The goal: the clearest, most accurate image possible.

Q.Freeze combines the quantitative benefits of 4D phase-matched PET/CT imaging into a single static image.  By collecting CT and PET data at each phase of the breathing cycle, then matching the data for attenuation consistency.  None of the acquisition data is wasted, as 100% of the counts collected are combined to create a single static image.  The goal – a resulting image that has the dual benefit of frozen patient motion and reduced image noise.


The induced motion artifacts from respiratory motion may introduce significant image distortion, potentially leading to clinical misinterpretation involving apparent increase of lesion size and reduction of measured Standardized Uptake Value (SUV), and in many cases, potential miss of small lesions.

Q.Freeze addresses each of these challenges by creating a single static image corrected for respiratory motion using a low dose CT technique.

The resulting image has multiple benefits: 

  • Frozen patient motion 
  • Reduced image noise 
  • Consistency quantitative accuracy


Q.Freeze has been designed to overcome these challenges by using the entire acquired data to create a single 3D motion corrected image, and to provide quantitative accuracy equivalent to 4D phase-matched PET/CT. Unlike conventional 4D PET imaging, Q.Freeze combines 100% of the PET counts into a 3D motion corrected image that has a comparable acquisition time and the equivalent image noise of a static acquisition.

Case 1

Q.Freeze helps to highlight small lesion in the lung

Reconstruction: VUE Point HD with SharpIR*
Post injection time: 55 min
Acquisition time:

  • Standard: 1.5 min/bed
  • Q.Freeze: 30 sec/bed

Dose: 325 MBq of 18F-FDG

Standard PET Acquisition:
An additional small lung lesion was detected in the localization CT without visible uptake in the PET data.

Q.Freeze Acquisition:
Using motion correction technique, the small lung lesion was clearly showing metabolic activity and was classified as a positive findings.

Using Q.Freeze technology significantly improved the signal to noise ratio by removing the motion impact, thus allowing visual detection of a small lung uptake.

Case 2

Q.Freeze helps increase staging accuracy

PET acquisition
Reconstruction: VUE Point HD with SharpIR*
Post injection time: 63 min
Acquisition time:

  • Standard: 1.5 min/bed
  • Q.Freeze: 30 sec/bin

Dose: 260 MBq of 18F-FDG

CT acquisition
Whole-body acquisition for localization and attenuation purpose.
4D acquisition both for CTAC and diagnosis.

Patient History
Patient treated surgically for a left colon adenocarcinoma followed by several chemotherapy cycles.
After 2 years, an increase of the serum marker ( GICA 76 U/ml) is noticed. Patient submitted to contrast enhanced CT with a suspicious relapse in the colon hepatic flexure. The colonoscopy showed tubular polypoid lesion with moderate dysplasia. No other pathological findings were found.
Patient submitted the for PET/CT for staging of the disease.

Standard Acquisition:
Small focus uptake area localized on the gastric wall difficult to classify . Several mismatch artifacts due to the patient breathing on the abdominal area.

Q.Freeze acquisition:
The focal uptake area is clearly localized in the pancreatic tail as well as new pathological uptake area corresponding to a peritoneal nodule.

After the motion correction performed by the Q.Freeze technology the localization of the lesion and extent of the disease is confirmed. Correctly localizing the metastasis benefited the patient with a more accurate staging.



Q.Suite Brochure

  • Date Created: 5/7/2013
  • Document ID: DOC1036682