October 31, 2025
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October 31, 2025

MRI vs CT Scan for Lung Cancer: What’s the Difference?

Health and Wellness
,
Lung Health
,
Reviewed By:
Dr Michael Williams
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MRI vs CT Scan for Lung Cancer: What’s the Difference?

Contents

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Early and accurate detection of lung cancer is essential for effective treatment and improved survival rates. Imaging tools are essential for lung cancer diagnosis, including CT and MRI. While both provide detailed internal images, they differ in technology, applications, and advantages. This article compares MRI and CT scans in the context of lung cancer, exploring how each works, when they are used, and what factors determine which imaging method is best suited for a particular case.

How Does Lung Cancer Develop?

Lung cancer occurs when lung cells mutate. The primary cause of such mutation is exposure to (and inhalation of) harmful chemicals. However, lung cancer can also affect people without any known exposure to toxic substances. Unlike healthy cells, cancerous cells grow uncontrollably and form a cluster, leading to a tumour that destroys healthy lung tissue around it. Symptoms usually don't appear until the cancer cells spread to other parts of the body, hindering their proper functioning. At this stage, treating lung cancer becomes challenging1. 

How Common Is Lung Cancer in the United Kingdom?

MRI vs CT scan for lung cancer: person holding a model of the human lungs

Lung cancer is the most common cause of cancer death in the UK, accounting for 20 percent of all cancer deaths2. It is also the leading cause of cancer deaths. It is the leading cause of cancer deaths globally, with an estimated 1.8 million deaths3.

There are around 50,000 new cases of lung cancer in the UK every year, making it the 3rd most common cancer. Around 72 percent of lung cancer cases in the UK are caused by smoking, and 79 percent of cases are preventable2.

MRI vs CT for Lung Cancer: Which One Should You Choose?

While each type of scan has its advantages, computed tomography (CT) scans remain the gold standard for lung cancer imaging4. This is due to their superior spatial resolution and ability to detect small pulmonary nodules. However, MRI is a valuable tool in specific scenarios, and its use in lung cancer assessment is evolving5. 

Your doctor will recommend the most appropriate imaging test based on your circumstances. Some of the factors they will consider include the reason for the scan (detection, cancer staging, follow-up), suspected location of the cancer, specific information needed, and patient factors, such as allergies to contrast agents (like gadolinium), presence of pacemakers, claustrophobia, etc5.

Magnetic Resonance Imaging for Lung Cancer

MRI scans utilise a powerful magnetic field and radio waves to generate detailed images of soft tissues within the body. These scans excel at imaging the brain, spinal cord, joints, and other soft tissues, providing superior soft-tissue contrast for visualising ligaments and other structures6,7.

An MRI scan showing spine metastasis from lung cancer. Source. Used under Creative Commons license

MRI applications for lung cancer include:

  • Detecting brain metastases: Excels at detecting metastases (cancer that has spread) to the brain and spine8.
  • Characterising lesions: Effective in differentiating benign from malignant lesions9.
  • Soft tissue imaging: Useful in examining chest wall invasion by lung tumours9.

Advantages of using MRI:

  • Superior soft tissue contrast: MRI is excellent for differentiating between soft tissues, making it ideal for detecting brain and spinal cord metastases7.
  • No radiation exposure: Unlike CT scans, MRI machines do not use ionising radiation, which is better for frequent monitoring.
  • Multiplanar imaging capabilities: MRI can acquire images in multiple planes without moving the patient, aiding in comprehensive tumour assessment7.

Disadvantages of using MRI:

  • Susceptibility to motion artefacts: Patient motion can create poor image quality10.
  • Longer scan times: MRI typically takes longer than CT, which can be uncomfortable for some patients.
  • Expensive and less available: MRI is generally more costly and less widely available than CT scans.

Computed Tomography Scan for Lung Cancer

CT scans use X-ray technology to create cross-sectional images of the body. These types of scans provide exceptional detail of the lungs, abdomen, pelvis, and bones. CT scans are ideal for detecting lung nodules, tumours, and metastases and assessing their size, location, and spread11,12.

A CT scan of the lung. Source. Used under Creative Commons license

CT scan applications for cancer include:

  • Initial diagnosis and lung nodule detection: Ideal for identifying lung nodules and initial lung cancer diagnosis4,8.
  • Staging of lung cancer: Helps assess the size of the tumour, lymph node involvement, and distant metastasis13.
  • Guiding biopsies: Used to guide needle biopsies of lung nodules or masses14.
  • Treatment monitoring and follow-up: Useful for evaluating response to therapy and monitoring for recurrence15.

Advantages of CT scans:

  • Rapid imaging: CT scans are quick and can minimise motion artefacts.
  • High resolution for lung structures: Excellent for visualising lung parenchyma and identifying small nodules16.
  • Widely available and cost-effective: CT scans are accessible in most healthcare settings and are less expensive than MRI scans.

Disadvantages of CT scans:

  • Ionising radiation: Repeated exposure to this carries a greater cancer risk with cumulative radiation dose17.
  • Less effective for soft tissue: CT is less capable of differentiating between types of soft tissue compared to MRI.
  • Contrast-induced nephropathy: In cancer patients with renal impairment, contrast agents used in CT can worsen kidney function18.

Other Imaging Techniques for Diagnosing Lung Cancer

Other imaging modalities that are important for lung cancer include:

  • PET/CT scan: This combination scan combines the strengths of positron emission tomography (PET) and CT, showing both structural information and areas of metabolic activity potentially related to cancer19.
  • X-ray: While less sensitive than CT, chest X-rays may still be used to evaluate potential lung abnormalities20.

Lung Cancer Screening: The Importance of Early-Stage Detection

Early detection is paramount for those at high risk of lung cancer, such as those with a history of smoking. Low-dose CT (LDCT) screening has proven lifesaving by detecting cancer at its earliest, most treatable stages21. The five-year survival rate for those diagnosed at the earliest stage (Stage 1A) is around 90 percent, while this drops drastically at later stages of disease. For those diagnosed at stage 4, it is only around 10 percent22.

MRI vs. CT for Lung Cancer: Calculate Your Risk

MRI vs CT scan for lung cancer: mother and her kids playing with bubbles outdoors

MRI and CT scans play important roles in finding, evaluating, and managing lung cancer. Your healthcare provider will discuss your options based on your specific clinical scenario, the area of interest, and patient factors. 

CT scans are often the first choice for initial diagnosis and cancer staging due to their speed and effectiveness in lung imaging. MRI, conversely, is better suited for detecting metastases, especially in the brain, central nervous system, and spinal cord, and for detailed assessment of soft-tissue involvement. The combined use of these modalities can provide a comprehensive picture of the disease, aiding in optimal patient management.

Summary: Choosing Between MRI and CT Scans for Lung Cancer

Understanding the differences between MRI and CT scans is essential for anyone seeking clarity about lung cancer detection and management. While CT scans remain the gold standard for identifying and staging lung cancer due to their high resolution and speed, MRI offers distinct advantages in soft tissue evaluation and the detection of metastases, especially in the brain and spinal cord.

Both imaging tools play a crucial role in comprehensive lung cancer care. If you’re looking to be proactive about your lung health, consider scheduling a lung CT scan with Ezra today. 

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References

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2. Lung cancer statistics. Cancer Research UK. May 14, 2015. Accessed October 29, 2025. https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/lung-cancer 

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4. Lung cancer - Diagnosis. nhs.uk. October 23, 2017. Accessed October 29, 2025. https://www.nhs.uk/conditions/lung-cancer/diagnosis/ 

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8. Tests for lung cancer. Accessed October 29, 2025. https://www.cancerresearchuk.org/about-cancer/lung-cancer/getting-diagnosed/tests-for-lung-cancer 

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14. Needle biopsy through the skin for lung cancer. Accessed October 29, 2025. https://www.cancerresearchuk.org/about-cancer/tests-and-scans/needle-biopsy-through-skin 

15. Lam S, Bai C, Baldwin DR, et al. Current and Future Perspectives on Computed Tomography Screening for Lung Cancer: A Roadmap From 2023 to 2027 From the International Association for the Study of Lung Cancer. J Thorac Oncol Off Publ Int Assoc Study Lung Cancer. 2024;19(1):36-51. doi:10.1016/j.jtho.2023.07.019 

16. Dilger SK, Uthoff J, Judisch A, et al. Improved pulmonary nodule classification utilizing quantitative lung parenchyma features. J Med Imaging. 2015;2(4):041004. doi:10.1117/1.JMI.2.4.041004 

17. Cao CF, Ma KL, Shan H, et al. CT Scans and Cancer Risks: A Systematic Review and Dose-response Meta-analysis. BMC Cancer. 2022;22(1):1238. doi:10.1186/s12885-022-10310-2 

18. Shams E, Mayrovitz HN. Contrast-Induced Nephropathy: A Review of Mechanisms and Risks. Cureus. 2021;13(5):e14842. doi:10.7759/cureus.14842 

19. Farsad M. FDG PET/CT in the Staging of Lung Cancer. Curr Radiopharm. 2020;13(3):195-203. doi:10.2174/1874471013666191223153755 

20. Nooreldeen R, Bach H. Current and Future Development in Lung Cancer Diagnosis. Int J Mol Sci. 2021;22(16):8661. doi:10.3390/ijms22168661 

21. England NHS. NHS England » Rolling out targeted lung health checks. January 18, 2024. Accessed October 28, 2025. https://www.england.nhs.uk/blog/rolling-out-targeted-lung-health-checks/ 

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