Lene

AU - Uldbjerg, Niels

PY - 2016/9/6

Y1 - 2016/9/6

N2 - CONTROL ID: 2522419ABSTRACT FINAL ID: EP22.04TITLE: Reference Cap of Poly Vinyl Alcohol for Quantitative Elastography of the Human Uterine CervixAUTHORS (FIRST NAME, LAST NAME): Anne Katrine Leonhard1, Puk Sandager1, Christina K. Rasmussen1, Hee Lene1, Niels Uldbjerg1INSTITUTIONS (ALL): 1. Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus N, Denmark. ABSTRACT BODY: Objectives: To develop a reference cap for the ultrasound probe that allows for quantitative elastography of the cervical uterine tissue with preservation of a good ultrasonic image. Further to perform inter-intra observer evaluations.Methods: Two types of reference caps were developed. Cap 1 made of Poly Vinyl Alcohol [PVA] with the Young’s modulus [E] of 0.09 N/mm2. Cap 2 made of silicone and oil with the Young’s modulus of 0.4 N/mm2. Elastography was conducted with the caps applied to a 2D transvaginal ultrasound transducer on seven non-pregnant and six full-term pregnant women. Strain ratio between selected Region of Interest was calculated by the software. The approximated E of the anterior cervical lip was calculated by multiplying strain ratio by the E of the reference cap. To assess the inter-intra observer variability, two observers performed elastography on four phantoms with different E using both reference caps.Results: Reference Cap 1 had an improved fit for the ultrasound probe and imaging of optimal quality compared to reference Cap 2. The results obtained with the two different caps were consistent. The approximated E of the cervical tissue in non-pregnant women was 0.25 N/mm2 (0.09-0.72) using Cap 1 vs. 0.18 (0.8-0.38) using Cap 2, p= 0.74 (Wilcoxon signed-rank test). The approximated E in the full-term pregnant women was 0.02 (0.01-0.04) using Cap 1 vs 0.02 (0.01-0.03) using Cap 2, p= 0.45 (Wilcoxon signed-rank test). The stiffness of the tissue was significantly different between non-pregnant and full-term pregnant women, p= 0.003 (Wilcoxon rank-sum test). Inter-observer and intra-observer limits-of-agreements were 55% and 23% respectively.Conclusions: The reference cap of PVA constitutes a promising tool for quantitative elastography of the anterior cervical lip, with an ultrasonic image of good quality and ability to significantly distinguish between cervical mechanical properties.

AB - CONTROL ID: 2522419ABSTRACT FINAL ID: EP22.04TITLE: Reference Cap of Poly Vinyl Alcohol for Quantitative Elastography of the Human Uterine CervixAUTHORS (FIRST NAME, LAST NAME): Anne Katrine Leonhard1, Puk Sandager1, Christina K. Rasmussen1, Hee Lene1, Niels Uldbjerg1INSTITUTIONS (ALL): 1. Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus N, Denmark. ABSTRACT BODY: Objectives: To develop a reference cap for the ultrasound probe that allows for quantitative elastography of the cervical uterine tissue with preservation of a good ultrasonic image. Further to perform inter-intra observer evaluations.Methods: Two types of reference caps were developed. Cap 1 made of Poly Vinyl Alcohol [PVA] with the Young’s modulus [E] of 0.09 N/mm2. Cap 2 made of silicone and oil with the Young’s modulus of 0.4 N/mm2. Elastography was conducted with the caps applied to a 2D transvaginal ultrasound transducer on seven non-pregnant and six full-term pregnant women. Strain ratio between selected Region of Interest was calculated by the software. The approximated E of the anterior cervical lip was calculated by multiplying strain ratio by the E of the reference cap. To assess the inter-intra observer variability, two observers performed elastography on four phantoms with different E using both reference caps.Results: Reference Cap 1 had an improved fit for the ultrasound probe and imaging of optimal quality compared to reference Cap 2. The results obtained with the two different caps were consistent. The approximated E of the cervical tissue in non-pregnant women was 0.25 N/mm2 (0.09-0.72) using Cap 1 vs. 0.18 (0.8-0.38) using Cap 2, p= 0.74 (Wilcoxon signed-rank test). The approximated E in the full-term pregnant women was 0.02 (0.01-0.04) using Cap 1 vs 0.02 (0.01-0.03) using Cap 2, p= 0.45 (Wilcoxon signed-rank test). The stiffness of the tissue was significantly different between non-pregnant and full-term pregnant women, p= 0.003 (Wilcoxon rank-sum test). Inter-observer and intra-observer limits-of-agreements were 55% and 23% respectively.Conclusions: The reference cap of PVA constitutes a promising tool for quantitative elastography of the anterior cervical lip, with an ultrasonic image of good quality and ability to significantly distinguish between cervical mechanical properties.

M3 - Poster

T2 - 26th World Congress on Ultrasound in Obstetrics and Gynecology

Y2 - 25 September 2016 through 28 September 2016

ER -