systemGE HealthCareCTfamily: discovery-ct750

GE Discovery CT750 HD

Family: GE Discovery CT750 · Modality: CT

High-definition / dual-energy CT built around the Gemstone detector — GE's garnet-based scintillator that replaced gadolinium-oxysulfide (GOS) scintillators and represented the first new CT scintillator material in 20 years at launch. Paired with the Gemstone Clarity tube and fast-kVp-switching Gemstone Spectral Imaging (GSI), Discovery CT750 HD delivers dual-energy imaging with a single tube on a 64-slice platform. Predecessor-class to the current Revolution Apex and Revolution HD; large secondary-market install base.

Gemstone detector

  • Garnet-based scintillator — faster light transfer to the photodiode than GOS, with dramatically shortened afterglow. OEM claims ~100× faster primary-speed characteristics than conventional GOS detectors of the era.
  • Supports high-definition reconstruction — spatial resolution up to ~230 µm in the HD mode (inner-ear, coronary small-vessel, temporal bone).
  • Enables dual-energy at rapid kVp switch rate — the fast scintillator is what makes GSI practical on a single tube; slower scintillators can't resolve the tube-switch period.

Gemstone Spectral Imaging (GSI)

  • Fast kVp switching — tube kVp alternates 40 / 120 kVp view-by-view at high switching rate, acquiring low- and high-energy data within the same rotation.
  • Material decomposition — post-processing derives material-density images (water/iodine, calcium/iodine pairs), virtual monoenergetic images (40–140 keV), virtual non-contrast, effective-Z maps.
  • Single-tube dual-energy — fundamentally different architecture than Siemens' dual-source approach or Philips' dual-layer detector: one tube, one detector, switched kVp.

Specs

  • 64 slices (128i overlap reconstruction) · 70 cm gantry aperture
  • 0.35 sec minimum rotation
  • Gemstone detector (garnet scintillator)
  • Gemstone Clarity tube (Performix HD class)
  • 100 kW generator · up to 140 kVp / 835 mA
  • GSI fast kVp switching (40 / 120 kVp)
  • ASiR iterative reconstruction standard (ASiR-V software upgrade available on supported hosts)
  • SnapShot Pulse cardiac gating
  • HD mode resolution to ~230 µm

Clinical positioning

  • Cardiac — coronary CTA at 64-slice + 0.35 s rotation with the additional advantage of spectral monoenergetic reconstructions reducing beam-hardening around calcium and stents.
  • Inner-ear / temporal bone — the HD 230 µm mode is a recognized clinical differentiator for small-bone and otology work.
  • Oncology — iodine-map and virtual-non-contrast from GSI reduce multi-phase protocol redundancy.
  • Urology — uric-acid vs calcium stone differentiation from spectral results.
  • Neuro — dual-energy bone removal, hemorrhage vs contrast extravasation differentiation.

Relationship to siblings and successors

  • vs LightSpeed VCT XT — same 64-slice class, different scintillator generation (Gemstone vs V-Res pre-Gemstone). GSI is not available on VCT; the detector doesn't support it.
  • Successor-class — Revolution HD replaces CT750 HD at the same clinical tier on the Revolution chassis. Revolution Apex extends the Gemstone lineage to 256 slices and 160 mm Z-axis coverage.
  • vs Discovery 690 — Discovery 690 pairs a VCT-era CT with PET. CT750 HD is not a PET/CT scanner; the Discovery branding covers both separately.

Parts

(Detector is Gemstone class — see Gemstone detector.)

Related