Pulmonary tuberculoma commonly causes an increase in FDG uptake. These results suggest that in geographic regions with a high prevalence of granulomatous lesions, positive FDG PET results should be interpreted with caution in differentiating benign from malignant pulmonary abnormalities.

We investigated whether serum thyroglobulin (Tg) measured at the time of remnant ablation (ablation-Tg) could be a prognostic indicator complementary to serum Tg levels at the time of the first diagnostic whole-body scan (WBS) after thyroid hormone withdrawal (control-Tg; approximately 6-12 months after ablation-Tg) and whether ablation-Tg could predict the persistence or recurrence of disease in low-risk patients with differentiated thyroid carcinoma. Patients with differentiated thyroid carcinoma (n = 268) treated with total or near-total thyroidectomy followed by immediate (131)I remnant ablation were studied. Patients with anti-Tg autoantibodies and those showing evidence of extracervical metastases were excluded. Two patients showing remnant uptake on follow-up diagnostic WBS received a second ablation. We found significant correlation between ablation-Tg and control-Tg levels; 114 of 143 patients (80%) with ablation-Tg greater than 2 microg/liter showed detectable (>/=1 microg/liter) control-Tg, and 70 of 125 (56%) patients with ablation-Tg 2 microg/liter or less showed undetectable (<1 microg/liter) control-Tg [odds ratio 5.1, 95% confidence interval (CI) 3.0-8.9, P < 0.001]. When the 268 patients were followed up for a mean period of 5.7 +/- 1.4 yr (range 2.8-8.3 yr), 35 (13%) had recurrences; 73 (27%) were classified as "Tg positive, no evidence of disease"; and 160 (60%) showed complete remission. Of 143 patients with ablation-Tg greater than 2 microg/liter, recurrence was observed in 33 cases (23%); "Tg positive, no evidence of disease," was observed in 52 cases (36%); and complete remission was observed in 58 cases (41%). Of 125 patients with ablation-Tg 2 microg/liter or less, two patients (2%) showed recurrence during the follow-up; 21 patients (17%) were regarded as "Tg positive, no evidence of disease"; and 102 patients (81%) showed complete remission. The positive predictive value for recurrence in patients having ablation-Tg greater than 2 microg/liter was found to be 23.1% (33 of 143 patients, 95% CI 16.4-30.8%). The negative predictive value for recurrence in patients having ablation-Tg 2 microg/liter or less was found to be 98.4% (123 of 125 patients, 95% CI 94.4-99.8%). These data indicate that serum Tg levels measured at the time of immediate postoperative (131)I remnant ablation correlated well with serum Tg levels at the time of the initial diagnostic WBS and had a complementary role for predicting persistence or recurrence of disease in the earliest postoperative period.

A 5Hz high-frequency rTMS on contra-lesional pharyngeal motor cortex might be beneficial for post-stroke dysphagic patients. This intervention can be used as a new treatment method in post-stroke patients with dysphagia.

The fact that some brain tumors show hypo- or isometabolism on fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) has caused problems in the detection of primary or recurrent tumors and in the differentiation from benign lesions. We investigated the usefulness of carbon-11 methionine PET in characterizing brain lesions under these conditions. 11C-methionine PET was performed in 45 patients with brain lesions (in 34 for initial diagnosis and in 11 for detection of recurrence) that showed hypo- or isometabolism compared with normal brain tissue on FDG PET. Ten minutes after the injection of 555-740 MBq of 11C-methionine, attenuation-corrected brain images were obtained with a dedicated PET scanner. The brain lesions comprised 24 gliomas, five metastatic brain tumors, four meningiomas, two other brain tumors and ten benign lesions (including three cases of cysticercosis, two cases of radiation necrosis, one tuberculous granuloma, one hemangioma, one benign cyst, and one organizing infarction). Proliferative activity was measured using the Ki-67 immunostaining method in glioma tissues. Thirty-one of 35 brain tumors (89% sensitivity) showed increased 11C-methionine uptake despite iso- or hypometabolism on FDG PET. By contrast, all ten benign lesions showed decreased or normal 11C-methionine uptake (100% specificity). Twenty-two of 24 gliomas (92%) showed increased 11C-methionine uptake, the extent and degree of which exceeded 18F-FDG uptake, and the 11C-methionine uptake correlated with the proliferation index (r=0.67). The mean (+/-SD) uptake ratios of glioma to normal brain on FDG and 11C-methionine PET were 0.92+/-0.34 and 2.54+/-1.25, respectively. All metastatic tumors except one showed intense 11C-methionine uptake in the entire tumor or in the peripheral margin of the tumor. In meningiomas, 11C-methionine uptake showed a variable increase. In conclusion, brain lesions that show hypo- or isometabolism on FDG PET can be detected and differentiated with high sensitivity and good contrast using 11C-methionine PET. 11C-methionine PET can provide additional information when used in combination with FDG PET in the evaluation of these patients.

These findings indicate that FLT PET is useful for evaluating tumor grade and cellular proliferation in brain tumors. It displayed high sensitivity and good contrast in evaluating brain lesions that showed similar or decreased uptake compared with normal gray matter on FDG PET. FLT PET, however, did not appear to be sufficiently useful for differentiating tumors from nontumorous lesions.