counts collected to lower the photon statistical noise in the image by operating the camera at the maximum rate for the entire imaging period 3 decreases the detection dead time to allow another effective increase in true counts collected in the final image the multiple increase in collected counts and the additional suppression in the 34 accidental 34 noise combines to lower the noise of pet substantially this allows the current high resolution pet camera to produce a higher 34 usable 34 resolution which is closer to the 34 intrinsic 34 resolution because less image smoothing is needed to lower the noise this invention also presents a very inexpensive and easy way to improve the image quality or resolution of any existing old camera without any internal hardware or software modification hence a ring or rings of high atomic number at least 82 and high density modulator is proposed here to modulate the incoming count which will have the same effect as the dynamic energy window method with the added advantage of lowering the gamma flux impringing onto the detectors the most obvious reservation to this method is the possibility of increasing the scatter gamma which in turn increases the accidental coincidences this is indeed true if we are imaging a point source but since we are imaging an extended source which introduce a large amount of scatters a high z modulator in fact suppresses more patient scatters than generates them this study examines such issues by measuring the scatter accidental and true in 20 and.