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INTRODUCTION: The ramifications of preterm birth on society and the role of cervical length in identifying cervical insufficiency are well known. The main goal of this work was to apply shear wave elastography to the maternal cervix to assess the stiffness of the cervix and identify cervical insufficiency, using a transabdominal ultrasound approach. METHODS: Measurements of shear wave speed were obtained using a transabdominal ultrasound approach, at the anterior and posterior portions of the internal and external cervical os on 504 participants. A total of 455 participants were contacted following the expected date of birth of the fetus and birth details were obtained. RESULTS: The anterior and posterior portions of the internal os showed a significant correlation between shear wave speed and time until delivery of the fetus for women who gave birth spontaneously, with R (2) Linear being 0.024 (P = 0.012) and 0.017 (P = 0.05) respectively, and these correlations increased for the group of participants that were scanned between the 18th and end of the 20th week of pregnancy to R (2) Linear = 0.043 (P = 0.001) and 0.021 (P = 0.040) respectively. A ratio of internal os/external os anteriorly also showed a correlation of R (2) Linear = 0.030 (P = 0.009). CONCLUSION: A transabdominal ultrasound technique has identified a reduction in shear wave speeds at the internal os in the mid‐trimester, in women who had a subsequent preterm birth.

This work aimed to compare the use of shear wave elastography on the maternal cervix with transvaginal (TV) and transabdominal (TA) ultrasound approaches to assess differences in shear wave speeds (SWSs) obtained for possible clinical use.In both TV and TA ultrasound approaches, SWS measurements were attempted at the anterior and posterior portions of the internal and external cervical os on 38 gravid participants.A larger number of SWS measurements were obtained at the anterior portion of the cervix by both approaches. The numbers of reliable measurements of the SWS obtained at the anterior and posterior portions of the internal and external os were 99, 65, 103, and 77 in the TA approach and 93, 53, 110, and 87 in the TV approach, respectively. The mean difference in -the SWS obtained between the TV and TA ultrasound approaches was statistically significant at the anterior and posterior portions of the internal os, with differences of 0.67 and 0.52 m/s (P .05). Differences were not significant at the external os both anteriorly and posteriorly, with differences of 0.15 and - 0.07 m/s (P .05).Both TA and TV ultrasound approaches may be used to obtain SWSs in the maternal cervix. This study has shown that SWSs obtained by each approach need to be considered independently, as the TV approach produced significantly greater SWSs at the internal os compared to the TA approach, but the values were similar at the external os.

INTRODUCTION: Reduced cervical length as seen on transvaginal ultrasound is a strong indicator of spontaneous preterm birth in the high‐risk population. In low‐risk women the appropriate method to assess this risk is still debatable. Ultrasound elastography has been used to assess cervical strength. This research aimed to assess the accuracy of shear wave speeds (SWS) obtained deep to echo free fluid‐filled structures, and the use of two‐dimensional shear wave on the maternal cervix using a transabdominal ultrasound approach. METHOD: Agreement of SWS measurements obtained through fluid and directly onto an ultrasound phantom was assessed for accuracy. Speed measurements were obtained in the anterior and posterior portions of the internal and external cervical os on 50 gravid participants in the mid‐trimester of pregnancy. RESULTS: No difference in SWS was obtained in the phantom with either direct contact or through the saline water‐bath (P > 0.05). In 50 participants, measurements were obtainable at the external os anterior and posterior in 49 and 38 participants, respectively, and in 47 and 42 participants for internal os anterior and posterior. The mean speed obtained at the external os anterior and posterior was 2.01 ± 0.51 and 2.38 ± 0.47 m/s, respectively, and at the internal os anterior and posterior, 2.49 ± 0.50 and 2.58 ± 0.41 m/s. CONCLUSION: Shear wave speed measurements can be obtained in the maternal cervix using a transabdominal approach with a moderately full maternal bladder in most patients, with a larger number of shear wave measurements obtained in the anterior cervix compared to posterior.

Ultrasound (US) shear wave technology providers have either point shear wave elastography (SWE) or 2-dimensional SWE available on their US systems. With 2-dimensional SWE, larger regions of interest can be interrogated, with both the main acoustic radiation pulses and the resultant shear waves potentially being affected by US artifacts. Some providers assist the operator with elastographic maps indicating the reliability or precision of the shear wave propagation. This Technical Innovation explores the importance of the consideration of the precision maps and standard deviation output available on some devices and the implications for conversion of shear wave speed to pressure.

Introduction The incidence of preterm birth has continued to rise in most countries in the world during the last decade. There are many clinical risk factors that increase the risk of preterm birth. It has been shown that a sonographically shortened cervical length is a strong indicator of subsequent preterm birth in pregnancy. Background It has been established that women at an increased risk of preterm birth should have the cervical length recorded using a transvaginal approach. The sensitivity of a shortened cervical length to predict preterm birth is higher in women with a previous preterm birth, with reduced sensitivity in low risk women. The maternal cervix may be assessed using transabdominal, transperineal and transvaginal ultrasound approaches. This article discusses the available research into the use of these differing techniques and current guidelines for measuring maternal cervical length. Summary Measuring the maternal cervical length has become an important part of the mid trimester morphology examination. The appropriate technique to screen the cervical length in women at low risk of preterm birth is still debatable throughout the wider obstetric and ultrasound communities.

Introduction: The appropriate ultrasound technique to assess the maternal cervical length in women at low risk of preterm birth is yet to be established. This study aimed to determine the accuracy of different ultrasound approaches for measuring the maternal cervix in patients between 17 and 22 weeks gestation. Methods: The prospective study recruited 50 patients who were at a low risk of preterm birth. All measurements were acquired by one operator who was blind to the measurements being acquired in all approaches. The cervical length was registered using the transabdominal approach with a full and empty bladder, the transperineal approach and the transvaginal. The transvaginal approach was used as the reference measurement. Results: The transabdominal full bladder, post void, transperineal and transvaginal measurements were obtainable in 50, 49, 45 and 50 participants respectively. The transabdominal post void measurements showed a bias of −0.06 mm from perfect agreement with transvaginal. The transperineal measurements showed a bias of −0.16 mm. The transabdominal full bladder measurements were positively biased by 14.05 mm (p < 0.05). All transabdominal post void cervical lengths of 30 mm or greater registered a transvaginal cervical length greater than 25 mm in this study. Conclusion: The cervix should not be assessed in the transabdominal approach with a full maternal bladder due to overestimation of cervical length. Transvaginal cervical length can be reproduced accurately by post void transabdominal cervical length in most cases. Transperineal cervical length should be considered if transvaginal cervical length is contraindicated.

Introduction Ultrasound strain elastography may be able to identify women presenting with a normal cervical length, who are at an increased risk of preterm birth due to softening of the cervix.1,2 Shear wave elastography (SWE) uses acoustic radiation force impluse to produce shear waves.3 It is expected that SWE will produce a more objective and reproducible mechanical evaluation of the cervix than strain elastography.4,5 There is promise for the use of SWE on the maternal cervix to assess cervical strength.6,7 Objectives The primary aim of this study is to assess if reduced cervical strength and imminent cervical insufficiency can be identified by shear wave elastography. Methods This is a cross-sectional study of patients presenting for their mid-trimester ultrasound examination. Ethics approval was from the Curtin University Human Research Ethics Committee and SKG Radiology Clinical Standards Committee. All data has been collected at sites of SKG Radiology in Perth, Western Australia. Informed consent was required to participate. Imaging Methodology The transabdominal approach utilizes a 6C1 curvilinear transducer and a partially full maternal bladder.8 The transvaginal approach utilises an endocavity transducer with an empty maternal bladder. Shear wave elastography speed measurements are acquired at the external and internal os anterior and posterior portions.8,9 Results Data assessment currently includes 156 of the 473 participants enrolled to date. Participants were from varying ethnicity with a mean age of 29 years (18-33 years), mean gestation of 2(0-5), mean number of births 1(0-5), 102 cases of spontaneous labour, 38 of induced labour and 16 planned c-section. Mean shear wave speeds and number of cases at varying gestation for patients going into spontaneous labour are as follows: Conclusion Early results indicate the shear wave speeds may be reduced in patients with a subsequent preterm birth. Larger numbers will need to be assessed to substantiate these findings.

Introduction Ultrasound shear wave elastography has the potential to assess the strength of the maternal cervix for signs of insufficiency.1, 2 The reliability of shear wave elastography in biological tissues can be affected by numerous ultrasound artifacts and prestress of tissues in the region of interest can also affect the shear wave speed. This study investigates the use of the transvaginal ultrasound approach to obtain shear wave speeds in the uterine cervix with the aim of identifying factors that affect shear wave speed and transmission. Objectives The primary aim of this study is to identify biological and technical confounders for the use of two dimensional shear wave elasography applied to the uterine cervix. The goal was to identify confounders, and develop shear wave technique in the low risk non-gravid population. Methods Sixty nine non-gravid participants with varying medical history and ethnicity consented to be part of this research. Inter-operator testing was performed on fifteen participants.Imaging methodology As an adjunct to the normal imaging examination extra imaging of cervical speed measurements using two dimensional shear wave elastography was performed.The transvaginal approach utilises an endocavity transducer with an empty maternal bladder. Shear wave elastography speed measurements are acquired at the external and internal os anterior and posterior portions. Results Reliable measurements were obtained at the external os and internal os, anteriorly and posteriorly, in 63, 55, 55 and 26 patients respectively. The mean speed obtained at the external os, anteriorly and posteriorly, was 2.52 ± 0.49 m/s and 2.87 ± 0.63 m/s respectively, and at the internal os anteriorly and posteriorly, 3.29 ± 0.79 m/s and 4.10 ± 1.11 m/s respectively. The difference in speed between all regions was statistically significant] (p Interoperator testing The intraclass correlation coefficient obtained at the regions of the cervix was as follows - external os anterior 0.83 (CI 0.45 – 0.95), external os posterior 0.69 (CI 0.07-0.90), internal os anterior 0.92 (CI 0.76 – 0.97), internal os posterior 0.90 (CI 0.37-0.98) Conclusion Biological factors and ultrasound induced artifacts appear to affect the transmission of the elastographic main pulse, with cervical position appearing to affect shear wave production. Reliable shear wave propagation can be achieved in the anterior cervix in most patients.

Introduction Breast elastography improves the diagnostic performance of B mode ultrasound to characterise lesions. There are many methods to use shear wave values to assess breast lesions. The aim was to assess elastography of the breast to characterise breast lesions. Assessment of the breast lesion including histological profile, tumour grade and molecular subtype. Method A prospective study, the patients were self selected into the study. The patients were routine visits to the ultrasound department and any lesions were assessed with measurements, colour doppler, vocal fremitis and elastography. The treatment pathway was not altered by this study. If they required a biopsy and were in agreeance for the pathology results and ultrasound results to be used, they were consented into the study. The lesions had the elastography value taken in radial and antiradial images. Results The elastography values in mean and maximum showed a statistically significant result. Malignant lesions had higher quantitative values then benign breast lesions. The elastography ratio of lesion:fat was statistically higher in malignant lesions. The luminal results showed that ER- and PR-negative breast cancers have a higher elastography maximum than ER- and PR-positive breast cancer. HER-2 positive and triple-negative breast cancers have higher ratios compared to ER-positive breast cancers. Conclusion The preliminary results show that elastography may be a complementary technique to conventional sonography to help characterise breast lesions. Take home message - Breast elastography improves the diagnostic performance of B mode ultrasound to characterise lesions including histological profile, tumour grade and molecular subtype.