The SOLUS instrument: Optical characterization of the first hand-held probe for multimodal imaging (ultrasound and multi-wavelength time-resolved diffuse optical tomography)

• Published in: Optics and lasers in engineering Vol. 176; p. 108075
• Main Authors: Maffeis, Giulia, Di Sieno, Laura, Dalla Mora, Alberto, Pifferi, Antonio, Tosi, Alberto, Conca, Enrico, Giudice, Andrea, Ruggeri, Alessandro, Tisa, Simone, Flocke, Alexander, Rosinski, Bogdan, Dinten, Jean-Marc, Perriollat, Mathieu, Lavaud, Jonathan, Arridge, Simon, Di Sciacca, Giuseppe, Farina, Andrea, Panizza, Pietro, Venturini, Elena, Gordebeke, Peter, Taroni, Paola
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2024; Elsevier
• Subjects: Breast lesion diagnosis; Diffuse optical tomography; Engineering Sciences; Miniaturized diffuse optical system; Multimodal hand-held probe; Optics; Physics; SOLUS; Time-resolved near-infrared spectroscopy; SOLUS; Miniaturized diffuse optical system; Multimodal hand-held probe; Diffuse optical tomography; Time-resolved near-infrared spectroscopy; Breast lesion diagnosis; Multimodal hand-held probeBreast lesion diagnosis
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/j.optlaseng.2024.108075

•First miniaturization of an 8-wavelength (640–1050 nm) US-guided diffuse optical tomography device in time domain.•Optical performance assessment on tissue-mimicking phantoms.•SOLUS system for the multiparametric non-invasive diagnosis of breast cancer.•Example of in vivo measurement. SOLUS is a multimodal imaging system comprising the first miniaturized handheld device to perform time domain Diffuse Optical Tomography at 8 visible and near infrared wavelengths. The hand-held probe also includes B-mode ultrasounds, Shear Wave Elastography and Color Doppler sonography, being its first goal the multiparametric non-invasive diagnosis of breast cancer. This work aims at presenting the system and its main capabilities, focusing on the optical characterization carried out to assess the overall performance of the developed photonics technologies (picosecond pulsed lasers, high-sensitive time-gated sensors and integrated electronics) and of the software for tomographic reconstructions (perturbative model based on Born approximation). Systematic measurements performed on tissue-mimicking phantoms, reproducing a perturbation (e.g., a lesion) in a homogenous background, helped understand the system efficiency range. Variations in absorption are tracked with acceptable quality, which is key to estimate tissue composition, up to 0.25 cm−1 for the bulk (relative error on average of 16 %) and 0.16 cm−1 for sufficiently big perturbations (relative error on average of 26 % for 6 cm3 inhomogeneities). Instead, the system showed low sensitivity to a localized perturbation in scattering and a relative error on average of 17 % for the scattering bulk assessment. An example case of clinical measurement is also discussed.