Bayesian shear wave speed estimation for in vivo 3D imaging of the prostate

Quantitative measures of radiation-induced breast stiffness are required to support clinical studies of novel breast radiotherapy regimens and exploration of personalised therapy, however, variation between shear-wave elastography (SWE) machines may limit the usefulness of shear-wave speed (cs) for this purpose. Mean cs measured in four healthy volunteers’ breasts and a phantom using 2D-SWE machines Acuson S2000 (Siemens Medical Solutions) and Aixplorer (Supersonic Imagine) were compared. Shear-wave speed was measured in the skin region, subcutaneous adipose tissue and parenchyma. cs estimates were on average 2.3% greater when using the Aixplorer compared to S2000 in vitro. In vivo, cs estimates were on average 43.7%, 36.3% and 49.9% significantly greater (p << 0.01) when using the Aixplorer compared to S2000, for skin region, subcutaneous adipose tissue and parenchyma, respectively. In conclusion, despite relatively small differences between machines observed in vitro, large differences in absolute measures of shear wave speed measured were observed in vivo, which may prevent pooling of cross-machine data in clinical studies of the breast.

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Fetal adrenal gland biometry and cervical elastography as predictors of preterm birth: A comparative study

Ultrasound ◽

10.1177/1742271x17748515 ◽

2018 ◽

Vol 26 (1) ◽

pp. 54-62 ◽

Cited By ~ 10

Author(s):

Shubhra Agarwal ◽

Arjit Agarwal ◽

Pawan Joon ◽

Shalini Saraswat ◽

Shruti Chandak

Keyword(s):

Preterm Birth ◽

Adrenal Gland ◽

Shear Wave ◽

Sensitivity And Specificity ◽

Wave Speed ◽

Clinical Signs ◽

Developed Countries ◽

Speed Estimation ◽

Major Health Problem ◽

Shear Wave Speed

Background Preterm birth is a major health problem in developing and developed countries leading to rising health care costs and long-term neurodevelopmental disability. The study aims to evaluate the role of new quantitative markers, like the elastography of cervix (shear wave speed estimation), fetal adrenal zone enlargement, and corrected fetal adrenal gland volume; in preterm birth prediction and analyze their relative importance. Thus, these markers may be beneficial in early preterm birth detection and prevent the related morbidities. Methods Thirty pregnant females (from 28 to 37 weeks of gestational age), showing clinical signs and delivery outcome of preterm birth were included in the study with an equal number of not-in-labor antenatal females at ≥37 weeks as controls. These patients were categorized as preterm and term groups. Both the groups were subjected to trans-abdominal ultrasonography where cervical length, cervical shear wave speed (dynamic elastography) and fetal adrenal gland parameters were measured. Results Shear wave speed estimation of the antenatal cervix showed the highest sensitivity and specificity (96.7% and 87% respectively) in the prediction of preterm birth and also showed a strong correlation with fetal adrenal gland enlargement. Fetal adrenal zone enlargement was also shown to be a reliable marker of preterm birth, however, with reduced sensitivity and specificity than shear wave speed. Conclusion The elastographic advancement and fetal adrenal biometry derived quantitative markers can be used as an objective and standard criterion for accurate prediction of preterm birth.

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