Non-invasive detection and differentiation of cardiac amyloidosis using <sup>99m</sup>Tc-pyrophosphate scintigraphy and <sup>11</sup>C-Pittsburgh compound B PET imaging
Ken Takasone, Nagaaki Katoh, Yusuke Takahashi, Ryu Abe, Naoki Ezawa, Tsuneaki Yoshinaga, Shin Yanagisawa, Masahide Yazaki, Kazuhiro Oguchi, Jun Koyama, Yoshiki Sekijima
Abstract
Purpose To investigate the utility of the combined use of 11C-Pittsburgh compound B (11C-PiB) positron emission tomography (PET) imaging and 99mTc-pyrophosphate (99mTc-PYP) scintigraphy for detection and differentiation of three major types of cardiac amyloidosis, i.e. immunoglobulin light chain (AL), hereditary transthyretin (ATTRv), and wild-type transthyretin (ATTRwt) amyloidosis.Methods Whole-body 11C-PiB PET and 99mTc-PYP scintigraphy were performed in 17 patients with AL amyloidosis, 22 patients with ATTRv, and eight patients with ATTRwt amyloidosis. The correlations between organ involvement and the uptake of 11C-PiB and 99mTc-PYP were analyzed in each patient.Results Cardiac amyloidosis was detectable by 99mTc-PYP scintigraphy or 11C-PiB PET in all systemic amyloidosis patients with cardiac involvement. 99mTc-PYP scintigraphy and 11C-PiB PET showed an interesting complementary relation. Strict combination of positive 11C-PiB and negative 99mTc-PYP uptake (PiB pattern) was observed in all AL amyloidosis patients with cardiac involvement. In contrast, strict combination of positive 99mTc-PYP and negative 11C-PiB uptake (PYP pattern) was observed in all ATTRwt amyloidosis patients with cardiac involvement. ATTRv amyloidosis patients with cardiac involvement were divided into two groups: PiB pattern or PYP pattern. All of the early-onset V30M (p.V50M) ATTRv patients showed the PiB pattern, whereas all of the late-onset V30M and non-V30M ATTRv patients showed the PYP pattern.Conclusions All three major types of cardiac amyloidosis can be detected and differentiated non-invasively by combined use of the two amyloid imaging methods and TTR gene testing.