The fourth edition of the European guidelines for quality assurance in breast cancer screening and diagnosis was published by the European Commission in 2006. The present supplements to the fourth edition have been produced by the same groups of experts originally established under the Europe Against Cancer programme that have developed and updated the guidelines since the early 1990s. Over the years, the scope and the depth of the multidisciplinary guidelines have expanded, and recommendations and protocols have been updated to keep pace with developments in the field. The present supplements lay a cornerstone for a new, completely revised fifth edition of the guidelines

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European guidelines for quality assurance in breast cancer screening and diagnosis

Comparison of the elastic and yield properties of human femoral trabecular and cortical bone tissue.

An MR angiographic technique, referred to as 3D TRICKS (3D time-resolved imaging of contrast kinetics) has been developed. This technique combines and extends to 3D imaging several previously published elements. These elements include an increased sampling rate for lower spatial frequencies, temporal interpolation of k-space views, and zero-filling in the slice-encoding dimension. When appropriately combined, these elements permit reconstruction of a series of 3D image sets having an effective temporal frame rate of one volume every 2-6 s. Acquiring a temporal series of images offers advantages over the current contrast-enhanced 3D MRA techniques in that it I) increases the likelihood that an arterial-only 3D image set will be obtained. II) permits the passage of the contrast agent to be observed, and III) allows temporal-processing techniques to be applied to yield additional information, or improve image quality.

Time-resolved contrast-enhanced 3D MR angiography

A three-dimensional extension of two-dimensional digital image correlation has been developed. The technique uses digital image volumes generated through high-resolution X-ray tomography of samples with microarchitectural detail, such as the trabecular bone tissue found within the skeleton. Image texture within the material is used for displacement field measurement by subvolume tracking. Strain fields are calculated from the displacement fields by gradient estimation techniques. Estimates of measurement precision were developed through correlation of repeat unloaded data sets for a simple sum-of-squares displacement-only correlation formulation. Displacement vector component errors were normally distributed, with a standard deviation of 0.035 voxels (1.22 μm). Strain tensor component errors were also normally distributed, with a standard deviation of approximately 0.0003. The method was applied to two samples taken from the thigh bone near the knee. Strains were effectively measured in both the elastic and postyield regimes of material behavior, and the spatial patterns showed clear relationships to the sample microarchitectures.

Digital volume correlation : Three-dimensional strain mapping using X-ray tomography

Rak piersi jest najczestszą przyczyna zgonu wśrod kobiet i stanowi istotny problem kliniczny. Wczesne
wykrycie raka piersi dzieki regularnie prowadzonym badaniom przesiewowym za pomocą mammografii
umozliwia rozpoznanie choroby w stadium, w ktorym leczenie jest skuteczniejsze i zazwyczaj wiąze sie
z lepszą jakością zycia. Jednakze mammografia moze byc przyczyną niepotrzebnego stresu, dolegliwości,
kosztow finansowych oraz narazenia na promieniowanie jonizujące. Z tego powodu nalezy polozyc
mozliwie najwiekszy nacisk na kontrole jakości. Opracowanie Europejskich zalecen dotyczących kontroli
jakości badan przesiewowych i rozpoznawania raka piersi bylo inicjatywą programu Europa przeciwko
rakowi . Czwartą edycje interdyscyplinarnych zalecen opublikowano w 2006 roku. Sklada sie z okolo 400
stron podzielonych na 12 rozdzialow przygotowanych przez ponad 200 autorow i wspolautorow. Interdyscyplinarna
rada wydawnicza przygotowala streszczenie dokumentu w celu przedstawienia podstawowych
zasad i zalozen, na ktorych powinny opierac sie badania przesiewowe oraz diagnostyka raka piersi.
Opracowanie zawiera takze tabele podsumowującą wskaźniki wydajności, aby szersze grono naukowcow
moglo sie z nią zapoznac.

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European guidelines for quality assurance in breast cancer screening and diagnosis. Fourth edition - summary document

The modulation transfer function (MTF) of radiographic systems is frequently evaluated by measuring the system's line spread function (LSF) using narrow slits. The slit method requires precise fabrication and alignment of a slit and high radiation exposure. An alternative method for determining the MTF uses a sharp, attenuating edge device. We have constructed an edge device from a 250-microm-thick lead foil laminated between two thin slabs of acrylic. The device is placed near the detector and aligned with the aid of a laser beam and a holder such that a polished edge is parallel to the x-ray beam. A digital image of the edge is processed to obtain the presampled MTF. The image processing includes automated determination of the edge angle, reprojection, sub-binning, smoothing of the edge spread function (ESF), and spectral estimation. This edge method has been compared to the slit method using measurements on standard and high-resolution imaging plates of a digital storage phosphor (DSP) radiography system. The experimental results for both methods agree with a mean MTF difference of 0.008. The edge method provides a convenient measurement of the presampled MTF for digital radiographic systems with good response at low frequencies.

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A method for measuring the presampled MTF of digital radiographic systems using an edge test device

Human vertebral body apparent and hard tissue stiffness.

This article presents the technical aspects of a linear filter, referred to as eigenimage filtering, and its applications in magnetic resonance (MR) imaging. The technique is used to obtain a single composite image depicting a particular feature of interest while suppressing one or more interfering features. The appropriate weighting components to be used in the linear filter are determined on the criterion that the desired feature is enhanced while the interfering features are suppressed. The criterion is expressed mathematically as a ratio. By applying Rayleigh's principle, the ratio is maximized by finding the eigenvector associated with the maximum eigenvalue of the corresponding generalized eigenvalue problem. The appropriate weighting factors for the linear filter are the elements of the eigenvector which maximize the ratio. The utilization of the technique is demonstrated in its application to a simulated MR image sequence as well as to acquired MR image sequences of a normal and an abnormal brain.

Eigenimage filtering in MR imaging.

An analytic model for the performance of cone beam microtomography is described. The maximum power of a microfocus X-ray source is assumed to be approximately proportional to the focal spot size. Radiation flux penetrating the specimen is predicted by a semi-empirical relation which is valid for X-ray energies less than 20 keV. Good signal to noise ratio is predicted for bone specimens of 0.1 to 10 mm when scanned at the optimal energy. A flux of about 1 × 10 10 photons/mm 2 /s is identified for 0.2 mm specimens. Cone beam volumetric microtomography is found to compare favorably with synchrotron based methods.

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David A. Reimann

Papers

A method for measuring the presampled MTF of digital radiographic systems using an edge test device

Human vertebral body apparent and hard tissue stiffness.

Eigenimage filtering in MR imaging.

Microfocus X-ray sources for 3D microtomography

A cone beam computed tomography system for true 3D imaging of specimens