title: Increased (18)F-fluorodeoxyglucose accumulation in bilateral adrenal glands of the patients suffering from vasovagal reaction due to blood vessel puncture.
abstract: OBJECTIVE
  The purpose of the study was to evaluate the hypothesis that patients having a vasovagal reaction (VVR) after blood vessel puncture show increased FDG accumulation in bilateral adrenal glands.
  
  
  METHODS
  Over the past 8 years, 26 patients experienced a VVR after blood vessel puncture following intra-venous injection of FDG at our institution. Of the 26 patients, 16 underwent multiple-occasion FDG-PET/CT scans while suffering a VVR at only one examination. All 16 patients had no morphological abnormality in the adrenal glands on FDG-PET/CT and follow-up examination. For the 16, we retrospectively reviewed the FDG-PET/CT scan with respect to the adrenal glands and compared the result to that for the FDG-PET/CT scan of the same patient when there was no VVR event. We used both visual analysis and semi-quantitative analysis employing either maximum standardized uptake value (SUVmax) or adrenal-to-liver (A/L) SUVmax ratio.
  
  
  RESULTS
  On visual analysis of the FDG-PET/CT with VVR, accumulations in both of the adrenal glands was judged positive, defined as higher than the hepatic accumulation, in 84 % of the cases. The SUVmax in the right adrenal gland was 2.79 ± 0.69 with VVR and 1.92 ± 0.33 without VVR; this value in the left adrenal gland was 3.07 ± 0.71 with VVR and 2.05 ± 0.39 without. Mean SUVmax of both adrenal glands was 2.93 ± 0.66 with VVR and 1.98 ± 0.35 without. The A/L SUVmax ratio in the right adrenal gland was 1.02 ± 0.26 with VVR and 0.69 ± 0.11 without; this value in the left was 1.11 ± 0.23 with VVR and 0.74 ± 0.15 without. The mean A/L SUVmax ratio of both adrenal glands was 1.06 ± 0.24 with VVR and 0.72 ± 0.13 without. Each parameter with VVR was significantly higher than that without. For the two adrenal glands, the mean SUVmax with VVR was 48 % higher than that without VVR.
  
  
  CONCLUSIONS
  We confirmed the hypothesis that patients having a VVR after blood vessel puncture show increased FDG accumulation in their bilateral adrenal glands. This may reflect hyper-metabolism of the adrenal glands in synthesizing and secreting catecholamine.
authors.affiliation: Department of Radiology, Tokushima University Hospital, Tokushima, 2-50-1 Kuramoto-cho, Tokushima, 770-8503, Japan. otomi.yoichi@tokushima-u.ac.jp.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Otomi
authors.affiliation: Department of Radiology, Tokushima University Hospital, Tokushima, 2-50-1 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Shinya
authors.affiliation: Department of Medical Imaging/Nuclear Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Otsuka
authors.affiliation: Department of Radiology, Tokushima University Hospital, Tokushima, 2-50-1 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Terazawa
authors.affiliation: Department of Radiology, Tokushima University Hospital, Tokushima, 2-50-1 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Saho
authors.initials: S
authors.lastname: Irahara
authors.affiliation: Department of Radiology, Tokushima University Hospital, Tokushima, 2-50-1 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Saki
authors.initials: S
authors.lastname: Nagase
authors.affiliation: Department of Radiology, Tokushima University Hospital, Tokushima, 2-50-1 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Takahashi
authors.affiliation: Department of Radiology, Tokushima University Hospital, Tokushima, 2-50-1 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Kubo
authors.affiliation: Department of Radiology, Tokushima University Hospital, Tokushima, 2-50-1 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Harada
mesh_terms: D000311:Adrenal Glands / Q000000981:diagnostic imaging / Q000378:metabolism*; D000328:Adult; D001692:Biological Transport; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006801:Humans; D008297:Male; D000072078:Positron Emission Tomography Computed Tomography; D011677:Punctures / Q000009:adverse effects*; D019462:Syncope, Vasovagal / Q000000981:diagnostic imaging / Q000209:etiology* / Q000378:metabolism*; D014656:Vascular Surgical Procedures / Q000009:adverse effects*
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Adrenal gland; FDG; PET/CT; Vagal reflex; Vasovagal reaction