Figure 4.

SPECT Images of ^99mTc-PYP Scintigrams

Single photon emission computed tomographic (SPECT) images of technetium-99m-pyrophosphate (^99mTc-PYP) scintigrams with fusion to computed tomographic (CT) images obtained 2 h (A to D) and 4 h (A′ to D′) after injection of the radiotracers. Images show horizontal plane at the level of the heart and at the level of the umbilicus, respectively (A/A′, B/B′); coronal plane (C/C′); sagittal plane (D/D′). Horizontal lines in A/A′ indicate the level of the coronal slice shown by C/C′, and the vertical lines in A/ A′ indicate the sagittal plane shown by D/D′, respectively. There is some misregistration of SPECT/CT fusion images resulting from patient movement and respiration. However, the impact on image interpretation due to this misregistration is minimal. Arrowheads indicate abnormal accumulation of ^99mTc-PYP in chest and abdominal walls.