technetium-tc-99m-sulfur-colloid and Bacterial-Infections

The objectives of this study were to investigate (18)F-FDG imaging, using a coincidence detection system, for diagnosing prosthetic joint infection and to compare it with combined (111)In-labeled leukocyte/(99m)Tc-sulfur colloid marrow imaging in patients with failed lower extremity joint replacements.. Fifty-nine patients--with painful, failed, lower extremity joint prostheses, 40 hip and 19 knee--who underwent (18)F-FDG, labeled leukocyte, and bone marrow imaging, and had histopathologic and microbiologic confirmation of the final diagnosis, formed the basis of this investigation. (18)F-FDG images were interpreted as positive for infection using 4 different criteria: criterion 1: any periprosthetic activity, regardless of location or intensity; criterion 2: periprosthetic activity on the (18)F-FDG image, without corresponding activity on the marrow image; criterion 3: only bone-prosthesis interface activity, regardless of intensity; criterion 4: semiquantitative analysis--a lesion-to-background ratio was generated, and the cutoff value yielding the highest accuracy for determining the presence of infection was determined. Labeled leukocyte/marrow images were interpreted as positive for infection when periprosthetic activity was present on the labeled leukocyte image without corresponding activity on the marrow image.. Twenty-five (42%) prostheses, 14 hip and 11 knee, were infected. The sensitivity, specificity, and accuracy of (18)F-FDG, by criterion, were as follows: criterion 1: 100%, 9%, 47%; criterion 2: 96%, 35%, 61%; criterion 3: 52%, 44%, 47%; criterion 4: 36%, 97%, 71%. The sensitivity, specificity, and accuracy of labeled leukocyte/marrow imaging were 100%, 91%, and 95%, respectively. WBC/marrow imaging, which was more accurate than any of the (18)F-FDG criteria for all prostheses, as well as for hips and knees separately, was significantly more sensitive than criterion 3 (P < 0.001) and criterion 4 (P < 0.001) and was significantly more specific than criterion 1 (P < 0.001), criterion 2 (P < 0.001), and criterion 3 (P < 0.001).. Regardless of how the images are interpreted, coincidence detection-based (18)F-FDG imaging is less accurate than, and cannot replace, labeled leukocyte/marrow imaging for diagnosing infection of the failed prosthetic joint.

Topics: Adult; Aged; Aged, 80 and over; Bacterial Infections; Bone Marrow; Female; Fluorodeoxyglucose F18; Hip Prosthesis; Humans; Image Interpretation, Computer-Assisted; Indium Radioisotopes; Knee Prosthesis; Leukocytes; Male; Middle Aged; Prosthesis-Related Infections; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Subtraction Technique; Technetium Tc 99m Sulfur Colloid

Small intestinal hypomotility is an important cause of small intestinal bacterial overgrowth, yet assessment of small intestinal motility in this setting is problematic. This study was performed to investigate the validity of a bacteriological method for detecting small intestinal hypomotility.. Twenty-five subjects without previous gastric surgery were studied with (i) concurrent bacteriological analyses of fasting saliva and gastric and proximal small intestinal aspirates, (ii) measurement of gastric pH, and (iii) scintigraphic assessment of small intestinal transit rates of a liquid test meal. The reproducibility of bacteriological analyses of saliva and small intestinal secretions was determined in 12 subjects.. Serial bacteriological analyses of saliva and proximal small intestinal secretions yielded reproducible results over time periods of up to 1 month. Eleven subjects were deemed to harbor Enterobacteriaceae of nonsalivary origin in proximal small intestinal secretions. Orocaecal transit, but not gastric emptying, of a liquid test meal was significantly delayed in this group (p = 0.002 and p = 0.84, respectively), suggesting the presence of small intestinal hypomotility. Impaired gastric acidity unlikely confounded assessment of the origin of small intestinal Enterobacteriaceae in any instance.. The presence of Enterobacteriaceae of nonsalivary origin in proximal small intestinal secretions may be taken to reflect the presence of small intestinal hypomotility. The presence of impaired gastric acidity does not confound this approach. Because small intestinal intubation and culture of aspirate are required anyway to accurately diagnose small intestinal bacterial overgrowth, the simple addition of concurrent bacteriological analysis of saliva may allow small intestinal hypomotility to be detected at the same time as the presence or absence of small intestinal bacterial overgrowth itself is established, thus streamlining the investigation of subjects for this disorder and its possible causes.

Topics: Bacterial Infections; Enterobacteriaceae; Gastric Emptying; Gastric Juice; Gastrointestinal Motility; Gastrointestinal Transit; Humans; Hydrogen-Ion Concentration; Intestinal Secretions; Intestine, Small; Middle Aged; Radionuclide Imaging; Reproducibility of Results; Saliva; Streptococcus; Technetium Tc 99m Sulfur Colloid

In-111 WBC scintigraphy supplemented by visual comparison with concurrent Tc-99m SC bone marrow imaging is used to identify infection within the marrow-containing skeleton. This retrospective study demonstrates the value of the computer-generated WBC/SC bone marrow subtraction image. Thirty-one patients with various conditions (postsurgery with or without orthopedic hardware, bacteremia with persistent fever, joint arthroplasty, and miscellaneous) underwent combined WBC/SC with bone marrow subtraction imaging. Infection was present in 21 of 36 possible sites (14 osseous, 7 soft tissue; 8 acute, 13 chronic). The bone marrow subtraction image identified two of these sites, which were not appreciated by visual inspection. The sensitivity, specificity, and accuracy for bone marrow subtraction were 95%, 93%, and 94%, respectively, as compared to 86%, 93%, and 89%, respectively, for the visual assessment of WBC and SC images. Computer-assisted subtraction imaging improves overall accuracy and enhances diagnostic certainty of combined WBC/SC scintigraphy for infection in the marrow-containing skeleton.

Topics: Adult; Aged; Bacterial Infections; Bone Diseases; Bone Marrow; Child; Female; Humans; Image Processing, Computer-Assisted; Indium Radioisotopes; Leukocytes; Male; Muscular Diseases; Radionuclide Imaging; Retrospective Studies; Sensitivity and Specificity; Subtraction Technique; Surgical Wound Infection; Technetium Tc 99m Sulfur Colloid

Splenic function in sickle hemoglobinopathy syndromes was assessed to determine the developmental pattern of splenic dysfunction. Nonvisualization of the spleen using technetium-99 metastable (99mTc) spleen scans correlated strongly with pocked (vesiculated) RBCs greater than or equal to 3.5%. Cross-sectional analysis of pocked RBC data from 2,086 patients showed differences in the developmental pattern of splenic dysfunction between several disorders. In hemoglobin SS disease (sickle cell anemia) and hemoglobin S beta(0) thalassemia, splenic dysfunction (greater than or equal to 3.5% pocked RBCs) often occurred in the first 6 to 12 months of life. In hemoglobin S beta(+) thalassemia, splenic dysfunction occurred less frequently and later. Splenic dysfunction in hemoglobin SC disease (sickle cell-hemoglobin C) was intermediate. The level of pocked RBCs was inversely associated with fetal hemoglobin (P less than .007) and directly associated with age (P less than or equal to .001). These patterns of splenic dysfunction reflect the known severity of hemolysis and intravascular sickling and are consistent with the epidemiology of severe bacterial meningitis and sepsis in these diseases. Serial measurement of pocked RBCs permits determination of the onset of splenic dysfunction and the time of increased susceptibility to severe bacterial infections.

Topics: Age Factors; Anemia, Sickle Cell; Bacterial Infections; Erythrocytes, Abnormal; Fetal Hemoglobin; Hemoglobin SC Disease; Humans; Infant; Microscopy, Phase-Contrast; Radionuclide Imaging; Risk; Spleen; Technetium Tc 99m Sulfur Colloid; Thalassemia