iaea human health series publications - SEDIM

— Choose a system that can be adequately serviced and supported at that location. Acceptable performance of adigital system can only be realized consistently if the system is maintained properly and software is keptcurrent by timely updates.— Consider whether the image interpretation will be performed on a vendor specific display workstation or whethera PACS workstation with suitable mammographic software and hardware provides an adequate solution. Ideally,all systems should meet the specifications set out in the IHE mammography display profile [19].— Ensure compatibility of any new digital mammography system with existing digital mammography systemsand information systems (e.g. PACS, radiology information system (RIS), hospital information system(HIS)). Worklist capability at the acquisition workstation generated by the RIS/PACS is a key feature of thiscompatibility. Adequate archival storage must be available for the large datasets encountered inmammography (see Table 1).— Consider how images may be made available to other facilities and referring physicians. This may requireprinting capabilities (see next item in list) or the ability to produce DVDs.— Decide whether the images will be reported from a monitor (soft copy) or from printed film. To fully realizethe benefits of digital mammography in terms of flexibility of display and to avoid the disadvantages of usingfilm, soft copy reporting is preferable. However, there may well be circumstances where film printing isjustified. If film printing is undertaken, the printer should have specifications appropriate to mammographicimage printing (e.g. the pixel size on the printer must closely match that of the acquired images). The size ofthe film available with the printer should be compatible with the film viewing device and should result innearly life-size images, with the chest wall located at the edge of the film.— It is important to ensure that means are available to view previous examinations. This is a challengingproblem, as it always involves compromise. One possibility is to include a film viewer in the reading room. Ifthis is done, it is essential that the area be designed so that light from the viewbox causes minimal interferencewith viewing of digital images on the monitor. Some facilities may instead choose to digitize prior images sothat they can be viewed on the monitor alongside the current digital images [20, 21].2.2.2. Purchase specificationsThe following should be considered when purchasing a digital mammography system:— Ensure that all digital systems as well as displays and printers meet the relevant Digital Imaging andCommunications in Medicine (DICOM) standards [22] as well as the IHE mammography display profile.— Ensure that the digital mammography system has in place a mechanism that provides automated transfer ofthe image acquisition parameters (kilovolts (kV), milliampere-seconds (mAs), target and filter material,breast thickness, compression force) for each exposure into the DICOM header. It should be noted thatalthough this is a very important feature, at the time of writing not all digital mammography systems have thiscapability. Separate interfaces [23] to accomplish this transfer automatically are available commercially.— In addition, it is useful to include in the DICOM header information such as the estimated mean glandulardose (MGD) and entrance air kerma.TABLE 1. DAILY DATA VOLUMES FROM UNCOMPRESSED DIGITAL MAMMOGRAPHY IMAGES(MEGABYTES) aExaminations per day Images per day Image field (cm × cm)Detector element (del) size (μm)50 70 85 10020 80 18 × 24 2 765 1 411 957 69120 80 24 × 30 4 608 2 351 1 594 1 152100 400 18 × 24 13 824 7 053 4 783 3 456100 400 24 × 30 23 040 11 755 7 972 5 760aIt is assumed that 2 bytes are required per pixel.6