Comparison of LDPI to SPECT perfusion imaging using (99m)Tc-sestamibi and (99m)Tc-pyrophosphate in a murine ischemic hind limb model of neovascularization

EJNMMI Res. 2016 Dec;6(1):44. doi: 10.1186/s13550-016-0199-2. Epub 2016 May 27.


Background: We aimed to determine the accuracy of laser Doppler perfusion imaging (LDPI) in an animal model for hind limb ischemia.

Methods: We used a murine (C57Bl/6 mice) ischemic hind limb model in which we compared LDPI with the clinically used (99m)Tc-sestamibi SPECT perfusion imaging (n = 7). In addition, we used the SPECT tracer (99m)Tc-pyrophosphate ((99m)Tc-PyP) to image muscular damage (n = 6).

Results: LDPI indicated a quick and prominent decrease in perfusion immediately after ligation, subsequently recovering to 21.9 and 25.2 % 14 days later in the (99m)Tc-sestamibi and (99m)Tc-PyP group, respectively. (99m)Tc-sestamibi SPECT scans also showed a quick decrease in perfusion. However, nearly full recovery was reached 7 days post ligation. Muscular damage, indicated by the uptake of (99m)Tc-PyP, was highest at day 3 and recovered to baseline levels at day 14 post ligation. Postmortem histology supported these findings, as a significantly increased collateral diameter was found 7 and 14 days after ligation and peak macrophage infiltration and TUNEL positivity was found on day 3 after ligation.

Conclusions: Here, we indicate that LDPI strongly underestimates perfusion recovery in a hind limb model for profound ischemia.

Keywords: Hind limb ischemia; Laser Doppler perfusion imaging (LDPI); Overestimation of therapeutic window; Perfusion recovery; Single-photon emission computed tomography (SPECT).