ACR/NEMA (now DICOM) has released for public comment the Display Function Standard document. This standard, produced by ACR/NEMA Working Group XI, has been developed in order to solve the problem of standardizing the response of grey scale display systems . This paper presents a methodology proposed in the Display Function Standard for quantitatively calculating the conformance of a display dev...

The detection of scattered photons affects both image quality and accuracy of quantitation accuracy in Single Photon Emission Computed Tomography (SPECT). The aim of this work was to evaluate three scatter correction methods: Jaszczak subtraction, the triple energy window method and an artificial neural network based approach. This evaluation was performed not only in terms of contrast and spat...

H. Kabasawa, C. Guclu, Z. Li Applied Science Laboratory Japan, GE Yokogawa Medical Systems, Hino-shi, Tokyo, Japan, GE Healthcare-Technologies, 3200 Grandview Blvd, Waukesha, WI, United States [Introduction] MR imaging with phased array receive coils became available at 3T and higher field strengths. In lower field strength systems, uniformity correction methods using body coil image as homogen...

PURPOSE The purpose of this study was to apply a newly developed free software program, at low cost and with minimal time, to evaluate the quality of dental and maxillofacial cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS A polymethyl methacrylate (PMMA) phantom, CQP-IFBA, was scanned in 3 CBCT units with 7 protocols. A macro program was developed, using the free software ...

A common need of the INCITS W1.1 Macro Uniformity, Color Rendition and Micro Uniformity ad hoc teams is to digitize image quality test targets and derive parameters that correlate with image quality assessments. The digitized data should be in a colorimetric color space such as CIELAB and have no spatial artifacts that reduce image quality parameter accuracy. Input digitizers come in many forms...

The purpose of this work was to develop an optimized transmit/receive birdcage coil to extend the possibilities of a 7T preclinical MRI system to conduct improved full body imaging in medium-sized animals, such as large New Zealand rabbits. The coil was designed by combining calculation and electromagnetic simulation tools. The construction was based on precise mechanical design and careful bui...

INTRODUCTION Although flat-panel based X-ray imaging has been well tested in diagnostic radiology, its use as an image-guided-radiotherapy (IGRT) system in a treatment room is new and requires systematic assessment. MATERIALS AND METHODS BrainLab Novalis IGRT system was used for this study. It consists of two floor mounted kV X-ray tubes projecting obliquely into two flat-panel detectors moun...

Small-animal single-photon emission computed tomography (SPECT) system plays an important role in the field of drug development and investigation of potential drugs in the preclinical phase. The small-animal High-Resolution SPECT (HiReSPECT) scanner has been recently designed and developed based on compact and high-resolution detectors. The detectors are based on a high-resolution parallel hole...

This paper describes the application of human visual models in (i) defining a visually uniform colour representation space and (ii) the formulation of visually weighted Kalman filtering for image restoration. The former being useful in colour image quantisation and compression. For (i), the uniformity of chromaticity differences at the ouptut of Frei ’s colour vision model [3] is tested and com...

In digital image processing, thresholding is a well-known technique for image segmentation. Because of its wide applicability to other areas of the digital image processing, quite a number of thresholding methods have been proposed over the years. In this paper, we present a survey of thresholding techniques and update the earlier survey work by Weszka (Comput. 3-16). We attempt to evaluate the...