Introduction: Doppler mode ultrasound is widely used in prenatal scanning and known to produce a higher acoustic
output which later leads to higher heat energy conversion compared to other ultrasound modes. It has been reported
that the use of Doppler imaging might increase the temperature of tissues, thus, when Doppler is used in combination with 2D ultrasound, the risks of bioeffects tend to increase more. It is also known that prolonged exposure to
ultrasound during pregnancy can cause irreversible biological destructions to the fetus. Despite the benefits of using
Doppler ultrasound, its potential adverse effects have received scant attention in the research literature. Therefore,
this study aimed to examine a correlation between gestational stages (GS) and newborn rabbit’s body weight at different prenatal Doppler ultrasound exposure durations. Methods: Twelve pregnant New Zealand white rabbits (NZWR)
were exposed once using three different Doppler ultrasound exposure durations (30, 60, 90 minutes exposure) at
three different GSs (1st, 2nd, and 3rd GS). After delivery, the mean weights of the 62 newborns were statistically analysed. Results: Strong negative and positive correlation between newborn’s body weight at different GSs and Doppler
ultrasound exposure durations with a significant result found in 60 minutes exposure (p =
The purpose of the study was to assess the size for both kidneys based on the position of
patient during ultrasonography examination. Normal renal size measurement is very important to evaluate in determining a healthy kidney. Method: Thirty volunteers, consist of 15 males and 15 females were involved in this study. The patients were scanned in supine, oblique, and prone position. The readings were repeated for three times for each position. Results: The mean length of kidney in supine, oblique and prone were 99.03 mm, 96.32 mm and 95.94 mm, respectively. Meanwhile, the mean width of kidney were 44.30 mm, 44.31 mm and 46.65 mm, respectively. The renal length measurement in prone position was statistically significant with p = 0.023 (p < 0.05), while the renal width measurement in oblique and prone position were statistically significant with p = 0.006 and p = 0.009 respectively. Conclusion: This research emphasised the importance of investigating the different types of position of patient during the ultrasound scanning. The importance mentioned were the reduction of scanning time for patient and cost- effectiveness
of the procedures. Besides, it also gave accurate result for the renal measurement.
The application of ultrasound technology has been widely accepted in clinical settings, particularly in Obstetrics and Gynaecology. This is in light of its ability to detect early foetal malformations apart from enabling foetal monitoring throughout gestation. While ultrasonography is an imaging method that is regularly used in Obstetrics, it is questionable as to whether it is safe for foetuses. The purpose of this paper was to review the evidence regarding the thermal effects of ultrasound exposure on foetal development, particularly. It is hoped that the importance of prudent usage of prenatal ultrasonography will be impressed on clinicians and the public in order to avoid the unnecessary usage of ultrasonography when it is not medically indicated. This is so that the welfare of pregnant women will be looked after, besides contributing to the better health of the next generation by ensuring that the benefits outweigh the known risks or potential harms.
Doppler ultrasound is used in obstetrics and gynecology fields to serve as the complement
mode in the standard prenatal scan. It aids in investigating fetus blood flow in expectant
mothers’ wombs, usually those who come with pregnancy complications. In the conventional
ultrasound beam, the heat produced by attenuation is distributed over the area. However, the
Doppler ultrasound beam is focused at only one point. This leads the heat to accumulate at
that particular area and hence there is an increase in the temperature. Heat is considered as
a teratogen in pregnancy, whereby an increase in the fetal temperature can be fatal to the
fetus. Studies have found that Doppler mode is associated with higher acoustic output as
compared to the conventional two-dimensional (2D) ultrasound mode. Several studies done
on animals have ruled out the evidence of Doppler ultrasound bioeffects. This narrative
review only discusses the thermally induced effect of ultrasound by using Doppler mode.
This study reviews prior studies with keywords such as Doppler ultrasound, bioeffects,
heating effects, rabbit, and pregnancy. Earlier studies noted that the risk of thermal effects
increased with the increase of exposure time. However, Doppler ultrasound wave inducing
fetal hyperthermia is not the main reason for
causing adverse neonatal outcomes without
taking into account other external factors.
Therefore, it is essential for the practitioners
to adopt and adapt the concept of ‘as low as
reasonably achievable’ (ALARA) to avoid
any subtle adverse effects.