Christian Blendl

Technische Hochschule Köln | FH Köln · Institute for Media and Imaging Technology

Purpose: The study investigates how far diagnostic usability can be reached in digitized X-ray films using newly developed software. In a considerable part of the images, Gamma-correction of the display slope only yields a quality sufficient for presentation. The study is based on 134 examinations of various organs (49 chest, 22 abdomen/pelvis, 27...

A new test procedure is presented to check the A new correspondence between various screen-film systems (SFS) with the specification of the manufacturer in respect to the speed S according to DIN 6867-1 or rather which dose K is required for the SFS in dependence on the X-ray tube voltage (kV) to give the net density D(n) = 1.00. It is based on mea...

Purpose: The purpose of this study was to determine the values for noise equivalent quanta, detective quantum efficiency, modulation transfer function, noise power spectrum, and the values for the parameters for automated CDMAM test phantom analyses required to achieve satisfactory quality of digital mammograms. Materials and methods: During the...

Flat panel cone-beam computed tomography (CBCT) is developing to the state-of-the-art technique in several medical disciplines such as dental and otorhinolaryngological imaging. Dental and otorhinolaryngological CBCT systems offer a variety of different field-of-view sizes from 6.0 to 17.0 cm. Standard phantoms are only designed for the use in mult...

The study aims at investigating how far image quality (MTF and NPS) differs in between CT, CBCT and DVT units and how far the geometrical 3 D accuracy and the HU calibration differ in respect to surgical or radio therapeutic planning. X ray image stacks have been made using a new designed test device which contains structures for measuring MTF, NPS...

Ziele: Diagnostische Referenzwerte wurden durch das Bundesamt fur Strahlenschutz (BfS) veroffentlicht. Sie wurden i.d.R. mit Film-Folien-Systemen ermittelt. Die bei Untersuchungen applizierte Dosis war mit einer ausreichenden Bildqualitat (mittl. Dopt.) verknupft. Dieser Zusammenhang (ALARA-Prinzip) ist bei digitalen Systemen verloren gegangen. Des...

Aim: To test whether image processing methods are suitable for detecting differences in the image quality of digital mammography units and whether the methods are more sensitive than visual test methods like the evaluation of CDMAM test images. Methods: Test images according to PAS 1054 were acquired with CR and DR systems and analyzed automatic...

To test whether image processing methods are suitable for detecting differences in the image quality of digital mammography units and whether the methods are more sensitive than visual test methods like the evaluation of CDMAM test images. Test images according to PAS 1054 were acquired with CR and DR systems and analyzed automatically. Only parame...

To test the sensitivity of automatic methods for evaluating CDMAM test images with respect to noise. CDMAM test images were analyzed with two computer programs. The images were made with different tube loads [mAs]. The other exposure conditions remained constant. They were analyzed with the CDCOM program, which is offered by the EUREF as a free dow...

Ziel: Es sollte geprüft werden, wie die Sensitivität verschiedener automatischer Verfahren zur Auswertung von CDMAM-Prüfkörperaufnahmen gegenüber Rauschänderungen ist. Material und Methode: CDMAM-Prüfkörperaufnahmen wurden mit zwei unterschiedlichen Computerprogrammen ausgewertet. Die Aufnahmen wurden mit unterschiedlichen Ladungen Q [mAs] und anso...

Ziele: Die Durchführung der Konstanzprüfung in der diagnostischen Radiologie sind durch verschiedene gesetzliche Regelungen vorgeschrieben mit dem Ziel, eine hohe Bildqualität bei möglichst geringer Dosis zu gewährleisten. Das Forschungsprojekt OPTIMAGE entwickelt eine zentral organisierte Lösung zur Durchführung von Konstanzprüfungen. Hierbei sol...

To find out whether the quality requirements in daily, weekly or monthly tests of the "European protocol for the quality control of the physical and technical aspects of mammographic screening (EPQC)" can be maintained when screening the population of a large area. Furthermore, to check the specific tolerances of different test positions given by t...

Purpose: To find out whether the quality requirements in daily, weekly or monthly tests of the "European protocol for the quality control of the physical and technical aspects of mammographic screening (EPQC)" can be maintained when screening the popu- lation of a large area. Furthermore, to check the specific toler- ances of different test positio...

Constancy tests of film processing according to DIN 6868-2 require the measurement of the quantities “Empfindlichkeitsindex EI” (Speed Index) and “Kontrastindex KI” (Contrast Index), aimed at determining changes of film processing that can influence the resulting radiographic image. In this study it was investigated whether these quantities are act...

The point of time, in which archived X-ray films were processed, can be proved with the determination of the remaining content of thiosulphate. The methylene blue method of DIN 19069 (equivalent to ISO 18917) was adapted to X-ray films. The range of time is in about two and a half year,in which the remaining content of thiosulphate is correlatable...

It was tested with 5 different types of mammography films in which manner the values of "Lightspeed" (LS) and "Lightcontrast" (LC), according DIN V 6868-55 will be changed, when preexposed film strips are used, stored at different climates and spaces of time in comparison to strips, which are exposed immediately before processing. It was proved, th...

It was tested with 5 different types of mammography films in which manner the values of “Lightspeed” (LS) and “Lightcontrast” (LC), according DIN V 6868-55 will be changed, when preexposed film strips are used, stored at different climates and spaces of time in comparision to strips, wich are exposed immediatly before processing. It was proved, tha...

Zusammenfassung Mit einer Restthiosulfatbestimmung, die durch eine Anpassung der Methylenblaumethode nach DIN 19069 an Röntgenfilme erreicht wurde, lässt sich der Zeitpunkt der Verarbeitung von Röntgenfilmen abschätzen. Der Zeitraum,in dem aus dem Restthiosulfatgehalt auf den Zeitpunkt der Verarbeitung zurückgeschlossen werden kann, beträgt ca. 2,...

Constancy tests of film processing according to DIN 6868-2 require the measurement of the quantities "Empfindlichkeitsindex EI" (Speed Index) and "Kontrastindex KI" (Contrast Index), aimed at determining changes of film processing that can influence the resulting radiographic image. In this study it was investigated whether these quantities are act...

The relation of dose and optical density in a conventional X-ray unit working with Screen Film Systems is subject to inherent fluctuations. For conventional equipment, the fluctuations of the components in conformity to the manufacturer instructions are calculated in such a fashion that the X-ray images of the patients fulfil the requirements of th...

The requirements for the target value of the mean optical density (o.d.) including proper tolerances of mammograms are determined in the "European Protocol for the Quality of the Physical and Technical Aspects of Mammography Screening (EPMS)". These requirements are not only applicable to screening mammography. 22 mammography devices were tested wi...

The requirements for the target value of the mean optical density (o. d.) including proper tolerances of mammogrammes are determined in the “European Protocol for the Quality of the Physical and Technical Aspects of Mammography Screening (EPMS)”. These requirements are not only applicable to screening mammography. 22 mammography devices were tested...

The relation of dose and optical density in a conventional X-ray unit working with Screen Film Systems is subject to inherent fluctuations. For conventional equipment, the fluctuations of the components in conformity to the manufacturer instructions are calculated in such a fashion that the X-ray images of the patients fullfil the requirements of t...

The effects of different film processing conditions on light and x-ray sensitometric responses were compared for a variety of double-emulsion x-ray films. The processing conditions were altered by changes of the developer temperature. Three different exposure variants were applied: x-ray sensitometry using two stepped neutral density attenuators be...

The object of this investigation was to compare different intraoral, analog and digital X-ray image detector systems with respect to the diagnostic performance and to the relation of dose and image quality. Three different intraoral film types and one digital system were compared. The same basic image quality-related technical parameters were measu...

Unlabelled: The object of this investigation was to compare different intraoral, analog and digital X-ray image detector systems with respect to the diagnostic performance and to the relation of dose and image quality. Methods: Three different intraoral film types and one digital system were compared. The same basic image quality-related technic...

The German standard series DIN 6868 does not include a separate requirement for deviations in the sensitivity of different emulsion numbers or, respectively, the relative contribution of the film to sensitivity S of a screen film system (SFS) whose sensitivity is determined according to DIN 6867-1 [1]. The inclusion and interpretation of these cont...

A new method is presented to check several automatic exposure control systems (AEC) for their suitability in radiological image production. It is based on measurements of dose and density with water as an absorbing and scattering medium. The characteristic curves of an AEC can be recorded, i.e., in what way is the dose K in the image receptor plane...

A new test procedure is presented to check the correspondence between various screen-film systems (SFS) with the specification of the manufacturer in respect to the speed S according to DIN 6867-1 or rather which dose K is required for the SFS in dependence on the X-ray tube voltage (kV) to give the net density Dn = 1.00, it is based on measurement...

To evaluate the image quality of an asymmetric film-screen combination (a-FSC), a conventional screen-film combination (FSC) at speed class 200, a lung filter, and digital luminescence radiograms in detecting pulmonary nodules. Detail perception studies were carried out with an anthropomorphic phantom. The image systems were exposed under standardi...

A new method is presented to check several automatic exposure control systems (AEC) for their suitability in radiological image production. It is based on measurements of dose and density with water as an absorbing and scattering medium. The characteristic curves of an AEC can be recorded, i.e., in what way is the dose K in the image receptor plane...

Aim: To evaluate the image quality of an asymmetric film-screen combination (a-FSC), a conventional screen-film combination (FSC) at speed class 200, a lung filter, and digital luminescence radiograms in detecting pulmonary nodules. Methods: Detail perception studies were carried out with an anthropomorphic phantom. The image systems were exposed u...

To compare the performances of 4 imaging systems in the diagnostic radiology of the chest: an asymmetric screen-film combination (a-SFC); a conventional screen-film combination of speed class 200 (SFC); a screen-film combination of speed class 200 with an aluminium lung filter; and digital luminescence radiographs (DLR). Object detectability studie...

To examine the diagnostic advantages of an asymmetric film-screen system (a-FSS) compared to a conventional 200-speed FSS with and without anatomical lung filter. Standard radiographs were obtained from an anthropomorphic chest phantom with simulated pulmonary nodules. The existence or non-existence of nodules was assessed in 7344 individual observ...

Purpose: To examine the diagnostic advantages of an asymmetric film-screen system (a-FSS) compared to a conventional 200-speed FSS with and without anatomical lung filter. Methods: Standard radiographs were obtained from an anthropomorphic chest phantom with simulated pulmonary nodules. The existence or non-existence of nodules was assessed in 7...

The permissible tolerances for processing are determined by different object transmission ranges. A figure of ? D = ± 0.20 appears suitable for exposure with pocket sensitometers. In terms of standardisation: ? D = ± 0.20 shall be maintained; whenever possible ? D should be maintained at ± 0.15 or better, but only when all other parts of the imagin...

Exposures of an anthropomorphic thorax phantom in posteroanterior projection were made using a focus-film distance of 200 cm and 125 kV with film-screen combinations in class 200 (Curix RP 1L/MR 200) and class 400 (Curix ST-L/Regular). Pathomorphological structures of the lung parenchyma of fine nodular, linear and reticular types were simulated by...

An einem anthropomorphen Thoraxphantom wurden bei einem Fokus-Film-Abstand von 200 cm und 125 kV Röhrenspannung Aufnahmen im posterioren anterioren Strahlengang mit einer Film-Folien-Kombination der Empfindlichkeitsklasse 200 (Curix RP 1L/ MR200) und 400 (Curix ST-L/Regulär) durchgeführt. Zur Simulation pathomorphologischer Strukturdetails bei Lung...