technetium-tc-99m-exametazime and gallium-citrate

With a current annual mortality rate of around 35% worldwide, infection remains a significant concern, and the diagnosis and localization of infectious foci is an important health issue. As an established infection-imaging modality, nuclear medicine plays a vital health-care role in the diagnosis and subsequent effective treatment of this condition. Despite the development of several newer radiopharmaceuticals, (67)Ga and leukocyte imaging procedures have maintained their established place for infection. Several techniques in nuclear medicine significantly aid infection diagnosis, including imaging with (111)In-oxine-, (99m)Tc-hexamethylpropyleneamine oxime-, and (99m)Tc-stannous fluoride colloid-labeled leukocytes and with (67)Ga-citrate. Each radiopharmaceutical has specific advantages and disadvantages that make it suitable to diagnose different infectious processes (e.g., soft-tissue sepsis, inflammatory bowel disease, osteomyelitis, occult fever, fever of unknown origin, and infections commonly found in immunocompromised patients). After finishing this article, the reader should be able to identify the properties of an ideal radiopharmaceutical for infection imaging, list a range of available infection-imaging radiopharmaceuticals, compare the relative results of a range of radiopharmaceuticals used internationally to detect infection in the body, understand several common infectious processes that can be diagnosed using nuclear medicine techniques, and select an appropriate radiopharmaceutical to image a range of infectious processes.

Topics: Citrates; Fever of Unknown Origin; Gallium; Humans; Infections; Irritable Bowel Syndrome; Leukocytes; Nuclear Medicine; Organometallic Compounds; Osteomyelitis; Oxyquinoline; Practice Patterns, Physicians'; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Sepsis; Technetium Compounds; Technetium Tc 99m Exametazime; Tin Fluorides; Tomography, Emission-Computed

Diffuse infiltrative lung disease (ILD) includes a heterogeneous group of disorders predominantly affecting lung parenchyma and sparing the airway. To assess the degree of pulmonary vascular endothelial damage in active ILD, lung/liver uptake ratios (L/L ratio) on technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) lung scan were determined in 30 patients with active ILD. Meanwhile, the gallium-67 citrate (Ga-67) uptake index (GUI) on Ga-67 lung scan was used to evaluate the severity of lung inflammation in active ILD. In this study, high-resolution CT (HRCT) was used to evaluate disease activity in ILD. The results show statistically significant differences between normal controls and patients with active ILD as shown in L/L ratios and GUI. However, when the patients were divided into two groups of 15 patients with normal chest X-ray findings and 15 with abnormal X-ray findings, there was no significant difference in those parameters. In addition, there was no statistically significant difference between the groups in HRCT scoring. No good correlation between the degree of pulmonary vascular endothelial damage and the severity of lung inflammation was found. In addition, there were no good correlations between HRCT scoring vs GUI and HRCT vs L/L ratio in different study subgroups. In conclusion, L/L ratios on Tc-99m HMPAO and GUI on Ga-67 lung scans differ from chest X-ray findings and have the potential to detect the degree of pulmonary vascular endothelial damage and severity of lung inflammation in active IDL. However, the relationships between HRCT scoring, GUI, and L/L ratio in patients with collagen vascular diseases and active ILD are not significant.

Topics: Adult; Aged; Citrates; Endothelium, Vascular; Female; Gallium; Humans; Image Interpretation, Computer-Assisted; Lung; Lung Diseases, Interstitial; Male; Middle Aged; Pilot Projects; Radiography, Thoracic; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, X-Ray Computed

Diffuse infiltrative lung disease (ILD) is a heterogeneous group of disorders that predominantly affect the lung parenchyma and spare the airway. To objectively assess the degree of pulmonary vascular endothelium damage in active ILD, lung/liver uptake ratios (L/L ratios) on 99mTc hexamethylpropylene amine oxime (99mTc-HMPAO) lung scans were determined in 21 patients with active ILD. Meanwhile, the 67Ga citrate uptake index (GUI) on 67Ga lung scans was measured in order to evaluate the severity of lung inflammation in active ILD. The results show there were statistically significant differences between normal controls and patients with active ILD, as shown in the L/L ratio and GUI. However, when the patients were divided into two groups: (1) eight patients with normal chest X-ray findings, and (2) 13 patients with abnormal X-ray findings, there was no significant difference between groups 1 and 2 for the results of L/L ratio and GUI. In addition, no correlation between the degree of damage to the pulmonary vascular endothelium and the severity of lung inflammation was found. In conclusion, L/L ratios on 99mTc-HMPAO lung scans and GUI on 67Ga lung scans are different to the findings of chest X-rays and have the potential to objectively detect the degree of damage to the pulmonary vascular endothelium and the severity of lung inflammation in active IDL. However, the relationship between L/L ratio and GUI in active ILD is not significant.

Topics: Acute Disease; Adult; Aged; Citrates; Female; Gallium; Humans; Image Interpretation, Computer-Assisted; Lung Diseases, Interstitial; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Exametazime

Topics: Citrates; Gallium; Gallium Radioisotopes; Humans; Indium Radioisotopes; Leukocytes; Male; Middle Aged; Pancreatitis; Postoperative Complications; Recurrence; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Pulmonary vascular endothelium damage in 34 patients with systemic lupus erythematosus (SLE) was measured by technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) lung scan. The degree of damage was represented as lung/liver uptake (L/L) ratio. The patients were divided into two subgroups according to the following criteria: (a) clinical features, separated as stable or flare stage and (b) chest X-ray findings separated as positive or negative results. Meanwhile, quantitative gallium-67 citrate (Ga-67) lung scan was performed as Ga-67 uptake index (GUI) to evaluate the severity of inflammation in the SLE lungs. The results show (a) no significant statistical differences in the degree of pulmonary vascular endothelium damage (the L/L ratio on Tc-99m HMPAO lung scan) between the two subgroups according to clinical features or chest X-ray findings and (b) no good correlation between the degree of pulmonary vascular endothelium damage and lung inflammation (GUI on Ga-67 lung scan). In conclusion, the change in pulmonary vascular endothelium damage in SLE may be unrelated to the clinical presentation or chest X-ray findings, and its degree is not related to the severity of pulmonary inflammation.

Topics: Adult; Citrates; Endothelium, Vascular; Female; Gallium; Humans; Inflammation; Lung; Lung Diseases; Lupus Erythematosus, Systemic; Male; Radionuclide Imaging; Radiopharmaceuticals; Respiratory Function Tests; Severity of Illness Index; Technetium Tc 99m Exametazime; Vascular Diseases

A case of Ga-67 and Tc-99m WBC imaging in a patient is shown in which the discrepancy in the accumulation of the two imaging agents in radiated bone indicates that gallium accumulated predominantly in marrow lymphocytes in the skeleton of this patient.

Topics: Adult; Bone Marrow; Citrates; Female; Gallium; Gallium Radioisotopes; Humans; Lymphatic Metastasis; Lymphocytes; Radionuclide Imaging; Radiopharmaceuticals; Radiotherapy, High-Energy; Technetium Tc 99m Exametazime; Uterine Cervical Neoplasms

We evaluated radiolabeled liposomes (liposomes labeled both with 99mTc and 111In) for the early detection of osteomyelitis in an experimental model.. Liposomes, containing 5% polyethylene glycol-distearoyl phosphatidylethanolamine with encapsulated glutathione and deferoxamine, were prepared and labeled with 99mTc and 111In by a previously described method. Acute osteomyelitis was induced in male New Zealand rabbits by intramedullary injection of sodium-morrhuate and Staphylococcus aureus in the tibial bone marrow. Serial imaging studies, consisting of radiolabeled liposome imaging (2-4 mCi 99mTc and 75-125 microCi 111In), 99mTc-methylene diphosphonate (MDP) (3-5 mCi) and 67Ga-citrate (500 microCi), were performed starting at the third day after injection. Each radionuclide study was separated by at least 2 days. The animals also underwent radiography of the lower extremities. The animals were then killed and the infected tibia was excised for histopathology.. For interpreting relative efficacy of individual radiopharmaceuticals, only animals showing positive histopathological findings (n = 9) were considered. Radiographs (Days 12, 13) were conclusive for osteomyelitis in only 3 rabbits. Radiolabeled liposome imaging (Days 4-6) showed positivity in 8 cases and was equivocal in 1. Though the lesion could be delineated as early as 8 hr postinjection in the 99MTc window, the best target-to-nontarget ratio (T/NT) of 1.86 +/- 0.19 was obtained at 48 hr in the 111In window. Three-phase 99mTc-MDP scan (Day 7) was positive in only 5 rabbits with 3 hr T/NT of 1.6 +/- 0.23. Galium-67-citrate images (Days 9-11) were positive in 8 cases and equivocal in 1, the mean 48 hr T/NT being 1.74 +/- 0.24. These results show liposomes are better than 99mTc-MDP for imaging bone infection. Given the early localization and better quality of the images, radiolabeled liposomes also exhibited advantages over 67Ga-citrate for detection of acute osteomyelitis.

Topics: Acute Disease; Animals; Citrates; Gallium; Indium Radioisotopes; Liposomes; Male; Osteomyelitis; Rabbits; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Technetium; Technetium Tc 99m Exametazime; Technetium Tc 99m Medronate