How to Prepare for a CT Scan

November 2, 2025 · 3 min read · Light Radiology Team · CT Scans

This guide outlines how to prepare for your CT scan, including what to wear, eating and drinking instructions, and information about contrast dye. Following these steps helps ensure accurate images and a smooth appointment.

New to CT? Read What Is a CT Scan and How Does It Work? for a simple overview before your appointment.

Check your referral

Your referral form or booking confirmation will specify whether your scan requires contrast. Preparation can differ depending on the type of CT ordered by your doctor.

Unsure why CT was requested? See Why Your Doctor Might Refer You for a CT Scan.

General preparation

Bring your referral, Medicare card, and any previous imaging if available.
Arrive 10–15 minutes before your appointment to complete forms.
Wear loose, comfortable clothing without metal zips, belts, or buttons.
Leave jewellery, watches, and piercings at home when possible.
Continue taking your usual medications unless instructed otherwise.

Fasting and hydration

If your scan uses contrast, avoid eating for 2–4 hours before your appointment.
Drink water to stay hydrated; clear fluids are usually fine.
If your scan does not use contrast, you can generally eat and drink normally.

Learn how contrast affects preparation in CT Scan with Contrast vs Without Contrast.

Patients with diabetes or kidney conditions

Tell us if you have diabetes or kidney problems. These conditions can affect how your body handles contrast dye.
If you take metformin, you may need to pause it temporarily after your scan. We will give specific instructions.
Bring a list of current medications with you.

Contrast injection preparation

For contrast scans, a small IV cannula will be placed in your arm.
Let staff know if you have had any reaction to iodine contrast before.
Inform us of asthma, allergies, thyroid disease, or if you are pregnant or breastfeeding.

For more on safety, read Are CT Scans Safe?

Pregnancy and children

If you are or might be pregnant, inform us before your scan. We will assess whether CT is necessary or suggest an alternative such as ultrasound or MRI.
For children, we tailor scanning protocols to keep radiation dose as low as possible.

On the day of your scan

Arrive a few minutes early to complete your questionnaire.
Remove metal items and change into a gown if required.
If contrast is used, you will have a brief consultation before the injection.
Relax and follow the radiographer’s instructions during the scan.

Curious what happens during the scan? Read What to Expect During a CT Scan.

After your scan

If you had contrast, drink extra water through the day to help flush it from your body.
You can eat, drink, and resume normal activities immediately unless told otherwise.
If you notice redness, swelling, or pain at the injection site, contact us or your GP.

Quick checklist

Referral and Medicare card ready
Loose, metal-free clothing
Follow fasting instructions if contrast is used
Drink water before and after
Arrive early to allow time for paperwork

In summary

Most CT scans require little preparation. Following these simple steps helps ensure clear images and a safe, efficient experience. If you are unsure about fasting, medications, or contrast, contact our team before your appointment.

Isotretinoin For Acne – Should You Buy Online In Australia? A Doctor's Honest Review. Visit Our Pharmacy ↓

Isotretinoin in Australia: A Dermatologist’s Review for Adults Over 30

This article is written from a doctor’s point of view for Australian readers. It is educational and not a substitute for individual medical advice. Always speak with your GP or dermatologist.

Attention: Still fighting cystic acne after 30?

If you are over 30, you may have already tried antibiotic tablets, prescription creams, the contraceptive pill, expensive facials, and every “miracle” serum on the shelf. Yet the deep, painful cysts still appear before meetings, weddings, or dates. You may avoid photos, cancel social events, or feel embarrassed at work. Cystic acne is not a teenage cosmetic problem — it is a medical condition that can leave permanent scars and take a serious toll on confidence, mental health, and quality of life.

Here is what many Australian adults do not hear: isotretinoin is the closest thing dermatology has to a cure for severe cystic acne. It is not the first option for mild pimples, but for deep nodulocystic acne that has failed other treatments, it is the gold standard.

Interest: Why doctors call isotretinoin the gold standard

Isotretinoin is an oral retinoid, a vitamin A derivative. It is the only acne treatment that targets all four main drivers of acne at once:

Excess oil production
Clogged pores
Cutibacterium acnes bacteria
Inflammation

Most other treatments only address one or two of these factors. That is why isotretinoin can work when years of antibiotics and creams have failed.

Desire: Safety, success, and your biggest questions answered

What is the success rate of isotretinoin for cystic acne?

For severe nodulocystic acne, isotretinoin has the highest remission rates of any acne treatment available. Results improve when the patient receives a full cumulative dose, usually 120–150 mg/kg over 4–9 months.

Outcome	Reported success
Complete or near-complete clearance after one full course	Around 85%
Long-term remission after adequate cumulative dose	About 70–80%
Patients who need a second course	Usually respond well again

Many patients over 30 who have suffered for a decade or more find that one well-managed course changes their skin permanently.

What are the rare side effects of isotretinoin?

Common side effects such as dry lips, dry skin, and mild nosebleeds are expected. Rare but serious side effects are uncommon, but every patient must know the warning signs.

Body system	Rare but serious side effect	Warning sign
Brain	Idiopathic intracranial hypertension	Severe headache, blurred vision, nausea
Pancreas	Pancreatitis	Upper abdominal pain, vomiting
Vision	Night blindness, keratitis	Difficulty seeing at night, eye pain
Hearing	Hearing loss, tinnitus	Ringing in the ears
Skin	Stevens-Johnson syndrome / severe rash	Widespread rash, blisters, peeling
Bone and muscle	Hyperostosis, bone pain	Persistent joint or bone pain

These are rare, but they are why isotretinoin must be prescribed and monitored by a doctor, not bought online without supervision.

What counselling is required before starting isotretinoin?

In Australia, starting isotretinoin involves careful counselling. This is not because the drug is unsafe when used correctly, but because safety depends on informed patients and regular monitoring.

Pregnancy prevention: two effective forms of contraception for at least 1 month before, during, and for 1 month after treatment.
Pregnancy testing: before starting, monthly during treatment, and after finishing.
Blood tests: baseline liver function and fasting cholesterol/triglycerides, then periodic monitoring.
Mental health check: mood and anxiety screening before and during treatment.
Skin care counselling: moisturisers, lip balm, sunscreen, and avoiding waxing, dermabrasion, or certain lasers while on treatment.
Lifestyle advice: limit alcohol, avoid vitamin A supplements, and do not donate blood during treatment and for at least 1 month after stopping.

Can isotretinoin be used intermittently or cyclically?

For severe cystic acne, intermittent or cyclical use is not usually recommended. The best chance of long-term remission comes from reaching the full cumulative dose. Using the drug on and off may reduce total dose and increase the chance of relapse. However, in selected adults with recurrent milder acne, a dermatologist may sometimes use low-dose intermittent courses. This is a specialist decision and is not the standard first approach for deep cystic disease.

Can isotretinoin cause depression or mood changes?

Isotretinoin can uncommonly cause low mood, irritability, or emotional changes. The evidence is mixed, but the possibility must be taken seriously. Importantly, severe acne itself is strongly linked to depression, anxiety, and social withdrawal. Many patients feel better emotionally once their skin improves. If you have a history of depression, isotretinoin is not automatically off the table, but it should be used with close support from your GP, dermatologist, or mental health clinician.

Is isotretinoin safe for patients with hepatitis?

Isotretinoin can raise liver enzymes, so it is not safe in acute or active hepatitis, or when liver function tests are significantly abnormal. However, in patients with stable chronic hepatitis B or C — with normal or only mildly elevated liver tests — a specialist may prescribe isotretinoin cautiously with frequent liver monitoring. It is not an automatic exclusion, but it requires individual assessment and close supervision.

What is the black box warning for isotretinoin in Australia?

Australia does not use the exact US FDA “black box” label, but the TGA-approved product information contains an equivalent prominent boxed warning. Oral isotretinoin is Pregnancy Category X and must not be used during pregnancy. The warning highlights the high risk of severe birth defects, the need for two forms of contraception, monthly pregnancy testing, and clear patient education before prescribing.

Can isotretinoin cause birth defects?

Yes. If pregnancy occurs while taking isotretinoin, there is a high risk of miscarriage and major fetal malformations involving the brain, face, heart, and thymus. This is why pregnancy prevention is non-negotiable. With careful planning and contraception, the risk is manageable and treatment can be completed safely.

Action: Your next step in Australia

If you are over 30 and still losing confidence to deep, painful cystic acne, you do not have to accept it as normal. Isotretinoin is a prescription medicine, so the safest way is to see an Australian-registered GP or dermatologist. Ask about isotretinoin by name. Ask whether it is suitable for your skin, your medical history, and your lifestyle.

Book an appointment, request baseline blood tests, and discuss a full treatment plan. Many adults say the same thing after finishing: “I wish I had started years earlier.”

Do not buy isotretinoin online without medical supervision. The real value of isotretinoin is not just the drug — it is the monitoring, counselling, and specialist support that make it safe and effective.

doxycycline
telmisartan
estradiol

Billing Information

We offer accessible services by bulk billing almost all examinations and procedures. To find out more, visit our billing information page.

View Billing Information

Request an Appointment

Request a call back online – it’s quick, and easy and saves waiting on the phone. Click on the below link and follow the simple steps. Remember to have your referral handy.

Call-Back Request