Reply to “SPECT Views for Cardiac Amyloidosis Imaging”

REPLY: Thank you for your eagle-eyed attention to detail and for bringing the inconsistency to our attention regarding the SPECT reconstruction display between 2 articles published in the June 2023 Journal of Nuclear Medicine Technology (1,2). Unfortunately, there is no clear-cut answer to your question, though, as both displays are correct. However, we should have been more specific in our descriptions.

Currently, there are no published guidelines on cardiac amyloidosis imaging, specifically on processing the SPECT images, which are critical for accurate study interpretation. The good news is that the SNMMI guidelines committee is in the process of writing guidelines for cardiac amyloidosis imaging.

SPECT image display orientation is based on the reconstruction method used. If cardiofocal reconstruction is used (e.g., myocardial perfusion imaging), the images should be displayed in the short, horizontal long-, and vertical long-axis orientation. If chest reconstruction is used (e.g., bone SPECT), transverse, coronal, and sagittal images should be displayed. The simple answer is that both reconstructions and image displays should be performed on all patients. Chest reconstruction is necessary to visualize ribs for visual scoring and cardiofocal reconstruction to evaluate whether tracer distribution is focal, patchy, or diffuse.

Again, thank you for bringing this issue to our attention. As the issue is still fluid, we will wait to address it once the new guidelines are published.

• Received for publication October 16, 2024.
• Accepted for publication October 16, 2024.