How obesity and the position of the fetus influence the quality of 3d 4d ultrasound images.

3D Scans, even on advanced ultrasound systems, could produce poor results.

Images appeared to be blurry and non-usable for a visual evaluation of primary organs and also seeing a baby’s face.  

The accuracy of the ultrasound scan depends on many factors such as skills of the ultrasound technician, proper training, right protocol of the examination, women body mass index (BMI), time of the session, quality of the ultrasound equipment, and a fetus position.  

The most common reasons for poor ultrasonic visualization during a second-trimester, with all other factors to be equal, are a “bad” fetus position and a beam distortion based on overlying fatty tissues.

A number incomplete scans because of an unfavorable fetal position.

The wrong position of the fetus for viewing would result when shadowing from overlying bones and structures obscures the location of the fetus. The only solution to that problem is to change the position of the fetus. That could take some extra time that is not always available during a scheduled session. The follow-up session would often cure that problem.

The survey was conducted on pregnant women from Altamedica Fetal-Maternal Medical Center, who were evaluated for prenatal testing. Out of 4000 women, only 169, or about 4.2% had to come back for the second examination. That fact shows that only a small percentage of all exams were affected by a “bad” fetus position. However, even superior sonographers’ skills could not solve the problem.

The biggest problem during the scans was the bodies’ physique of the women who were overweight. 

According to the World Health Organization 

 body mass index (BMI) of 30kg/m2 or higher is a definition of obesity in a person. The number of obese people, especially for developed countries, is continuously growing in increasing rates. That trend affects pregnant women as well. The obesity rate in the US among pregnant women ranges from 18% to 40%. 

During a session, subcutaneous, just under the skin, tissues absorb ultrasound beams.

That makes it difficult to evaluate visualized data. Tissue Harmonic Imaging (THI) 

helped to improve a contrast resolution and tissue difference. As a result, the quality of the images was much better to compare with conventional 2d ultrasound.

Having said that does not imply that all women with a high BMI would not get good photos and visa versa. The problem is not just obesity but the type of non-uniform fatty issues that compound of fat with unequal density. Bad quality images could be taken from women with low body fat but having a layer of that tissue. And women with high BMI could receive almost perfect photos of the fetus. However, the trend is that women with high BMI would be less likely to receive perfect images as opposed to women with low body fat.

Educational benefits for pregnant women in explaining how the scan works.

Many pregnant women do not have a clear understanding of how the ultrasound session works, and why the images could be of not perfect quality. As a result, expectant moms-to-be would blame a sonographer or the ultrasound equipment of the imaging center. Some could take it personally when an ultrasound tech would suggest that obesity was a patient-related factor in the failure to produce decent photos. Then, it is essential to explain before the session how obesity factors would influence the result of the scan. 

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