All images on this web page are displayed at default contrast settings.
No contrast tenhancement or “background subtraction” has been performed.
History: 9 y/o woman. Prior stenosis of the right coronary artery, treated by angioplasty.
Current complaint: Recurrent exertional chest pain similar to that before her angioplasty.
Height: 5' 0”
Weight: 276 pounds. Very obese.
Tracer dose: 26.2 mCi at peak treadmill stress
Timing: Tracer was injected at peak treadmill exercise. After a 30 minute delay, SPECT images were obtained on a conventional, dual-detector, dedicated cardiac SPECT system. Approximately one hour later, images were obtained on the CardiArc® scanner. No additional tracer was administered between the two scans.
| Acquisition Duration |
Conventional
dual-detector w
LEHR collimation |
10.6 min |
| CardiArc® |
3.3 min |
Scan findings: The CardiArc® images reveal an inferior and inferobasal defect consistant with re-stenosis of previously dilated right coronary artery - later verified. This is poorly visualized on the conventional system images, but is identified by quantitative analysis of those images (below).
Discussion: The CardiArc® images have higher resolution, better target to background ration and less scatter than do same-day, same-injection images obtained with a conventional high-resolution, dual-detector system. These factors result in reduced partial-volume effect and higher lesion contrast.

Conventional system - 10.6 min acquisition
(click image for full screen comparison)

CardiArc® - 3.3 min acquisition
(click image for full screen comparison)

Concentional system - 10.6 min acquisition
(click image for full screen comparison)

CardiArc® - 3.3 min acquisition
(click image for full screen comparison)

Concentional system - 10.6 min acquisition
(click image for full screen comparison)

CardiArc® - 3.3 min acquisition
(click image for full screen comparison)

Quantitative analysis of images from the dual-detector, conventional system identifies the same inferior / inferobasal abnormality (yellow arrows) seen visually on the CardiArc® images.
Final diagnosis: Recurrent stenosis of the right coronary artery.
| Return to Cases | |