On scan day you will probably meet two kinds of imaging professional without realising it. One is the person who explains the exam, helps you onto the table and works the controls from behind a window. The other, the radiologist, you may never see at all, because they read the pictures afterwards. This page explains the first role in general terms, using public descriptions, so that the day feels less mysterious. It describes what the role involves; it is not careers or training guidance, and it does not speak for anyone in the profession. For the whole route from appointment to result, see preparing for a scan and your results.
Technologist, radiographer, sonographer
The names vary. The US Bureau of Labor Statistics (BLS) says radiologic technologists, also known as radiographers, perform X-rays and other diagnostic imaging examinations on patients, and that MRI technologists operate MRI scanners. In the NHS in England the term used on its patient pages is radiographer, as in its descriptions of MRI scans. A diagnostic radiographer is described there as using advanced technology to look inside patients' bodies and taking part in a wider team that consults colleagues on diagnosis and treatment plans.
Specialisation is common. RadiologyInfo.org says radiologic technologists administer radiology procedures including X-ray, MRI, nuclear medicine, CT and ultrasound exams, and that some also perform radiation therapy treatments. The BLS points out that some technologists specialise, for example in X-ray, mammography or CT, and refers separately to nuclear medicine technologists, diagnostic medical sonographers (who operate ultrasound equipment) and cardiovascular technologists as other healthcare workers who specialise in other diagnostic equipment. Which title you meet depends on the scan and on the country.
What they do during your exam
RadiologyInfo.org lists three strands. The first is patient care: technologists work closely with patients, explaining procedures and answering questions, accurately positioning patients for their exams and adjusting immobilisation devices to obtain the best views. The second is operating the equipment, including mobile X-ray or ultrasound equipment in the emergency room, operating room or at the bedside, and capturing quality images for the radiologist to interpret. The third is recording exam details such as the imaging techniques used, and checking the captured images to ensure they are of high enough quality for accurate interpretation.
The BLS gives a similar list of typical duties: following precise orders from physicians on what areas of the body to image, preparing patients for procedures including taking a medical history and shielding exposed areas that do not need to be imaged, positioning the patient and the equipment, operating the computerised equipment, working with physicians to evaluate the images and decide whether additional images are needed, and keeping detailed patient records.
That is why the technologist may ask you to wait at the end. RadiologyInfo.org explains in its preparation pages that the technologist may ask you to remain until the images have been checked, in case more are needed. It is also why you are alone in the room for some exams: the same source says the technologist walks behind a wall or into the next room to activate an X-ray machine, and for CT that you will be alone in the exam room unless there are special circumstances, with the technologist always able to see, hear and speak with you through an intercom. An MRI technologist, it adds, will be able to see, hear and talk to you at all times.
Why they ask so many questions
Many of the questions at the start come from the technologist, and they matter. For MRI, RadiologyInfo.org says the technologist will ask a variety of questions on a screening form, including whether you have implants or devices, and will tell you which metal objects to remove. For contrast scans they ask about allergies and kidney problems, and every exam involving radiation begins with the question of whether you might be pregnant. The reasons are explained in radiation, contrast and imaging safety. The most useful thing you can do is answer fully and mention anything you are unsure about.
Radiation safety is part of the role
RadiologyInfo.org states that the technologist is responsible for radiation safety. They follow protocols so that exposures for staff and patients meet the ALARA (As Low As Reasonably Achievable) standard, may use lead aprons and shields, and adjust the X-ray beam to target the area of interest and minimise scatter. The BLS notes that, because they work with imaging equipment that uses radiation, radiologic technologists wear badges that measure radiation levels, that detailed records of cumulative lifetime dose are kept, and that hazards are minimised by protective lead aprons, gloves and other shielding devices.
Who reads the pictures, and who tells you
The distinction to hold on to is the one between operating the scanner and interpreting the images. RadiologyInfo.org describes the radiologist as the doctor who supervises exams, reads and interprets the images, and writes a report for the referring provider. The technologist works closely with radiologists and captures the images for them to interpret. Practices about what a technologist can discuss differ, and in most places results come through the doctor who ordered the scan, as described in reading a radiology report. If you have a question during the exam about the exam itself, such as how long it will take or what the noise is, the technologist is the right person to ask.
Frequently asked questions
What is the difference between a radiologist and a radiologic technologist?
According to RadiologyInfo.org, the radiologist is a doctor who reads and interprets the images and writes a report, while the technologist operates the imaging equipment, positions patients and captures the images for the radiologist.
Is a radiographer the same as a radiologic technologist?
The BLS states that radiologic technologists are also known as radiographers. Titles and duties differ by country and by scan type, so the names are not always interchangeable.
Can the technologist tell me what the scan shows?
Image interpretation is the radiologist's role, and results are normally sent to the doctor who ordered the scan. Facility practice varies, so ask what the arrangements are where you are being scanned.
Can I ask for someone to stay in the room with me?
The NHS page on X-rays says you can let the person doing your X-ray know that you would like a chaperone, either someone you know or a trained colleague of the radiographer. Policies vary for other scans, and RadiologyInfo.org notes that some facilities let a friend or parent stay for MRI after safety screening.
The short version
The technologist or radiographer is the person who explains your exam, positions you, runs the equipment, protects you and the team from unnecessary radiation and checks that the images are good enough to read. The radiologist reads them. Titles and arrangements differ by country, so your own imaging team can tell you who does what where you are being scanned.