BACKGROUND: Myocarditis is most often caused by Coxackie B virus, influenza
viruses, and echoviruses. It is usually self-restricting and ending in full recovery,
but in some patients the infection leads to congestive cardiomyopathy. It is difficult
to identify patients with myocarditis using clinical criteria, laboratory tests,
ECG and ultrasonography, and currently a myocardial biopsy is required to establish
the diagnosis. The risk of complications, sampling error and costs of this procedure
underline the need of non-invasive but sensitive methods of imaging. Several radiopharmaceuticals
have been used so far to confirm inflammation: 67Ga, 99mTc-nanocolloids and 111In-leucocytes.
Scintigraphy with radiolabeled autologous white blood cells (WBCs) is considered
a very useful method in identifying sources of inflammation but is difficult to
perform and time-consuming. AIMS: The aim of our study was to investigate whether
scintigraphy with 99mTc-Anti-Granulocyte BW 250/183 antibody is a valuable diagnostic
method in evaluating focal and diffuse inflammation of the heart and could therefore
be suggested for use in screening for acute myocarditis.
MATERIAL AND METHODS: A two dimensional scintigraphy and SPECT mode of
heart imaging with the use of 99mTc-Anti-Granulocyte antibody (740 MBq) was performed
on 14 subjects (11 males and 3 females) aged 25–60 years with a positive myocardial
biopsy confirming an inflammatory process in the myocardium. After i.v. administration
of the tracer a 1 minute series of planar scans was performed within the first
60 minutes. Delayed static scans were performed at 1, 2, 4 and 24 hours.
RESULTS: The scintigraphic scans revealed the uptake of the tracer in the heart
area in 13 patients, confirming active inflammatory process. Follow-up scintigraphy
was performed 3–5 months after the first study, when the control myocardial biopsy
was negative. The results of the study showed the concordance between myocardial
biopsy and scintigraphy results in patients with an inflammatory process in the
heart.
CONCLUSIONS: Scintigraphy with the use of 99mTc-Anti-Granulocyte seems
to be a useful diagnostic method in evaluating patients with suspected myocarditis,
but further studies are needed to establish its sensitivity and specificity
