General ultrasound examinations

This information explains what you can expect if you are having  a general (non-obstetric) ultrasound examination at Chelsea and Westminster Hospital. If you have any questions or concerns after you have read this information guide, please discuss these with your sonographer or doctor on the day of your scan.

What is an ultrasound examination?

An ultrasound scan is a widely used diagnostic test most commonly used to assess organs, soft tissues and blood flow. High-frequency sound waves that cannot be heard by the human ear are used to create images of the inside of the body. The small hand held ultrasound transducer generates sound waves as it moves across the skin surface and also detects sound waves which are reflected back to the surface after hitting surfaces and tissue boundaries of internal organs. The returning echoes’ are turned into a moving image that is displayed on a monitor while the scan is carried out. By moving the transducer around the body, organs can be viewed from different directions. 

Who will perform my examination?

An ultrasound scan is most commonly carried out by specially trained doctors called Radiologists or by highly trained professionals called Sonographers. Certain doctors, nurses, midwives and physiotherapists are also trained to undertake ultrasound scans.

Chelsea and Westminster Hospital is PROUD to be a teaching hospital. A student or training sonographer under the careful supervision of a trained professional may be present or may perform part or all of your ultrasound scan. If you do not wish a student to be present for your scan, please inform staff.

If you wish for a Doctor or Sonographer of a specific gender to perform your scan, all efforts will be made to find an appropriate professional. If this cannot be accommodated at the time of your scan, a further appointment on a different day, when your preferences can be met will be arranged.

Can I bring a relative/friend or request a chaperone?

Yes, if you wish to have a relative or friend present during your scan, there is space in the scan room for one person to join you. It is not recommended that you bring young children with you for your scan.

If you wish for a chaperone to be present during your scan, please inform staff during your appointment and an appropriate chaperone will be provided.

Are there any risks or side effects?

Standard diagnostic ultrasound scans are safe with no known harmful effects. There is no exposure to ionising radiation during an ultrasound scan.

External and internal ultrasound scans don't have any side effects and are generally painless, although you may experience some discomfort as the probe is pressed over your skin or inserted into a body cavity.

If you're having an internal scan and are allergic to latex, it's important to let the sonographer or doctor carrying out the scan know this so they can use a latex-free probe cover.

If you are having an injection or biopsy under ultrasound guidance there is a very small chance of bleeding or infection. Risks and side effects involved in these examinations will be discussed with you by your referring doctor and by the Doctor or Sonographers performing your examination. You will be provided with an aftercare sheet at the end of your examination.

How long does an ultrasound take?

An ultrasound examination usually takes between 15 and 30 minutes—however some vascular examinations which investigate the arteries and veins can take up to 90 minutes.

We strive to ensure that our lists run on time, however delays may occur and you may have a short wait for your appointment. Staff in the waiting areas and reception will be available to help you if you have any concerns about waiting times.

Preparing for your scan

Please read through your appointment letter to see if you have been asked to complete any preparation prior to your scan. Some examinations require that you follow certain instructions. For example, you may be asked:

  • ‘Drink 1,000 ml (1 l) of water and do not go to the toilet until after the scan’. This is to ensure your bladder is full which may be needed for a scan of your kidneys and bladder or a scan of your pelvis.
  • ‘Do not eat or drink anything other than water for 6 hours before the scan, you may drink water normally’. This may be needed for a scan of your abdomen, liver and/or gallbladder.
  • If you are having a scan of both your abdomen and pelvis, you will be asked not to eat for 6 hours and to drink 1,000 ml (1 l) of water 45 minutes prior to the scan.

Diabetic patients

Ideally, we try and schedule diabetic patients into early morning or early afternoon appointments. Please contact the department if you need a more appropriate appointment time. Diabetic patients should bring any insulin or diabetic tablets with them to the hospital and a light meal, such as a sandwich for after the examination. You may continue to take medication (unless it should be taken with food) as normal. If you have any queries contact the department or your doctor for advice.

What does an ultrasound examination involve?

When you are called into the ultrasound room your identity will be checked and then the examination will be explained to you so that you may give informed consent for the examination to proceed. If you have any questions or concerns about the examination, please do not hesitate to ask the doctor/sonographer who will carry out the scan.

You may be asked to remove or loosen your clothing or asked to change into a gown in order to be examined. You will be asked to lie or sit on a couch for the examination and the room lights will be dimmed to allow a clear view of the screen.

A clear, water based gel will be applied and spread over the area to be examined. The operator will run the ultrasound transducer through the gel. Pressure may need to be applied and you may be asked to turn on your side or perform breathing exercises to gain better views. Selected images produced during the scan will be saved as a record of the examination.

Biopsies and injections

If you are scheduled to have an injection or a biopsy, your doctor will have discussed this with you before referring you for your scan. The Radiologist or Sonographer performing your scan will also explain and discuss the injection or biopsy with you before commencing your procedure. You can decline a biopsy or injection at any time. All injections and biopsies are carried out using aseptic techniques. If you are having a biopsy or received an injection, the doctor or sonographer will give you appropriate aftercare information and you will receive an aftercare leaflet at the end of your appointment. 

What happens after the scan?

After the gel has been wiped away and you have dressed, the operator will explain how you receive your results and then you are free to leave. After your scan you may eat and drink as normal. Aftercare instructions for biopsy and injections will be given to patients following their procedures.

How do I get my results?

You will not receive your scan results during your scan appointment. The sonographer/doctor will write a report after performing the scan. The report will be sent to the doctor/clinic who requested your examination. You will need to arrange a follow up appointment with that doctor/clinic to discuss your results. GP patients’ results will be sent to the GP within 7–10 working days.

Contact information

Imaging Department
1st Floor, Lift Bank D
Chelsea and Westminster Hospital
369 Fulham Road
London
SW10 9NH

Mon–Fri, 9am–5pm

If you need to change your appointment date or time, or if require an interpreter for your examination, please contact the booking team on 020 3315 2785/3.

Contributors
jaimeg George Vasilopoulos