title: [99mTc-MIBI scintigraphy of hypofunctional thyroid nodules. Comparison of planar and SPECT imaging].
abstract: 99mTc-MIBI-scintigraphy allows to assess the dignity of hypofunctional thyroid nodules. A concordant pattern in MIBI- and pertechnetate-scintigraphy excludes malignancy with high accuracy. For increased MIBI-uptake histological evaluation is advised. The assessment of MIBI-isointense nodules is discussed controversially. Objective of our study was to analyse the prevalence of malignancy for isointense nodules and the diagnostic accuracy of image acquisition in SPECT-technique.
  
  
  METHODS
  MIBI-scintigraphies were analysed retrospectively. Imaging was performed 60 min after intravenous injection of 510 MBq 99mTc-MIBI. Thyroid nodules were assessed as hypo-, iso- or hyperintense compared to the paranodular tissue.
  
  
  RESULTS
  83 of 225 patients underwent thyroid surgery (age 48.6 ± 12.6 years, 72% women). In 12 (14.5%) cases a papillary carcinoma was diagnosed. In planar imaging 12, 34 and 37, in tomographical imaging 16, 21 and 46 nodules, respectively, were classified as hypo-, iso- oder hyperintense. Among hypo-, iso- and hyperintense nodules in planar imaging 1, 5 and 6 carcinomas were found, resp. In tomographical imaging no, 4 and 8 carcinomas were found, respectively. Classification of iso- and hyperintense nodules as "suspicious for malignancy" showed for planar imaging a sensitivity, specificity, NPV and PPV of 91.7, 15.5, 91.7 and 15.6%, for tomographical imaging of 100, 22.5, 100 and 17.9%, respectively.
  
  
  CONCLUSIONS
  Hypofunctional thyroid nodules with iso- and hyperintense MIBI-Uptake have a comparable prevalence of malignancy. Image acquisition in SPECT-technique results in improved diagnostic sensitivity and negative predictive value.
authors: Dr. med. Simone Schenke, ÜBAG für Nuklearmedizin Hanau Leimenstr. 20, 63450 Hanau, E-Mail: simoneschenke@web.de.
authors: S
authors: S
authors: Schenke
authors: M
authors: M
authors: Zimny
authors: T
authors: T
authors: Rink
authors: U
authors: U
authors: Stahl
authors: M
authors: M
authors: Fritzel
authors: R
authors: R
authors: Klett
mesh_terms: D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000000981:diagnostic imaging*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D013964:Thyroid Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D016606:Thyroid Nodule / Q000150:complications / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi
keywords: 99mTc-MIBI-scintigraphy; MIBI-positive thyroid nodule; hypofunctional thyroid nodule; isointense pattern; prevalence of malignancy