Measurement of Thermal Effects of Doppler Ultrasound: An In Vitro Study.

OBJECTIVE:Ultrasound is considered a safe imaging modality and is routinely applied during early pregnancy. However, reservations are expressed concerning the application of Doppler ultrasound in early pregnancy due to energy emission of the ultrasound probe and its conversion to heat. The objective of this study was to evaluate the thermal effects of emitted Doppler ultrasound of different ultrasound machines and probes by means of temperature increase of in-vitro test-media. METHODS:We investigated the energy-output of 5 vaginal and abdominal probes of 3 ultrasound machines (GE Healthcare, Siemens, Aloka). Two in-vitro test objects were developed at the Center for Medical Physics and Biomedical Engineering, Medical University Vienna (water bath and hydrogel bath). Temperature increase during Doppler ultrasound emission was measured via thermal sensors, which were placed inside the test objects or on the probes' surface. Each probe was emitting for 5 minutes into the absorbing test object with 3 different TI/MI settings in Spectral Doppler mode. RESULTS:During water bath test, temperature increase varied between 0.1 and 1.0°C, depending on probe, setting and focus, and was found highest for spectral Doppler mode alone. Maximum temperature increase was found during the surface heating test, where values up to 2.4°C could be measured within 5 minutes of emission. CONCLUSIONS:Activation of Doppler ultrasound in the waterbath model causes a significant increase of temperature within one minute. Thermally induced effects on the embryo cannot be excluded when using Doppler ultrasound in early pregnancy

Surface heating of probes within 5 minutes of spectral- Doppler and color Doppler emission.

<p>Surface heating of probes within 5 minutes of spectral- Doppler and color Doppler emission.</p

Water bath model.

<p>TI is displayed as the TI setting, at which the highest temperature increase could be measured (e.g. probe IC5-9D: TIC setting showed a larger increase in temperature in all measurements compared to TIS or TIB); (TIS) Thermal Index Soft- Tissue (TIB) Thermal Index Bone (TIC) Thermal Index Cranium; Spectral Mode (SD), Colour Mode (CD)</p><p>Maximal temperature increase after 1 minute at different TI/ MI settings.</p

Surface heating test object.

<p>Persplex cube containing hydrogel; sides covered with damping material (Aptflex, Precision Acoustics, UK). Surface heating of the different probes was measured via a sensor, which was attached to the probe’s surface within the Doppler sound path.</p

Decline of semen quality during IVF is not associated with subjective male stress

The aim of the present study was to assess if semen quality declines during in vitro fertilization (IVF) and whether or not this phenomenon is triggered by chronic male stress. In order to test this hypothesis, we first investigated a retrospective cohort of 155 male IVF patients (testing cohort). Subsequently, we started a prospective cohort study in men undergoing their first IVF and assessed semen quality and subjective male chronic stress using a validated tool, i.e. the Fertility Problem Inventory (FPI) questionnaire. The association between stress and sperm quality decline measured 4-6 weeks before the start of IVF (T1) and at the day of oocyte retrieval (T2) was the primary outcome. Live birth rate, first trimester abortion and rate of poor responders were secondary outcomes. In the testing cohort, mean progressive motility, but not mean sperm density significantly declined. There were 78/154 (51%) men who showed a decline in semen density and 50/154 (32%) men who showed a decline in progressive motility. In the validation cohort, progressive motility declined, whereas, sperm density increased from T1 to T2. Of 78 men, 27 men had increased stress (FPI-score > 146). Sperm density and progressive motility were not significantly different in men with and without stress. However, in the presence of male stress, couples had a higher rate of poor responders, miscarriages and a lower rate of live births. Subjective stress is not associated with a decline in semen quality observed during IVF but may be associated with adverse pregnancy outcome

Investigated ultrasound machines and vaginal/ abdominal probes.

<p>Investigated ultrasound machines and vaginal/ abdominal probes.</p

Development of a tool for prediction of ovarian cancer in patients with adnexal masses: Value of plasma fibrinogen

<div><p>Objective</p><p>To develop a tool for individualized risk estimation of presence of cancer in women with adnexal masses, and to assess the added value of plasma fibrinogen.</p><p>Study design</p><p>We performed a retrospective analysis of a prospectively maintained database of 906 patients with adnexal masses who underwent cystectomy or oophorectomy. Uni- and multivariate logistic regression analyses including pre-operative plasma fibrinogen levels and established predictors were performed. A nomogram was generated to predict the probability of ovarian cancer. Internal validation with split-sample analysis was performed. Decision curve analysis (DCA) was then used to evaluate the clinical net benefit of the prediction model.</p><p>Results</p><p>Ovarian cancer including borderline tumours was found in 241 (26.6%) patients. In multivariate analysis, elevated plasma fibrinogen, elevated CA-125, suspicion for malignancy on ultrasound, and postmenopausal status were associated with ovarian cancer and formed the basis for the nomogram. The overall predictive accuracy of the model, as measured by AUC, was 0.91 (95% CI 0.87–0.94). DCA revealed a net benefit for using this model for predicting ovarian cancer presence compared to a strategy of treat all or treat none.</p><p>Conclusion</p><p>We confirmed the value of plasma fibrinogen as a strong predictor for ovarian cancer in a large cohort of patients with adnexal masses. We developed a highly accurate multivariable model to help in the clinical decision-making regarding the presence of ovarian cancer. This model provided net benefit for a wide range of threshold probabilities. External validation is needed before a recommendation for its use in routine practice can be given.</p></div

ROC-curves representing the accuracy for detection of ovarian malignancy in patients with adnexal masses for CA-125, fibrinogen, the full model (including fibrinogen, CA-125, malignancy-criteria on ultrasound), and the model without fibrinogen.

<p>AUC = area under the curve.</p

Decision curve analysis of the effect of the presented nomogram for predicting ovarian cancer in patients with adnexal masses.

<p>Assumption was made that the identification of ovarian cancer would lead to surgery. Net benefit of the presented nomogram is plotted against threshold probabilities for ovarian cancer compared with the strategies of treating all patients with adnexal masses or no one. The nomogram showed an improved net benefit between 5% and 90% threshold probability.</p

Diagnostic performance of serum fibrinogen and CA-125 to detect ovarian malignancy in 906 patients with adnexal masses.

<p>Diagnostic performance of serum fibrinogen and CA-125 to detect ovarian malignancy in 906 patients with adnexal masses.</p