Evaluation of Bone or Soft Tissue Infection with Tc-99m Hmpao White Blood Cell Scintigraphy: Semiquantitative Method

Objective: Aim the aim of this study was to investigate semiquantitatively the diagnostic performance of Tc-99m hexamethypropylene amine oxime labeled white blood cell (Tc-99m HMPAO-WBC) scintigraphy in patients with suspected bone or soft tissue infections. Methods: Material and Method twenty one patients who applied to Nuclear Medicine Departmant (for suspected prosthesis infection, diabetic foot, bone infection, graft infection) were evaluated retrospectively. Tc-99m HMPAO WBC scintigraphy imaging were performed to all patients. Planar images were taken 1., 2., and 4. hours after injecting the labeled leukocytes. Evaluation of infection with Tc-99m HMPAO WBC scintigraphy was done semiquantitatively. Relative uptake was determined by setting the region of interest (ROI) of lesion area on the anterior view. Rectangular ROI was set on the against limb (nonlesion). The ratio of the average pixel count in the lesion (L) to that in the non-lesion (NL) (L/NL ratio) was calculated at 1., 2., and 4. hours images. Final diagnosis was based on histopathology, microbiologic assays, or clinical and imaging follow-up. Results: 0.55 and 1.55±0.74, 1.42±0.55, 1.40±0.55 in positive and control groups, respectively. Positive group revealed a statistically significant increase L/NL values in the data 3 hours images (p=0.002). However, no statistically significant was found between L/NL values in 3 hours imaging data in control group (p=0.223). All the data in the positive group found a statistically increased steadily. Furthermore, statistically significant difference was found between the positive and control group at 2., and 4. hours images (p=0.015, and p=0.006) .±0.43, 2.05±0.35, 1.90±SD) values were found to be 1.74±Results of the 21 patients, 11 were found to have infection (positive group), whereas 10 had normal (control group) pathologies on histopathology, microbiologic assays, or clinical and imaging follow-up. First, 2., and 4. hours L/NL (mean Conclusion: Leukocyte scintigraphy has been described as a useful diagnostic tool in the diagnosis of suspicion of bone and soft tissue infection, fever of unknown origin and suspicion of acute appendicitis. Tc-99m HMPAO labeled WBC scintigraphy is a rapid and very accurate method for detecting those pathologies, and it is evaluated visually. Our results showed that WBC scintigraphy might be evaluated semiquantitatively and reliable used for diagnosis of suspected bone and soft tissue infection