Abstract
Technetium-99m-methoxy isobutyl isonitrile (99mTc-MIBI) imaging can be useful to assess myocardial salvage following thrombolysis. In such acute conditions, MIBI must be readily available. The standard labeling method requires a 10-min boiling period in a boiling water bath (BWB). The purpose of this study was to compare the BWB technique to a microwave oven heating (MOH) method. Two series of 10 MIBI vials (8 cc)—one for BWB and one for MOH—were evaluated after removal of 7-8 cc of head space volume and the addition of 100 mCi (3 cc) of [99mTc]-pertechnetate. The two heating processes were evaluated as follows: (1) BWB: vials were put in boiling water for 10 min, (2) MOH: vials were put in a 0.4-cu ft lead-shielded microwave oven for 13 sec. A styrofoam cap protected the aluminum seal from sparking. Labeling efficiency was evaluated by radiochromatography with Baker flex aluminum oxide plates/absolute ethanol system at 1 min, 10 min, 6 hr and 24 hr after reconstitution. The labeling efficiency (percentage of primary complex) was determined and the results showed no significant differences between the two methods. MOH considerably reduces the heating period (13 sec) and provides a good labeling efficiency for in vivo imaging.
