Before Having a CT Scan: Costs, Side Effects & FAQ

When it comes to cancer screening, accuracy and efficiency are crucial. Computed tomography (CT) scans are widely used because they provide clear internal images quickly, making them a common diagnostic tool. However, concerns about cost differences, radiation exposure, and side effects of contrast agents often leave patients uncertain. This article offers a comprehensive overview of CT scan applications, pricing comparisons, and potential risks to help you make a well-informed decision.

What Is a CT Scan?

A CT scan is a diagnostic imaging technique that uses X-rays and computer processing to generate detailed cross-sectional and 3D images of the body. It allows doctors to detect hidden abnormalities with precision.

Why Might You Need a CT Scan?

CT scans offer high resolution and rapid imaging, making them a common tool for diagnosing cancer and other medical conditions.

Cancer Diagnosis and Monitoring Treatment

CT scans play a key role in identifying certain types of cancer and are used throughout the diagnostic and treatment process to:

Determine the site and size of tumours
Assess cancer staging
Guide biopsy procedures
Monitor for recurrence
Evaluate treatment effectiveness

CT is particularly useful for diagnosing:

Lung cancer* – the most common and fatal cancer in Hong Kong
Colorectal cancer* – the third most common cancer in Hong Kong

*Based on 2022 statistics from the Hong Kong Cancer Registry.

CT scans can also detect cancers in the bladder, kidneys, ovaries, stomach, and pancreas.

Diagnosing Other Medical Conditions

Beyond cancer, CT scans are widely used to diagnose a range of conditions, such as fractures, joint abnormalities, internal bleeding, infections, blood clots, heart disease, emphysema, and liver masses.

CT Scan Costs in Hong Kong

The cost of a CT scan in Hong Kong varies depending on the type of medical service providers, the area being examined, and whether a contrast agent is used.

CT Scan Fees: Public Hospitals vs Private Sectors

Public hospitals: Lower fees. Eligible in-patients receive CT scans free of charge; non-urgent outpatient CT scans cost HK$500^†.

Private services referred by public hospitals: HK$740–$5,480.

Private sectors: More expensive, with standard outpatient CT scans ranging from HK$3,060 to HK$22,590.

^†Effective from 1 January 2026.

Did you know? As of 2023–2024, the median waiting time for a CT scan in public hospitals in Hong Kong is up to 69 weeks (approximately 1.3 years) 2. While public hospital is more affordable, private medical service providers often offer more flexible scheduling and shorter waiting times. Understanding the differences in prices and service can help you choose the most suitable option.

OT&P also offers CT services—please consult our family doctors for personalised advice and pricing.

Costs Vary by Scan Area

CT scan fees can differ depending on the body part being examined. For example, abdominal or pelvic scans often require assessment of multiple organs and the use of contrast agents, making them generally more expensive than a straightforward head scan. Before booking, it’s advisable to confirm the scan details and costs with your hospital or clinic to plan your budget accordingly.

Are CT Scans Safe? Understanding Potential Side Effects

Radiation Exposure

While CT scans do involve exposure to ionising radiation, which may slightly increase the risk of developing cancer, modern technology has significantly reduced the radiation dose required per scan, making the procedure safer and more reliable.

Allergic Reactions to Contrast Agents

Some patients may experience an allergic reaction to the contrast agent used during certain CT scans. Common and mild symptoms include: mild fever, itching, nausea, vomiting, pain or itchiness at the injection site, rash, or swelling of the salivary glands.

2. Are Contrast Agents Harmful?

Gadolinium-based contrast agents are generally considered safe. Allergic reactions are rare, with the risk of a fatal reaction estimated at about 1 in 400,000. In very rare cases, patients with kidney failure may develop nephrogenic systemic fibrosis after receiving gadolinium contrast. If you have any concerns, discuss them with your doctor prior to the scan.

Frequently Asked Questions

1. How long does a CT scan take? Is it painful?

A CT scan only takes around 10 to 15 minutes and is completely painless.

2. Can I have a CT scan without a contrast agent?

Some scans do not require a contrast agent. However, the use of contrast agent can provide clearer contrast when visualising blood vessels or subtle changes in soft tissue. Contrast use is on as-needed basis.

3. Is low-dose CT (LDCT) better than standard-dose CT?

Low-dose CT (LDCT) uses about one-fifth of the radiation of a standard CT, greatly reducing exposure. It is suitable for lung cancer screening and patients who need to undergo frequent CT examinations. However, the image resolution of LDCT may be slightly lower. Your doctor will recommend the appropriate scan based on your clinical needs.

4. Does using a contrast agent affect the cost?

Yes, the use of a contrast agent usually increases the overall cost of a CT scan.

5. Can I have a CT scan if I am pregnant?

If you are pregnant, CT scans should generally be avoided unless absolutely necessary. Non-radiation alternatives, such as ultrasound or MRI, are preferred. If a CT scan is essential, discuss the risks and benefits with your doctor.

Make the Right Choice

A CT scan is a safe and rapid imaging technique, playing a key role in diagnosing cancers and other health conditions. Whether you choose a public hospital or a private healthcare provider, it’s most important to base your decision on your health needs, budget, and time constraints. If you have any questions, consult your doctor for professional advice to ensure your scan is both safe and effective.

References

WebMD. (2023). ‘What is a CT scan?’ Available at <https://www.webmd.com/cancer/what-is-a-ct-scan> [Accessed 4 June 2025].
Cancer Research UK. (2022). ‘What is a CT scan (CAT scan)?’ Available at: <https://www.cancerresearchuk.org/about-cancer/tests-and-scans/ct-scan> [Accessed 4 June 2025].
Hospital Authority. (2024). ‘Overview of Hong Kong Cancer Statistics of 2022’ Available at : <https://www3.ha.org.hk/cancereg/pdf/overview/Overview%20of%20HK%20Cancer%20Stat%202022.pdf> [Accessed 4 June 2025].
Hospital Authority. (2025). ‘List of Private Service’ Available at: <https://www3.ha.org.hk/fnc/Radiology.aspx?lang=CHIB5> [Accessed 4 June 2025].
Gleneagles Hospital. (2025). ‘Radiology Services – CT Scan’ Available at: <https://gleneagles.hk/media/5ai.-CT_20250601.pdf> [Accessed 4 June 2025].
Hong Kong Sanatorium & Hospital. (2024). ‘Computed Tomography (CT Scan) Price list.’ Available at: <https://mobile.hksh.com/zh-hk/fees-and-charges/price-list/department-of-diagnostic-and-interventional-radiology-computed-tomography-ct-scan> [Accessed 4 June 2025]. 
HK01. (2025). ‘公立醫院收費懶人包｜4服務變免費　急症室專科門診新舊收費對照’ Available at: <https://www.hk01.com/article/60223141?utm_source=01articlecopy&utm_medium=referral> [Accessed 4 June 2025].
National Institutes of Health. (2025). ‘Radiation from CT scans and cancer risks’ Available at: <https://www.nih.gov/news-events/nih-research-matters/radiation-ct-scans-cancer-risks> [Accessed 4 June 2025].
RadiologyInfo.org. (2025). ‘CT safety during pregnancy’. Available at: <https://www.radiologyinfo.org/en/info/safety-ct-pregnancy> [Accessed 4 June 2025].