I have been looking into a program like that near me. It's 15 months long, but really 4 semesters year-round including summer. Even though I am an RN, I would still have to take 2 prereqs for this particular program. I spoke with the program coordinator over the phone and asked about whether most people worked during the program (since the program requires you to be a rad tech, RN, or in another allied health profession already), and she said it is very difficult to work because classes and clinicals are Monday through Saturday. I was very surprised since I don't think quitting a job you have in this economy is a good idea. She told me each of the 4 semesters is 17-18 credit hours, and those who work often fail out. I was really bummed because I can't completely quit work -- could maybe cut back on my hours, but not quit entirely. Since you have to have proof of medical insurance to be in the program, I would think it would be difficult for most people to leave a job. It seemed to me the only people who could do it are young people living with their parents or someone whose spouse carries medical insurance through his/her job and who could live on the one income for the 15 months.
I got frustrated by the prospect since although sonography is considered a job growing faster than average, there is NO guarantee you'll get a job after school. All through nursing school, all I heard about was the nursing shortage, and I got out just in time to get a job. I feel bad for new RN grads who can't get hired. Due to my family situation, I cannot quit a job in the hand for a possible other career, even though I think I'd really like sonography.
I hope you get better news about the sonography programs near you. I would still love to hear what others have to say about it, especially any RNs who have pursued sonography after being licensed as a nurse.