Hi all,

Seems CT, PET and MRI are used more. Has anyone had an ultra sound for follow ups?

Any info on ultra sounds would be good. What can they show? are they accurate? etc.

Thanks and Take care.

Ok to add to my post. The Dr said ultrasound has less radiation and therefore good for close follow up scans.

I heard elsewhere that thick necks can be hard to ultrasound. Anyone else hear this?

How do they compare to CT? Some articles I read say about the same and others say not as accurate. ??

What do you know or have been told or read?

Thanks!

Ultrasound has 0 radiation, but MRI's don't have any radiation either, plus their image quality is truly the gold standard of all soft tissue imaging. Ultrasound is grainy and does not have the resolution or exquisite detail of an MRI. CT would be the second highest image quality.

There is no comparison of either CT or MRI to ultrasound, they are the gold standard of diagnostic imaging.

The only typical ultrasound studies, that I am aware of, done on the neck, have to do with calcium scoring of the carotid artery for heart attack risk evaluation. It just doesn't have the resolution for complex structures like the head and neck region and the signals will bounce off of bones as well.

Progress is constantly being made in the area of ultrasound image quality/resolution and I would anticipate that eventually it will emerge as a more mature imaging modality than it is today. Not that it doesn't have many uses already, especially OB/GYN imaging...

Lisa - I was treated at MD Anderson and go there for my follow-up exams every 3 months. I am having an ultrasound (soft tissue- neck) as part of my next appt in early March, not a CT. My dr. thinks it's just as good for showing the lymph node system and structures in the neck. Also, on my last appt I had an enlarged lymph node and since it didn't go away, I had an ultrasound here in Georgia to follow up and then an ultrasound with fine needle biopsy. (luckily all negative)

One thing I will say - a lot of this depends on the skill of the US tech, as well. I had my first US done at a different hospital than my second, and it was night and day... My second one was done at a large teaching hospital here and the US tech only did head and neck - and the radiologist was also right there. I think my first one was done by someone who has only ever done OB ultrasounds :-)

I forgot to mention the ultrasound is used frequently for (fine) Needle Guided Biopsy as well.

It is not listed in the NCCN Oncology Practice Guidelines for either original workup or followup exams for H&N patients.

It would not be an "off label" use for the device though since most US systems are indicated for "small parts". Ideal frequencies for the probes used in the head & neck area would be in the 7Mhz to 24MHz range depending on the depth of the region of interest, the higher frequencies being used for areas close to the skin.

I would add to what Ginny had to say in that there is also a wide variation in the quality of the machines out there as well, everything from inexpensive black & white mechanical sector to phased, linear and curved array, multiple channel, tissue harmonic imaging, 3D/4D (4D meaning 3D with motion), color machines, such as the GE Voluson 730.

There is also a shortage of trained sonographers in the US today. It is a good profession but handling the probes all day, with the pressure required for good coupling, takes it's toll on the operators and technicians. Many suffer from carpal tunnel syndrome and their careers are cut short.

Thanks Gary and Ginny,

so with all that being said; do US have more false positives or false negatives?

Thanks again.

Lisa - I'm definitely not an expert on this - that's my disclaimer! But I am an RN and I work for Kodak in their health imaging group so have some knowledge.

So, basically my understanding is that there really isn't anything such as "false" positives or negative in US. That's more related to PET scans. Basically, an ultrasound can show the structures very well and a skilled radiologist can tell from the images what the characteristics of any abnormalities look like and make a more informed diagnosis on what the pathology might be. For example, when looking at my US the radiologist dictated "subcentimeter left level 1B lymph node which has benign characteristics. Under the area of palpable concern, there is a 10 mm level 2A lymph node with no suspicious features..."

And, as said before, much of this is determined by the quality of the equipment and the skill of both the sonographer and radiologist. And, in order to make any definitive dx, a biopsy is necessary... but that's the same with CT, MRI or PET...

Ginny,
I too have worked in ultrasound (and other radiological devices) for many decades (and still am, being VP of an ultrasound manufacturer) and when they (the ultrasound manufacturer's) were attempting to make transrectal US prostate exams the "gold standard" exam, over digital (PSA was still in development then). The death rate went up 5% (due to sepsis), as a result of false positives and unneccessary biopsies. Transrectal prostate screening exams, with US, died a timely death as a result. US is still used for guided biopsy of the prostate but not for screening.

They are using US for breast for follow-up of suspicious areas and regions of interest (ROI). I am not sure that US has the resolution to pick up microcalcifications (which can be the size of a pixel) so I believe that mammograms will continue to be the gold standard.

I honestly have never seen any hard data on this issue (with the exception of transrectal for prostate cancer).

ALL scans are merely a component of the entire diagnostic workup and, as many of us have discovered, far from perfect. All of my first MRI's were terrible and I had much angst as a result until an entire year later when I finally had a "clean" one.

The term "false positive (or negative)" is used far more in conjunction with lab work than anything else. Manufacturer's of lab test reagent, etc. are required to submit extensive clinical data to the FDA concerning the false or negative positive rates and the hemotologist or your doctor typically knows that number.

Scans, on the other hand, are pretty much the responsibility of the reading radiologist and manufacturers are not required to submit data on false or negative results, only basic specifications for the device and indications and limitations for use. It could be rationalized that the false (or negative) postive rate is in the hands of the reading radiologist and that is the reason that congress enacted the Mammography Quality Assurance Act several years ago.

The ACR (American College of Radiology) has done a good job of training radiologists and certification of mammography scanning centers and you be sure that this also has played a role in the improvement of survival rates for breast cancer anyway.

This is also a good time to interject that this is one of the main reasons why we implore people to go to a CCC - the reading radiologists see almost nothing but cancer and are very skilled at reading it as a consequence.

PET is in a space by itself but PET/CT has upped the accuracy considerably.

It has always resorted back to the tried and true - direct visualization, palpation and biopsy if needed.

So there really isn't an answer for LisaB's question.