Intra-osseous Ice Ball Visualization During Cryoablation Using Photon-Counting Detector Computed Tomography: An In-Vivo Swine Pilot Study.

PURPOSE: To evaluate the visualization of the ice ball during cryoablation of vertebral bodies and the bony pelvis in an in vivo swine model using virtual non-calcium imaging (VNCa) derived from photon-counting detector computed tomography (PCD-CT).

MATERIALS AND

METHODS

Cryoablation was performed at six locations in the spine and pelvis of three live swine. Spectral ultra-high resolution image acquisition using PCD-CT was conducted before ablation and at 2, 4, 6 and 8 min after initiation of the cryoablation cycle. Artifacts were suppressed using iterative metal artifacts reduction. Ice ball visualization within bone and soft tissue was assessed on both, conventional and VNCa images. At each time point the presence and size of the ice ball visualization was evaluated.

RESULTS

A total of 12 needle placements was analyzed. In conventional images the ice ball could not be seen within bone at any time. In contrast, in VNCa images the ice ball became visible after 2 min in all cases. However, the ice ball was less clearly visualized in the soft tissue on VNCa images. Mean ice ball volume at 2, 4, 6, 8 min was 1.6 ± 0.9, 2.8 ± 1.7, 5.5 ± 2.9 and 8.3 ± 3.2 ml in the vertebral bodies and 0.8 ± 0.3, 2.0 ± 0.4, 4.4 ± 0.6, 6.2 ± 1.1 ml in the bony pelvis, respectively.

CONCLUSION

PCD-CT enables early visualization of the ice ball within vertebral bodies and the bony pelvis in a swine model using VNCa images.