Optical transfer functions are presented for the 4pi’ microscope. The effects of the size of the confocal pinhole on the threedimensional resolution are studied. It is shown that the resolution of the 4Pi’ microscope depends weakly on the pinhole size. This result suggest that the pinhole can be removed in order to increase the signal-to-noise ratio. PACS: 42.30.Lr; 42.30.-d; 87.64.Rr

Received 3/30/2009; revised 4/13/2009; accepted 4/21/2009. For correspondence and reprints contact: Chi-Yun Chen, M.D., Department of Nuclear Medicine, Antai Tian-Sheng Memorial Hospital. 210 Section 1, ChungCheng Road, Tungkang, Pingtung 92842, Taiwan. Tel: (886)8-8329966 ext. 1631, Fax: (886)8-8329977, E-mail: [email protected] Objective: The purpose of this study was to compare the image...

The pinhole collimator is currently the collimator of choice in small animal single photon emission computed tomography (SPECT) imaging because it can provide high spatial resolution and reasonable sensitivity when the animal is placed very close to the pinhole. It is well known that if the collimator rotates around the object (e.g., a small animal) in a circular orbit to form a cone-beam imagi...

Multiple-pinhole (MPH) glasses are currently sold in many countries with unproven advertisements; however, their objective and subjective effects have not been investigated. Therefore, to investigate the effects of MPH glasses excluding the single-pinhole (SPH) effect, we compared the visual functional changes, reading speed, and ocular discomfort after reading caused by MPH and SPH glasses. He...

We analyze the coherence properties of a partially coherent field emerging from two pinholes in an opaque screen and show that the spectral degree of coherence possesses phase singularities on certain surfaces in the region of superposition. To our knowledge, this is the first illustration of the singular behavior of the spectral degree of coherence, and the results extend the field of singular...

Seven-pinhole emission tomography has been studied under conditions that simulate clinical myocardial imaging with thallium-201, and is compared with planar imaging with a heart phantom. The seven-pinhole technique produces reconstructed images that offer a tomographic presentation of the object but do not quantitatively represent true cross sections of the object's activity distribution. Tomog...

PURPOSE This paper presents new spectral measurements of a tungsten-target digital breast tomosynthesis (DBT) system, including spectra of 43-49 kVp. METHODS Raw x-ray spectra of 20-49 kVp were directly measured from the tube port of a Selenia Dimensions DBT system using a CdTe based spectrometer. Two configurations of collimation were employed: one with two tungsten pinholes of 25 μm and 200...

Soft x-ray emission from plasmas produced by ablation from a magnesium target employing a ruby laser is studied using a grazing incidence spectrograph in the spectral region 3–12 nm. Emission intensities are investigated for different ionic lines as a function of position, time after the maximum of the laser pulse and laser irradiance. A gated pinhole camera is employed for studying the evoluti...

where c is the column and r is the row. (This is a Point Grey convention, and it assumes the camera center is exactly in the center column and row of the image. In fact, proper camera calibration can be done to get a better estimate of the center.) The (X,Y,Z) coordinate system is shown in Fig. 1, and the (u, v) system in Fig. 2: Z points along line of sight, away from camera; X (and also u) po...