Can administration of metoclopramide reduce artefacts related to abdominal activity in myocardial perfusion SPECT?

Myocardial perfusion SPECT is frequently affected by artefacts related to abdominal activity. Metoclopramide has been suggested to relieve this, but two previous studies have shown conflicting results.

Ninety-five patients received 10 mg metoclopramide orally after injection of 99mTc-tetrofosmin for the stress scan and 86 patients had metoclopramide after their rest injection. A control group of 82 patients did not receive metoclopramide. Scans were evaluated visually by three readers.

Metoclopramide given before the stress scan led to abdominal activity being visually better in 16 scans, worse in 10, and unchanged in 67 scans, compared to the same patient's rest scan without metoclopramide administration. Metoclopramide administered before the rest scan resulted in abdominal activity in 11 scans being visually better, in 19 worse, and 53 scans were deemed unchanged. These differences were not significant. The number of repeat stress or rest scans was not significantly different between patients who had received metoclopramide and those who had not. The administration of metoclopramide, irrespective of whether it was given before the stress or rest scan, made no significant difference to inferior wall-to-abdomen count ratio.

Neither qualitative nor quantitative analysis showed an effect of metoclopramide on abdominal activity in myocardial perfusion SPECT.