title: Preoperative 4D CT Localization of Nonlocalizing Parathyroid Adenomas by Ultrasound and SPECT-CT.
abstract: OBJECTIVE
  To evaluate 4-dimensional (4D) computed tomography (CT) for the localization of parathyroid adenomas previously considered nonlocalizing on ultrasound and single-photon emission CT with CT scanning (SPECT-CT). To measure radiation exposure associated with 4D-CT and compared it with SPECT-CT.
  
  
  METHODS
  Case series with chart review.
  
  
  METHODS
  University tertiary hospital.
  
  
  METHODS
  Nineteen adults with primary hyperparathyroidism who underwent preoperative 4D CT from November 2013 through July 2014 after nonlocalizing preoperative ultrasound and technetium-99m SPECT-CT scans. Sensitivity, specificity, predictive values, and accuracy of 4D CT were evaluated.
  
  
  RESULTS
  Nineteen patients (16 women and 3 men) were included with a mean age of 66 years (range, 39-80 years). Mean preoperative parathyroid hormone level was 108.5 pg/mL (range, 59.3-220.9 pg/mL), and mean weight of the excised gland was 350 mg (range, 83-797 mg). 4D CT sensitivity and specificity for localization to the patient's correct side of the neck were 84.2% and 81.8%, respectively; accuracy was 82.9%. The sensitivity for localizing adenomas to the correct quadrant was 76.5% and 91.5%, respectively; accuracy was 88.2%. 4D CT radiation exposure was significantly less than the radiation associated with SPECT-CT (13.8 vs 18.4 mSv, P = 0.04).
  
  
  CONCLUSIONS
  4D CT localizes parathyroid adenomas with relatively high sensitivity and specificity and allows for the localization of some adenomas not observed on other sestamibi-based scans. 4D CT was also associated with less radiation exposure when compared with SPECT-CT based on our study protocol. 4D CT may be considered as first- or second-line imaging for localizing parathyroid adenomas in the setting of primary hyperparathyroidism.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA Thyroid Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Hinson
authors.affiliation: College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Lee
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Hobbs
authors.affiliation: Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Fitzgerald
authors.affiliation: Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA Thyroid Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
authors.forename: Donald L
authors.initials: DL
authors.lastname: Bodenner
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA Thyroid Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA bstack@uams.edu.
authors.forename: Brendan C
authors.initials: BC
authors.lastname: Stack
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000000981:diagnostic imaging*; D010282:Parathyroid Neoplasms / Q000175:diagnosis* / Q000601:surgery; D016105:Parathyroidectomy; D011300:Preoperative Care / Q000379:methods*; D012372:ROC Curve; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014463:Ultrasonography
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi
keywords: 4-dimensional computed tomography; adenoma; nonlocalizing; parathyroidectomy; preoperative localization; primary hyperparathyroidism