This site scored very well with a mombubot score of 7. Only a few standard things to work on to make that 7 into a 10! Even though this page is a UK page it has a fairly good ranking in google.com at 11. Sure this is on page two like the others but it is from another continent.
Some great particulars are that the keyword is the first word in the title tag and is in a prominent position within and H1 tag in the text. This page is certainly setup for the keyword ultrasound.
One thing which mombubot doesn't check for is the use of the keyword in the URL or address for the page. Many pages like this one simply use and article number in the URL to identify the page. Another best practice is to have a reference in the URL of the page. Positioned in the domain name is the best but somewhere in the URL is second best.
Another major benefit to this page and the site is that the domain has been around from April of 1997, which provides some ranking as well. Trust is built up over time and as pages become a reliable source of information for people, the pages ranking improves as well!