Dataset Information

Temperature elevation measured in a tissue-mimicking phantom for transvaginal ultrasound at clinical settings.

ABSTRACT:

Introduction

This paper reports the results of an audit to assess the possible thermal hazard associated with the clinical use of ultrasound scanners in UK Hospitals for transvaginal ultrasound imaging.

Methods

An anatomically relevant phantom composed of a block of agar-based tissue mimicking material with embedded thermal sensors was developed. Seventeen hospitals around the UK were visited and a total of 64 configurations were tested. A representative typical scanning protocol was adopted, which primarily used B-mode with 30?s periods of colour-flow and pulsed Doppler modes for both gynaecology and obstetrics pre-sets.

Results

The results confirmed that the highest temperature increase is always at the surface. The greatest temperature rise measured across all the systems was 3.6?, with an average of 2.0? and 2.16? for gynaecology and obstetrics pre-sets, respectively. For some systems, the temperature increased rapidly when selecting one of the Doppler modes, so using them for longer than 30?s will in many cases lead to greater heating. It is also shown that, in agreement with previous studies, the displayed thermal index greatly underestimates the temperature rise, particularly close to the transducer face but even to distances approaching 2?cm.

Conclusions

Overall, the results of the audit for the temperature rise during transvaginal ultrasound at clinical settings fell within the limits indicated by the national and international standards, for the pre-sets tested and following a representative typical scanning protocol. Only selected pre-sets were tested and the scanner outputs were not maximised (for example by using zoom, greater depth or narrow sector angles). Consequently, higher temperatures than those measured can certainly be achieved.

SUBMITTER: Miloro P

PROVIDER: S-EPMC5308387 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Temperature elevation measured in a tissue-mimicking phantom for transvaginal ultrasound at clinical settings.

Miloro Piero P Martin Eleanor E Shaw Adam A

Ultrasound (Leeds, England) 20161221 1

<h4>Introduction</h4>This paper reports the results of an audit to assess the possible thermal hazard associated with the clinical use of ultrasound scanners in UK Hospitals for transvaginal ultrasound imaging.<h4>Methods</h4>An anatomically relevant phantom composed of a block of agar-based tissue mimicking material with embedded thermal sensors was developed. Seventeen hospitals around the UK were visited and a total of 64 configurations were tested. A representative typical scanning protocol ...[more]

PMID: 28228820

Similar Datasets

Project description:IntroductionThe clinical management of placenta accreta spectrum (PAS) depends on placental topography and vascular involvement. Our aim was to determine whether transabdominal and transvaginal ultrasound signs can predict PAS management.Material and methodsWe conducted a retrospective cohort study of consecutive prenatally suspected PAS cases in a single tertiary-care PAS center between January 2021 and July 2022. When PAS was confirmed during surgery, abdominal and transvaginal ultrasound scans were analyzed in relation to PAS management. The preferred surgical approach of PAS was one-step conservative surgery (OSCS). Massive blood loss and PAS topography in the lower bladder trigone necessitated cesarean hysterectomy. Transvaginal ultrasound-diagnosed intracervical hypervascularity was split into three categories based on their quantity. Anatomically, the internal cervical os is located at the level of the bladder trigone and was used as landmark for upper and lower bladder trigone PAS.ResultsNinety-one women underwent OSCS and 35 women underwent cesarean hysterectomy (total 126 women with PAS). Abdominal and transvaginal ultrasound features differed significantly between women that underwent OSCS and cesarean hysterectomy: decreased myometrial thickness (<1 mm), 82.4% vs. 100%, p = 0.006; placental bulge, 51.6% vs. 94.3%, p < 0.001; bladder wall interruption, 62.6% vs. 97.1%, p < 0.001; abnormal placental lacunae, 75.8% vs. 100%, p < 0.001; hypervascularity (large lacunae feeding vessels, 57.8% vs. 94.6%, p < 0.001; parametrial hypervascularity, 15.4% vs. 60%, p < 0.001; the rail sign, 6.6% vs. 28.6%, p = 0.003; three-dimensional Doppler intra-placental hypervascularity, 81.3% vs. 100%, p < 0.001; intracervical hypervascularity 60.4% vs. 94.3%, p < 0.001); and cervical length 2.5 ± 0.94 vs. 2.2 ± 0.73, p = 0.038. Other ultrasound signs were not significantly different. The results of multivariable logistic regression showed placental bulge (odds ratio [OR] 9.3; 95% CI 1.9-44.3; p = 0.005), parametrial hypervascularity (OR 4.1; 95% CI 1.541-11.085; p = 0.005), and intracervical hypervascularity (OR 9.2; 95% CI 1.905-44.056; p = 0.006) were weak predictors of OSCS. Intracervical hypervascularity Grade 1 (vascularity <50% of cervical tissue) was more present in OSCS than higher gradings two and three (91% vs. 27.6% vs. 14.3%; p < 0.001).ConclusionsCesarean hysterectomy is associated with the PAS signs of placental bulge and Grade 2 and 3 intracervical hypervascularity. OSCS is associated with intracervical hypervascularity Grade 1 on transvaginal ultrasound. Prospective validation is required to formulate predictors for PAS management.

Dataset Information

Temperature elevation measured in a tissue-mimicking phantom for transvaginal ultrasound at clinical settings.

Introduction

Methods

Results

Conclusions

Publications

Temperature elevation measured in a tissue-mimicking phantom for transvaginal ultrasound at clinical settings.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets