Introduction
A sonographer’s knowledge of fundamental principles and knobology is critical to obtaining the most accurate diagnostic image possible. It is essential to consider the patient’s position, understand the principles of operation of transducers, perform the necessary manipulations and adapt modes, and know the functionality of the knobs of the device. Therefore, this paper summarizes the fundamental principles and knowledge required for sonographers’ work.
Transducers
A transducer, or probe, is used to obtain ultrasound images. The crystal inside the transducer emits an ultrasonic wave that bounces off internal organs, helping form the image on the screen (Penny, 2020). Depending on the required examination area, probes with phased, linear, or convex arrays can be used (Penny, 2020).
An acoustic gel acts as a conductor during ultrasound, simplifying manipulations and facilitating the passage of ultrasonic waves. Manipulation of the transducer helps to create an optimal acoustic window for better visualization (Penny, 2020). In addition, it is crucial to maintain the probe’s orientation to obtain an accurate image, and the patient must be in the correct anatomical position. Proper care and cleaning of transducers are essential for proper device operation and patient safety.
Planes and Modes
For a comprehensive organ scan, the sonographer uses multiple planes of view. The most common are sagittal, transverse, and coronal planes (Penny, 2020). A special diagnostic method is echocardiography, which allows evaluation of the heart’s function. Due to this organ’s location, scanning requires multiple views, including the parasternal long-axis, subxiphoid, and apical four-chamber views (Penny, 2020). Therefore, a specialist may need to carry out additional manipulations.
Furthermore, modes help improve scanning and obtain more accurate visualization. The sonographer can use brightness (B-mode) or amplitude (A-mode) (Penny, 2020). In addition, during diagnostics, continuous-wave (CW), pulse-wave (PW), color, and power Doppler can be used. PW Doppler is more adaptable because it allows one to determine the depth of the ultrasound beam.
Knobology
Since ultrasound machines have many function buttons, learning knobology is essential. The sonographer must thoroughly understand the device’s functionality and operating principles to obtain the most accurate results, contributing to the correct diagnosis. Essential functions include setting the ultrasound power, color, brightness, field of view, and depth (Penny, 2020). Moreover, using knobs, one can zoom an image and freeze it for measuring dimensions.
Reference
Penny, S. M. (2020). Basic principles and knobology. In Introduction to Sonography and Patient Care (2nd ed.). Wolters Kluwer.