Spin Echo-Based Families

Spin Echo (SE)

• Design: 90° excitation followed by a 180° refocusing pulse.
• Key characteristics: High robustness to B₀ inhomogeneity; flexible contrast via TE and TR.
• Clinical applications: General T1-, T2-, and proton-density imaging.
• Vendors: All vendors SE.

Turbo Spin Echo (TSE / FSE)

• Design: Multiple refocusing pulses following a single excitation.
• Key characteristics: Faster than SE with preserved contrast; reduced susceptibility artifacts.
• Clinical applications: Routine neuro and body imaging.
• Vendors:
  • GE: FSE
  • Siemens: TSE
  • Philips: TSE
  • Canon: FASE
  • Fujifilm: FSE

Single-Shot Fast Spin Echo (SS-FSE)

• Design: Entire k-space acquired after one excitation using long echo trains.
• Key characteristics: Strong T2 weighting; highly motion-robust.
• Clinical applications: Pediatric imaging, fetal imaging, non-breath-hold abdominal imaging, MRA.
• Vendors:
  • GE: SSFSE
  • Siemens: HASTE
  • Philips: SSh-TSE
  • Canon: FASE
  • Fujifilm: SSFSE

Inversion Recovery (IR) Spin-Echo

• Design: Inversion pulse followed by SE acquisition.
• Key characteristics: Strong T1 contrast control via inversion time selection.
• Clinical applications: Soft tissues, tumors, musculoskeletal imaging.
• Vendors: All vendors IR-SE.

Inversion Recovery Turbo Spin Echo (IR-TSE / STIR)

• Design: IR-prepared TSE with tissue-specific signal nulling.
• Key characteristics: Robust fat suppression independent of B₀; increased SAR.
• Clinical applications: STIR-based musculoskeletal imaging.
• Vendors: All vendors STIR.

Fluid-attenuated inversion recovery (FLAIR)

• Design: IR-prepared TSE with CSF-nulling inversion time.
• Key characteristics: Suppresses fluid signal while preserving T2 lesion contrast.
• Clinical applications: Brain imaging, white-matter pathology.
• Vendors: All vendors FLAIR.

3D Double Inversion Recovery Turbo Spin Echo (3D DIR-TSE)

• Design: Two inversion pulses followed by 3D TSE readout.
• Key characteristics: Dual tissue suppression; high lesion conspicuity.
• Clinical applications: Brain imaging, multiple sclerosis.
• Vendors: All vendors DIR-TSE.

Three Dimensional (3D) Turbo Spin Echo (3D TSE)

• Design: Slab-selective 3D TSE acquisition.
• Key characteristics: Isotropic resolution with high anatomical detail.
• Clinical applications: Brain, spine, joints, MRCP.
• Vendors:
  • GE: CUBE
  • Siemens: SPACE
  • Philips: VISTA
  • Canon: 3D FASE
  • Fujifilm: 3D FSE