Spatial Recognition: A Temporal Tale of Multiple Window Spatial Registration.

PURPOSE: The performance ability of position logic circuitry of gamma-camera to superimpose the X-Y gains obtained from different pulse height analyzers is multiple window spatial registration (MWSR). This study was conducted to evaluate the feasibility of dual-tracer method using 99mTc and 131I to assess MWSR.

MATERIALS AND

METHODS

The procedure was carried out on a dual-head gamma-camera with rectangular NaI (Tl) crystal using a point source containing 99mTc pertechnetate and 131I-NaI. Pixel coordinates, full width at half-maximum of point spread function at 364 keV and 140 keV, and pixels with maximum count of images for dual detectors were analyzed and compared.

RESULTS

The experiment demonstrated an excellent correlation between the X and Y coordinates identified on 364 keV and 140 keV images (Spearman's coefficient of rank correlation: 0.9, P < 0.0001). Intraclass correlation of studies performed on two separate occasions showed a good correlation (k = 0.87) demonstrating the reproducibility of the procedure.

CONCLUSION

Dual-tracer method for evaluation of MWSR is a reproducible, accurate, and logical alternative to the routine National Electrical Manufacturers Association procedure.