title: Incremental value of single-photon emission computed tomography/computed tomography in the diagnosis of active condylar hyperplasia.
abstract: OBJECTIVE
  To evaluate the incremental value of technetium-99m methylene diphosphonate (Tc-MDP) single-photon emission computed tomography/computed tomography (SPECT/CT) over planar bone scintigraphy (BS) and SPECT for the diagnosis of active condylar hyperplasia (CH).
  
  
  METHODS
  Data of 21 patients (mean age: 21.9±5.3 years, 10 males, 11 females) who underwent Tc-MDP BS along with regional SPECT/CT for the diagnosis of active CH were retrospectively evaluated. Planar BS, SPECT, and SPECT/CT images were evaluated by two nuclear medicine physician in consensus. Radioactive counts were measured per region of interest and the respective ratios were calculated. A percentage of condylar uptake 55% or higher, generating differences of 10% or more between condyles, was considered to be indicative of active unilateral condylar hyperactivity. Sensitivity, specificity, and positive and negative predictive values were calculated separately for planar BS, SPECT, and SPECT/CT. Clinical/imaging follow-up and histopathology was considered the reference standard.
  
  
  RESULTS
  Planar BS, SPECT, and SPECT-CT of 21 patients with suspected CH were retrospectively evaluated. Planar BS was positive in eight patients, of whom six had active CH as the final diagnosis. SPECT was positive in 14 patients, of whom 12 patients had CH. Out of 14 patients who were positive in SPECT, two patients were considered negative in SPECT-CT. The diagnostic accuracy was the lowest for planar BS (47.6%) and the highest for SPECT/CT (85.8%). SPECT/CT and SPECT had similar sensitivity (80%), whereas SPECT-CT had the highest specificity (100%).
  
  
  CONCLUSIONS
  SPECT/CT is superior to planar BS and SPECT for the diagnosis of active CH.
authors.affiliation: Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Krishan Kant
authors.initials: KK
authors.lastname: Agarwal
authors.forename: Anirban
authors.initials: A
authors.lastname: Mukherjee
authors.forename: ArunRaj
authors.initials: A
authors.lastname: St
authors.forename: Madhavi
authors.initials: M
authors.lastname: Tripathi
authors.forename: Chandrasekhar
authors.initials: C
authors.lastname: Bal
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis / Q000000981:diagnostic imaging; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D000072098:Single Photon Emission Computed Tomography Computed Tomography / Q000379:methods*; D013669:Technetium Tc 99m Medronate; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate