Background. Although heart-to-mediastinum (H/M) ratio in a planner image has been used for practical quantification for I-metaiodobenzylguanidine (MIBG) imaging, standardization of the parameter is not yet established. We hypothesized that the value of H/M can be standardized to the various types of camera-collimator combinations. Methods and Results. Standard phantoms consisting of the heart, ...

The high beam intensities in the next linear collider can damage the collimation system jaws if a failure of the electronic machine protection system allows the acceleration of a mis-launched pulse. We are developing a prototype collimator that will allow a new jaw surface to be moved into place after beam damage. We are also developing a prototype collimator based on continuously reforming the...

INTRODUCTION Lymphoscintigraphy is an important part of sentinel node mapping in breast cancer patients. Sometimes star shaped artefacts due to septal penetration can be problematic during imaging. In the current study, we evaluated the possibility of high energy (HE) collimators use for lymphoscintigraphy. PATIENTS AND METHODS Twenty patients with early breast carcinoma were included. Thirty...

The Relativistic Heavy Ion Collider (RHIC) will experience increasing longitudinal and transverse heavy ion emittances, mostly due to intra-beam scattering (IBS). The experiments in RHIC are expected to not only have reduced luminosi-ties due to IBS but also an unwanted beam halo. Primary betatron collimators will be used to remove the large amplitude particles. The efficiency of the primary co...

99mTc methoxyisobutylisonitrile planar scintimammography (SMM) is mostly performed using low-energy high-resolution (LEHR) parallel collimators. We studied whether using a different collimator could improve the detection of small (< 1.5 cm) lesions for which SMM sensitivity is poor. Thirty four breast phantom configurations were considered, either with hot spheres simulating lesions or without ...

PURPOSE Small field-of-view CdZnTe (CZT) gamma cameras are increasingly studied for breast lesion detection to complement mammography or ultrasonographic findings. However, in classical collimation configurations, they remain limited by the trade-off between spatial resolution and sensitivity. The HiSens architecture was proposed to overcome these limitations. Using an accurate 3D localization ...

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...

Collimators are used as lateral beam shaping devices in proton therapy with passive scattering beam lines. The dose contamination due to collimator scattering can be as high as 10% of the maximum dose and influences calculation of the output factor or monitor units (MU). To date, commercial treatment planning systems generally use a zero-thickness collimator approximation ignoring edge scatteri...