A nonuniform detector aperture for CT.
نویسندگان
چکیده
The finite width of the X-ray beam determined by the source and detector aperture limits the resolution of computed tomography (CT) images. Improved resolution can be obtained by reducing the width of the detector, but at a cost in dose utilization efficiency. We show that it is possible to improve the resolution in a CT image with a minimum cost in dose efficiency by varying the sensitivity of (apodizing) the detector response function. Further, we demonstrate how to construct detectors with nonuniform response by changing the reflective coating on the scintillator. Finally, we show improved calculated point response functions for such modified detectors.
منابع مشابه
Extended ratio edge detector for despeckled SAR image evaluation
Synthetic aperture radar (SAR) images due to the usage of coherent imaging systems are affected by speckle. So lots of despeckling filters have been introduced up to now to suppress the speckle. Hence, objective and subjective evaluation of the denoised SAR images becomes a necessity. Thereby lots of objective evaluating estimators are introduced to evaluate the performance of despeckling filte...
متن کاملA reconstruction method for helical computed tomography
This paper presents a method for volumetric reconstruction from Helical Computerized Tomography (H-CT) data which are collected with a fan beam source. An interpretation of the HCT data in terms of the Axial Computerized Tomography (ACT) data is provided. This analysis indicates that the H-CT data for positive and negative detector angles can be combined to form periodically nonuniform hexagona...
متن کاملPhase retrieval with the transport-of-intensity equation in an arbitrarily shaped aperture by iterative discrete cosine transforms.
A transport-of-intensity equation (TIE)-based phase retrieval method is proposed with putting an arbitrarily shaped aperture into the optical wavefield. In this arbitrarily shaped aperture, the TIE can be solved under nonuniform illuminations and even nonhomogeneous boundary conditions by iterative discrete cosine transforms with a phase compensation mechanism. Simulation with arbitrary phase, ...
متن کاملPatient doses from X-ray computed tomography examinations by a single-array detector unit: Axial versus spiral mode
Background: X-ray computed tomography (CT) examinations deliver a significant amount of radiation doses to patients comparing to conventional radiography examinations. The objective of the current study was to analyze and investigate the average patient received dose from axial and spiral CT exams in a medical imaging center. Material and Methods: In this study, the patient imaging tec...
متن کاملAssessment of X-Ray Crosstalk in a Computed Tomography Scanner with Small Detector Elements Using Monte Carlo Method
Introduction: Crosstalk is a leakage of X-ray or light produced in a matrix of X-ray detectors or array of photodiodes in one element to other elements affecting on image contrast and spatial resolution. In this study, we assessed X-ray crosstalk in a computed tomography (CT) scanner with small detector elements to estimate the effect of various parameters such as X-ray tube voltage, detector e...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of computer assisted tomography
دوره 5 3 شماره
صفحات -
تاریخ انتشار 1981