Clinical doppler ultrasound in imaging practices
“NO MEDICAL treatment can be considered until a proper diagnosis has been established”. Ultrasound is one of the most basic and important medical imaging technologies yet. The past few years have witnessed a vast proliferation in the use and applications of ultrasound to diagnose circulatory disorders.
Imaging possibilities of Doppler ultrasound have revolutionized radiology and imaging practices dramatically. Since, during the mid of the twentieth century new imaging techniques, including some based on principles totally different from those of X-rays, were discovered.
Ultrasonography was one such method that demonstrated fastidious potential and advanced greater benefit than traditional X-ray-based imaging.
During the last decade of the twentieth century, Doppler advancements have made ultrasound techniques so useful, so that the use of ultrasonography became increasingly common in medical practice and hospitals around the world. Scientific publications concluded the advantage and even the dominancy of ultrasonography over commonly used X-ray techniques, resulting in various significant changes in diagnostic imaging methods.
Clinical Doppler Ultrasound is a comprehensive analysis of the applications of Doppler Ultrasonography (US) and is particularly designed for radiologists, sonographers, and vascular surgeons engaged with laboratory and clinical practices.
Clinical Doppler Ultrasound systems have been used clinically in two ways. Firstly, ultrasound can provide an anatomical description of underlying tissues and their relative movement by direct echo, with display in one or two dimensions.
Secondly, flow and flow patterns in blood vessels or chambers may be studied when the Doppler principle is applied to ultrasound. In practice, echo and Doppler ultrasound are seen often complementary to each other rather than representing alternatives.
The capabilities of ultrasound flow imaging are also increasing enormously. Doppler ultrasound in general uses pulsed wave ultrasound. This allows measurement of the depth (or range) of the flow site as well as changing the size of the sample volume (or range gate). Color flow imaging can be used to recognize vessels requiring examination, to identify the presence and direction of flow, to highlight gross circulation anomalies, throughout the entire color flow image, and to provide beam/vessel angle correction for velocity measurements. Color flow Doppler ultrasound produces a color-coded map of Doppler shifts superimposed onto a B-mode ultrasound image. Although color flow imaging uses pulsed wave ultrasound, its processing differs from that used to provide the Doppler sonogram.
Apart from these all clinical Doppler ultrasound is also dealing with vascular diseases treatments. Transcutaneous Doppler ultrasound is being used widely in the diagnosis of many forms of peripheral vascular disease.
Clinical Doppler Ultrasound imaging is now in very widespread clinical use. This increasing curiosity reflects the fact that many tests being conducted by Doppler ultrasound technique are non-invasive and reliable, which do not require large investment of equipment or personnel. It can provide additional information during an ultrasound examination. Its role in the diagnosis is likely to continue to increase over the next few years as more centres and general practitioners turn to Doppler alternative techniques.
The writer is the Chairman, Biomedical Association of Students for Excellence (BASE) and B.E. (Biomedical Engineering), Mehran University of Engineering and Technology, Jamshoro, Sindh, Pakistan.