Kish Chakrabarti

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Published results of medical imaging studies which make use of contrast detail mammography (CDMAM) phantom images for analysis are difficult to compare since data are often not analyzed in the same way. In order to address this situation, the concept of ideal contrast detail curves is suggested. The ideal contrast detail curves are constructed based on the(More)
RADIOLOGISTS routinely are required to view radiographs to identify the presence or absence of disease or other malady. After careful exposure from a uniform x-ray source and careful processing, the most common way of viewing a radiograph is to place it on a viewbox. Viewboxes, however, are constructed rather inexpensively using fluorescent bulbs,(More)
The viewbox luminance and viewing room light level are important parameters in a medical film display, but these parameters have not had much attention. Spatial variations and too much room illumination can mask real signal or create the false perception of a signal. This presentation looks at how scotopic light sources and dark-adapted radiologists may(More)
PURPOSE The purpose of this work is to evaluate the performance of the image acquisition chain of clinical full field digital mammography (FFDM) systems by quantifying their image quality, and how well the desired information is captured by the images. METHODS The authors present a practical methodology to evaluate FFDM using the task specific(More)
PURPOSE We define a general method for assessing imaging and dosimetric characteristics of tomosynthesis units that can be used under MQSA for acceptance and maintenance tests under 900.12 (e). METHODS Several QC tests have been selected as criteria for the evaluation, which are: geometric accuracy, flat-field uniformity and noise, in-plane resolution and(More)
A straightforward method is presented to estimate peak skin doses (PSDs) delivered by computed tomography (CT) scanners. The measured PSD values are related to the well-known volume CT dose index (CTDI(vol)), displayed on the console of CT scanners. PSD measurement estimates were obtained, in four CT units, by placing radiochromic film on the surface of a(More)
PURPOSE To measure radiation absorbed dose and its distribution in an anthropomorphic head phantom under clinically representative scan conditions in three widely used computed tomography (CT) scanners, and to relate those dose values to metrics such as high-contrast resolution, noise, and contrast-to-noise ratio (CNR) in the American College of Radiology(More)
This presentation will describe the role of medical physicists during FDA's certificate extension process (CE). The presentation will outline FDA's CE process, with detailed discussions on training, MEE, and requirements for continued QA for the facility, vis-a-vis medical physicist's responsibilities. A few important tests will be discussed that need(More)
Digital breast tomosynthesis is a form of limited angle tomography, in which section (slice) images are produced from a series of discrete projection images acquired at different angles. Tomosynthesis can be useful in breast imaging by providing potentially better visibility of lesions over conventional mammography, especially in patients with dense(More)