OBJECTIVES To establish a digital subtraction radiography scheme for aligning clinical in vivo radiographs based on the implementations of an automatic geometric registration method and a contrast correction technique. METHODS Thirty-five pairs of in vivo dental radiographs from four clinical studies were used in this work. First, each image pair was automatically aligned by applying a multir...

For 4 months, a prototype digital subtraction system was used to obtain images of the cerebral vasculature after intraarterial contrast injections. In 12 instances, the intraarterial injections were recorded with both a digital subtraction unit and conventional direct magnification film-screen system. The digital subtraction and conventional film subtraction images were compared and graded for ...

BACKGROUND AND AIMS In periapical radiographic technique, the changes will be visible only after considerable deposi-tion or resorption while digital subtraction technique visualizes slight density changes. This study was aimed to compare visualization of density changes in conventional periapical radiographs and digital subtraction technique with or without image enhancement. MATERIALS AND M...

Subtraction is useful in detecting small changes in sequentially acquired radiographs. Even if the imaging geometry is constant, radiographs must be registered after their digitization. To compare different algorithms for image registration and to register digital X-rays themselves, various similarity measures have been proposed. This study compares eight mathematical similarity standards using...

abstract background and aim: considering the widespread development of implants in dental treatment plans, linear measurements on panoramic radiography are of especial importance. in the present study we investigated the effect of head misalignment up to 15° around vertical and horizontal axes on the magnification rate of digital panoramic radiography in each part of upper and lower jaws. mater...

BACKGROUND The number of rejected images is an indicator of image quality and unnecessary imaging at a radiology department. Image reject analysis was frequent in the film era, but comparably few and small studies have been published after converting to digital radiography. One reason may be a belief that rejects have been eliminated with digitalization. PURPOSE To measure the extension of de...

Background: Analog radiography has been replaced with digital radiography for canine diagnostic imaging in many veterinary clinics. There is no data comparing these modalities in a veterinary clinical setting to detect bronchial pattern signs in dogs. Objectives: In this study, computerized digital radiography (CR) and analog radiography were compared for diagnosis of bronchial pattern in dogs....