What is a body scan?

What is a Body Scan?

A body scan refers to a medical imaging procedure that examines the entire body or large portions of it using various imaging technologies such as PET/CT, CT, MRI, or bone scintigraphy to detect abnormalities, tumors, inflammation, or metastatic disease. 1, 2

Types of Body Scan Technologies

Computed Tomography (CT)

• Uses X-rays to create three-dimensional images of the body by measuring variations in tissue density 2
• Appears as a large donut-shaped machine that patients pass through during scanning
• Can be performed with or without contrast enhancement (oral or intravenous)
• Standard CT scan delivers radiation equivalent to approximately 150 chest X-rays
• Whole-body CT (WBCT) typically includes imaging of the head, neck, chest, abdomen, and pelvis 1
• Average time for a complete CT study is approximately 136 minutes, with the active scanning portion lasting about 60 minutes 3

Positron Emission Tomography/Computed Tomography (PET/CT)

• Combines a PET scan (which detects metabolic activity) with CT (which provides anatomical detail)
• Uses radioactive tracers like [¹⁸F]FDG (fluorodeoxyglucose), a radioactive glucose analogue that accumulates in areas with high glucose metabolism 1
• Particularly useful for detecting cancer, infection, and inflammation
• Imaging field may include:
  • Torso imaging: From skull base to mid-thighs (standard in Europe and USA)
  • Whole-body imaging: From skull vertex to feet 1

Magnetic Resonance Imaging (MRI)

• Uses a strong magnetic field and radio waves to generate detailed images without ionizing radiation 4
• Excellent for soft tissue contrast and can be tailored to highlight specific tissue characteristics 1
• Whole-body MRI can be performed in a relatively short time period for cancer screening or vascular disease evaluation 5
• May include specialized techniques such as diffusion-weighted imaging or spectroscopy 1

Bone Scintigraphy (Bone Scan)

• Nuclear medicine technique using radioactive compounds with affinity for bone matrix
• Detects areas of increased bone turnover that may indicate metastatic disease 1
• Primary techniques include:
  • Conventional bone scan using ⁹⁹ᵐTc-medronate and gamma camera
  • PET bone scan using ¹⁸F-NaF and PET scanner 1

Dual-Energy X-ray Absorptiometry (DEXA)

• Uses radiation attenuation at two energies to determine body composition
• Primarily used to assess body fat percentage and bone mineral density
• Can also evaluate regional body fat distribution 1

Clinical Applications

Cancer Evaluation

• Detection, staging, and monitoring of various cancers
• Particularly valuable for multiple myeloma, prostate cancer, and other malignancies with potential for metastatic spread 1
• Helps identify bone metastases, lymph node involvement, and visceral disease

Trauma Assessment

• Whole-body CT is valuable for polytrauma patients to rapidly assess multiple potential injuries 1
• Can detect injuries to head, neck, chest, abdomen, pelvis, and extremities

Child Abuse Evaluation

• Skeletal surveys and bone scans may be used to detect occult fractures in suspected child abuse cases 1

Body Composition Analysis

• DEXA, CT, and MRI can assess adiposity and body composition
• Useful for research and clinical evaluation of obesity 1

Considerations and Limitations

• Radiation exposure varies by modality (CT and PET involve ionizing radiation; MRI does not)
• Cost and availability differ significantly between imaging types
• Patient factors such as claustrophobia, implanted devices, or contrast allergies may limit certain scan types
• Specific protocols should be selected based on the clinical question being addressed

Body scans provide valuable diagnostic information but should be used judiciously considering radiation exposure, cost, and the specific clinical scenario requiring investigation.