title: Pediatric 99mTc-MDP bone SPECT with ordered subset expectation maximization iterative reconstruction with isotropic 3D resolution recovery.
abstract: OBJECTIVE
  To perform a preliminary evaluation of the image quality of pediatric technetium 99m ((99m)Tc) methylene diphosphonate (MDP) bone single photon emission computed tomography (SPECT) by using iterative reconstruction-ordered subset expectation maximization with three-dimensional resolution recovery (OSEM-3D)-and to assess whether any improvements with use of this technique could lead to a reduction in patient dose or a shortening in imaging time.
  
  
  METHODS
  Institutional advisory board approval was obtained for this investigation. Fifty (99m)Tc-MDP SPECT studies of the spine were evaluated (36 female and 14 male patients; mean age, 15.5 years). Each study was acquired by using a dual-detector camera, with each detector rotating 360°. By using filtered back projection (FBP) and OSEM-3D, images were reconstructed from data generated by both detectors. Likewise, OSEM-3D was used to reconstruct data from a single detector simulating half the administered radiopharmaceutical activity. Two nuclear medicine physicians, blinded to the patient data, reviewed the images for image quality in four different categories by using a four-point scale: artifacts (category 1), lesions (category 2), noise (category 3), and image sharpness (category 4).
  
  
  RESULTS
  Compared with FBP, images reconstructed by using OSEM-3D with one or two detectors showed significant improvement in image quality with regard to lesion detection, noise level, and image sharpness (P < .02, .01, and .001, respectively). With OSEM-3D, no significant differences were observed when either one or two detectors were used.
  
  
  CONCLUSIONS
  Improved image quality of skeletal SPECT with either a 50% reduction in radiation dose or a 50% reduction in acquisition time or combination of the two can be achieved by using OSEM-3D.
authors.affiliation: Joint Program in Nuclear Medicine, Harvard Medical School, Boston, Mass, USA.
authors.forename: Eryn Caamano
authors.initials: EC
authors.lastname: Stansfield
authors.forename: Niall
authors.initials: N
authors.lastname: Sheehy
authors.forename: David
authors.initials: D
authors.lastname: Zurakowski
authors.forename: A Hans
authors.initials: AH
authors.lastname: Vija
authors.forename: Frederic H
authors.initials: FH
authors.lastname: Fahey
authors.forename: S Ted
authors.initials: ST
authors.lastname: Treves
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D016015:Logistic Models; D017116:Low Back Pain / Q000000981:diagnostic imaging*; D008297:Male; D011829:Radiation Dosage; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012984:Software; D018709:Statistics, Nonparametric; D013669:Technetium Tc 99m Medronate; D015899:Tomography, Emission-Computed, Single-Photon; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate