CT Checkpoint Scanners

Computed Tomography (CT) checkpoint scanners represent the most significant advancement in aviation security screening since 9/11. TSA authorization of CT technology in 2017 allows passengers to keep laptops and liquids in bags, while automated explosive detection (AED) algorithms achieve detection rates exceeding human operators.

Advanced CT scanner with 3D imaging and automated threat recognition

CT vs. Conventional X-Ray Technology

Fundamental Differences

Feature	Conventional 2D X-Ray	CT Scanner
Imaging Technique	Single transmission image	360° volumetric reconstruction
Threat Detection	Operator visual identification	Automated explosive detection (AED)
Material Analysis	Dual-energy Z_eff estimation	Precise density and atomic number mapping
Laptop/Liquid Removal	Required	Not required (TSA authorized)
Throughput	300-400 bags/hour	250-300 bags/hour
Cost	$80K-$150K	$300K-$500K

Technical Architecture

Core Components

X-Ray Source: Rotating tube assembly (120-140 kVp, continuous emission)
Detector Ring: Multiple detector arrays capturing projections from all angles
Reconstruction Computer: High-performance workstation for 3D image generation
AED Algorithm: Machine learning models trained on explosive signatures
Multi-Planar Display: Axial, coronal, and sagittal slice viewing

CT Scanning Process

Bag Entry: Conveyor transports bag through tunnel (0.20 m/s typical)
Data Acquisition: Detector captures 360° projections (500-1000 views)
Image Reconstruction: Filtered back-projection or iterative algorithms create 3D volume
Automated Analysis: AED software identifies suspicious regions
Operator Review: Flagged bags examined with 3D manipulation tools
Resolution: Clear or secondary screening (ETD, manual search)

Technical Specifications

Parameter	Typical Value
Tunnel Size	75 x 65 cm (slightly smaller than conventional)
Scan Time	6-10 seconds per bag
Slice Thickness	0.5-2.0 mm
Spatial Resolution	0.5-1.0 mm (superior to 2D systems)
X-Ray Energy	120-140 kVp
Power Consumption	5-10 kW (higher than conventional)
Throughput	250-300 bags/hour (algorithm dependent)

Automated Explosive Detection (AED)

Detection Methodology

AED algorithms analyze multiple physical properties simultaneously:

Density Measurement: Explosives typically 1.0-1.8 g/cm³
Effective Atomic Number: Z_eff range characteristic of organic explosives (7-8)
Shape Analysis: Geometric patterns consistent with IED construction
Contextual Assessment: Suspicious placement within bag (concealed in electronics)
Mass Calculation: Volumetric measurement of potential explosive quantity

Machine Learning Models

Modern CT systems employ deep learning for threat recognition:

Convolutional Neural Networks (CNNs): Image analysis for pattern recognition
Training Data: Millions of threat and benign images from TSA libraries
Continuous Learning: Algorithm updates based on operational performance
False Alarm Reduction: AI distinguishes threats from harmless items (cosmetics, batteries)

Performance Metrics

Metric	CT System	Conventional 2D
Probability of Detection (Pd)	>98% (automated)	95% (operator dependent)
False Alarm Rate	3-5%	5-8%
Operator Workload	Reduced (review alarms only)	High (visual inspection of all bags)

TSA Certification and Deployment

Regulatory Approval Process

QPL Certification: TSA Qualified Products List testing (12-24 months)
Performance Testing: Detection trials with representative threat articles
Operational Pilot: Live airport deployment for validation
Laptop/Liquid Authorization: Requires separate approval beyond basic QPL

U.S. Deployment Status

As of 2026, TSA has deployed CT scanners at:

Major Hubs: JFK, LAX, ORD, ATL, DFW (complete coverage)
Category X Airports: ~500+ CT units nationwide
Expansion Goal: Full replacement of 2D scanners by 2030
Investment: $1.2 billion TSA modernization program

Leading Manufacturers and Models

Analogic (Safran Detection)

ConneCT Series

ConneCT 1000: First TSA-approved checkpoint CT (2017)
Market Leader: Largest installed base in U.S. airports
Features: 0.5mm slice thickness, automated bin return

Smiths Detection

CTiX Series

CTiX: High-throughput CT with advanced AED algorithms
Deployment: European and Asian airports primarily
Features: Multi-energy spectral imaging, remote screening capability

Rapiscan Systems

RTT (Real-Time Tomography)

RTT 110: Compact CT for checkpoint screening
Technology: Proprietary tomographic reconstruction
Features: Rapid scan times (under 6 seconds)

Nuctech

XT2080 Series

Global Deployment: 100+ airports in China, Middle East, Africa
Cost Advantage: 30-40% lower than Western competitors
U.S. Restrictions: Not approved for U.S. airport use

Operational Benefits

Passenger Experience Improvements

No Laptop Removal: Electronics remain in bags (TSA authorized)
No Liquid Removal: 3-1-1 rule relaxed at CT-equipped checkpoints
Reduced Divesting Time: 15-30 second savings per passenger
Fewer Bag Checks: Lower false alarm rate reduces secondary screening

Security Enhancements

Orientation Independence: Detects threats regardless of bag position
Volumetric Analysis: Virtual dissection reveals concealed items
Consistent Performance: Algorithm performance not subject to operator fatigue
Small Threat Detection: Improved detection of minimal explosive quantities

Operational Efficiency

Reduced Staffing: Single operator can monitor multiple lanes
Remote Screening: Centralized image review from off-site facilities
Training Simplification: Operators review alarms vs. interpreting all images

Deployment Considerations

Capital and Operating Costs

Cost Category	Amount (USD)
Equipment Purchase	$300,000 - $500,000
Installation and Integration	$50,000 - $100,000
Annual Maintenance	$25,000 - $40,000
Power/Utilities (annual)	$4,000 - $8,000
Operator Training	$8,000 - $15,000 (initial)

Infrastructure Requirements

Floor Space: 6-8 meters length including roller tables
Power: 208-240VAC, 40-60A dedicated circuit
Cooling: Enhanced HVAC for high heat generation (10kW+)
Network: Gigabit Ethernet for image transfer and remote screening
Floor Loading: 300-400 kg/m² capacity

Future Developments

Technology Roadmap

Spectral CT: Multi-energy imaging for enhanced material discrimination
Faster Reconstruction: GPU-accelerated processing reducing scan times to 3-4 seconds
AI Advancement: Explainable AI providing reasoning for threat detections
Compact Designs: Smaller footprint systems for space-constrained checkpoints
Checked Baggage Integration: Unified platform for both cabin and checked bags

Note: CT scanner specifications and TSA approvals subject to change. Verify current QPL status and operational authorizations with TSA. See our full disclaimer.