Computed Tomography
CT scans use X-rays to create detailed cross-sectional images of the body. They are particularly useful for detecting bone fractures, tumors, and internal bleeding.
~350-700 chest X-rays
What is CT?
CT (Computed Tomography) is an advanced imaging technique that combines multiple X-ray images taken from different angles to create detailed cross-sectional views of bones, blood vessels, and soft tissues. Unlike traditional X-rays, CT provides 3D visualization of internal body structures.
How it works: During a CT scan, you lie on a table that slides through a large, doughnut-shaped scanner. The X-ray tube rotates around your body, taking multiple images. A computer then processes these images to create cross-sectional slices which can be viewed individually or stacked together for 3D visualization.
Common Uses of CT
Emergency trauma assessment
Quickly identify internal injuries, bleeding, and fractures
Cancer detection and monitoring
Locate tumors, assess their size, and monitor treatment response
Cardiovascular imaging
Visualize heart structures and detect blockages in blood vessels
Abdominal and pelvic issues
Diagnose conditions affecting organs like liver, kidneys, and intestines
Lung and chest examination
Detect infections, blood clots, and lung diseases
Acute abdomen clarification
Evaluate appendicitis, bowel obstruction, and pancreatitis
Emergency neuroimaging
Quickly detect intracerebral or subdural hemorrhage
Advantages
- ✓Fast and painless procedure
- ✓Excellent for viewing bones and detecting calcifications
- ✓Can image multiple types of tissue simultaneously
- ✓Widely available in most hospitals and imaging centers
Limitations
- ⚠Involves exposure to ionizing radiation
- ⚠May require contrast dye which can cause allergic reactions
- ⚠Less detailed for soft tissues compared to MRI
- ⚠Not recommended during pregnancy
Radiation Dose Calculator
Each scan delivers approximately 10 mSv, equivalent to about 500 chest X-rays or 3-5 years of natural background radiation.
Preparation Checklist
0 of 6 completed
⚖️CT vs MRI
Related Imaging Modalities
For soft tissue detail, consider MRI. For quick bone assessment, standard X-rays may suffice. For real-time imaging, ultrasound is an option.
MRI
MRI uses powerful magnets and radio waves to produce detailed images of organs and soft tissues. Excellent for brain, spine, and joint imaging.
Ultrasound
Ultrasound uses sound waves to create real-time images. Commonly used for pregnancy monitoring and examining organs like the heart, liver, and kidneys.
Frequently Asked Questions
Find answers to common questions about this imaging modality.
Browse CT Terms
Explore common terms in CT reports, each with detailed explanations, clinical significance, and related lab tests to help you understand your imaging results. lab tests.
Acute Pancreatitis
Enlarged pancreas with peripancreatic fat stranding; possible fluid collections or necrosis.
Acute Appendicitis
Dilated appendix (>6 mm) with wall thickening and peri-appendiceal fat stranding.
Small Bowel Obstruction
Dilated proximal small bowel loops with a transition point to collapsed distal bowel; possible closed-loop configuration.
Pulmonary Consolidation
Dense opacification of lung tissue with air bronchograms
Descending Thoracic Aortic Aneurysm
Dilated descending thoracic aorta >3.5 cm with mural thrombus or calcification; best seen on CTA.
Ground-glass Opacity (GGO)
Hazy increased attenuation of lung parenchyma with preserved bronchial and vascular margins
Intracerebral Hemorrhage (ICH)
Hyperdense parenchymal bleed with surrounding edema; possible intraventricular extension and midline shift.
Kidney Stone (Nephrolithiasis)
Hyperdense calculus along urinary tract with upstream hydronephrosis; soft tissue rim sign helpful.
Liver Lesion (Hepatic Lesion)
Focal abnormality in liver parenchyma with variable enhancement pattern
Pleural Effusion
Fluid collection in pleural space, appearing as dependent density
Pneumonia with Consolidation
Air space consolidation with air bronchograms, often lobar or segmental distribution
Pulmonary Embolism (PE)
Intraluminal filling defect in pulmonary arteries on CT angiography; possible wedge-shaped infarcts.
Pulmonary Nodule
Round or oval opacity in lung parenchyma, usually < 3 cm
Subdural Hematoma
Crescent-shaped extra-axial hyperdensity crossing suture lines; may become isodense/hypodense over time.
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Medical References
This content is referenced from authoritative medical organizations:
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