Kidney Stones in Ajax: How X-Ray and Ultrasound Each Help
Ajax patients can learn why kidney stones may be imaged with ultrasound, X-ray or both, what each test sees well, what it misses, and when pain needs the ER.
· 8 min read
A kidney stone starts as a chemistry problem and becomes a plumbing problem. Minerals and other substances in urine, which normally stay dissolved, come together and form a small, hard crystal. While it sits quietly inside the kidney, many people never know it is there. The trouble usually begins when it moves into the narrow tube that carries urine down to the bladder, called the ureter, and partly blocks the flow.
When providers want to look for a stone, follow one that has already been found or check whether urine is backing up behind it, they reach for imaging. In a community setting, the two tests that come up most often are ultrasound and plain X-ray. They are not rivals. Each one sees different things, and they are frequently used together. This article explains why, for people in Ajax, Pickering, Whitby and the surrounding area who have been sent for one test, the other, or both.
First, the pain that cannot wait
Stone pain is famous for a reason. It often comes in waves, starting in the side or back below the ribs and sometimes moving toward the groin. Some people feel sick or vomit. It can be severe enough that a booked scan a few days away is simply not the right plan.
Call 911 or go to the nearest emergency department if you have:
- severe pain in the side, back or abdomen that you cannot control
- pain along with fever, chills or shaking, which can be a sign of infection behind a blockage
- vomiting that prevents you from keeping fluids or medication down
- very little or no urine
- a known single kidney or a kidney transplant, with new pain
- pain during pregnancy that is new or severe
A community imaging clinic is set up for planned and walk-in diagnostic tests, not for emergency care. Our article on abdominal pain and ultrasound talks more about telling an urgent situation from one that can be booked.
Two different ways of seeing
The simplest way to understand the two tests is to think about what each one responds to.
Ultrasound sends sound waves into the body and listens for the echoes. It is excellent at showing the outline and inner structure of soft organs and at telling fluid from solid tissue. It uses no ionizing radiation.
X-ray passes a small amount of radiation through the body and records what gets through. Dense materials, such as bone and anything containing a lot of calcium, block more of the beam and appear white. Soft organs mostly blend together in shades of grey.
A kidney stone sits right where those two strengths overlap. It is a dense object inside a soft, fluid-filled organ. Depending on what the stone is made of, how big it is and where it is lodged, one test may see it clearly while the other struggles.
What ultrasound brings to the question
It shows whether urine is backing up
Perhaps the most useful thing ultrasound does in stone care is not seeing the stone at all, but seeing its effect. When a stone blocks the ureter, urine can collect inside the kidney, which makes the central drainage area look swollen. The report may call this hydronephrosis. Spotting that swelling helps a provider judge how much the stone is interfering with drainage, which matters more for decisions than the stone’s exact appearance.
It can find stones inside the kidney
Stones sitting in the kidney itself often show up as bright spots with a dark band behind them, a shadow cast because the sound cannot pass through. Ultrasound can see stones regardless of their chemical make-up, which is an advantage over X-ray for certain types.
It needs no radiation
For people who need repeated checks over months or years, for younger patients, and for anyone who is pregnant, the absence of radiation is a real benefit. It is one reason ultrasound is so often the starting point.
Where it struggles
The ureter runs deep in the body behind loops of bowel, and bowel gas blocks sound. A stone partway down the ureter can be very difficult to see on ultrasound, even when the swelling above it is obvious. Very small stones may not be visible, and body build can affect image quality. Our post on kidney and gallbladder ultrasound explains the scanning positions and breath holds involved, which are part of how sonographers work around these limits.
What X-ray brings to the question
It shows many stones in a single picture
A plain abdominal X-ray that covers the kidneys, ureters and bladder can show stones along the whole path at once, provided they contain enough calcium to be visible. Many stones do. Because the image is wide, it can capture stones in places ultrasound might not reach easily, including the lower ureter.
It is good for tracking a known stone
When a stone has already been identified and is known to show on X-ray, a follow-up X-ray is a straightforward way to see whether it has moved, changed size, or passed. Comparing today’s image with an earlier one is often more informative than either image alone, which is why it helps to bring previous images or know where they were taken.
Where it struggles
Some stones are made of material that does not block X-rays well and barely show up. Small stones can hide behind bone or bowel contents. And an X-ray cannot show whether the kidney is swollen from a blockage. We describe the general strengths and limits of abdominal X-ray in our article on that exam, so if you are curious about the bigger picture, start there.
Side by side
| Question | Ultrasound | Plain X-ray |
|---|---|---|
| Is urine backing up in the kidney? | Usually shows this well | Cannot show it |
| Are there stones inside the kidney? | Often, regardless of stone type | If the stones contain enough calcium |
| Is there a stone partway down the ureter? | Often hard to see | Sometimes visible along the whole path |
| Has a known stone moved or passed? | Sometimes | Often useful if it showed before |
| Radiation? | None | A low dose |
This is a simplification, and every person’s anatomy is different. But it shows why a provider might order both: ultrasound to judge the kidney and any blockage, X-ray to map stones along the route.
Where other tests come in
In emergency departments and hospital settings, providers often use CT scanning when they need a highly detailed look for stones, particularly when the diagnosis is uncertain or a procedure is being considered. CT is not one of the services offered at our clinic, and whether you need it is a decision for your provider or the emergency team.
Imaging is also only part of stone care. Urine tests, blood tests and, sometimes, analysis of a stone that has passed help providers understand why stones are forming and what may lower the chance of new ones. If you catch a stone, ask your provider whether they would like it tested.
If you are being followed for stones
People who have had one stone sometimes have another, and some live with small stones that are watched over time. A few habits make follow-up imaging more useful:
- Keep track of where earlier images were done. Comparison is the heart of follow-up. If you have images from another facility, ask for copies. Our guide to getting copies of your imaging explains how that usually works.
- Tell staff about procedures. Stents, previous stone treatments and surgery change what the images show.
- Note when symptoms happened. A short record of pain episodes, blood in the urine or infections helps your provider decide when imaging is worth repeating.
- Follow the preparation you are given. Kidney ultrasound preparation varies. Some requests include the bladder and may ask you to drink water beforehand, and some abdominal scans require fasting. The clinic confirms your instructions at booking.
Common questions
Will an X-ray hurt if I am already in pain?
The X-ray itself causes no sensation. Lying flat on the table can be uncomfortable when you are sore, so tell the technologist and they will help you get into position as gently as possible.
Does a normal ultrasound mean there is no stone?
Not necessarily. Small stones and stones in the ureter can be missed. A normal scan is still useful, especially if it shows no swelling of the kidney, and your provider will weigh it alongside your symptoms and any other tests.
I am pregnant. Can I have stone imaging?
Ultrasound is generally the preferred first test during pregnancy because it uses no radiation. Always tell staff if you are or might be pregnant before any X-ray, and talk with your provider about which tests are right for you. New or severe pain during pregnancy should be assessed urgently.
Can I have both tests the same day?
That depends on your requisition and the day’s schedule. Call the clinic to confirm what is possible before you plan around it.
Booking stone imaging in Ajax
Rossland Diagnostic Clinic, at Unit 102, 300 Rossland Road East in Ajax, offers ultrasound by appointment and walk-in digital X-ray. The clinic is open Monday to Friday from 9:00am to 5:00pm and Saturday from 8:00am to 3:30pm, with free parking and ground-floor access. Bring your health card and requisition. You can read more about our ultrasound services, request an appointment online, or call 905-426-3111 for preparation instructions or live X-ray availability.