Clinical case: Sharpening in lesion delineation

Lesion Delineation

Who we are

Professor Juhani Knuuti
Director

Adj. Prof. Marko Seppänen
Diagnostic Service Manager

 

Turku PET Centre
Turku, Finland

As a Finnish National Research Institute, Turku PET Centre led by Professor J. Knuuti, promotes the use of PET in the medical research field. The Centre was founded in 1974 by the University of Turku, Åbo Akademi University and the Turku University Hospital. The Centre integrates top scientific expertise with excellent facilities and equipments. Fruitful interaction and collaboration between basic scientists and clinical investigators is a long-standing tradition.

The latest imaging technology is available, some unique in Europe. The Centre provides several tracers for routine and research clinical imaging in Oncology, Neurology and Cardiology, using the Europe's first 64 slices PET/CT system. With its excellent cyclotron and radiochemistry laboratories, Turku PET Centre develops and produces the latest PET tracers for clinical imaging.

Patient History

Female - 45 years old - 168 cm - 55 kg

This patient has been treated for a poorly differentiated breast cancer in 1998. Received post-operative radiotherapy. Suffered chest pain since 2006 and, thereafter, diagnosed lytic destruction in sternum for which she received palliative chemo-radiotherapy in fall 2007.

Referred to 18F-FDG PET/CT for re-staging purposes.

Acquisition

Scanner: GE Discovery VCT

PET acquisition: Whole-body acquisition

  • 3D acquisition using both VUE Point & VUE Point HD reconstructions
  • Acquisition time: 12 min
  • Post-injection time: 62 min
  • Dose: 370 MBq of 18F-FDG

CT acquisition: Low dose with shallow breathing without contrast media

  • Rotation speed: 0.8 second
  • FOV: 70 cm
  • Pitch: 1.375 mm/rot
  • Slice thickness: 3.75 mm
  • Smart mA, NI: 25, kVp: 140, mA: 80
  • Dose: 4 mSv

Findings

                        

      Whole-body static image – VUE Point HD

             

      VUE Point : Matrix of 128 x 128 pixels

             

      VUE Point HD : Matrix of 256 x 256 pixels

There are metabolically active lymph nodes in
both sides of the supra clavicular region. In addition,
a metabolically active lesion was found in the sternum
representing bone metastasis. A suspicion of left
adrenal gland metastasis was discovered.

Conclusion

Using a matrix of 256x256 pixels improved the diagnostic confidence since it is possible to better delineate all metastases. This is particularly evident in the left supra clavicular region where two different lesions are visible using 256x256 matrix compared to only one single lesion with 128x128 matrix (on the top). Using a matrix 256x256 pixels improves the staging confidence and may be beneficial for the radiotherapy planning.