Imaging of Abdominal Inflammation Using Other Radioisotope Techniques

Abstract

^99mTc-HMPAO-labelled white cell scanning is compared with other radionuclide techniques in this contribution. The sensitivity and specificity using both ¹¹¹In and ^99mTc-HMPAO-labelled leucocytes are comparably high. Both imaging methods are therefore suitable for imaging inflammation. However. images are available more quickly using ^99mTc-HMPAO; their quality is superior and the radiation dose is lower. ¹¹¹In is beneficial for chronic infections. ⁶⁷Ga citrate is less specific for inflammation, since it also localizes in tumours, but it is useful in chronic infection. ^99mTc nanocolloid has not been found suitable for imaging abdominal inflammation, but more so for bone and joint diseases. Comparisons of ^99mTc-HMPAO leucocytes with ¹²³I-labelled monoclonal antibodies show poorer results using the monoclonal antibody because of non-specific binding to plasma proteins. Visualization of lesions is generally poorer using ^99mTc-HIG than ^99mTc-HMPAO leucocytes and is less sensitive and specific. Few reports using ^99mTc-labelled monoclonal antibodies are available. Early results are promising and more specific antibodies may be available in the future. Synthetic chemotactic peptides offer a novel approach to the detection of infection. However, at present the recommended method for imaging acute abdominal inflammation is ^99mTc-HMPAO leucocytes.

Key Words:

• ⁶⁷Gallium
• immunoglobulin
• ¹¹¹In
• infection
• inflammation
• leucocytes
• monoclonal antibodies
• radionuclide imaging
• ^99mTc-HMPAO