title: Iterative reconstruction: an improvement of technetium-99m MIBI SPET for the detection of parathyroid adenomas?
abstract: The purpose of this study was to assess the value of technetium-99m methoxyisobutylisonitrile (MIBI) single-photon emission tomography (SPET) and an iterative reconstruction algorithm for the preoperative localisation of parathyroid adenomas (PTAs). Seventy-two patients (26 male, 46 female, mean age 58+/-16 years) with known primary hyperparathyroidism were examined preoperatively. First, a thyroid examination was performed to detect possible MIBI-accumulating thyroid lesions. Planar scans were then acquired 15 and 120 min and tomographic images 120 min after intravenous injection of 740 MBq 99mTc-MIBI, using a triple-head gamma camera (Picker Prism 3000). Additionally, 99mTc-MIBI/ 99mTc-pertechnetate subtraction scintigraphy of the early planar images was performed. The SPET data were evaluated using an iterative reconstruction (multiplicative iterative SPET reconstruction: MISR) as well as a standard algorithm (FBP: filtered back-projection with application of a 3-D low-pass postfilter). The weight of the resected PTAs ranged from 110 mg to 5 g. Using planar MIBI scans, correct localisation of the side of the PTA was possible in 81% of cases (58% for PTAs weighing less than 500 mg). Sensitivity increased to 94% using SPET and FBP, while with MISR it rose further, to 97%. Patients with PTAs weighing less than 500 mg showed a sensitivity of 88% with MISR and 81% with FBP. Furthermore, there was a clear improvement in image quality using MISR. None of the normal parathyroid glands were visualised. This study indicates that, in comparison with planar scintigraphy, 99mTc-MIBI SPET is a more sensitive and specific tool for topographical localisation of PTAs, especially those that are small. There is a further improvement in sensitivity and image quality when iterative reconstruction is used instead of FBP.
authors.affiliation: Department of Nuclear Medicine, University of Cologne, Germany. detlef.moka@uni-koeln.de
authors.forename: D
authors.initials: D
authors.lastname: Moka
authors.forename: W
authors.initials: W
authors.lastname: Eschner
authors.forename: E
authors.initials: E
authors.lastname: Voth
authors.forename: M
authors.initials: M
authors.lastname: Dietlein
authors.forename: A
authors.initials: A
authors.lastname: Larena-Avellaneda
authors.forename: H
authors.initials: H
authors.lastname: Schicha
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D000465:Algorithms; D005260:Female; D015902:Gamma Cameras; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging; D010282:Parathyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi