PII S1095-0397(99)00018-7 Clinical Positron Imaging Vol. 2, No. 3, 137–143. 1999 Copyright  1999 Elsevier Science Inc. Printed in the USA. All rights reserved. 1095-0397/99 $–see front matter ORIGINAL ARTICLE Image Fusion System Using PACS for MRI, CT, and PET Images Saleh Alyafei, BHSc 1 , Tomio Inoue, MD 1 , Hong Zhang, MD 1 , Khalil Ahmed, MD 1 , Noboru Oriuchi, MD 1 , Noriko Sato, MD 1 , Hideki Suzuki, MD 2 , Keigo Endo, MD 1 1 Department of Nuclear Medicine and Diagnostic Radiology, Gunma University School of Medicine. Showa machi 3-39-22, Maebashi, Gunma 371-8511, Japan; 2 Department of Medical Information, Gunma Prefectural College of Health Sciences, Gunma, Japan This paper presents and evaluates Picture Archiving and Communication System (PACS) and its interaction with the image fusion applications using positron emission tomography (PET), CT, and MRI, as well as some clinical applications of fusion images. A network connections between medium-sized PACS involving CT, MRI, SPECT, and PET were developed. Image registration and fusion was achieved in the PET’s workstation by Advanced Visual System (AVS) software. Reconstructed datasets of CT, MRI, SPECT, and PET were transferred and archived in PACS servers. Series of anatomical images of CT and MRI were fused with metaboli- cal images of PET with 18 F labeled fluoro-2-deoxy-D-glucose (FDG). Throughput rate of image data, as well as clinical applications of fusion images were evaluated and correlated with phantom studies. The average throughput rate of archiving and processing steps was 0.45 Mbps, 0.77 Mbps, respectively. Image fusion experiment using phantom and patients’ data showed high accuracy in all directions. The combination of PACS and image fusion provided very useful clinical tools and made it quite easy to maximize the benefit from the diagnostic imaging. (Clin Pos Imag 1999;2:137–143)  1999 Elsevier Science Inc. All rights reserved. Key Words: Picture Archiving and Communication System; PACS; Image Fusion. could provide access to relevant reference images for Introduction comparison during reading sessions; and 5) PACS pro- P icture Archiving and Communication Systems mote and incorporate research results of multimodality (PACS) is becoming an integral part of most fusion, into clinical use. modern medical imaging departments. Tremen- PACS is the foundation resource of image registra- dous volume of images accumulates in PACS database tion and fusion applications. Multimodality image fu- from different modalities such as CT, MRI, SPECT, sion application requires standardized parameters to and PET. 1 PACS is the infrastructure supporting ad- be clinically useful. These parameters should cover vances in many areas, such as in 1) hospital operations, interface of digital image transmission, filing and re- it gives faster and more widely available access to image trieval, image compression, and multi-image database. and reports offer the potential for savings in clinician In contrast to these facts, the Digital Imaging and Com- time and length of stay; 2) radiology operations, it munications in Medicine (DICOM) V3.0 was devel- provides timely access to the images to improve the oped to aid in the acquisition and transport of images patient flow, throughput and image reporting; 3) case via PACS. 2–3 Also, PACS is eliminating the need of multi- management, it can provide image data for systems streamlining the presentation of case review confer- ple single-connections between workstation of image ences; 4) teaching files, both educational and clinical fusion and each workstation of CT, MRI, nuclear medi- goals are enhanced by convenient access to teaching cine, and PET. cases during reading sessions. An on-line teaching file This paper describes and evaluates image fusion method using the advantage of a DICOM based PACS. Also, it presents some clinical applications of registra- Address correspondence to: Saleh Alyafei, Department of Nuclear tion and image fusion of multimodality such as CT, Medicine, Gunma University School of Medicine, Showa machi 3-39- 22, Maebashi, Gunma 371-8511, Japan. MRI, and PET. 137