Sequence Overview
Sequence Type: 3D Spin-Echo Gradient (SEG) High-Resolution Imaging

Field Strength: 1.5T / 3T (Optimized for 3T)

Primary Applications:

Neurological Imaging (Brain, Spine)

Musculoskeletal (Cartilage, Tendons, Small Joints)

Oncology (High-Contrast Tumor Delineation)

Vendor Classification: Proprietary Woodward Protocol

Core Technical Parameters
1. Sequence Encoding (MRG3D)
MRG: Magnetization-Prepared Rapid Gradient Echo (Hybrid SE-GRE)

3D: Volumetric Isotropic Acquisition

2. Acquisition Parameters
TR (Repetition Time): 1200-2500 ms (T1/T2 Adjustable)

TE (Echo Time): 15-30 ms (Short TE for PD/T1, Long TE for T2)

Flip Angle: 90° (Excitation) / 180° (Refocusing) – True Spin-Echo Core

Bandwidth: ±25 kHz (Optimized for SNR vs. Speed Trade-Off)

Resolution:

In-Plane: 0.4 × 0.4 mm (High-Res Mode)

Slice Thickness: 0.8-1.2 mm (Isotropic Voxel Optional)

3. Contrast Options
T1-Weighted: TR = 500-800 ms, TE = 15 ms (Magnetization-Prepared)

Proton Density (PD): TR = 1500-2000 ms, TE = 20 ms

T2-Weighted: TR = 2500+ ms, TE = 30 ms

Advanced Features
1. Acceleration & Efficiency
Turbo Factor (ESP): Up to 25 (Fast SE Readout Segments)

Parallel Imaging (SENSE): Factor 2-3 (Reduces Scan Time by 50%)

Compressed Sensing (Optional): 4D Dynamic Acquisitions (e.g., Joint Motion Studies)

2. Artifact Reduction
Flow Compensation: 3D Motion-Compensated Gradients

CSF Suppression (FLAIR-like): Inversion Recovery Prep (TI = 2200 ms)

Metal Artifact Reduction (MARS-W™): Adaptive k-Space Filtering

3. Specialized Post-Processing
Multiplanar Reformation (MPR): Real-Time Orthogonal Views

Cartilage Thickness Mapping: Automated Edge Detection

Tumor Volume Analysis: AI-Based Segmentation (DICOM Export)

Clinical Applications & Protocol Setup
1. Neuroimaging (Brain/Spine)
Recommended Settings:

TR = 2000 ms, TE = 25 ms (PD-Weighted)

0.8 mm Isotropic, SENSE Factor 2

Enable CSF Suppression for MS/Leptomeningeal Disease

Use Cases:

Multiple Sclerosis (MS) Plaque Detection

Spinal Cord Compression (T2-Weighted Sagittal)

2. MSK (Cartilage/Joint Imaging)
Recommended Settings:

TR = 1500 ms, TE = 20 ms (PD-Weighted, Fat-Sat)

0.6 mm Isotropic, Turbo Factor 15

Enable MARS-W for Post-Operative Scars

Use Cases:

Hip Labral Tears

Knee Cartilage Degradation (Early OA Detection)

3. Oncology (Tumor Delineation)
Recommended Settings:

TR = 2500 ms, TE = 30 ms (T2-Weighted)

1.0 mm Isotropic, Compressed Sensing ON

Contrast-Enhanced (Gadolinium Optional)

Performance Metrics
Scan Time:

Brain (0.8 mm iso, PD): 5 min 10 sec

Knee (0.6 mm iso, T2): 6 min 30 sec

Image Quality:

SNR (White Matter): ≥28 dB

CNR (Gray/White Matter): ≥2.3

Geometric Distortion: <1.0% (B0 Shim Active)

Technologist Notes
1. Protocol Optimization
For 3T Scans: Reduce Turbo Factor to 15 (SAR Management)

Fat Suppression: Use SPIR (Spectral Inversion) for Homogeneous Saturation

Motion-Prone Patients: Enable Prospective Motion Correction

2. Troubleshooting
Ghosting Artifacts: Increase Phase Oversampling +30%

Low SNR: Reduce Bandwidth to ±20 kHz or Increase Averages (NEX=2)

3. Contraindications
Non-Compatible With:

Legacy Pacemakers (Unless MRI-Safe Mode Active)

Extreme Obesity (FOV Limitations)