We propose an integrated front-end data acquisition circuit for a hybrid ultrasound (US)-gamma probe. The proposed circuit consists of three main parts: (1) a preamplifier for the gamma probe, (2) a preprocessing analog circuit for the US, and (3) a digitally controlled analog switch. By exploiting the long idle time of the US system, an analog switch can be used to acquire data of both systems using a single output channel simultaneously. On the nuclear medicine (NM) gamma probe side, energy resolutions of 18.4% and 17.5% were acquired with the standalone system and with the proposed switching circuit, respectively, when irradiated with a Co-57 radiation source. Similarly, signal-to-noise ratios of 14.89 and 13.12 dB were achieved when US echo signals were acquired with the standalone system and with the proposed switching circuit, respectively. Lastly, a combined US-gamma probe was used to scan a glass target and a sealed radiation source placed in a water tank. The results confirmed that, by using a hybrid US-gamma probe system, it is possible to distinguish between the two objects and acquire structural information (ultrasound) alongside molecular information (gamma radiation source).

This paper presents the first fully integrated, highly compact single-element integrated Gamma-Ultrasound (γ-US) probe for simultaneous molecular and anatomical imaging. The probe integrates a PZT-5A US transducer with a Ce:GAGG scintillator and silicon photomultiplier (SiPM), enabling dual-modality detection along the same line-of-sight (LOS). The tungsten-epoxy composite serves dual roles as both the US backing layer and γ collimator, making it innovative and significantly reduces size and complexity. Furthermore, a single-channel frequency-based multiplexed circuit enables real-time dual-modality data acquisition. The γ part of the probe achieves 17.3% energy resolution (FWHM at 122 keV), 80.0 cps/MBq sensitivity, and 2.69 mm spatial resolution at 1 cm distance in air. The US component provides a 5.95 dB SNR, 1.32 mm axial resolution, and 4.90 mm lateral resolution at 5 cm depth in water. Finally, a fused B-mode image of a breast phantom validates the probe’s imaging capability. This integrated probe design offers a compact, cost-effective solution for handheld medical diagnostics and non-destructive testing, with minimal performance trade-offs compared to standalone systems.