Nuclear Instruments and Methods in Physics Research A 571 (2007) 498–501 Raytest ClearPET TM , a new generation small animal PET scanner P. Sempere Roldan a,Ã , E. Chereul c , O. Dietzel b , L. Magnier c , C. Pautrot a , L. Rbah c , D. Sappey-Marinier c , A. Wagner b , L. Zimmer c , M. Janier c , V. Tarazona a , G. Dietzel b a Raytest France, 4 Place des Vosges, 92400 Courbevoie, France b Raytest Germany, Benzstrasse 4, D-75334 Straubenhardt, Germany c Animage, Bat. CERMEP, 59 Bd. Pinel, 69677 Bron, France Available online 13 November 2006 Abstract The ClearPET is a high-performance small animal PET scanner that has been developed by the Crystal Clear Collaboration (CCC) and is now commercially available to customers worldwide through the Raytest group. Its high sensitivity and spatial resolution are achieved, thanks to a patented phoswich configuration made of two types of scintillating crystals: L(Y)SO and LuYAP:Ce, thus providing depth of interaction information. The ClearPET presents a modular design and it allows for 3601 rotation of the detector modules around the field of view (FOV). The ClearPET also presents the unique feature of having an adjustable FOV diameter, thus being suitable for small and medium size animal PET studies. This paper shows the performances of the commercial ClearPET in terms of its spatial resolution, sensitivity and quality of phantoms and preclinical images obtained. It also describes the updated situation of the first commercial unit sold to the Animage platform in Lyon. r 2006 Elsevier B.V. All rights reserved. PACS: 29.40.Mc; 87.58.Fg; 87.62.+n Keywords: PET; Small animal imaging; Molecular imaging; Depth of interaction; Performance evaluation 1. Introduction Small animal PET scanners have become an extremely useful tool in new drug development and in imaging gene expression [1,2]. The possibility of having dedicated small animals PET scanners with a size adapted to the animal object of study allows to perform the clinical studies with a much better spatial resolution and sensitivity. In consequence, many biomedical research groups and pharmaceutical companies are interested in acquiring dedicated high-resolution small animal PET scanners. The Crystal Clear Collaboration (CCC) was set up in 1990 having as main goal the development of new scintillating materials, which would be suitable for use in high-energy physics experiments. In 1995, the focus of the collaboration shifted towards g-ray detection in biomedical applications. One of the first projects of the CCC was the so-called ClearPET project [3], the aim of which was to develop small animal PET scanners with a high sensitivity and resolution, and offering a maximum of flexibility and modularity. A total of five different ClearPET prototypes [4] have been successfully built and at present the performances expected, therefore, a commercial version of this product was conceived. This new product (see Fig. 1) is commer- cially available through the Raytest group 1 and presents the excellent performances of the existing prototypes, i.e., it is flexible and modular but indeed it presents an excellent sensitivity and spatial resolution all along the field of view (FOV). 2. Description of the commercial ClearPET The commercial ClearPET scanner is based on the use of the multi-channel photomultiplier tube (PMT) Hamamatsu ARTICLE IN PRESS www.elsevier.com/locate/nima 0168-9002/$ - see front matter r 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.nima.2006.10.143 Ã Corresponding author. Tel.: +33 06 76 19 66 86; fax: +33 01 47 89 23 88. E-mail address: psempere@raytest.fr (P. Sempere Roldan). 1 http://www.raytest.com/