Microwave bone imaging: a preliminary scanning system for proof‐of‐concept

Abstract

This Letter introduces a feasibility study of a scanning system for applications in biomedical bone imaging operating in the microwave range 0.5–4 GHz. Mechanical uncertainties and data acquisition time are minimised by using a fully automated scanner that controls two antipodal Vivaldi antennas. Accurate antenna positioning and synchronisation with data acquisition enables a rigorous proof-of-concept for the microwave imaging procedure of a multi-layer phantom including skin, fat, muscle and bone tissues. The presence of a suitable coupling medium enables antenna miniaturisation and mitigates the impedance mismatch between antennas and phantom. The three-dimensional image of tibia and fibula is successfully reconstructed by scanning the multi-layer phantom due to the distinctive dielectric contrast between target and surrounding tissues. These results show the viability of a microwave bone imaging technology which is low cost, portable, non-ionising, and does not require specially trained personnel. In fact, as no a-priori characterisation of the antenna is required, the image formation procedure is very conveniently simplified.

Incoherent Radar Imaging for Breast Cancer Detection and Experimental Validation against 3D Multimodal Breast Phantoms

“…The pictorial view of the measurement set-up is shown in Figure 4 and basically coincides with the measurement scheme adopted in [ 36 ]. A breast phantom was scanned by an antipodal Vivaldi antenna in the frequency range [0.5–5] GHz connected to a VNA.…”

Multimodal Breast Phantoms for Microwave, Ultrasound, Mammography, Magnetic Resonance and Computed Tomography Imaging

“…MWI scans of phantoms were performed by using the measurement setup adopted in [46] and sketched for convenience in Figure 10. According to a multi-monostatic radar configuration, an antipodal Vivaldi antenna scanned the phantoms in the frequency range 0.5-3 GHz.…”

“…Images were obtained by first processing data by means of a clutter rejection algorithm aiming at mitigating the signal distortions coming due to the antenna's internal reflection, the skin interface, and other non-tumor breast tissues. In particular, the algorithm was based on a hybrid artefact removal algorithm consisting of a two-step entropy computation and a subspace projection stage [46][47][48][49]. In more detail, the method allowed the setting of the time-gating window (before the signal is ruled out since assumed to be mainly clutter) and to select the subset of sensors' positions where tumor contribution is stronger.…”

A Phantom Investigation to Quantify Huygens Principle Based Microwave Imaging for Bone Lesion Detection

“…The authors in [18] performed a study for bone imaging, collecting the signals in multi-monostatic fashion and using antennas immersed in a coupling liquid. In [18], imaging was performed using a beamforming procedure named non-coherent migration, after applying an average trace subtraction strategy to remove the artefact.…”

“…The authors in [18] performed a study for bone imaging, collecting the signals in multi-monostatic fashion and using antennas immersed in a coupling liquid. In [18], imaging was performed using a beamforming procedure named non-coherent migration, after applying an average trace subtraction strategy to remove the artefact. Instead, here, we collect the signals in multi-bistatic fashion, using antennas in free space; imaging was performed using an HP based algorithm, which operated in the frequency domain, after applying a rotation subtraction strategy to remove the artefact.…”