PET/CT scanners

In 1998, the first PET/CT scanner, combining functional information with morphological information, was introduced by Townsend and co-workers [3], Combined PET/CT devices offer an efficient tool for whole-body staging and restaging functional assessment within one imaging modality. PET/CT scanners allow a merging of complementary information from CT and PET, leading to a more accurate anatomic localization. Furthermore, a more precise assessment of tumor volume is possible in comparison to PET. 

Prior to the introduction of PET/CT, multimodahty images were fused by the algorithm technique that was limited mainly to the brain. In 1999, GE Healthcare introduced the first PET/CT, called the Hawkeye, using a dualhead Nal(Tl) camera and a low-energy CT scanner, followed later in 2001 by the Discovery LS (GE Healthcare). Since then, manufacturers such as Siemens, GE, and Philips have brought a variety of much improved PET/CT units into the market. The physical features of a few PET/CT scanners are listed in Table 2.3 and a typical PET/CT scanner is shown in Fig.2.9. 

If the travel range of the scanning table is 180 cm, and the displacement distance between the centers of the scan fields of CT and PET scanners is 60 cm, what is the maximum body length that can be scanned in this PET/CT scanner ... 

A cyclotron is required to be registered with the state since it produces radionuclides. A dedicated PET scanner may or may not be required to be registered in a state depending on the state s statutes on this matter. Many states require a certificate of need (CON) prior to the purchase of a PET scanner, a mobile PET, or a PET/CT scanner. A PET/CT scanner is required to be registered with the state because of the CT unit, since all states require registration of radiation-generating machines. 

For taking the exam, the candidates must have active certification in NMTCB, ARRT(N), and Canadian Association of Medical Radiation Technologists [CAMRT(RTNM)] and 700 h of clinical experience as a certi-fied/registered nuclear medicine technologist working on a dedicated PET scanner or a PET/CT scanner. 

The scanner section should have six rooms a scan room, a control room, an electronics room, a patient preparation room, an injection room, and a patient uptake room. The scanner room size depends on the dimension of the PET/CT scanner, but the variations in dimensions of scanners from different vendors are not significant. A room of at least 25 x 20 feet can be optimally used to install a PET/CT scanner from any vendor, along with storage for all supplies. 

Delivery of sophisticated local treatment can only yield a survival advantage for patients with truly localized disease, or those with controlled or controllable systemic disease. The success of stereotactic radiotherapy, e.g., for early-stage non-small cell lung cancer (NSCLC) is critically dependent on the correct identification of node-negative patients. For this purpose, a hybrid PET-CT scanner and the tracer FDG might be used. Correct staging is also required for other diseases commonly treated with high-dose radiotherapy such as prostate cancer. In numerous chnical trials, PET and... 

Recently developed PET-CT scanners, which combine the advantages of PET (functional imaging with high sensitivity) with the advantages of CT (morphological imaging with high spatial resolution) within one... 

Commercially available PET-CT scanners are based on the imaging principle described by Beyer et al. (2000). Two separate scarmers, a CT and a PET, are installed in series. A single examination table serves both imaging components of the PET-CT (Fig. 33.4). The patient is positioned on the examination table this is followed by acquisition of the CT, and then by acquisition of the PET. In between the two scans, the patient remains in the same position on the examination table. This assures that morphological and functional data sets can be accurately fused after image acquisition. Patient motion in between the two scans or motion of internal organs may result in different positions of an organ or a lesion... 

Beyer T, Townsend DW et al. (2000) A combined PET CT scanner for clinical oncology. J Nucl Med 41 1369-1379 Bohuslavizki KH, Klutmann S et al. (2000) Correlation of F FDG-PET and histological findings in patients with malignant melanoma. J Nucl Med 41 302P... 

N. Zoraatkar, et al., "Quantitative Investigation of Inter-Crystal Scat-to and Penetration in the GE Discovery RX PET/CT Scanner using Monte Carlo Simulations."... 

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