Difference in F-18 FDG Uptake After Esophagogastroduodenoscopy and Colonoscopy in Healthy Sedated Subjects / 대한핵의학회잡지

PURPOSE: We aimed to evaluate the difference in fluorodeoxyglucose (FDG) uptake in sedated healthy subjects after they underwent esophagogastroduodenoscopy (EGD) and colonoscopy procedures.METHODS: The endoscopy group (n = 29) included healthy subjects who underwent screening via F-18 FDG positron emission tomography/computed tomography (PET/CT) after an EGD and/or colonoscopy under sedation on the same day. The control group (n = 35) included healthy subjects who underwent screening via PET/CT only. FDG uptake in the tongue, uvula, epiglottis, vocal cords, esophagus, stomach, duodenum, liver, cecum, colon, anus, and muscle were compared between the two groups.RESULTS: Maximum standardized uptake value (SUVmax) in the tongue, pharynx, larynx, and esophagus did not significantly differ between the endoscopy and control groups. In contrast, mean SUVmax in the whole stomach was 18 % higher in the endoscopy group than in the control group (SUVmax: 2.96 vs. 2.51, P = 0.010). In the lower gastrointestinal track, SUVmax from the cecum to the rectum was not significantly different between the two groups, whereas SUVmax in the anus was 20% higher in the endoscopy group than in the control group (SUVmax: 4.21 vs. 3.50, P = 0.002). SUVmax in the liver and muscle was not significantly different between the two groups. Mean volume of the stomach and mean cross section of the colon was significantly higher in the endoscopy group than in the control group (stomach: 313.28 cm³ vs. 209.93 cm³, P < 0.001, colon: 8.82 cm² vs. 5.98 cm², P = 0.001).CONCLUSIONS: EGD and colonoscopy under sedation does not lead to significant differences in SUVmax in most parts of the body. Only gastric FDG uptake in the EGD subjects and anal FDG uptake in the colonoscopy subjects was higher than uptake in those regions in the control subjects.

Juvenile Dermatomyositis Diagnosed by (99m)Tc-HDP Three-phase Bone Scintigraphy / 핵의학분자영상

Juvenile dermatomyositis is a common inflammatory muscle disease of childhood, characterized by weakness in proximal muscles and specific skin rash. In case of juvenile dermatomyositis without characteristic clinical features, non-invasive imaging tools such as (99m)Tc-HDP three-phase bone scan are very helpful in diagnostic workup of myopathies. We report a case of 13-year old female with juvenile dermatomyositis, in which (99m)Tc-HDP three-phase bone scan was useful in diagnosis and assessing therapy response.

Detection of Occult Thymoma Using Tc-99m tetrofosmin Scintigraphy / 핵의학분자영상

Tetrofosmin is a ligand that forms a lipophilic, cationic complex with Tc-99m.1) Tc-99m tetrofosmin was developed as a myocardial perfusion imaging agent and also used to depict tumors.1-3) Mediastinal tumors is also detected by Tc-99m tetrofosmin.2-5) We report a case of extracardiac mediastinal activity detected by Tc-99m tetrofosmin scintigraphy, which revealed thymoma.

Dual Lingual Thyroid Mimicking Mono-ectopic Thyroid in the Anterior View of Tc-99m Sodium Pertechnetate Thyroid Scan / 핵의학분자영상

Ectopic thyroid is not common disease and double ectopic thyroid is rare. Until January of 2008, dual ectopic thyroid has been reported only 23 cases in international literatures. Tc-99m sodium pertechnetate scan is playing an important role in the diagnosis of ectopic thyroid. In most of the cases, dual lingual thyroid tissues could be detected as two radiotracer uptake foci. We report a case of dual lingual thyroid mimicking mono-lingual thyroid in the anterior view of thyroid scan. Lateral view helped in this case to detect the dual lingual thyroid. With lateral view, the anatomical position and relationship could be examined in more detail.

Significant Mismatch between FDG Uptake and Size after Chemotherapy in a Patient with Non-small Cell Lung Cancer / 핵의학분자영상

A 75-year-old man with non-small cell lung cancer (NSCLC) underwent F-18 fluorodeoxyglucose (FDG) PET/CT for staging. PET/CT showed distant metastases to intra-abdominal lymph nodes (LNs) as well as bilateral mediastinal LNs (stage IV). He underwent PET/CT (restaging PET/CT) 1 week after the completion of first-line chemotherapy (docetaxel + carboplatin). It showed markedly increased FDG uptake in primary tumor, whereas tumor size decreased significantly, compared to prior PET/CT. This lesion was aggravated on follow-up CT 3 months after the completion of chemotherapy. Although there are several reports that FDG PET has potential to evaluate early response to chemotherapy and prognosis, there are a few cases to show mismatch between FDG uptake and size on PET/CT. Thus we report a case of NSCLC showed increased FDG uptake of primary tumor while decreased tumor size on restaging PET/CT.