PURPOSE: In prior study, we synthesized 99mTc-galactosylated chitosan (GC) and performed in vivo biodistribution study, showed specific targeting to hepatocyte. The aim of this study is to evaluate the labeling efficiency and cytotoxicity of modified galactosylated chitosan compounds, galactosyl methylated chitosan (GMC) and HYNIC-galactosylated chitosan (GCH). MATERIALS AND METHODS: GC, GMC and GCH were synthesized and radiolabeled with 99mTc. Then, they were incubated for 6 hours at room temperature and human serum at 37 degrees C. Labeling efficiencies were determined at 15, 30 m, 1, 2, 3 and 6 h after radiolabeling. To evaluate cytotoxicity, MTT assay was performed in HeLa and HepG2 cells. RESULTS: In comparison with them of 99mTc-GC, labeling efficiencies of 99mTc-GMC were significantly improved (100, 97 and 89% in acetone and 96.3, 95.8 and 75.6% in saline at 15 m, 1 and 6 h, respectively). Moreover, 99mTc-GCH showed more improved labeling efficiencies (> 95% in acetone and human serum and > 90% in saline at 6 h). In MTT assay, cytotoxicity was very low and not different from that of controls. CONCLUSION: These results represent that these compounds are radiochemically compatible radiopharmaceuticals, can be used in hepatocyte specific imaging study and in vivo gene or drug delivery monitoring.
Acetone ; Chitosan* ; Hep G2 Cells ; Hepatocytes ; Humans ; Radiopharmaceuticals

Hepatic hemangioma is the most common benign liver tumor and must be considered in the differential diagnosis of other space occupying hepatic masses. A 54-year-old man was referred to evaluate bone metastases of lung adenocarcinoma. In our case, we thought that a focal hepatic uptake in the bone scan was a metastatic lesion, because of underlying lung adenocarcinoma. However, the findings of abdominal CT and Tc-99m RBC scan results were deemed to be characteristic of hepatic hemangioma. The biopsy of the lesion was not performed.
Adenocarcinoma ; Biopsy ; Diagnosis, Differential ; Hemangioma* ; Humans ; Liver ; Lung ; Middle Aged ; Neoplasm Metastasis ; Tomography, X-Ray Computed

A 26 years old male patient with Hodgkin's disease, considered as complete remission, underwent 18F-FDG whole body PET/CT. 18F-FDG whole body PET/CT showed unexpected hypermetabolic nodule in left quadratus femoris muscle suggesting local recurrence. Subsequent MRI also revealed well-enhancing nodular lesion with intermediate and high signal intensity on T1WI and T2WI, respectively. The lesion was confirmed as nodular fasciitis by pathologic examination of the excised specimen.
Adult ; Fasciitis* ; Fluorodeoxyglucose F18* ; Hodgkin Disease ; Humans ; Magnetic Resonance Imaging ; Male ; Positron-Emission Tomography and Computed Tomography* ; Recurrence

PURPOSE: Gastric emptying scan (GES) is usually acquired up to 2 hours. Our study investigated whether a fraction of meal-retention in the stomach at 120 minutes (FR120) was predicted from the data measured for 90 minutes by using non-linear curve fitting. We aimed at saving the delayed imaging by utilizing mathematical models. MATERIALS AND METHODS: Ninety-six patients underwent GES immediately after taking a boiled egg with 74 MBq (2 mCi) Tc-99m DTPA. The patients were divided into Group I (T1/2 < or=90 min) and Group II (90 min< T1/2< or=120 min). Group I (n=51) had 21 men and 30 women, and Group II (n=45) 15 men and 30 women. There was no significant difference in age and sex between the two groups. Simple exponential, power exponential, and modified power exponential curves were acquired from the measured fraction of meal-retention at each time (0, 15, 30, 45, 60, 75, and 90 min) by non-linear curve fitting (MATLAB (R) 5.3) and another simple exponential fitting was performed on the fractions at late times (60, 75, and 90 min). A predicted FR120 was calculated from the acquired functional formulas. A correlation coefficient between the measured FR120 and the predicted FR120 was computed (MedCalc (R) 6.0). RESULTS: Correlation coefficients (r) between the measured FR120 and the predicted FR120 of each mathematical functions were as follows: simple exponential function (Group I: 0.8858, Group II: 0.5982, p< 0.0001), power exponential function (Group I: 0.8755, Group II: 0.6008, p< 0.0001), modified power exponential function (Group I: 0.8892, Group II: 0.5882, p< 0.0001), and simple exponential function at the late times (Group I: 0.9085, Group II: 0.6832, p< 0.0001). In all the fitting models, the predicted FR120 were significantly correlated with the measured FR120 in Group I but not in Group II. There was no statistically significant difference in correlation among the 4 mathematical models. CONCLUSION: In the cases with T1/2 < or=90 min, the predicted FR120 is significantly correlated with the measured FR120. Therefore, FR120 can be predicted from the data measured for 90 minutes by using non-linear curve fitting, saving the delayed imaging after 90 minutes when T1/2 < or=90 min is ascertained.
Female ; Gastric Emptying* ; Humans ; Male ; Models, Theoretical* ; Ovum ; Pentetic Acid ; Radionuclide Imaging* ; Stomach

PURPOSE: Thyroglobulin (Tg) is a valuable and sensitive tool as a marker for diagnosis and follow-up for several thyroid disorders, especially, in the follow-up of patients with differentiated thyroid cancer (DTC). Often, clinical decisions rely entirely on the serum Tg concentration. But the Tg assay is one of the most challenging laboratory measurements to perform accurately owing to antithyroglobulin antibody (Anti-Tg). In this study, we have compared the degree of Anti-Tg effects on the measurement of Tg between availale Tg measuring kits. MATERIALS AND METHODS: Measurement of Tg levels for standard Tg solution was performed with two different kits commercially available (A/B kits) using immunoradiometric assay technique either with absence or presence of three different concentrations of Anti-Tg. Measurement of Tg for patient's serum was also performed with the same kits. Patient's serum samples were prepared with mixtures of a serum containing high Tg levels and a serum containg high Anti-Tg concentrations. RESULTS: In the measurements of standard Tg solution, presence of Anti-Tg resulted in falsely lower Tg level by both A and B kits. Degree of Tg underestimation by A kit was more prominent than B kit. The degree of underestimation by B kit was trivial therefore clinically insignificant, but statistically significant. Addition of Anti-Tg to patient serum resulted in falsely lower Tg levels with only A kit. CONCLUSION: Tg level could be underestimated in the presence of anti-Tg. Anti-Tg effect on Tg measurement was variable according to assay kit used. Therefore, accuracy test must be performed for individual Tg-assay kit.
Diagnosis ; Follow-Up Studies ; Humans ; Immunoradiometric Assay* ; Thyroglobulin* ; Thyroid Gland ; Thyroid Neoplasms

PURPOSE: There has been many reports for the effect of attenuation correction on myocardial perfusion SPECT. We studied the effect of attenuation correction with CT (computed tomography) in patients with normal coronary angiography. MATERIALS AND METHODS: Fifteen patients with normal coronary artery on angiography and low likelihood of coronary artery disease were enrolled in this study (male: 6, female: 9, mean age: 58+/-8 year). Myocardial perfusion SPECT was done with Millennium VG with Hawkeye device (GE, SPECT/CT camera). A visual analysis and polar map quantification (Emory tool box) was performed. In quantitative analysis, percent uptake of each myocardial wall on polar map (percent of maximal uptake) was compared between non-corrected (NC) and corrected (AC) images. RESULTS: Visual analysis showed AC images led to an increase of uptake in the inferior wall, but decrease of uptake in the anterior wall, apex and septum. Liver activity is also increased in AC images. In quantitative analysis, the percent uptake is decreased in the anterior wall, apex and septum, but increased in the inferior wall. It is helpful to interpret the images in the inferior wall after AC, but difficult in the apex and anterior wall after AC. CONCLUSION: AC is helpful in the inferior wall. But in the apex or anterior wall, AC must be carefully applied to normal perfused myocardium.
Angiography ; Coronary Angiography ; Coronary Artery Disease ; Coronary Vessels ; Female ; Humans ; Liver ; Myocardium ; Perfusion* ; Tomography, Emission-Computed, Single-Photon*

PURPOSE: Hypereosinophilic syndrome (HES) is an infiltrative disease of eosinophils affecting multiple organs including the lung. F-18 2-fluoro-2-deoxyglucose (F-18 FDG) may accumulate at sites of inflammation or infection, making interpretation of whole body PET scan difficult in patients with cancer. This study was to evaluate the PET findings of HES with lung involvement and to find out differential PET features between lung malignancy and HES with lung involvement. MATERIAL AND METHODS: F-18 FDG PET and low dose chest CT scan was performed for screening of lung cancer. Eight patients who showed ground-glass attenuation (GGA) and consolidation on chest CT scan with peripheral blood eosinophilia were included in this study. The patients with history of parasite infection, allergy and collagen vascular disease were excluded. CT features and FDG PET findings were meticulously evaluated for the distribution of GGA and consolidation and nodules on CT scan and mean and maximal SUV of abnormalities depicted on F-18 FDG PET scan. In eight patients, follow-up chest CT scan and FDG PET scan were done one or two weeks after initial study. RESULTS: F-18 FDG PET scan identified metabolically active lesions in seven out of eight patients. Maximal SUV was ranged from 2.8 to 10.6 and mean SUV was ranged from 2.2 to 7.2. Remaining one patient had maximal SUV of 1.3. On follow-up FDG PET scan taken on from one to four weeks later showed decreased degree of initially noted FDG uptakes or migration of previously noted abnormal FDG uptakes. CONCLUSIONS: Lung involvement in the HES might be identified as abnormal uptake foci on FDG PET scan mimicking lung cancer. Follow-up FDG PET and CT scan for the identification of migration or resolution of abnormalities and decrement of SUV would be of help for the differentiation between lung cancer and HES with lung involvement.
Collagen ; Eosinophilia ; Eosinophils ; Fluorodeoxyglucose F18 ; Follow-Up Studies ; Humans ; Hypereosinophilic Syndrome* ; Hypersensitivity ; Inflammation ; Lung ; Lung Neoplasms ; Mass Screening ; Parasites ; Positron-Emission Tomography* ; Tomography, X-Ray Computed ; Vascular Diseases

PURPOSE: We investigated prospectively whether the interpretation considering the patterns of FDG uptake and the findings of unenhanced CT for attenuation correction can improve the diagnostic accuracy for assessing malignant lymph node (LN) and N stage in non-small cell lung cancer (NSCLC) using CT-corrected FDG-PET (PET/CT). MATERIALS AND METHODS: Subjects were 91 NSCLC patients (M/F: 62/29, age: 60+/-9 yr) who underwent PET/CT before LN dissection. We evaluated the maximum SUV ( (max) SUV), patterns of FDG uptake, short axis diameter, and calcification of LN showing abnormally increased FDG uptake. Then we investigated criteria improving the diagnostic accuracy and correlated results with postoperative pathology. In step 1, LN was classified as benign or malignant based on (max) SUV only. In step 2, LN was regarded as benign if it had lower (max) SUV than the cut-off value of step 1 or it had calcification irrespective of its (max) SUV. In step 3, LN regarded as malignant in step 2 was classified as benign if they had indiscrete margin of FDG uptake. RESULTS: Among 432 LN groups surgically resected (28 malignant, 404 benign), 71 showed abnormally increased FDG uptake. We determined the cut-off as (max) SUV = 3.5 using ROC curve analysis. The sensitivity, specificity, and accuracy for assessing malignant LN were 64.3%, 86.9%, 85.4% in step 1, 64.3%, 95.0%, 93.1% in step 2, and 57.1%, 98.0%, 95.4% in step3, respectively. The accuracy for assessing N stage was 64.8% in step 1, 80.2% in step 2, and 85.7% in step 3. CONCLUSION: Interpreting PET/CT, consideration of calcification and shape of the FDG uptake margin along with (max) SUV can improve the diagnostic accuracy for assessing malignant involvement and N stage of hilar and mediastinal LNs in NSCLC.
Axis, Cervical Vertebra ; Carcinoma, Non-Small-Cell Lung* ; Humans ; Lung ; Lymph Nodes ; Pathology ; Positron-Emission Tomography and Computed Tomography ; Prospective Studies ; ROC Curve ; Sensitivity and Specificity

PURPOSE: The maximal elastance (E (max) ) of myocardium has been established as a reliable load-independent contractility index. Recently, we developed a noninvasive method to measure the regional contractility using gated myocardial SPECT and arterial tonometry data. In this study, we measured regional E (max) (rE (max) ) in the patients who underwent coronary artery bypass graft surgery (CABG), and assessed its relationship with other variables. MATERIALS AND METHODS: 21 patients (M: F=17: 4, 58+/-12 y) who underwent CABG were enrolled. (201) Tl rest/ dipyridamole stress (99m) Tc-sestamibi gated SPECT were performed before and 3 months after CABG. For 15 myocardial regions, regional time-elastance curve was obtained using the pressure data of tonometry and the volume data of gated SPECT. To investigate the coupling with myocardial function, preoperative regional E (max) was compared with regional perfusion and systolic thickening. In addition, the correlation between E (max) and viability was assessed in dysfunctional segments (thickening < 20% before CABG). The viability was defined as improvement of postoperative systolic thickening more than 10%. RESULTS: Regional E (max) was slightly increased after CABG from 2.41+/-1.64 (pre) to 2.78+/-1.83 (post) mmHg/mL. E (max) had weak correlation with perfusion and thickening (r=0.35, p< 0.001). In the regions of preserved perfusion (> or=60%), E (max) was 2.65+/-1.67, while it was 1.30+/-1.24 in the segments of decreased perfusion. With regard to thickening, E (max) was 3.01+/-1.92 mmHg/mL for normal regions (thickening > or=40%), 2.40+/-1.19 mmHg/mL for mildly dysfunctional regions (< 40% and > or=20%), and 1.13+/-0.89 mmHg/mL for severely dysfunctional regions (< 20%). E (max) was improved after CABG in both the viable (from 1.27+/-1.07 to 1.79+/-1.48 mmHg/mL) and non-viable segments (from 0.97+/-0.59 to 1.22+/-0.71 mmHg/mL), but there was no correlation between E (max) and thickening improvements (r=0.007). CONCLUSIONS: Preoperative regional E (max) was relatively concordant with regional perfusion and systolic thickening on gated myocardial SPECT. In dysfunctional but viable segments, E (max) was improved after CABG, but showed no correlation with thickening improvement. As a load-independent contractility index of dysfunctional myocardial segments, we suggest that the regional E (max) could be an independent parameter in the assessment of myocardial function.
Coronary Artery Bypass ; Dipyridamole ; Humans ; Manometry ; Myocardium* ; Perfusion ; Tomography, Emission-Computed, Single-Photon ; Transplants

Current interest in the regioselective N-functionalization of tetraazacycloalkanes (cyclen and cyclam) stems mainly from their complexes with radioactive metals for applications in diagnostic (64Cu, 111In, 67Ga) and therapeutic (90Y) medicine, and with paramagnetic ions for magnetic resonance imaging (Gd+3). Selective methods for the N-substitution of cyclen and cyclam is a crucial step in most syntheses of cyclen and cyclam-based radiometal complexes and bifunctional chelating agents. In addition, mixing different pendent groups to give hetero-substituted cyclen derivatives would be advantageous in many applications for fine-tuning the compound's physical properties. So far, numerous approaches for the regioselective N-substitution of tetraazacycloalkanes and more specifically cyclen and cyclam are reported. Unfortunately, none of them are general and every strategy has its own strong points and drawbacks. Herein, we categorize numerous regioselective N-alkylation methods into three strategies, such as 1) direct substitution of the macrocycle, 2) introduction of the functional groups prior to cyclization, and 3) protection/functionalization/deprotection. Our discussion is also split into the methods of mono- and tri-functionalization and di-functionalizataion based on number of substituents. At the end, we describe new trials for the new macrocycles which form more stable metal complexes with various radiometals, and briefly mention the commercially available tetraazacycloalkanes which are used for the biconjugation of biomolecules.
Chelating Agents ; Coordination Complexes ; Cyclization ; Ions ; Ligands* ; Magnetic Resonance Imaging ; Metals