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1.  Differences of Various Region-of-Interest Methods for Measuring Dopamine Transporter Availability Using 99mTc-TRODAT-1 SPECT 
The Scientific World Journal  2014;2014:837439.
This study was to investigate whether various region-of-interest (ROI) methods for measuring dopamine transporter (DAT) availabilities by single photon emission computed tomography (SPECT) are statistically different, whether results of medical research are thereby influenced, and causes of these differences. Eighty-four healthy adults with 99mTc-TRODAT-1 SPECT and magnetic resonance imaging (MRI) scans were included. Six major analysis approaches were compared: (1) ROI drawn on the coregistered MRI; (2) ROIs drawn on the SPECT images; (3) standard ROI templates; (4) threshold-ROIs; (5) atlas-based mappings with coregistered MRI; and (6) atlas-based mappings with SPECT images. Using the atlas-based approaches we assessed the influence of striatum ROIs by slice-wise and voxel-wise comparisons. In (5) and (6), three partial-volume correction (PVC) methods were also explored. The results showed that DAT availabilities obtained from different methods were closely related but quite different and leaded to significant differences in determining the declines of DAT availability per decade (range: 5.95–11.99%). Use of 3D whole-striatum or more transverse slices could avoid biases in measuring the striatal DAT declines per decade. Atlas-based methods with PVC may be the preferable methods for medical research.
PMCID: PMC4102026  PMID: 25101323
2.  Review Analysis of the Association between the Prevalence of Activated Brown Adipose Tissue and Outdoor Temperature 
The Scientific World Journal  2012;2012:793039.
Brown adipose tissue (BAT) is important for regulating body weight. Environmental temperature influences BAT activation. Activated BAT is identifiable using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). 18F-FDG PET/CT scans done between June 2005 and May 2009 in our institution in tropical southern Taiwan and BAT studies from PubMed (2002–2011) were reviewed, and the average outdoor temperatures during the study periods were obtained. A simple linear regression was used to analyze the association between the prevalence of activated BAT (P) and the average outdoor temperature (T). The review analysis for 9 BAT studies (n = 16, 765) showed a significant negative correlation (r = −0.741, P = 0.022) between the prevalence of activated BAT and the average outdoor temperature. The equation of the regression line is P(%) = 6.99 − 0.20 × T  (°C). The prevalence of activated BAT decreased by 1% for each 5°C increase in average outdoor temperature. In a neutral ambient temperature, the prevalence of activated BAT is low and especially rare in the tropics. There is a significant linear negative correlation between the prevalence of activated BAT and the average outdoor temperature.
PMCID: PMC3349155  PMID: 22593707
3.  The Relationship between Brown Adipose Tissue Activity and Neoplastic Status: an 18F-FDG PET/CT Study in the Tropics 
Brown adipose tissue (BAT) has thermogenic potential. For its activation, cold exposure is considered a critical factor though other determinants have also been reported. The purpose of this study was to assess the relationship between neoplastic status and BAT activity by 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in people living in the tropics, where the influence of outdoor temperature was low.
18F-FDG PET/CT scans were reviewed and the total metabolic activity (TMA) of identified activated BAT quantified. The distribution and TMA of activated BAT were compared between patients with and without a cancer history. The neoplastic status of patients was scored according to their cancer history and 18F-FDG PET/CT findings. We evaluated the relationships between the TMA of BAT and neoplastic status along with other factors: age, body mass index, fasting blood sugar, gender, and outdoor temperature.
Thirty of 1740 patients had activated BAT. Those with a cancer history had wider BAT distribution (p = 0.043) and a higher TMA (p = 0.028) than those without. A higher neoplastic status score was associated with a higher average TMA. Multivariate analyses showed that neoplastic status was the only factor significantly associated with the TMA of activated BAT (p = 0.016).
Neoplastic status is a critical determinant of BAT activity in patients living in the tropics. More active neoplastic status was associated with more vigorous TMA of BAT.
PMCID: PMC3267802  PMID: 22182284
Neoplastic status; BAT; 18F-FDG PET
4.  Angiographic-CT-FDG-Pathologic Correlations of the Incidentally Discovered Adrenal Mass 
During abdominal ultrasonography of a 37-year-old man a 3.2 cm hypoechoic mass in the right hepatic lobe was found incidentally. This prompted an abdominal CT, an FDG PET/CT, and an angiography to evaluate the nature of the mass. Laboratory data showed positive anti-HBs/anti-HBe, and negative HCV antibody. The alfa-fetoprotein and liver function tests were within normal limits. Contrast-enhanced CT found an enhanced hepatic tumor and primary hepatocellular carcinoma was suspected. PET/CT revealed no abnormal FDG accumulation in the right hepatic mass. The digital subtraction angiographies of the right inferior phrenic artery and right renal artery revealed a hypervascular tumor in the right adrenal gland. Therefore, a diagnosis of a right adrenal tumor was made. Serum aldosterone, serum cortisol, and urine vanillylmandelic acid, and catecholamine were all within normal limits. Laparoscopic right adrenalectomy was performed and adrenal cortical adenoma was diagnosed on a histological study.
PMCID: PMC3272913  PMID: 22315709
Adrenal cortical adenoma; angiography; FDG PET/CT; primary hepatocellular carcinoma
5.  A False Positive 18F-FDG PET/CT Scan Caused by Breast Silicone Injection 
Korean Journal of Radiology  2009;10(2):194-196.
We present here the case of a 40-year-old woman with a greater than 10 year prior history of bilateral breast silicone injection and saline bag implantation. Bilateral palpable breast nodules were observed, but the ultrasound scan was suboptimal and the magnetic resonance imaging showed no gadolinium-enhanced tumor. The 18F-FDG PET/CT scan showed a hypermetabolic nodule in the left breast with a 30% increase of 18F-FDG uptake on the delayed imaging, and this mimicked breast cancer. She underwent a left partial mastectomy and the pathology demonstrated a siliconoma.
PMCID: PMC2651438  PMID: 19270867
Breast, siliconoma; 18F-FDG PET/CT

Results 1-5 (5)