Clinical and Experimental Results with a 9 Element High Purity Germanium Array

Patton, James A.; Price, Ronald R.; Rollo, F. D.; Brill, A. B.; Pehl, Richard H.

doi:10.1109/tns.1978.4329388

Cited by 9 publications

(3 citation statements)

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“…A detection area larger than can be obtained in a single Ge crystal has been achieved by placing several crystals adjacent to each other in a single cryostat for use as a scanner (Kraner et al 1973, Kirby, Phelps, Armantrout, Sawyer andBeck 1976). An array of 3 x 3 high-purity Ge planar detectors for use as a scanning camera has also been realised (Patton, Price, Brill and Pehl 1977). An array of ten planar detectors has been reported for non-medical applications (ORTEC 1977).…”

Section: Discussionmentioning

confidence: 99%

“…I n this study we make a determination of the Ge detection area that is required for obtaining an image having a signal-to-noise ratio (S/N) that is equal to what would be obtained with an NaI(T1) detector in an equal scanning time. The SIN is a function of the image contrast as well as the detection efficiency (Sherman, Strauss and Brenner 1978). The Ge detection efficiency 0031-9155/79/040702+09 $01.00 @ 1979 The Institute of Physics was previously measured by the authors, while values for image contrast are taken from reported studies.…”

Section: Introductionmentioning

confidence: 99%

“…Since the atomic number of Ge is lower than the effective atomic number of NaI(T1) the probability of detector scatter is higher in Ge and hence image degradation by this process is more pronounced. A study of this effect by the authors shows that when imaging small cold lesions much of the contrast advantage of Ge detectors that can be achieved by rejecting scatter in tissue appears to be offset by the scatter in Qe position-sensitive detectors and by the lower Ge detection efficiency (Sherman et al 1978). Moreover, a large-area position-sensitive detector is more difficult to realise than an array of detectors that are not position sensitive, Thus, since Ge scanners and non-position-sensitive scanning cameras appear to be more promising than Ge stationary position-sensitive cameras, we consider in this study only discrete detectors that are not position sensitive.…”

Section: Introductionmentioning

confidence: 99%

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Merit of Ge and Na(Tl) detectors as determined by imaging efficiency and scatter rejection

Strauss¹,

Sherman²

1979

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Deep-lying cold lesions are often of marginal object contrast. Any contrast reduction caused by the detector may hinder their detectability. The capabilities of Ge and NaI(Tl) detectors are compared on the basis of imaging efficiency and scatter rejection capability. When the NaI(Tl) baseline is at 126 ke V (for 99Tcm), the void contrast obtainable with Ge detectors is 50% higher than that with NaI(Tl) using collimators having equally high resolution. If the signal-to-noise ratio (S/N) with Ge is not equal to or higher than that with NaI(Tl), this contrast advantage can be masked by excessive statistical noise. Since the lower detection efficiency of Ge crystals largely offsets their higher contrast, to obtain equal S/N in equal imaging times the Ge detection area must be comparable to that of NaI(Tl). When the NaI(Tl) baseline is at 145 keV, the window efficiency is reduced but the contrast is nearly as high as that with Ge. The Ge detection area for equal S/N is then only 40% of the NaI(Tl) area. Thus, a Ge detector having only half the area of NaI(Tl) is of questionable merit. Ge detector arrays comparable in area to NaI(Tl) are feasible and would clearly be superior imaging devices.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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