180 degree pinhole SPET with a tilted detector and OS-EM reconstruction: phantom studies and potential clinical applications

Eur J Nucl Med. 2001 Dec;28(12):1836-41. doi: 10.1007/s002590100629. Epub 2001 Oct 3.


This study investigated the feasibility of ordered subsets expectation maximisation (OS-EM) reconstruction of pinhole single-photon emission tomography (SPET) acquired with a tilted detector head and a 180 degrees orbit. Phantom and patient data were recorded using a standard single-head camera. Reconstructions were performed using a dedicated OS-EM algorithm. Reconstructed images of line, uniformity and Picker's thyroid phantoms showed that the geometry, physical size and uniformity of the radioactive objects were preserved. For the range of radius corresponding to the patient studies, the measured full-widths at half-maximum lay between 4.90+/-0.25 mm and 6.05+/-0.25 mm. Finally, the gain in resolution associated with the use of the pinhole collimator instead of a parallel-hole collimator was highlighted in a parathyroid exploration and in a shoulder bone study.

MeSH terms

  • Aged
  • Algorithms
  • Female
  • Humans
  • Hyperparathyroidism / diagnostic imaging
  • Image Processing, Computer-Assisted / methods*
  • Middle Aged
  • Osteoporosis / diagnostic imaging
  • Phantoms, Imaging
  • Radiopharmaceuticals
  • Shoulder Pain / diagnostic imaging
  • Technetium Tc 99m Medronate
  • Technetium Tc 99m Sestamibi
  • Tomography, Emission-Computed, Single-Photon / instrumentation
  • Tomography, Emission-Computed, Single-Photon / methods*


  • Radiopharmaceuticals
  • Technetium Tc 99m Sestamibi
  • Technetium Tc 99m Medronate