LEARN ABOUT CT

CT Scan for Brain Cancer Detection

Learn how CT scans can help in the early detection of brain cancer. Discover the benefits, process, and what to expect.

Introduction

Brain cancer represents a significant health challenge in the United States, with an estimated 25,400 new cases of malignant brain and spinal cord tumors expected in 20241. This accounts for approximately 1.3 percent of all new cancer cases in the country. 

Computed tomography (CT) scans are crucial in diagnosing brain tumors. As a non-invasive imaging technique, CT scans use X-rays to create detailed cross-sectional brain images. With a total primary brain and central nervous system (CNS) tumor incidence rate of 25.34 cases per 100,000 population in the US, early and accurate diagnosis is critical2.

A man being prepared for a head CT scan

What Is A CT Scan?

A computed tomography (CT) scan is a diagnostic imaging procedure that uses X-ray technology and computer processing to create detailed cross-sectional images of the body3. It produces more detailed images than standard X-rays, allowing healthcare professionals to visualize internal structures such as bones, muscles, organs, and blood vessels.

CT scans are advanced medical imaging techniques that use X-rays and computer processing to create detailed cross-sectional images of the body. The technology involves a rotating X-ray tube and detectors that measure X-ray attenuation through different tissues4. These measurements are then processed using tomographic reconstruction algorithms to produce virtual “slices” of the body.

The CT machine consists of a motorized table that moves the patient through a circular opening called the gantry5. Inside the gantry, an X-ray source and detector assembly rotate around the patient, typically completing a rotation in less than a second. As the X-rays pass through the body, detectors register the radiation that emerges, creating snapshots from various angles. The computer then reconstructs these snapshots into cross-sectional images or slices of the internal organs and tissues.

CT scans differ from other imaging techniques in several ways:

  1. CT vs. MRI: CT scans use X-rays, while magnetic resonance imaging (MRI) uses magnetic fields and radio waves. CT scans are faster and quieter than MRIs, making them more suitable for emergency situations. However, MRIs provide superior soft tissue contrast and can detect certain abnormalities that CT scans might miss6.
  2. CT vs. X-ray: X-rays are commonly used to detect bone fractures and joint problems, identify lung conditions like pneumonia, dental imaging, mammography for breast cancer screening, and guide procedures such as catheter placement7. CT scans offer more detailed images than traditional X-rays, providing cross-sectional views and the ability to differentiate between various tissue densities.
  3. CT vs. PET: Positron Emission Tomography (PET) scans use radioactive tracers to visualize metabolic activity in tissues. While CT scans provide detailed anatomical images, PET scans highlight areas of increased metabolic activity, such as cancerous tumors8. The combination of PET and CT (PET/CT) offers complementary information, allowing for more accurate diagnosis and treatment monitoring.
  4. CT vs. Ultrasound: Ultrasound imaging uses high-frequency sound waves to create real-time images of internal structures without ionizing radiation. While ultrasound is portable and cost-effective, it has limitations in visualizing deep structures obscured by bone or gas9

How CT Scans Help in Brain Cancer Detection

CT scans provide detailed images that can reveal abnormalities in the brain’s structure. During a scan, a series of X-rays are taken from multiple angles as an X-ray beam rotates around the patient. This technique allows for the creation of cross-sectional images of the brain, which can highlight tumors, bleeding, or swelling. Sometimes, a contrast dye may be administered intravenously to enhance image clarity, allowing for better visualization of cancerous cells or abnormalities10

CT scans offer several advantages in the early detection of brain cancer. It has been found to significantly improve the sensitivity and specificity of glioma diagnosis and a reduction in the duration of symptoms of brain cancer before diagnosis11,12. Although MRI is often preferred for soft tissue imaging, CT scans are invaluable when MRI is contraindicated, such as in patients with pacemakers or claustrophobia. 

A man undergoing a head CT scan

Symptoms of Brain Cancer

Common symptoms of brain cancer can often prompt a healthcare provider to recommend a CT scan. These symptoms can include persistent headaches, which can worsen in the morning or with sudden movements, nausea and vomiting, seizures, blurred or double vision, and changes in personality or behavior, amongst other symptoms13.

Early detection of brain cancer is critical for improving treatment outcomes and patient prognosis. The sooner a tumor is identified, the more options are available for effective intervention. Timely consultation with a healthcare provider is essential when experiencing any concerning symptoms.

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CT Scan Benefits for Brain Cancer

CT scans offer significant benefits for brain cancer detection, combining accuracy, reliability, and efficiency. One study of 817 patients found that CT scans of the cerebrum (CT-C) demonstrated high sensitivity (98.5 percent) and specificity (98.4 percent) in detecting intracranial tumors14. This exceptional accuracy makes CT-C a viable primary screening tool for patients with suspected brain cancer.

The non-invasive nature and quick results of CT scans are major advantages. CT scanning is painless, fast, and can provide detailed images of bone, soft tissue, and blood vessels simultaneously. In emergency situations, CT scans can rapidly reveal internal injuries and bleeding, potentially saving lives15.

Compared to other diagnostic methods, CT scans offer some unique advantages. Magnetic resonance imaging (MRI), for instance, provides excellent soft tissue contrast but is typically more time-consuming16. Traditional X-rays, on the other hand, cannot match the detailed imaging capabilities of a CT scan, especially for complex areas like the brain17. Additionally, CT scans can often be combined with contrast agents to enhance visualization of blood vessels and tumors.

The CT Scan Procedure

Proper preparation for a CT will ensure an effective and smooth experience. You may need to fast for four hours before the scan, though clear fluids and regular medications are usually allowed18. Diabetic patients can have a light snack if needed. If contrast is required, you may need to drink water or a special liquid beforehand. 

Wear comfortable, loose clothing to your appointment and remove all metal objects. You may need to change into a hospital gown.

For scans requiring contrast, an IV might be used, or you might drink an oral contrast agent10. Notify your provider about allergies, especially to iodine or contrast materials. You should also inform your doctor if you are pregnant, have medical conditions, or take medications like metformin, which may need to be paused temporarily19.

What To Expect During The Procedure

A CT scan is a quick and painless process for capturing detailed internal images. The procedure usually lasts 15-30 minutes, with scanning taking about 10-15 minutes. You’ll lie on a moving table that slides into the scanner, and you’ll be instructed to stay still to ensure image quality. 

As the X-ray machine rotates, you’ll hear whirring sounds. The radiographer will guide you via intercom and may ask you to hold your breath briefly for clearer images. If you feel anxious, make sure you let the radiographer know. However, the scanner is open, unlike an MRI machine, which should reduce the likelihood of claustrophobia.

Understanding the Risks

CT scans are generally safe, but there are some potential risks to consider. Ionizing radiation in CT scans may slightly increase long-term cancer risk20. Low-dose CT (LDCT) minimizes radiation exposure and is particularly beneficial for routine screenings. Contrast agents enhance image quality but may not be suitable for patients with allergies or kidney issues. 

A medical professional looking over a CT scan.

FAQs

How does a CT scan detect brain cancer?

As mentioned above, CT scans take a series of X-ray images, providing a 3D image of brain tissues. It excels at providing detailed images of bone structures near brain tumors, such as the skull or spine, which can be important for diagnosis and treatment planning. CT scans are particularly effects at detecting calcifications and hemorrhages, which can be associated with certain types of brain tumors21. In many cases, CT scans will be used in conjunction with other diagnostic imaging methods to perform a comprehensive evaluation.

Are there any risks associated with CT scans?

CT scans are generally safe, but there are some potential risks to consider. Ionizing radiation in CT scans may slightly increase long-term cancer risk20. Low-dose CT (LDCT) minimizes radiation exposure and is particularly beneficial for routine screenings. Contrast agents enhance image quality but may not be suitable for patients with allergies or kidney issues.

Conclusion

CT scans are a vital tool in the early detection and diagnosis of brain cancer, offering high accuracy and efficiency. Their non-invasive nature and quick results make them indispensable, particularly in emergency and time-sensitive cases. For the diagnosis of brain cancer, CT scans are usually combined with MRI and PET scans. Despite minimal risks, advancements like low-dose CT (LDCT) enhance safety for routine screenings. When combined with timely medical consultation, CT scans play a crucial role in improving patient outcomes and facilitating effective treatment planning for brain cancer.

If you want to be proactive about your health, why not book an Ezra full-body Plus scan? Our scan uses MRI and LDCT to catch potential cancer earlier, leveraging AI through the screening process to make it more efficient, affordable, and faster.

References

1. Brain Tumor Facts. National Brain Tumor Society. Accessed December 13, 2024. https://braintumor.org/brain-tumors/about-brain-tumors/brain-tumor-facts/

2. Price M, Ballard C, Benedetti J, et al. CBTRUS Statistical Report: Primary Brain and Other Central Nervous System Tumors Diagnosed in the United States in 2017-2021. Neuro Oncol. 2024;26(Supplement_6):vi1-vi85. doi:10.1093/neuonc/noae145

3. Definition of CT scan - NCI Dictionary of Cancer Terms - NCI. February 2, 2011. Accessed December 9, 2024. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/ct-scan

4. CT scan - Mayo Clinic. Accessed December 9, 2024. https://www.mayoclinic.org/tests-procedures/ct-scan/about/pac-20393675

5. Computed Tomography (CT). National Institute of Biomedical Imaging and Bioengineering. Accessed December 9, 2024. https://www.nibib.nih.gov/science-education/science-topics/computed-tomography-ct

6. Health C for D and R. Benefits and Risks. FDA. Published online September 2, 2019. Accessed December 9, 2024. https://www.fda.gov/radiation-emitting-products/mri-magnetic-resonance-imaging/benefits-and-risks

7. Hutchison C. X-Ray Advantages and Disadvantages. Accessed December 9, 2024. https://www.patientimage.com/blog/x-ray-advantages-disadvantages

8. Radiology (ACR) RS of NA (RSNA) and AC of. PET/CT. Radiologyinfo.org. Accessed December 9, 2024. https://www.radiologyinfo.org/en/info/pet

9. Ultrasound - Mayo Clinic. Accessed December 9, 2024. https://www.mayoclinic.org/tests-procedures/ultrasound/about/pac-20395177

10. Rogers DC, Tadi P. Intravenous Contrast. In: StatPearls. StatPearls Publishing; 2024. Accessed December 9, 2024. http://www.ncbi.nlm.nih.gov/books/NBK557794/

11. Beltramello A, Zampieri P, Pinna G, Andrioli GC. Is computed tomography really effective in the early detection of brain tumors? A cooperative study. Acta Radiol Suppl. 1986;369:144-146.

12. Liu Y, Zhang Y, E Y, Zhang X, Ma H, Dong F. Abnormal expression of long non‑coding RNA LINC01270 in glioma and its correlation with X‑ray computed tomography signs. Acta Neurobiol Exp (Wars). 2024;84(1):43-50. doi:10.55782/ane-2024-2521

13. Jiang B, Liu H, Sun D, et al. Mortality due to primary brain tumours in China and detection rate in people with suspected symptoms: a nationally representative cross-sectional survey. World J Surg Oncol. 2021;19:71. doi:10.1186/s12957-021-02179-5

14. Mortensen SJ, Bjerrum SN, Hedegaard SF, Tietze A, Gottrup H, von Oettingen G. The role of computed tomography in the screening of patients presenting with symptoms of an intracranial tumour. Acta Neurochir (Wien). 2018;160(4):667-672. doi:10.1007/s00701-018-3478-z

15. Radiology (ACR) RS of NA (RSNA) and AC of. Body CT. Radiologyinfo.org. Accessed December 9, 2024. https://www.radiologyinfo.org/en/info/bodyct

16. Exploring the Brain: Is CT or MRI Better for Brain Imaging? UCSF Radiology. April 11, 2012. Accessed December 16, 2024. https://radiology.ucsf.edu/blog/neuroradiology/exploring-the-brain-is-ct-or-mri-better-for-brain-imaging

17. Radiology (ACR) RS of NA (RSNA) and AC of. Computed Tomography (CT) - Head. Radiologyinfo.org. Accessed December 9, 2024. https://www.radiologyinfo.org/en/info/headct

18. CT scan. nhs.uk. October 18, 2017. Accessed December 9, 2024. https://www.nhs.uk/conditions/ct-scan/

19. Imperial College Healthcare. Having a CT Scan. Having a CT Scan - Information for Patients. 2019. Accessed December 9, 2024. https://www.imperial.nhs.uk/-/media/website/patient-information-leaflets/imaging/having-a-ct-scan.pdf?rev=a4168516b0374dbf9ea6214e676c0d79&sc_lang=en

20. Computed Tomography (CT) Scans and Cancer Fact Sheet - NCI. January 3, 2024. Accessed July 16, 2024. https://www.cancer.gov/about-cancer/diagnosis-staging/ct-scans-fact-sheet

21. Brain Tumors Detection using Computed Tomography Scans Based on Deep Neural Networks. Inf Sci Lett. 2023;12(4):1173-1182. doi:10.18576/isl/120433