Performance characteristics obtained for a new 3-dimensional lutetium oxyorthosilicate-based whole-body PET/CT scanner with the National Electrical Manufacturers Association NU 2-2001 standard

J Nucl Med. 2005 Dec;46(12):2083-91.


This article reports the results of performance measurements obtained for the lutetium oxyorthosilicate (LSO)-based whole-body PET/CT scanner Biograph 16 HI-REZ with the National Electrical Manufacturers Association (NEMA) NU 2-2001 standard. The Biograph 16 HI-REZ combines a multislice (16-slice) spiral CT scanner with a PET scanner composed of 24.336 LSO crystals arranged in 39 rings. The crystal dimensions are 4.0x4.0x20 mm3, and the crystals are organized in 13x13 blocks coupled to 4 photomultiplier tubes each. The 39 rings allow the acquisition of 81 images 2.0 mm thick, covering an axial field of view of 162 mm. The low- and high-energy thresholds are set to 425 and 650 keV, respectively, acquiring data within a 4.5-ns-wide coincidence window.

Methods: Performance measurements for the LSO-based PET/CT scanner were obtained with the NEMA NU 2-2001 standard, taking into account issues deriving from the presence of intrinsic radiation.

Results: The results obtained with the NEMA NU 2-2001 standard measurements were as follows: average transverse and axial spatial resolutions (full width at half maximum) at 1 cm and at 10 cm off axis of 4.61 (5.10) mm and 5.34 (5.91) mm, respectively; average sensitivity of 4.92 counts per second per kilobecquerel for the 2 radial positions (0 and 10 cm); 34.1% system scatter fraction; and peak noise equivalent count (NEC) rates of 84.77 kilocounts per second (kcps) at 28.73 kBq/mL (k=1 in the NEC formula; noiseless random correction) and 58.71 kcps at 21.62 kBq/mL (k=2; noisy random correction).

Conclusion: The new integrated PET/CT system Biograph 16 HI-REZ has good overall performance, with, in particular, a high resolution, a low scatter fraction, and a very good NEC response.

MeSH terms

  • Humans
  • Image Processing, Computer-Assisted
  • Imaging, Three-Dimensional / methods*
  • Imaging, Three-Dimensional / standards
  • Lung / pathology
  • Lutetium / chemistry*
  • Phantoms, Imaging
  • Positron-Emission Tomography / methods*
  • Quality Control
  • Scattering, Radiation
  • Sensitivity and Specificity
  • Silicates / chemistry*
  • Subtraction Technique
  • Time Factors
  • Tomography Scanners, X-Ray Computed*
  • Tomography, X-Ray Computed / methods*
  • Tomography, X-Ray Computed / standards
  • Whole Body Imaging


  • Silicates
  • Lutetium