Bladder cancer is a disease that affects over 80,000 Americans annually. Early detection is critical for improving patient outcomes; early bladder cancer diagnosis can increase the 5-year survival rate to up to 100 percent1.
Computed tomography (CT) scans, particularly CT urography, play a pivotal role in diagnosing bladder cancer by providing detailed images of the urinary system, including the bladder, kidneys, and surrounding tissues. This non-invasive imaging method can identify tumors, detect metastasis, and guide treatment planning.
A CT scan is a diagnostic imaging procedure that uses X-ray technology and computer processing to create detailed cross-sectional images of the body2. 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 tissues3. 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 gantry4. 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 are important in detecting bladder cancer, offering several key advantages that make them the preferred choice for diagnosis and staging.
CT scans, particularly CT urography, demonstrate impressive accuracy in detecting bladder cancer. For example, a 2018 study found that CT urographies had a 91.5 percent accuracy rate in detecting urinary tract cancer5.
Furthermore, CT scans offer a comprehensive view of the urinary system. They can examine the entire urinary tract, including kidneys, ureters, and bladder. CT urography allows for visualization of upper urinary tract tumors, which occur in 2-4 percent of bladder cancer patients6.
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. This is particularly apparent compared to cystoscopy, which is the current gold standard for bladder cancer detection. In cystoscopy, a long, thin tube with a small camera inside is gently put into your urethra and moved through into your bladder7.
CT scans provide valuable information about tumors:
Common symptoms of bladder cancer include9,10:
Risk factors for bladder cancer include11:
Proper preparation for a CT scan 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 allowed12. 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 agent13. 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 temporarily14.
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 a Magnetic Resonance Imaging (MRI) machine, which should reduce the likelihood of claustrophobia.
CT scans are generally safe, but there are some potential risks to consider. Ionizing radiation in CT scans may slightly increase long-term cancer risk15. 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.
Early detection of bladder cancer offers significant benefits, substantially improving treatment outcomes and overall prognosis. As mentioned above, early detection can increase the 5-year survival rate of bladder cancer up to 100%. Early-stage detection often allows for less invasive treatment options, preserving bladder function and enhancing the patient’s quality of life16. Additionally, it can reduce healthcare costs associated with managing advanced disease and decrease the likelihood of requiring radical interventions such as cystectomy or systemic chemotherapy17.
Early detection also minimizes the risk of metastasis, as non-muscle-invasive bladder cancers are less likely to have spread to other parts of the body18. This increases the effectiveness of current treatment modalities, leading to higher cure rates and better long-term outcomes. By prioritizing early detection through screening programs and prompt investigation of symptoms, patients can significantly improve their chances of successful treatment and long-term survival19.
CT and MRI scans both effectively detect bladder cancer, each with unique strengths. CT scans, especially CT urograms, have a 91.5 percent sensitivity for urinary tract cancers and are excellent for visualizing the upper urinary tract5. They are widely available but involve radiation exposure. MRI scans offer superior soft tissue detail and better assess tumor invasion depth without radiation. While studies show similar detection rates, MRI may excel in evaluating bladder wall invasion20.
A CT scan without contrast can still detect bladder cancer, but it may be less effective. CT scans without contrast, also known as KUB (kidney, ureter, bladder) scans, can identify some bladder abnormalities and tumors. However, they have limitations in detecting small or early-stage tumors21.
CT scans are important tools for early detection and staging of bladder cancer, offering accuracy, non-invasive imaging, and tumor characterization. Their use, in combination with other imaging techniques like MRI, can enable healthcare professionals to provide precise diagnoses, tailor treatment plans effectively, and prioritize patient quality of life.
If you want to be proactive about your health, why not book an Ezra Full-Body Plus scan? We combine MRI with LDCT to catch abnormalities earlier, leveraging AI through the screening process to make it more efficient, affordable, and faster.
1. Rezaianzadeh A, Mohammadbeigi A, Mobaleghi J, Mohammadsalehi N. Survival analysis of patients with bladder cancer, life table approach. J Midlife Health. 2012;3(2):88-92. doi:10.4103/0976-7800.104468
2. 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
3. CT scan - Mayo Clinic. Accessed December 9, 2024. https://www.mayoclinic.org/tests-procedures/ct-scan/about/pac-20393675
4. 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
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6. Galgano SJ, Porter KK, Burgan C, Rais-Bahrami S. The Role of Imaging in Bladder Cancer Diagnosis and Staging. Diagnostics (Basel). 2020;10(9):703. doi:10.3390/diagnostics10090703
7. What is a cystoscopy. nhs.uk. February 12, 2024. Accessed December 17, 2024. https://www.nhs.uk/conditions/cystoscopy/what-is-a-cystoscopy/
8. Hu K, Zhu J, Li P, Ying L. Multiorientation Simultaneous Computation of Back-Projection CT Image Reconstruction Algorithm in Staging Diagnosis of Bladder Cancer. Comput Math Methods Med. 2022;2022:6731491. doi:10.1155/2022/6731491
9. Bladder Cancer Symptoms - NCI. February 16, 2023. Accessed December 17, 2024. https://www.cancer.gov/types/bladder/symptoms
10. Bladder cancer symptoms. Accessed December 17, 2024. https://www.macmillan.org.uk/cancer-information-and-support/bladder-cancer/signs-and-symptoms-of-bladder-cancer
11. Bladder Cancer Risk Factors | How Do You Get Bladder Cancer? Accessed December 17, 2024. https://www.cancer.org/cancer/types/bladder-cancer/causes-risks-prevention/risk-factors.html
12. CT scan. nhs.uk. October 18, 2017. Accessed December 9, 2024. https://www.nhs.uk/conditions/ct-scan/
13. Rogers DC, Tadi P. Intravenous Contrast. In: StatPearls. StatPearls Publishing; 2024. Accessed December 9, 2024. http://www.ncbi.nlm.nih.gov/books/NBK557794/
14. 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
15. 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
16. ecancer. Simple noninvasive test may lead to breakthrough in early diagnosis of bladder cancer - ecancer. Accessed December 17, 2024. http://ecancer.org/en/news/23525-simple-noninvasive-test-may-lead-to-breakthrough-in-early-diagnosis-of-bladder-cancer
17. Early cancer diagnosis saves lives, cuts treatment costs. Accessed December 17, 2024. https://www.who.int/news/item/03-02-2017-early-cancer-diagnosis-saves-lives-cuts-treatment-costs
18. Bladder Cancer Prognosis and Survival Rates - NCI. February 16, 2023. Accessed December 17, 2024. https://www.cancer.gov/types/bladder/survival
19. Khochikar MV. Rationale for an early detection program for bladder cancer. Indian J Urol. 2011;27(2):218-225. doi:10.4103/0970-1591.82841
20. Niiya A, Ohgiya Y, Seino N, Gokan T. Comparison of CT Urography and MRI in Bladder Cancer Detection. Showa Univ J Med Sci. 2016;28(1):55-62. doi:10.15369/sujms.28.55
21. Tins B, Teo HG, Popuri R, Cassar-Pullicino V, Tyrrell P. Follow-up imaging of the urinary tract in spinal injury patients: is a KUB necessary with every ultrasound? Spinal Cord. 2005;43(4):219-222. doi:10.1038/sj.sc.3101691
