This Article Abstract Full Text Full Text (PDF) Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Marsden, P K Articles by Cash, D Search for Related Content PubMed PubMed Citation Articles by Marsden, P K Articles by Cash, D

Simultaneous PET and NMR

¹ Division of Radiological Sciences, Guy's, King's and St Thomas' School of Medicine, Guy's Hospital, London SE1 9RT and ² Neuroimaging Research Group, Institute of Psychiatry, London SE5 8AF, UK

View larger version (12K): [in a new window]   Figure 1. Temporally correlated 31P NMR spectra and radiotracer (18F-fluorodeoxyglucose, FDG) uptake data acquired from an isolated perfused rat heart. Changes in both the NMR and PET data are recorded simultaneously as the heart changes from normoxic (A) to hypoxic (B) and then becomes normoxic again (C). The radiotracer uptake data were acquired using a simple non-imaging gamma-ray detector.

View larger version (14K): [in a new window]   Figure 2. Prototype NMR-compatible PET scanner. The scintillation crystals are connected to the photomultiplier tubes by 4 m long optical fibres. This allows the photomultipliers to be situated in a low field region away from the NMR magnet.

View larger version (45K): [in a new window]   Figure 3. Images of small phantoms obtained simultaneously with PET and MR. PET images were acquired with 18F in 15 min (total counts 300k, activity in phantom 10 MBq). MR images were acquired on a 4.7T, 30 cm bore system in 15 min (spin echo, TE 30 ms, TR 2000 ms). For the hot-spot phantom—spot diameter 2 mm, spot separation 6 mm. The spatial resolution of the PET scanner is about 2 mm FWHM.

View larger version (53K): [in a new window]   Figure 4. Example FDG uptake image of an isolated perfused rat heart acquired with the prototype scanner. Most of the uptake is in the left ventricle, and a faint outline of the right ventricle can just be seen. These images took 10 min to acquire.

View larger version (103K): [in a new window]   Figure 5. Simultaneously acquired FDG–PET (right) and MR (left) images of the brain of a mouse. The MR image was acquired in a 4.7T, 30 cm bore MR system. The 3D PET volume image was acquired by stepping the mouse throught the PET scanner in 2 mm steps (10 min per step).

View larger version (29K): [in a new window]   Figure 6. Schematic diagram of the new system currently under construction. This is a multilayer design which will have an order of magnitude greater sensitivity than the current prototype, allowing tracer uptake to be followed dynamically for small regions of interest.