Normal Thymic Uptake of 2-Deoxy-2[F-18]fluoro-D-Glucose

Abstract

In this study we assessed the normal physiological and dynamic thoracoabdominal distribution of 18 F fluorodeoxyglucose (18 F-FDG) uptake and the standardized uptake values (SUVs) of the major parenchymal organs in five normal young adult domestic short haired cats. Dynamic PET data were acquired with a transaxial field-of-view (FOV) PET/CT scanner, Regions of interests (ROIs) were manually drawn over the left ventricular free wall, left ventricular blood pool, liver, spleen, and left and right renal cortices. The SUVs of these organs were calculated for 5-min frames over the 90 min acquisition. The uptake of 18 F-FDG within the major organs, showed a tendency to gradually decline, except for the left ventricle and blood pool. The decrease in SUV was rapid after injection with a plateau occurring after 30 minutes. The uptake of 18 F-FDG within the hepatic parenchyma was low compared to that in the kidney at the beginning of study. A steady decline in the hepatic parenchyma SUV was quite similar to that observed for the kidneys .The SUV of 18 F-FDG within the spleen was low. Uptake of 18 F-FDG within the myocardium was minimal. These SUV data from the parenchymal organs of normal cats compares favourably with those of normal humans and dogs and can be used in feline studies using PET/CT for the evaluation of various diseases. Furthermore, PET/CT can provide higher quality images over shorter examination times than conventional PET.

Implications of mediastinal uptake of 131I with regard to surgery in patients with differentiated thyroid carcinoma

“…According to those data, pathologic examination of the resected specimen revealed the presence of thymus in only one patient with elevated Tg levels. This patient, who was reported on by Alibazoglu et al, 20 was a woman age 54 years with a Hü rthle cell carcinoma (high-risk) who also had histologically proven retrolaryngeal metastases, which probably increased her serum Tg level significantly. In a patient described by Michigishi et al, 19 a 19-year-old female with Tg antibodies, the thymus was removed but did not contain metastatic thyroid tissue; this patient also underwent therapeutic neck dissection for metastatic papillary thyroid carcinoma.…”

The anterior mediastinum: anatomy and imaging procedures

“…8). Physiological uptake by the thymus in the absence of intrinsic pathology has also been reported [29][30][31], and this is a frequent occurrence in children. The effect of treatment (chemotherapy, external beam radiotherapy, metabolic radiotherapy) on thymic uptake is not known, and literature data are conflicting.…”

“…8). È stato anche descritto l'uptake fisiologico, in assenza di patologia intrinseca, da parte del timo [29][30][31], che si verifica frequentemente in età pediatrica.…”

Unusual Urethral F18-FDG Accumulation on PET/CT

“…[1][2][3][4][5] Normal variants related to urinary excretion of FDG are well described in the literature. 6 -8 In clinical practice, marked FDG activity in the bladder catheter and physiologically slight activity in prostatic urethra may be seen.…”