This is a web site dedicated to DIAGNOSTIC SONOGRAPHY, with a large, free -to -view gallery of ultrasound images that I have collected over the years, as a sonologist.
(Important announcement: we are now shifting the gallery to a new site at:
http://www.ultrasound-images.com
Here too you will find more such high resolution ultrasound images as on this site. This (older) site will still be available).
Some of the images for my Ultrasound gallery are borrowed, with permission from fellow radiologists, from across the world.
Every effort has been made to keep the quality of the images, optimal.
Most of the images in this web site are plain grey scale B-mode ultrasound.
A few, of course, use color doppler imaging.
What is ultrasound?
I)The basics:
Ultrasound is based on the principle of sound wave echoes. Sound waves travel from the probe to the object, pass through it and are continuously reflected back to the probe from multiple points inside the object (human body). Sound that is audible to the human ear ranges from 20Hz to 20Khz. in frequency.
Ultrasound uses sound waves of frequency in the range of megahertz (millions of cycles or waves per second). Typically this ranges from 3.5 MHz-10 MHz. Most modern day probes are multi frequency i.e.: one can switch from lower to higher frequencies. Why so? Simple – lower the frequency (3-3.5Mhz) deeper the penetration of the sound beam; but the resolution (or quality of image) is poorer. The higher the frequency, it is just the opposite.
Thus, large structures like the liver, kidneys and spleen are imaged using frequencies ranging from 3 to 3.5 MHz. For superficial structures like the orbits (eyes), the testes and breast, the frequencies typically used, are in the range of 5-10MHz. The reflected sound waves are converted back to electrical signals in the probe and transmitted to the processing device (a high speed computer) which displays the image on the monitor
II) Hypoechoic/ hyperechoic etc:
Bright (or white areas) represent high relfectivity or reflective surfaces / interphases in the body. Hypoechoic- blacker or low signal reflection areas are called hypoechoic. Anechoic structures are usually filled structures like blood, urine etc. Bone, air and calcium contaning lesions (like stone) appear intensely bright (whiter) or hyperechoic. An acoustic shadow (dark area) is seen behind such structures. Structures like the liver and pancreas appear in various shades of gray depending upon their echogenicity (ability to reflect ultrasound waves). See th images below: the first is an ultrasound image of the gall bladder. This shows typical anechoic nature of the bile in the bladder (appears dark).
The image below shows the anechoic urine in the urinary bladder (dark) with a calculus (hyperechoic) appearing white; note the well defined shadow beyond the calculus.
The following images of the uterus show a large mass in the uterus, a fibroid (approximately 12 x 7 cms.). This shows a typical soft tissue echogenicity. This means its echogenicity is between that of a calculus and the urinary bladder (fluid). The soft tissue mass, typically, appears grey.
Further, an important point to note is that with a change in the scan plane, i.e. the plane of the probe, one can get sagittal or transverse sections of the part ( the uterus). In fact, it is easy to obtain any plane of section of the organ being viewed, by changing the position, plane, angle etc., of the ultrasound probe.
Like to download a useful e-book (Microsoft power point slide presentation) about the "Appendix and its diseases"? You'll find more than 25 high resolution ultrasound images, nicely labelled and with captions. A brief description of each pathology is also present. The cost.. a mere $ 5.0
To download via our secure site click here:
Sonographic atlas of appendix
You can also download version 2.0 of the Sonographic Atlas of the Appendix. This is priced at $ 7.0 and is available in Adobe acrobat form (.PDF file). All you need is Adobe Reader to view this file. Version 2.0 has more than 40 high res images of the appendix.