title: Virtual neck exploration: a new method for localizing abnormal parathyroid glands.
abstract: BACKGROUND
  Computed tomography (CT) together with 99mTc-sestamibi single photon emission computed tomography (MIBI-SPECT) image fusion (CT-MIBI-SPECT image fusion) allows virtual exploration of the neck. The aim of this study was to evaluate whether CT-MIBI-SPECT image fusion is superior to MIBI-SPECT and CT in detecting abnormal parathyroid glands in patients with primary hyperparathyroidism.
  
  
  METHODS
  CT-MIBI-SPECT image fusion for preoperative localization was performed in 116 patients with primary hyperparathyroidism (pHPT). Both investigations were performed with reproducible fixation of the patient on a vacuum mattress. At a special work station the neck was virtually explored by viewing the CT images in all 3 dimensions. The MIBI-SPECT images were superimposed on underlying CT images. Only patients with single-gland disease were evaluated (pHPT: 112, persistent pHPT: 1, recurrent pHPT: 1, persistent secondary hyperparathyroidism: 1, tertiary HPT after kidney transplantation: 1). CT-MIBI-SPECT image fusion results were compared with those obtained with CT alone and MIBI-SPECT alone. The predicted positions were correlated with the intraoperative findings.
  
  
  RESULTS
  CT-MIBI-SPECT image fusion was able to predict the exact position of the abnormal gland in 102 (88%) of the 116 patients, whereas CT alone showed in 75 (65%) patients and MIBI-SPECT alone in 64 (55%) patients the exact position of the abnormal gland. Sixty-two patients underwent minimally invasive surgery, namely in 21 patients with a unilaterally focused approach and in 33 patients with a bilateral approach (27 of these underwent simultaneous thyroid resection). Sensitivity for CT-MIBI-SPECT image fusion was 88%, for CT alone 70%, and for MIBI-SPECT alone 59%. Specificity for CT-MIBI-SPECT image fusion was 99%, for MIBI-SPECT alone 95%, for CT alone 94%. Overall accuracy for CT-MIBI-SPECT image fusion was 97%, for CT alone 89%, for MIBI-SPECT 87%.
  
  
  CONCLUSIONS
  This study provides evidence that CT-MIBI-SPECT image fusion is superior to CT or MIBI-SPECT alone for preoperative localization of enlarged parathyroid glands in patients with single-gland primary hyperparathyroidism.
authors.affiliation: Department of Operative Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria. rupert.prommegger@uki.at
authors.forename: Rupert
authors.initials: R
authors.lastname: Prommegger
authors.forename: Gerd
authors.initials: G
authors.lastname: Wimmer
authors.forename: Christoph
authors.initials: C
authors.lastname: Profanter
authors.forename: Tonja
authors.initials: T
authors.lastname: Sauper
authors.forename: Michael
authors.initials: M
authors.lastname: Sieb
authors.forename: Peter
authors.initials: P
authors.lastname: Kovacs
authors.forename: Reto
authors.initials: R
authors.lastname: Bale
authors.forename: Daniel
authors.initials: D
authors.lastname: Putzer
authors.forename: Michael
authors.initials: M
authors.lastname: Gabriel
authors.forename: Raimund
authors.initials: R
authors.lastname: Margreiter
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000000981:diagnostic imaging; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging; D010280:Parathyroid Glands / Q000000981:diagnostic imaging*; D010282:Parathyroid Neoplasms / Q000000981:diagnostic imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi