title: Is Brown Adipose Tissue Visualization Reliable on 99mTc-Methoxyisobutylisonitrile Diagnostic SPECT Scintigraphy?
abstract: The 99mTc-MIBI has been used with great value as a diagnostic technique in patients with primary hyperparathyroidism. False-positive scans may occur due to misinterpretation of the physiologic distribution of the 99mTc-MIBI. Reviewing consecutive SPECT scans, we evaluated this possibility and assessed how frequently brown adipose tissue (BAT) is seen on 99mTc-MIBI scintigraphy. Here, we retrospectively reviewed scans of consecutive patients who were evaluated for parathyroid adenomas from March 2015 to June 2015, using dual-phase (early and delayed) planar imaging and SPECT. We identified 60 patients (48 female and 12 male; mean age, 52.25 ± 15.20 years; range, 22-86 years).We detected the presence of 99mTc-MIBI uptake in BAT in 20 of 60 patients (33.33%) in the neck. Although the patients with T99mc-MIBI uptake in BAT were younger (mean age, 48.85 ± 15.27 years, range, 26-73 years) than the patients with no 99mTc-MIBI uptake (mean age, 53.95 ± 15.07 years, range, 22-86 years), this difference was not statistically significant (P = 0.224). The percentage of female patients with BAT detection was higher (17/48 patients; 37.5%) than that of the male population (3/12 patients; 25%), this difference was not also statistically significant (P = 0.85).In patient population referred to 99mTc MIBI scintigraphy of the parathyroid glands, uptake of 99mTc-MIBI in BAT should not be misinterpreted with 99mTc-MIBI-avid-tumors. Fused SPECT/CT images (not SPECT-only) are necessary to distinguish BAT from bone, muscle, thyroid, myocardium, parathyroids, and other structures in the neck and chest.
authors.affiliation: From the Nuclear Medicine and Molecular Imaging Research Center, Namazi Teaching Hospital, Shiraz University of Medical Sciences, Shiraz, Iran (MH, FF).
authors.forename: Mahdi
authors.initials: M
authors.lastname: Haghighatafshar
authors.forename: Farinaz
authors.initials: F
authors.lastname: Farhoudi
mesh_terms: D002001:Adipose Tissue, Brown / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon; D055815:Young Adult
chemical_list: D015609:Organotechnetium Compounds; C000607999:technetium 99m methoxyisobutylisonitrile