Federica Sammali

Effects of vibration-induced fatigue on the H-reflex

Vibration exercise (VE) has been suggested as an effective training for improving muscle strength and coordination. However, the underlying physiological adaptation processes are not yet fully understood, limiting the development of safe and effective exercise protocols. To better understand the neuromuscular responses elicited by VE, we aimed at investigating the acute effects of superimposed vibration on the Hoffmann reflex (H-reflex), measured after fatiguing exercise. Twenty-five volunteers performed four isometric contractions of the right Flexor Carpi Radialis (FCR) with baseline load at 80% of their maximal voluntary contraction (MVC), both with no vibration and with superimposed vibration at 15, 30, and 45 Hz. Fatigue was estimated by MVC test and estimation of electromyographic spectral compression. H-reflex suppression was estimated as the relative decrease after exercise. Our results show that fatiguing exercise determined a decrease in H-reflex amplitude compared to rest condition while vibration determined a lower H-reflex suppression as compared to no vibration. The superimposition of 30-Hz vibration determined the largest acute reduction in force generating capacity (36 N, p < 0.05) and the lowest H-reflex suppression (20%, p < 0.05). These results suggest VE to be particularly suitable in rehabilitation programs for rapid restoration of muscle form and function after immobilization periods.

Analysis of uterine activity in nonpregnant women by electrohysterography: A feasibility study

With an overall effectiveness below 30%, in vitro fertilization (IVF) is in urgent need for improvements, especially in view of the increasing trend in postponing childbirth in developed societies. Abnormal contraction of the uterus may underlie impaired fertility and unsuccessful IVF. However, currently, there is no method for quantitative assessment of uterine activity and guidance of dedicated intervention. Analysis of the electrohysterogram (EHG) has been extensively used in pregnancy for quantifying uterine contractions. In this paper, we evaluate, for the first time, the use of EHG analysis for characterizing contractions in women in two different phases of the menstrual cycle, when the uterus is expected to be active and quiescent. In this preliminary study, by estimating the time evolution of the EHG signal energy, we derive the contraction frequency, fC, as a possible marker for quantifying the activity of the uterus and discriminate between active and quiescent status. Ultrasound (US) image sequences are simultaneously recorded and visually analyzed for a qualitative validation of the results. The high correlation (0.91) between fC obtained by EHG and US analysis and the measured different values of fC in the two phases motivate further research to confirm the value of EHG analysis for contraction quantification in nonpregnant women.

OC22.04: Ultrasound-based strain mapping for contraction frequency in the non-pregnant uterus

Methods: A retrospective cohort study of women who underwent a laparoscopic myomectomy at University College London Hospital between December 2014 and November 2017 was carried out. Ultrasound images and operation notes were reviewed. The size and minimum distance of the fibroid from the endometrial cavity in a 2-dimensional longitudinal plane were determined from ultrasound images (negative distance was scored when the fibroid protruded into the cavity). Endometrial cavity breaches at the time of surgery were identified from the operation notes. Women who did not have a preoperative ultrasound and those who had more than two fibroids removed were excluded. Results: 74 women who had laparoscopic myomectomy and a preoperative ultrasound were identified. The median age was 36.0 (IQR 33 – 39.8) and the median fibroid diameter was 68.2mm (IQR 47.7 – 80.6). 10/74 (13.5%, 95% CI 5.7 – 21.3) had a breach of the endometrial cavity. Women who suffered a breach had a fibroid that was close to or within the endometrial cavity (distance from cavity -9.9 vs. 8.9mm, p=0.001, degree of protrusion 17% vs. 0.0% and intracavitary surface area 1463mm2 vs. 0.0). A logistic regression model with cavity breach as independent variable and ultrasonic variables as predictors selected minimum distance from cavity as the best predictor of cavity breach (OR 0.79, 95% CI 0.73 – 0.92). 10/19 (52.6%, 95% CI 30.2 – 15.1) of women with a submucosal component to their fibroid did not have a cavity breach. No women with a fibroid further than 5.2mm from the cavity had a breach identified at surgery. Conclusions: Identifying patients who are at increased risk of endometrial cavity breach based on ultrasound facilitates appropriate preoperative counselling regarding the risk of intrauterine adhesions and the need for Caesarean section.

Feasibility of Transabdominal Electrohysterography for Analysis of Uterine Activity in Nonpregnant Women

Purpose: Uterine activity plays a key role in reproduction, and altered patterns of uterine contractility have been associated with important physiopathological conditions, such as subfertility, dysmenorrhea, and endometriosis. However, there is currently no method to objectively quantify uterine contractility outside pregnancy without interfering with the spontaneous contraction pattern. Transabdominal electrohysterography has great potential as a clinical tool to characterize noninvasively uterine activity, but results of this technique in nonpregnant women are poorly documented. The purpose of this study is to investigate the feasibility of transabdominal electrohysterography in nonpregnant women. Methods: Longitudinal measurements were performed on 22 healthy women in 4 representative phases of the menstrual cycle. Twelve electrohysterogram-based indicators previously validated in pregnancy have been estimated and compared in the 4 phases of the cycle. Using the Tukey honest significance test, significant differences were defined for P values below .05. Results: Half of the selected electrohysterogram-based indicators showed significant differences between menses and at least 1 of the other 3 phases, that is the luteal phase. Conclusion: Our results suggest transabdominal electrohysterography to be feasible for analysis of uterine activity in nonpregnant women. Due to the lack of a golden standard, this feasibility study is indirectly validated based on physiological observations. However, these promising results motivate further research aiming at evaluating electrohysterography as a method to improve understanding and management of dysfunctions (possibly) related to altered uterine contractility, such as infertility, endometriosis, and dysmenorrhea.

Ex-vivo phantom for evaluation of ultrasound speckle tracking in the uterus

Uterine peristaltic movement plays an important role for the success of embryo implantation. This is especially relevant in the context of assisted reproductive technology. Unfortunately, the lack of tools for quantitative analysis limits our understanding of the uterine contractility. Recently, strain analysis by ultrasound speckle tracking has gained attention for the assessment of the uterine contractility. However, the absence of a ground truth hampers the optimization of this technology. This work proposes the first phantom based on a human ex-vivo uterus able to generate controlled tissue motion by sinusoidal (0,05 Hz), linear displacement of a syringe piston, injecting 3-mL water through a balloon catheter inserted into the uterine cavity. This way, controlled, realistic peristaltic movement was generated while maintaining original speckle characteristics. Uterine motion analysis was obtained by US speckle tracking on acquired B-mode imaging data using two block matching techniques, normalized cross-correlation (NCC) and sum of absolute differences (SAD). The proposed phantom based on a human ex-vivo uterus showed its value to assess US speckle tracking techniques providing a realistic ground truth that is fully controlled.

P26.02: Objective assessment of uterine peristalsis outside pregnancy by high-order texture analysis of ultrasound images

the mean uterine wall thickness was 8.05 (SD 2.29) mm and 8.05 (SD 2.24); the mean interostial line was 37.99 (SD 8.33) and 38.00 (SD 8.39); the mean internal midline indentation was 17.06 (SD 9.76) mm and 17.10 (SD 9.80); and the mean external indentation was 7.20 (SD 5.37) and 7.07 (SD 5.21).The Intra-class correlation coefficients were 0.99 for the interostial line, uterine wall thickness, and the external indentation and 1 for internal midline indentation (p<0.05). Conclusions: Three-dimensional ultrasound uterine measurements described in the ESHRE-ESGE consensus and the Thessaloniki ESHRE-ESGE consensus showed a good level of inter-observer reproducibility.

EP31.03: Ultrasound-based strain mapping for quantitative characterisation of uterine activity outside pregnancy

Objectives: To compare transvaginal ultrasound with water contrast (TVUWC) with computed tomography-based virtual colonoscopy (CTC) in the detection of bowel stenosis grade in patients affected by deep infiltrating endometriosis (DIE). Methods: IDEA criteria were used to assess DIE ultrasonographic stadiation. Patients suspected to have a rectosigmoidal localisation at the TVU (performed with a GE Voluson E8) underwent TVUWC and CTC to estimate and quantify bowel stenosis grade by percentage. Both the examination were performed and reported by high qualified sonographers and radiologists, experienced in instrumental detection and stadiation of DIE. Results: 28 patients were recruited. The two techniques showed a good concordance: CTC detected 8 (34,8%) bowel stenosis > 50%; 7 (30.4%) of them were either detected by the TVUWC examination. Stenosis < 50% was reported in 15 (65.2%) and 16 (69.6%) cases by CTC and TVUWC respectively, with a diagnostic accuracy of 85.7%. Related to CTC, TVUWC showed a sensitivity of 75% and a specificity of 90%; positive predictive value was 75% while the negative one was 90%. Conclusions: Our preliminary data suggest a strong concordance between TVUWC and CTC in the detection and estimation of bowel stenosis in patient affected by recto-sigmoidal DIE. We expected to apply TVUWC as a valid first line technique, alternative to CTC in addressing patient to surgery, in consideration of its simpler execution, lower costs and risks for the patient. More data are worth to be studied related to the histological data (gold standard).

Feasibility of uterine speckle tracking for improved embryo implantation

Infertility problems are involving an increasing number of women, also due to the trend of postponing conception. In-vitro fertilization represents nowadays the most advanced technology to approach infertility problems, but it still shows a low success rate of about 30%. A possible cause may reside in the uterine movement during embryo transfer, possibly hampering successful implantation. Unfortunately, no objective tools are nowadays available for the assessment of uterine movement. With the aim of filling this gap, here we present the first method for quantitative analysis of uterine movement. Being widespread accessible, ultrasound imaging is employed for the analysis. In particular, a speckle-tracking algorithm has been implemented that is based on block matching by normalized cross correlation. Wiener deconvolution is used to regularize the image resolution prior to speckle tracking and correlation filtering is adopted to improve the method reliability. The method feasibility was tested in vitro as well as for its ability to distinguish between active and non-active phase of a natural menstrual cycle in six women. Two pairs of sites were manually defined on the uterine muscle and automatically tracked over time. The extracted movement features permitted successful separation between the two classes (p <; 0.05 by paired, double-tailed Student t-test). Additional validation is however required to prove the clinical value of this method for in-vitro fertilization.