“We’ll send you for a scan.” It is one of the most common sentences in an Irish GP surgery, and one of the least explained. You leave with a referral letter and a head full of questions you did not think to ask. Which scan? Will it hurt? Is the radiation dangerous? How long will I be waiting?
Diagnostic imaging becomes a bigger part of life after 50, and understanding what each test does, and what it does not do, makes the whole experience far less unsettling.
TL;DR
- Four scans cover most of what you will meet after 50: X-ray (bones, chest), ultrasound (soft tissue, real time), CT (fast, detailed, higher radiation dose) and MRI (magnets, no radiation, excellent for soft tissue and the brain).
- Only X-ray, CT and DEXA use ionising radiation. A chest X-ray is roughly equivalent to a few days of the natural background radiation everyone in Ireland receives anyway, most of which comes from radon.
- Your GP can refer you directly for chest X-rays, many ultrasounds and DEXA scans through the HSE’s community diagnostics access, without needing a hospital consultant first.
- Preparation matters: fasting for abdominal ultrasound, a full bladder for pelvic scans, and a medication and implant check before any MRI or contrast-enhanced CT.
- You are entitled to your images and reports under GDPR, and to 20 per cent tax relief on privately funded scans referred by a doctor.
The four scans you are most likely to meet
X-ray is the workhorse: quick, cheap and superb at showing bone, so it is the first stop for suspected fractures, arthritic change and chest problems. It is poor at soft tissue detail, which is why a normal X-ray does not always mean nothing is wrong.
Ultrasound uses sound waves rather than radiation. A sonographer moves a probe over gel-covered skin and watches images in real time. It is the go-to for the gallbladder, liver, kidneys, thyroid and pelvis, and for tendons and blood flow in the legs. Nothing about it is harmful, and it can be repeated as often as needed.
CT (computed tomography) takes a rapid series of X-ray slices and reconstructs them into a detailed cross-section. It is exceptional in emergencies, for the abdomen and chest and for suspected bleeds. The trade-off is a meaningfully higher radiation dose than a plain X-ray, so it is used when the information genuinely changes what happens next.
MRI uses a powerful magnet and radio waves, with no ionising radiation at all. It gives outstanding detail on the brain, spinal cord, ligaments and cartilage. The downsides are practical: it takes twenty to forty-five minutes, it is genuinely loud, and you must lie still inside a tunnel.
You may also meet DEXA, a very low-dose ten-minute bone density scan central to diagnosing osteoporosis, and nuclear medicine scans, where a tracer shows how an organ is functioning rather than how it looks.
Radiation: the honest answer
Ultrasound and MRI involve no ionising radiation whatsoever. X-ray, CT, DEXA and nuclear medicine do, and it is reasonable to ask about it. Some context helps: everyone living in Ireland absorbs natural background radiation continuously, averaging in the region of four millisieverts a year, the majority of it from radon gas seeping up from the ground. A single chest X-ray adds the equivalent of a few days of that background. A CT of the abdomen adds considerably more, in the region of a few years’ worth.
This is why Irish law requires every exposure to be justified. Under the 2018 medical exposure regulations, monitored by the Health Information and Quality Authority, a scan must be clinically justified by the referrer and optimised by the radiographer, who is a registered professional regulated by CORU, so that the dose is as low as reasonably achievable. Nobody is meant to scan you casually, and you are entitled to ask “what will this scan change about my treatment?” before agreeing.
How you actually get a scan in Ireland
There are three routes. Your GP can refer you directly for a range of community diagnostics, including chest X-ray, many ultrasound examinations and DEXA, through HSE-funded access arrangements that have expanded considerably in recent years. This route exists precisely to avoid people waiting on an outpatient list for a test their GP already knows they need.
Second, a hospital consultant can order imaging as part of an assessment, and urgent suspected-cancer pathways such as the rapid access clinics move quickly by design.
Third, you can pay privately. Ultrasound typically runs to around a hundred euro or more and MRI and CT commonly fall in the low hundreds, though prices vary substantially, so ring two or three providers. If a doctor referred you, the cost qualifies for health expenses relief at 20 per cent through your Revenue Med 1 claim. Health insurance may cover it, but many policies require pre-approval, so check before booking.
Preparing well
Most of the stress around scans comes from avoidable surprises.
- Bring your medication list. This matters most for contrast dye, which is filtered by the kidneys. Your kidney function may be checked beforehand, and certain diabetes medications may need a short pause.
- Declare every implant before an MRI. Pacemakers, defibrillators, cochlear implants, aneurysm clips, joint replacements and even old metal fragments need flagging. Many modern devices are MR-conditional and safe with the right settings, but the team must know in advance.
- Follow the fasting or fluid instructions. Abdominal ultrasound usually requires several hours without food; pelvic scans usually require a comfortably full bladder. Turning up wrongly prepared often means being sent home.
- Say if you are claustrophobic. Wide-bore scanners, a cloth over the eyes, or a mild sedative arranged in advance all make MRI achievable.
- Mention mobility, pain or hearing difficulties. Lying flat on a hard table for forty minutes is not neutral if you have back pain, and instructions come through an intercom in a noisy room. Staff can pad, prop and repeat, but only if asked.
Getting your results, and reading them sensibly
A radiologist interprets the images and writes a report for whoever referred you. That referrer, not the radiographer on the day, is the person who explains what it means, so ask on the day how long the report will take and how you will hear.
Two things are worth knowing. You can request a copy of your report and images under GDPR, which is genuinely useful if you later see a different clinician. And modern scanners are so sensitive that they frequently pick up incidental findings: harmless cysts, nodules and age-related changes that were never causing symptoms. These are usually benign, but they can trigger anxiety and further tests, which is one good reason professional bodies do not recommend commercial whole-body scans for people with no symptoms.
The takeaway
A scan is a question, not a verdict. Knowing which question it answers, what it will feel like and who will explain the result turns an intimidating appointment into a manageable one. Ask what the scan is looking for, ask what happens next either way, and keep your own copy.
At Críonna Health we believe understanding the system is a health intervention in itself. Preparing properly, asking the right question and holding on to your own records is one of the most practical skills you can build for the decades ahead.
This article is for general information and is not a substitute for individual medical advice. Talk to your GP about your own circumstances.
📷 Photo by Tatiana Zanon on Unsplash
