The need to improve patient management in the surgical theatre has led to the development of many new medical imaging systems [1,2]. The Hybrid Compact Gamma Camera (HCGC) has been developed to provide additional localisation information during procedures such as sentinel lymph node (SLN) biopsies [3,4]. In this study, a lymph-node contrast (LNC) phantom was fabricated and idealised medical scenarios were modelled to study the HCGC detectability for varying radioactivity concentration and...

The LNC phantom is made of Perspex plates, with simulated SLNs of diameters ranging between 10mm and 2.5mm (16 SLNs in total). These simulated SLNs were positioned beneath thicknesses of scattering material ranging between 5mm and 40mm. The LNC phantom has four different background wells to simulate the activity uptake surrounding the SLNs (Figure 1). The simulated activities ranged between 4MBq and 25kBq for the SLNs following their sizes [5]. Modelled background activity was 1/10 of the...

Spatial resolution measurements and Signal to Noise Ratio (SNR) analysis of the SLN were used as the main criteria to compare imaging sets produced by the HCGC with acquisition times ranging between 60s and 240s. The HCGC can successfully detect 87.5% to 100% (depending on the acquisition time) and 75% to 93.75% of the SLNs that are positioned underneath 20mm and 40mm thicknesses of Perspex respectively (Figure 2). The HCGC provides good spatial resolution images; the detected SLNs were...

  A simulation technique and a scintigraphic phantom have been designed and utilised to validate the capability of the HCGC in SLN detection imaging. The evaluation of the HCGC in this study shows that it is well suited for SLN imaging. The HCGC capability to detect low activity uptake in a small SLN indicates its usefulness as an intraoperative imaging system during critical surgical SLN procedures. The procedures described could be of use to evaluate any gamma camera system.

Mohammed Alqahtani  Postgraduate Researcher BioImaging Unit  University of Leicester  Leicester  LE1 7RH UK Email: msma7@le.ac.uk   Tel: +44 (116) 229 7717 

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