Types of X-ray Examinations Available
X-ray imaging encompasses several distinct modalities including plain radiography (conventional X-rays), computed tomography (CT), fluoroscopy, and specialized contrast studies, each serving different diagnostic purposes across virtually all body regions.
Plain Radiography (Conventional X-rays)
Plain radiographs remain the most fundamental and widely used X-ray examination type:
- Chest X-rays: Portable anteroposterior (AP) and lateral views are standard for evaluating pulmonary and cardiac pathology 1, 2
- Skeletal radiographs: Single or multiple view examinations of extremities, spine, and pelvis for trauma and orthopedic conditions 2
- Trauma series: Typically consists of portable chest, pelvis, and cross-table cervical spine radiographs for initial trauma assessment 2
- Spine radiographs: Including cervical, thoracic, and lumbar views with standing or weight-bearing positions when indicated 3, 4
- Skull radiographs: Though less commonly used now, historically performed for head trauma evaluation 5
Plain radiographs use the least radiation exposure among X-ray modalities but provide limited soft tissue detail 6.
Computed Tomography (CT)
CT represents a more advanced X-ray technique providing cross-sectional imaging:
- CT without contrast: Used for bone evaluation, acute hemorrhage detection, and when contrast is contraindicated 2, 7
- CT with intravenous contrast: Provides superior sensitivity for detecting visceral organ and vascular injuries compared to noncontrast CT 2
- Whole body CT (WBCT): Encompasses head, cervical spine, chest, abdomen, and pelvis, typically used in major blunt trauma 2
- CT angiography (CTA): Specialized contrast-enhanced CT for vascular evaluation of extremities and other regions 2
- Multidetector CT (MDCT): Modern scanners with rapid acquisition times and thin-slice capability 8, 9
CT scans use significantly more radiation than plain radiographs—approximately equivalent to 150 chest X-rays for a single CT examination 10, 6. However, CT provides substantially more diagnostic information, particularly for soft tissue and complex anatomy 8.
Fluoroscopy and Dynamic Studies
Fluoroscopic examinations provide real-time X-ray imaging:
- Fluoroscopy-guided interventional procedures: Used for various therapeutic and diagnostic interventions 1
- Dynamic fluoroscopy: Can assess spinal stability and movement 8
- Contrast studies: Including gastrointestinal examinations (though these have declined with endoscopy availability) 11
- CT myelography: Combines CT with intrathecal contrast injection for detailed spinal canal evaluation 7, 4
Fluoroscopic procedures can impart higher radiation doses, particularly during prolonged interventional procedures 12.
Specialized Radiographic Examinations
Additional X-ray-based examinations include:
- Oblique radiographic views: Supplementary views for improved visualization of specific anatomical structures 9
- Flexion/extension radiography: Static radiographs at limits of neck movement for stability assessment 8
- Dental radiography: Including panoramic and intraoral views for oral and maxillofacial evaluation 13
- Mammography: Specialized low-dose X-ray examination for breast imaging (though not detailed in the provided evidence)
Important Considerations
Radiation exposure varies dramatically between examination types, from minimal doses with single plain radiographs to substantially higher doses with CT and fluoroscopic procedures 12. Modern technology continues to evolve toward dose reduction while maintaining diagnostic quality 12.
Clinical appropriateness is paramount—many examinations have specific indications and contraindications. For example, CT is not recommended as a screening tool for COVID-19 due to lack of specificity and resource consumption 1, and routine skull radiographs after minor head trauma in low-risk patients are not indicated 5.
Contrast administration enhances diagnostic capability for many CT examinations but carries risks including allergic reactions and contraindications in patients with renal impairment 10, 6.