systemPhilipsCTfamily: spectral-ct

Philips IQon Spectral CT

Family: Philips Spectral CT · Modality: CT

First clinical CT built around a dual-layer (sandwich) detector — every scan is spectral by default. Unlike dual-source, dual-spin, or kVp-switching approaches, the dual-layer detector acquires low- and high-energy data simultaneously through the same projection line, eliminating temporal / spatial registration as a source of artifact in material decomposition.

Detector architecture

  • Dual-layer ("sandwich") detector — top scintillator layer preferentially absorbs low-energy photons; bottom layer captures the high-energy remainder. Both layers are read out per view.
  • Every scan is spectral — no protocol decision, no dose penalty for spectral acquisition. Conventional images and spectral results are reconstructed from the same raw data.
  • Retrospective spectral analysis — material decomposition, virtual monoenergetic images (40–200 keV), iodine maps, Z-effective maps, virtual non-contrast are all derivable from any historical scan.

Specs

  • 128 slices · 70 cm gantry
  • 0.27 sec minimum rotation
  • MRC tube family · dual-layer detector
  • iDose4 (iterative reconstruction) + IMR (model-based iterative reconstruction) — retrospectively applicable
  • Spectral Diagnostic Suite on host
  • SmartShuttle / cardiac gating

Clinical positioning

  • Oncology — iodine quantification and virtual non-contrast reduce multi-phase exam redundancy.
  • Cardiac — monoenergetic reconstructions at 70–80 keV reduce beam-hardening artifact around coronary calcium and stents.
  • Renal / GU — uric acid vs calcium stone differentiation without a dedicated dual-energy protocol.
  • Incidental lesion characterization — spectral results available from any prior scan, which changes how incidentalomas are worked up.

Platform evolution

The IQon architecture underpins the newer Philips Spectral CT 7500, which carries the same dual-layer detector concept forward with an updated gantry, host, and reconstruction suite (System Card planned). IQon remains in active use and continues to receive software updates.

Parts

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