Improving the spatial resolution of the multiple multiwire proportional chamber gamma camera

1979 ◽  
Vol 24 (3) ◽  
pp. 639-642 ◽  
Author(s):  
J E Bateman ◽  
J F Connolly
Keyword(s):  
Spatial Resolution ◽  
Gamma Camera ◽  
Proportional Chamber ◽  
Multiwire Proportional Chamber

F-18-FDG Positron Imaging in Oncological Patients: Gamma Camera Coincidence Detection versus Dedicated PET

1999 ◽  
Vol 38 (04) ◽  
pp. 108-114 ◽  
Author(s):  
H.-J. Kaiser ◽  
U. Cremerius ◽  
O. Sabri ◽  
M. Schreckenberger ◽  
P. Reinartz ◽  
...  
Keyword(s):  
Attenuation Correction ◽  
Spatial Resolution ◽  
Gamma Camera ◽  
Lesion Detection ◽  
Coincidence Detection ◽  
System Sensitivity ◽  
Oncological Patients ◽  
Phantom Studies ◽  
Pet System ◽  
Dedicated Pet

Summary Aim of the present study was to investigate the feasibility of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) imaging in oncological patients with a dual head gamma camera modified for coincidence detection (MCD). Methods: Phantom studies were done to determine lesion detection at various lesion-to-background ratios, system sensitivity and spatial resolution. Thirty-two patients with suspected or known malignant disease were first studied with a dedicated full-ring PET system (DPET) applying measured attenuation correction and subsequently with an MCD system without attenuation correction. MCD images were first interpreted without knowledge of the DPET findings. In a second reading, MCD and DPET were evaluated simultaneously. Results: The phantom studies revealed a comparable spatial resolution for DPET and MCD (5.9 × 6.3 × 4.2 mm vs. 5.9 × 6.5 × 6.0 mm). System sensitivity of MCD was less compared to DPET (91 cps/Bq/ml/cmF0V vs. 231 cps/ Bq/ml/cmFOv). At a lesion-to-background ratio of 4:1, DPET depicted a minimal phantom lesion of 1.0 cm in diameter, MCD a minimal lesion of 1.6 cm. With DPET, a total of 91 lesions in 27 patients were classified as malignant. MCD without knowledge of DPET results revealed increased FDG uptake in all patients with positive DPET findings. MCD detected 72 out of 91 DPET lesions (79.1 %). With knowledge of the DPET findings, 11 additional lesions were detected (+12%). MCD missed lesions in six patients with relevance for staging in two patients. All lesions with a diameter above 18 mm were detected. Conclusion: MCD FDG imaging yielded results comparable to dedicated PET in most patients. However, a considerable number of small lesions clearly detectable with DPET were not detected by MCD alone. Therefore, MCD cannot yet replace dedicated PET in all oncological FDG studies. Further technical refinement of this new method is needed to improve image quality (e.g. attenuation correction).

Development of a simultaneous imaging system to measure the optical and gamma ray images of Ir-192 source for high-dose-rate brachytherapy

2021 ◽  
Vol 16 (12) ◽  
pp. T12005
Author(s):  
J. Nagata ◽  
S. Yamamoto ◽  
Y. Noguchi ◽  
T. Nakaya ◽  
K. Okudaira ◽  
...  
Keyword(s):  
Dose Rate ◽  
Spatial Resolution ◽  
Gamma Camera ◽  
Gamma Ray ◽  
Imaging System ◽  
High Dose Rate ◽  
High Dose ◽  
Cmos Camera ◽  
Absolute Position ◽  
The Absolute

Abstract In high-dose-rate (HDR) brachytherapy, verification of the Ir-192 source's position during treatment is needed because such a source is extremely radioactive. One of the methods used to measure the source position is based on imaging the gamma rays from the source, but the absolute position in a patient cannot be confirmed. To confirm the absolute position, it is necessary to acquire an optical image in addition to the gamma ray image at the same time as well as the same position. To simultaneously image the gamma ray and optical images, we developed an imaging system composed of a low-sensitivity, high-resolution gamma camera integrated with a CMOS camera. The gamma camera has a 1-mm-thick cerium-doped yttrium aluminum perovskite (YAIO3: YAP(Ce)) scintillator plate optically coupled to a position-sensitive photomultiplier (PSPMT), and a 0.1-mm-diameter pinhole collimator was mounted in front of the camera to improve spatial resolution and reduce sensitivity. We employed the concept of a periscope by placing two mirrors tilted at 45 degrees facing each other in front of the gamma camera to image the same field of view (FOV) for the gamma camera and the CMOS camera. The spatial resolution of the imaging system without the mirrors at 100 mm from the Ir-192 source was 3.2 mm FWHM, and the sensitivity was 0.283 cps/MBq. There was almost no performance degradation observed when the mirrors were positioned in front of the gamma camera. The developed system could measure the Ir-192 source positions in optical and gamma ray images. We conclude that the developed imaging system has the potential to measure the absolute position of an Ir-192 source in real-time clinical measurements.

A prototype BaF/sub 2//TMAE low pressure multiwire proportional chamber for PET

1991 ◽  
Vol 38 (2) ◽  
pp. 703-708 ◽  
Author(s):  
J. Suckling ◽  
R.J. Ott ◽  
P.K. Marsden ◽  
J.E. Bateman ◽  
J.F. Connelly ◽  
...  
Keyword(s):  
Low Pressure ◽  
Proportional Chamber ◽  
Multiwire Proportional Chamber

Multiwire proportional chamber focal-plane detector

1975 ◽  
Vol 127 (1) ◽  
pp. 29-39 ◽  
Author(s):  
E. Beardsworth ◽  
J. Fischer ◽  
S. Iwata ◽  
M.J. Levine ◽  
V. Radeka ◽  
...  
Keyword(s):  
Focal Plane ◽  
Proportional Chamber ◽  
Plane Detector ◽  
Multiwire Proportional Chamber ◽  
Focal Plane Detector

DNA-repair deficient cells identification with a multiwire proportional chamber

1982 ◽  
Vol 92 (3) ◽  
pp. 154-156 ◽  
Author(s):  
R. Bellazzini ◽  
G. Betti ◽  
A. Del Guerra ◽  
M.M. Massai ◽  
M. Ragadini ◽  
...  
Keyword(s):  
Dna Repair ◽  
Proportional Chamber ◽  
Multiwire Proportional Chamber

Microstrip Gas Counters

2014 ◽  
pp. 31-51
Keyword(s):  
Glass Surface ◽  
Two Dimensional ◽  
Large Area ◽  
Proportional Chamber ◽  
Microelectronic Technology ◽  
Multiwire Proportional Chamber ◽  
Dimensional Version ◽  
A Chain ◽  
New Generation ◽  
First Time

In this chapter, the first micropattern gaseous detector, the microstrip gas counter, invented in 1988 by A. Oed, is presented. It consists of alternating anode and cathode strips with a pitch of less than 1 mm created on a glass surface. It can be considered a two-dimensional version of a multiwire proportional chamber. This was the first time microelectronic technology was applied to manufacturing of gaseous detectors. This pioneering work offers new possibilities for large area planar detectors with small gaps between the anode and the cathode electrodes (less than 0.1 mm). Initially, this detector suffered from several serious problems, such as charging up of the substrate, discharges which destroyed the thin anode strips, etc. However, by efforts of the international RD28 collaboration hosted by CERN, most of them were solved. Although nowadays this detector has very limited applications, its importance was that it triggered a chain of similar developments made by various groups, and these collective efforts finally led to the creation of a new generation of gaseous detectors-micropattern detectors.

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