The reduction in the amount of asialoglycoprotein (ASGP) receptor, which resides exclusively on the plasma membrane of functioning mammalian hepatocytes, as a consequence of hepato-cellular damage has been demonstrated in various pathologic conditions of the liver. Galac tosylated human serum albumin (GSA) is a newly developed receptor-binding agent, specific for the ASGP receptor. Tc-99m GSA binds quantitatively to liver ASGP receptors and the rate of accumulation in the liver is dependent on hepatic function represented as the amount of receptor, as well as the amount of ligand injected, its affinity to the receptor and the hepatic blood flow. The findings of Tc-99m GSA scintigraphy were reported to reflect the hepatic function of the patients with large hepatic tumors, obstructive jauniice, acute and chronic liver disease. Tc-99m GSA scintigraphy is an easy and reliable test and has the clinical potentials to evaluate the liver function in the patients with hepatic disorders.
Asialoglycoprotein Receptor ; Cell Membrane ; Evaluation Studies as Topic* ; Hepatocytes ; Humans ; Liver Diseases ; Liver* ; Radionuclide Imaging* ; Serum Albumin*

Radioiodine has been known as an important and safe armamentarium in the diagnosis and treatment of differentiated thyroid cancer (DTC) for more than 70 years. The 2015 guidelines from the American Thyroid Association (ATA) for adults with thyroid nodules and DTC seem to be the most comprehensive guidelines in the thyroid cancer field. The 2015 ATA guidelines provided an advance in evidence-based management of DTC, and resulted in a significant change in the patterns of practice regarding the application of the radioiodine. However, the 2015 ATA guidelines also provoked much controversy because a substantial portion of the recommendations announced were not based on sufficiently strong evidence. While the number of radioiodine administrations in Korea in the year of 2018 has decreased to a level less than 50% of that in 2013, in this review, we address some of the current issues and controversies regarding the application of radioiodine for the diagnosis, ablation and treatment of DTC, especially related to the 2015 ATA guidelines. Possible strategies for the achievement of better quality in radioiodine imaging and improvement in treatment efficiency that can be used in the near future are also discussed here.
Adult ; Diagnosis ; Humans ; Iodine ; Korea ; Thyroid Gland ; Thyroid Neoplasms ; Thyroid Nodule

PURPOSE: Na+-K+ ATPase Activity has beem estimated by the degree of inhibition of cation transport by cardiac glycosides (ouabain) using Rb-86 as a substrate. The biological characterist-Isc of T1-201 is known to be simiIar to those of potassium as a transport substrate in the presence of glucose, insulin or phobol myristate acetate (PMA). The purpose of this study was to measure ouabain sensitive Na+-K+ ATPase activity using T1-201 and compare with that using Rb-86. MATERIALS AND METHODS: Smooth muscle cells isolated from rat aorta or human placental umbilical artery were cultured, and used to measure cellular Na+-K+ ATPase activity. Na+-K+ ATPase activity was measured as a percentage decrease in cellular uptake of T1-201 or Rb-86 by ouabain under the presence of glucose, insulin or PMA in media. RESULTS: Na+-K+ ATPase ase activity measured with T1-201, as a transport substrate, was not different from those measured with Rb-86 in rat or human smooth muscle cell preparation. Incubation with high concentration glucose resulted in about 30% decrease in enzyme activity. In contrast, insulin or PMA resulted in 50-70% or 28% increases from baseline activity, respectively. CONCLUSION: These results suggests that T1-201 could replace Rb-86 in measurement of ouabain sensititive Na+-K+ ATPase activity in vitro. High level of glucose concentration decreased cellular Na+-K+ ATPase activity, but insulin or PMA increased it.
Adenosine Triphosphatases* ; Animals ; Aorta ; Cardiac Glycosides ; Glucose ; Humans ; Insulin ; Membranes* ; Myocytes, Smooth Muscle ; Myristic Acid ; Ouabain ; Potassium ; Rats ; Umbilical Arteries

Radioactive iodine therapy using I-131 for hyperthyroidism has been used for more than 50 years, and generally considered safe and devoid of major side effects. Appropriate patient selection criteria and clinical judgement concerning patient preparation should be employed for its optimal use. It has not been possible to resolve the trade-off between efficient definite cure of hyperthyroidism and the high incidence of post-therapy hypothyroidism. The dose of the I-131 needed to maintain euthyroid state remains an area of uncertainity and debate. Early side effects are uncommon and readily managable. Other than the need for long-term monitoring and, in most cases, lifelong thyroid hormone treatment for late adverse consequences of this treatment remains only conjectural. We have reviewed general principles and recent advances in radioiodine treatment for Graves' hyperthyroidism, specially regarding to several controversies.
Humans ; Hyperthyroidism* ; Hypothyroidism ; Incidence ; Iodine ; Patient Selection ; Thyroid Gland

Pharmacologic stress testing for myocardial perfusion imaging is a widely used noninvasive method for the evaluation of known or suspected coronary artery disease. The use of exercise for cardiac stress has been practiced for over 60 years and clinicians are familiar with its using. However, there are inevitabe situations in which exercise stress is inappropriate. A large number of patients with cardiac problems are unable to exercise to their full potential due to comorbidity such as osteoarthritis, vascular disease and pulmonary disease and a standard exercise stress test for myocardial perfusion imaging is suboptimal means for assessment of coronary artery disease. This problem has led to the development of the pharmacologic stress test and to a great increase in its popularity. All of the currently used pharmacologic agents have well-documented diagnostic value. This review deals the physiological actions, clinical protocols, safety, nuclear imaging applications of currently available stress agents and future development of new vasodilating agents.
Clinical Protocols ; Comorbidity ; Coronary Artery Disease ; Exercise Test* ; Humans ; Lung Diseases ; Myocardial Perfusion Imaging ; Osteoarthritis ; Vascular Diseases

Although the outcome of cancer patients after cytotoxic chemotherapy is related diverse mechanisms, multidrug resistance (MDR) for chemotherapeutic drugs due to cellular P-glycoprotein (Pgp) or multidrug-resistance associated protein (MRP) is most important factor in the chemotherapy failure to cancer. A large number of pharmacologic compounds, including verapamil, quinidine, tamoxifen, cyclosporin A and quinolone derivatives have been reported to overcome MDR. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transporter. 99mTc-MIBI and other 99mTc-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of Pgp-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with 11C have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and N-[11C]acetyl-leukotriene E4 provides an opportunity to study MRP function non-invasively in vivo. SPECT and PET pharmaceuticals have successfully used to evaluate pharmacologic effects of MDR modulators. Imaging of MDR and reversal of MDR with bioluminescence in a living animal is also evaluated for future clinical trial. We have described recent advances in molecular imaging of MDR and reviewed recent publications regarding feasibility of SPECT and PET imaging to study the functionality of MDR transporters in vivo.
Animals ; Colchicine ; Cyclosporine ; Daunorubicin ; Drug Resistance, Multiple* ; Drug Therapy ; Humans ; Leukotrienes ; Molecular Imaging ; P-Glycoprotein ; Positron-Emission Tomography ; Quinidine ; Tamoxifen ; Tomography, Emission-Computed, Single-Photon ; Verapamil

Nuclear imaging studies have been used for individualized treatment planning, and to optimize management in patients with differentiated thyroid cancer (DTC). Nuclear imaging studies demonstrate whole body distribution of radioactive tracer and are complementary to radiological studies as they give functional information. Recently, hybrid imaging modalities such as single photon emission computed tomography (CT) with integrated CT and positron emission tomography with integrated CT allow the rapid and efficient fusion of functional and anatomical images, and provide diagnostic information that influence management decision in patients with DTC. This article reviewed nuclear imaging studies and hybrid imaging modalities used in patients with DTC, and future perspectives of functional molecular imaging of the thyroid cancer.
Chimera ; Humans ; Molecular Imaging ; Positron-Emission Tomography ; Thyroid Gland ; Thyroid Neoplasms ; Tomography, Emission-Computed, Single-Photon

A 52-year-old woman with a history of general weakness, fatigue, weight loss, elevated serum levels of liver transaminase enzyme for three months underwent an F-18 FDG PET/CT scan to evaluate a cause of the hepatosplenomegaly found on abdominal ultrasonography. Initial PET/CT revealed markedly enlarged liver and spleen with intense FDG uptake. Otherwise, there were no areas of abnormal FDG uptake in whole body image. Histological evaluation by a hepatic needle biopsy demonstrated diffuse large B cell type lymphoma and final diagnosis for this patient was hepatosplenic B-cell lymphoma. She received five cycles of CHOP chemotherapy, and second PET/CT scan was followed after then. Follow-up PET-CT revealed normal sized liver with disappearance of abnormal FDG uptake. Hepatosplenic B-cell lymphoma is relatively rare and mostly presents as single or multiple nodules.1,2 Diffuse type hepatosplenic lymphoma is extremely rare and poorly recognized entity.3 The diagnosis is very difficult and complicated by the presence of misleading symptoms.4 In this rare hepatosplenic B-cell lymphoma case, F-18 FDG PET/CT scan provided a initial diagnostic clue of hepatosplenic lymphoma and an accurate chemotherapy response.
B-Lymphocytes ; Biopsy, Needle ; Body Image ; Fatigue ; Female ; Follow-Up Studies ; Hepatomegaly ; Humans ; Liver ; Lymphoma ; Lymphoma, B-Cell ; Middle Aged ; Spleen ; Weight Loss

BACKGROUND: Lung-to-heart uptake ratio (LHR) in (201) Tl-chloride myocardial perfusion scan is believed to be a reliable marker for left ventricular (LV) dysfunction, but the clinical value of LHR is controversial for 99mTc-MIBI imaging. Furthermore, most of results suggesting lung uptake of 99mTc-MIBI as a potential marker for LV dysfunction used immediate post-stress images, instead of routine images acquired 1 hour after tracer injection. The goal of our study was to investigate whether LHR evaluated with routine gated 99mTc-MIBI imaging can reflect the degree of perfusion defect or left ventricular performance. SUBJECTS AND METHODS: 241 patients underwent exercise 99mTc-MIBI myocardial SPECT were classified into normal myocardial perfusion (NP, n=135) and abnormal myocardial perfusion (AP, n=106) group according to the presence of perfusion defect. LHR was calculated from anterior projection image taken at 1-hour after injection. Two regions of interest (ROIs) were placed on left lung above LV and on myocardium showing the highest radioactivity. Subjects were classified by left ventricular ejection fraction (LVEF), as Gr-I: > 50%, Gr-II: 36-50%, Gr-III: < 36% and by summed stress score (SSS), as Gr-A: < 4, Gr-B: 4-8, Gr-C: 9-13, Gr-D: > 13, LHR was compared among these groups. RESULTS: In NP group (n=135), LHR, were higher in men than women (men: 0.311+/-0.03, women: 0.296+/-0.03, p< 0.05). Significant difference, in LHR were found between NP and AP groups both for men and women (men: 0.311+/- 0.03 vs. 0.331+/- 0.06, women: 0.296+/-0.03 vs. 0.321+/-0.07, p< 0.05). There were weak negative correlation between LHR and LVEF (r=-0.342, p< 0.05) and weak positive correlation between LHR and SSS (r=0.478, p< 0.05) in men, but not in women (LVEF: r=-0.279, p=0.100, SSS: r=0.276, p=0.103). Increased LHR was defined when for more than mean + 2SD value (men> or = 0.38, women> or = 0.37) of the LHR of the subject with normal perfusion. Increased LHR were observed more frequently in subjects with lower LVEF (Gr-I: 11.1%, Gr-II: 27.0%, Gr-III: 36.4%, p< 0.05) and higher SSS (Gr-A: 14.0%, Gr-B: 6.7%, Gr-C: 18.2%, Gr-D: 40.7%, p< 0.05). CONCLUSIONS: LHRs obtained from routine 99mTc-MIBI gated SPECT images were weakly correlated with LVEF and perfusion defect. Although significant overlaps were observed between normal and abnormal perfusion group, LHRs could be used as an indirect marker of severe perfusion defect or reduced left ventricular function.
Female ; Humans ; Lung* ; Male ; Myocardium ; Perfusion* ; Radioactivity ; Stroke Volume* ; Technetium Tc 99m Sestamibi* ; Tomography, Emission-Computed, Single-Photon* ; Ventricular Function, Left

Adrenal incidentalomas are adrenal masses serendipitously detected during an imaging study performed for reasons unrelated to suspicion of adrenal disease. The incidence of adrenal incidentalomas has increased because of the widespread use of various imaging modalities. In oncology patients with adrenal incidentalomas, the characterization of the adrenal masses is challenging because nearly 50% of incidental adrenal masses are metastatic lesions that need special medical attention. Although unenhanced computed tomography (CT) densitometry, chemical shift magnetic resonance imaging (MRI), delayed contrast-enhanced CT and CT histogram analysis have been used as sensitive and specific modalities for differentiating benign from malignant adrenal masses, F-18 fluoro-2-deoxy-D-glucose positron emission tomography (F-18 FDG PET)/CT is a highly accurate imaging modality compared to CT or MRI, especially when these two imaging modalities are combined. In addition, a semiquantitative analysis using standardized uptake value ratio further improves the diagnostic accuracy of F-18 FDG PET/CT in differentiating benign from malignant adrenal masses. Thus, F-18 FDG PET/CT is very helpful for determining the best therapeutic management, especially for assessing the need for surgery.
Densitometry ; Diagnosis, Differential* ; Electrons* ; Fluorodeoxyglucose F18 ; Humans ; Incidence ; Magnetic Resonance Imaging ; Multidetector Computed Tomography ; Positron-Emission Tomography ; Positron-Emission Tomography and Computed Tomography ; Tomography, X-Ray Computed