Radiology

If your scan was asked for today

A scan ordered the same day for stroke symptoms, a head injury, severe chest pain, severe abdominal pain or heavy bleeding is not something to book and wait for. Come to the emergency department, or call 040 4699 9999. For an ambulance call 1800 2024. Stroke-protocol CT and MRI are done here, and speed is part of the treatment.

Does it hurt?

No scan on this page cuts or burns. What each one feels like:

• X-ray: nothing touches you except the plate you stand or lie against. You hold still and hold your breath for a few seconds.
• Ultrasound: warm gel and a smooth probe pressed on the skin. It can be uncomfortable if the area is already tender. For some pelvic scans you are asked to drink water and hold a full bladder, which is the least comfortable part of it.
• CT: the scan itself is felt as nothing at all. You lie on a table that slides through a ring.
• MRI: no sensation, but a lot of noise. The scanner knocks and buzzes loudly the whole time, and hearing protection is worn for it.
• Contrast: if the scan needs contrast, a cannula goes into a vein in your arm. That is a sharp scratch. When the contrast runs in you may feel a hot flush through the body and a metallic taste, and many people feel as though they have wet themselves. It passes in under a minute and it is expected.

If being shut in worries you

This is the commonest reason people put off an MRI, and it is worth saying what the machine is actually like.

The MRI here is a 3 Tesla scanner with a 70 cm bore. That is the width of the opening you lie in: 70 cm is a little over two feet across. Routine scans run in under ten minutes, so for many people the whole time inside is shorter than the wait outside. For a knee, foot or ankle you go in feet first and your head may never enter the bore at all. A longer study, prostate MRI for instance, takes more than ten minutes; ask when you book how long yours is expected to be, so you know what you are agreeing to.

CT is not a tunnel. It is a ring about as deep as a doorframe, open at both ends, and the part where you must hold still lasts seconds rather than minutes.

Two things are worth doing before the day. Say you are claustrophobic when you book, not when you are on the table. And when you get to the room, ask the radiographer to show you the scanner before you lie down, and ask how you call them from inside. Knowing you can stop the scan is, for most people, the thing that makes it possible to finish it.

How long it takes, and going home afterwards

Time in the scanner and time in the department are different things. An X-ray is minutes. A routine MRI runs under ten minutes in the magnet, a CT seconds, but around either one there is registration, billing, changing, positioning and, if contrast is used, a short wait afterwards before the cannula comes out.

A routine scan uses no sedation and no anaesthetic, so nothing stops you driving, working or travelling home on your own afterwards. If sedation is arranged for you, which is sometimes done for a small child or for someone who cannot lie still, you will be told beforehand and you will need an adult to take you home.

Can you eat first?

It depends on the scan, so take the instruction you were given rather than a general rule. A plain X-ray, a bone density scan and most MRI and unenhanced CT scans do not usually need an empty stomach. Scans using contrast and some abdominal ultrasound scans often do.

If nobody gave you a preparation instruction when the scan was booked, ring and ask before you set out. Arriving having eaten when you should not have usually means going home and coming back.

Tell us before the day

Some of these change what can be done, so they need saying at booking rather than at the scanner door.

• You are pregnant, or think you might be. This matters for X-ray and CT, which use ionising radiation. MRI and ultrasound use none.
• You have a pacemaker, defibrillator, cochlear implant, aneurysm clip, an implanted pump, or metal fragments in the eye or elsewhere from an injury or from metalwork. MRI uses a magnet that is always on, and you will be asked a safety checklist before you go near it.
• You have had a reaction to contrast before, or you have kidney problems, diabetes or asthma. A recent kidney blood test may be asked for before contrast is given.
• You cannot lie flat, or cannot lie still for several minutes, for any reason.

What it costs

This page does not publish prices: the bill depends on the study, on whether contrast is used, and on whether you are an outpatient or already admitted. What it can tell you is where the real number comes from.

For an outpatient scan, billing is completed before you go through to the scanner, so the amount is known and paid before anything is done. To find out beforehand, call 040 4699 9999 with your request slip in hand and read out exactly what your doctor has asked for, including whether it says with contrast. If you have insurance, a TPA card or a scheme card, bring it and ask at billing whether this scan is covered, as outpatient cover differs from policy to policy.

If you are already admitted, the scan is billed to your hospital account, and the ward will tell you what has been ordered.

When the report comes

You are told the expected turnaround time when the scan is booked and billed, so ask for it then and write it down. When the report is ready an automatic text goes to the mobile number registered with the hospital.

You can then read or download the report yourself, on the hospital website or the mobile app, using the login issued to you at registration. Hard copies can be collected when it suits you. Your consultant sees the same report in the hospital record, so you do not have to carry it to the follow-up appointment unless you are going back to a doctor outside the hospital.

Images from a scan are not the answer on their own. The report is the radiologist's reading of them, and what it means for you comes from the doctor who asked for the scan.

If you are admitted

You do not arrange anything yourself. The ward nurse books the slot with radiology and confirms it, the preparation is handled on the ward, and a nurse goes with you for the whole transfer. Patients in the intensive care units have bedside imaging where it can be done, and a duty medical officer goes with them and stays until they are back in the room if it cannot.

The scans done here

• X-ray, on twin-detector digital equipment: fractures, chest and lung infection, and post-operative checks.
• Ultrasound, including 3D and 4D Doppler: pregnancy, and the liver, kidneys, thyroid, abdomen and blood vessels. Doppler shows blood flow rather than structure.
• CT on a 128-slice dual-energy spectral scanner: injury, the chest and abdomen, finding and staging tumours, triphasic liver studies, and CT angiography for the blood vessels and for suspected stroke.
• MRI on a 3 Tesla scanner: brain, spinal cord, joints, muscle and abdomen, stroke-protocol imaging, multiparametric prostate MRI, MR angiography, and functional sequences that map brain activity and perfusion without contrast.
• Mammography and bone density (DEXA).
• Interventional radiology: treatment through a needle or a catheter under imaging guidance, instead of an open operation.

The scanners

The CT is a 128-slice dual-energy spectral scanner whose detector resolves to 0.23 mm. That resolution is not only detail for its own sake: it helps separate lesions, lymph nodes and hypervascular nodules that a conventional scanner struggles to tell apart, and it does so at a lower radiation dose and with less contrast injected.

The MRI is a 3 Tesla magnet, twice the field strength of a routine scanner, with a 70 cm bore and dedicated coils for knee, shoulder, breast and paediatric neuro imaging. It also runs MR elastography for liver, breast and brain lesions, and iron and fat quantification that can pick up early liver damage.