The most common reason an ultrasound appointment goes wrong is simple: the patient prepared for the wrong exam. Some ultrasounds need you to fast, some need a full bladder, some need both, and some need neither. This cheat sheet puts the rules for each exam in one place, based on the preparation instructions at Annex Medical Imaging in Toronto, so you can get ready with confidence and avoid a rescheduled visit.

Ultrasound Preparation by Exam Type

Select the exam named on your requisition:

Annex also provides a downloadable exam preparation sheet in multiple languages. If your requisition names an exam that is not on this list, such as a neck, breast or musculoskeletal ultrasound, follow any instructions your doctor gave you and call the clinic to confirm.

A Simple Way to Plan Your Day

Count backward from your appointment time. Here are two examples:

• Abdominal ultrasound at 10:00 am: your 8-hour fast starts at 2:00 am, so plan to finish eating the night before. Take any medication with water.
• Pelvic ultrasound at 2:00 pm: finish drinking 4 cups of water by 1:00 pm and do not use the washroom after that. Eat and drink normally earlier in the day.

If you have diabetes, take medication that must be taken with food, or have any other reason that fasting may be difficult, speak with your doctor before the exam. They can tell you how to handle it safely.

What to Bring and What to Wear

• Your requisition from your doctor, nurse practitioner, midwife or another eligible provider, and your Ontario health card
• Comfortable, loose-fitting clothing that gives easy access to the area being scanned. You may be asked to change into a gown.
• Information about any implants or medical devices you have, so you can tell the sonographer

Common Preparation Mistakes

• Using the washroom “just in case” during the hour before a pelvic scan, which means the bladder is no longer full
• Eating a small snack before an abdominal or renal exam, which can reduce image quality
• Mixing up exams: a pelvic exam needs a full bladder but no fast, while an abdominal exam needs a fast but not a full bladder
• Arriving without a requisition. Annex cannot perform exams without one
• Not calling to cancel. Please give at least 24 hours’ notice to cancel or reschedule so the spot can go to another patient

Booking Your Ultrasound in Toronto

Annex Medical Imaging is at 800 Bathurst St, Unit 304 (3rd floor), across from Bathurst subway station. Hours are Monday to Friday 9:00 am to 5:00 pm and Saturday 9:00 am to 3:00 pm. Ultrasound walk-ins are accepted only when a spot is open, and since fasting or a full bladder is part of many exams, booking ahead saves you a wasted trip. Call (416) 531-1128 or see our guide to walk-in diagnostic imaging at Annex.

Related Reading

• General Abdominal Ultrasound: What It Checks and How to Prepare (Fasting Guide)
• Pelvic ultrasound
• Obstetric ultrasound and preparation
• Kidney (Renal) Ultrasound in Toronto: How to Prepare and What to Expect
• Do You Need a Referral for an X-Ray, Ultrasound, or Mammogram in Toronto?

Frequently Asked Questions

Can I drink water before an abdominal ultrasound?

Annex’s instructions for an abdominal ultrasound say not to eat or drink for 8 hours, and to take medications with water only. If you have concerns, call the clinic or your doctor.

How much water is a full bladder?

For pelvic and combined exams, drink at least 4 cups of water (about 1 litre) so you finish one hour before your appointment, then avoid the washroom until after the scan.

What if I am pregnant?

Pregnancy scans are included in the pelvic preparation group, which calls for a full bladder. Your doctor or the clinic can confirm the instructions for your stage of pregnancy.

Do I need to prepare for an X-ray?

No special preparation is needed for an X-ray, but do not wear metal items such as jewelry on the day of your test, and tell the technologist if you are or might be pregnant. See our guide to X-ray services in Toronto.

Can I resume normal activities after an ultrasound?

In most cases yes. There are typically no restrictions after an ultrasound.

This article summarizes the preparation instructions published by Annex Medical Imaging and is for general information only. It is not medical advice. If your doctor gave you different instructions, follow your doctor’s instructions and let the clinic know.