Comparison of photoacoustic and fluorescence tomography for the in vivo imaging of ICG-labelled liposomes in the medullary cavity in mice

摘要

Few reports quantitatively compare the performance of photoacoustic tomography (PAT)versusfluorescence molecular tomography (FMT)in vivo. We compared both modalities for the detection of signals from injected ICG liposomes in the tibial medullary space of 10 BALB/c micein vivoandex vivo. Signals significantly correlated between modalities (R2?=?0.69) and within each modalityin vivo versus ex vivo(PAT: R2?=?0.70, FMT: R2?=?0.76). Phantom studies showed that signals at 4?mm depth are detected down to 3.3?ng ICG by PAT and 33?ng by FMT, with a nominal spatial resolution below 0.5?mm in PAT and limited to 1?mm in FMT. Our study demonstrates comparablein vivosensitivity, but superiorex vivosensitivity andin vivoresolution for our ICG liposomes of the VevoLAZRversusthe FMT2500. PAT provides a useful new tool for the high-resolution imaging of bone marrow signals, for example for monitoring drug delivery.