Ultrasound elastography is envisioned as an optional modality to augment standard

Ultrasound elastography is envisioned as an optional modality to augment standard ultrasound B-mode imaging and is a promising technique to aid in detecting uterine masses which cause abnormal uterine bleeding in both pre- and post-menopausal women. The screening frequencies were set Y320 to 1 1 10 20 and 30 Hz respectively. We also statement on stiffness variations with pre-compression from 1-6% for screening at 2 3 and 4% strain amplitude. Our results show that human uterine tissue is usually both dependent on percent pre-compression and screening frequencies. For ramp screening 20 samples obtained from 14 patients were used. A constant strain rate of 0.1% was applied and comparable results to dynamic screening were obtained. The mean modulus contrast at 2% amplitude between normal uterine tissue (the background) and leiomyomas was 2.29 and 2.17 and between the background and malignancy was 0.47 and 0.39 for dynamic and ramp screening respectively. (2006) measured the complex modulus in cervical and uterine hysterectomy samples using dynamic screening. Small compressions 1 were applied over a wide frequency range spanning 0.1-100 Hz. Modulus values for cervical and uterine tissue increased monotonically from approximately 30 kPa to 90 kPa with an increase in screening frequency. Leiomyomas exhibited modulus values that ranged from 60-220 kPa. Bauer (2007) utilized an aspiration device for cervical evaluations to evaluate physiological and biomechanical changes through gestation for detecting pregnant women at risk of cervical incompetence. For studies their stiffness parameter values varied from 0.065 to 0.315 bar/mm while softening parameter values ranged from 0.05 to 0.19. screening results ranged from 0.11 to 0.29. Myers (2008) performed ramp loading assessments on cervical ring sections under three different screening modes: load-unload cycle unconfined ramp-relaxation and confined ramp-relaxation. Ramp screening is usually a quasi-static approach which subjects the sample to a constant strain rate over a large applied deformation with the stress and strain measured constantly. Each specimen was first loaded under unconfined compression to a 15% axial strain and unloaded to 0% strain at a constant strain rate of 0.1% per second over three cycles. Their results indicated that cervical stroma has a nonlinear time-dependent stress response with varying degrees of conditioning and hysteresis depending on its obstetric background. Cervical tissue obtained from women who were by no means pregnant was significantly stiffer than women who underwent a pregnancy. DeWall (2010) quantified viscoelastic properties of normal human cervix through a range of pre-compressions (1-6%) compression amplitudes (2% 3 4 and screening frequencies (1 10 20 30 Hz). This study revealed lower modulus values by an order of 10 than those previously reported by Kiss with a frequency is the peak-to-peak Y320 strain amplitude then is the storage modulus (capability of the material to store energy during a loading cycle) and is the loss modulus (energy lost during each cycle). The loss factor is the Goat polyclonal to IgG (H+L). tangent of the phase shift (tanto and are the final height and surface area of the sample respectively. We quantify the viscoelastic properties of human uterine tissue at different screening frequencies of 1 1 10 20 and 30 Hz respectively. The impact of pre-compression around the storage modulus of cervical tissue has been previously reported (DeWall are the magnitude of the Young’s modulus for uterine fibroid malignancy and normal tissue respectively. Physique 8 shows the modulus contrast levels between normal uterine Y320 tissue and uterine leiomyomas as well as normal uterine tissue and the uterine carcinoma. The strain amplitude and mechanical screening frequency was set to 2% and 1 Hz respectively. Physique 8 shows that |with respect to background (normal uterine tissue) for fibroids and carcinoma versus the percent pre-compression. These results are for dynamically tested samples. Ramp Screening Human uterine tissue was also tested quasi-statically by applying a constant strain rate of from 0.1% to 15%. The number Y320 of samples tested was 20 obtained from 14 patients who underwent hysterectomies at UW Hospitals and Clinics. The 14 normal uterine tissue specimens exhibited no masses within the specimen itself however this determination was not based on pathology. Additionally 4 uterine fibroids and 2 uterine carcinomas were also assessed with mechanical screening. Physique 9a 9 and 9c present the stress-strain curves for the ramp assessments performed on normal uterine tissue leiomyoma.