Annual Check-Up

Hello everyone.

Thanks for allowing us

to answer your questions about kidney stones.

My name is Justin Ziemba

and I’m an assistant professor of urology and surgery

and my area of expertise is kidney stone disease.

We had a wonderful question from the community about how

to follow up with imaging

after you’re diagnosed with kidney stones.

So this is actually a really great question

and one that remains still under study

and debated amongst urologists

and uh, patients with kidney stones alike.

The best amount

of information comes from the European Association

of Urology, which has done a look at this question.

And so here is a flow chart from their guidelines,

which provides us with information on how to image patients

after treatment for kidney stones.

So in general, this was referring to treatment

with kidney stone surgery.

However, it’s also applicable to patients

who may have passed their stones since

that is a treatment option as well.

And so here they try to take a risk-based approach, meaning

that they try to put categories around how likely someone is

to recur or make new kidney stones and

therefore inform how long

and how frequently they should be imaged.

But before we get into this flow chart,

I think it’s important to think about

or discuss the three options in general that are available

for us to image people and identify kidney stones.

So the first option is the good old fashioned plain x-ray,

which will identify small to medium

and certainly large radio opaque kidney stones.

So that means stones that are capable

of being detected on X-ray.

The second option is an ultrasound of the kidneys, part

of the ureters and the bladder.

This can can detect additional kidney stones

that may not be visible by x-ray, so those stones

that are radiolucent.

In addition, it does provide additional imaging

and information about potential blockage of the kidney

and changes of the kidney structure itself,

which are not visible on x-ray.

The third option is a CT scan.

Now this is the gold standard on how we identify

and diagnose kidney stones.

Almost all kidney stones are visible on CT scan

and it provides three dimensional meaning.

We can see all the structures and anatomy

and where the kidney stones lie in the course

of the urinary tract.

There are some additional caveats to each one

of these imaging, particularly that plain x-ray

and CT scan both use radiation

or x-rays to be able

to detect the stones while ultrasound does not.

And so that may play a role in some people’s decision about

which imaging modality is right for them.

Now let’s go to this flow chart.

We can see here that there are three main buckets.

So these are patients for this flow that have already passed

or had their stones surgically treated.

And in the first bucket we see patients

who have had postoperative imaging proving

that they do not have stones after their treatment

and they break it down into three essential categories.

The first bucket is patients that have radiopaque stones,

meaning they can be seen on x-ray.

An 80% safety margin means that they will capture most

of those patients who will reoccur by following them

with this imaging strategy.

So in this case, they’re following patients

after their treatment every six to 12 months with an x-ray

to look for those radio opaque stones.

In the second bucket, we see patients

that have radiolucent stones,

meaning they cannot be generally detected on x-ray.

Again, looking at an 80% safety margin being meaning being

able to capture patients who are gonna make stones

80% of the time.

Here, they want to follow patients every six to 12 months

with both an x-ray and an ultrasound of the kidney

and bladder for up to three years.

In the third category here, they’re trying

to increase the safety margin, meaning capturing 90%

of patients who, if they’re gonna recur

or make new stones, will be captured.

And in this case, they’re using x-ray

and ultrasound every six to 12 months for up to five years.

Now if we go to the second category,

these are patients who’ve had postoperative imaging

and they’ve detected additional stones

directly after their treatment.

Here we have two different buckets.

We have small stones that are detected,

and this case, the option is for to go back to surgery

to remove those uh, remaining stones

or continue to follow them every six to 12 months

with an ultrasound and x-ray for up to four years.

In the next category with larger stones,

the recommendation is to repeat surgery.

In the final category here we’re

thinking about high risk patients.

So these are patients who have had recurrence in the past

who may have had additional testing to prove

that they’re at high risk of recurrence

or developing new stones.

And so in the first bucket we see patients

who are on medical therapy.

So this may be pharmacologic like medication

or dietary interventions.

Here the recommendation is to follow up every six

to 12 months with an x-ray

and an ultrasound for up to four years.

If there’s no recurrence

or things are stable, you may be able to dis be discharged

and not follow up further.

In the last category, again, high risk people who’ve been

identified as having recurrence

or abnormalities in their urine

that may predispose them to recurrence.

The plan is for a follow-up, again, every six to 12 months

with an x-ray and an ultrasound for at least four years

with potentially up to 10 years.

So these are great resources here about

what might be a reasonable strategy

for follow-up after treatment.

Of course, these are only guidelines, meaning

that they may not apply to you

or they may need, may need

to be modified in your specific situation.

So it’s always really important to talk

to your healthcare professional about what’s right for you.

Finally, what’s not listed in this chart is if you have new

symptoms or you’re concerned about a new obstructing stone

or pain that you may wanna move towards that CT scan,

which when we first discussed is the gold standard

for diagnosing kidney stones.

I hope this helps answer your question

with a little bit more clarity

and based on evidence from the European

Association of Urology.

We appreciate the question

and look forward to more from the community.

Thanks.