Radbook2012

MammographyRAD·BOOK 2012 67 IT-SOLUTIONS 51RAD·BOOK 2012 tion to patient management planning, there are a number of other issues to be considered, including: how comparison to priors will be handled; methods to ensure radiologists receive appropriate training prior to reading Tomo exams; how reading times for Tomo exams will affect workflow; and the impact tomo- synthesis will have on archiving and display requirements. These issues are discussed in more detail below, drawing from the experiences of users who have adopted tomosynthesis. Use of Tomosynthesis for Screening or Diagnostic Imaging Tomosynthesis has shown value in a diagnostic evaluation of a symptomatic breast. It also can be used as a screen- ing tool to improve sensitivity and reduce recalls. Therefore, either or both indi- cations are acceptable uses of tomosyn- thesis. Since diagnostic procedures often take longer than screening exams, more women per day can be accommodated on machines dedicated to screening use. This might be a consideration in situa- tions where a limited number of Tomo- capable systems are available. Use of Tomosynthesis for Women with Dense Breasts Tomosynthesis has been shown to have value in both fatty and dense breasts, but it has a greater impact for women with dense breasts. Therefore, if a practice does not have enough systems to screen all women, it is reasonable to reserve tomosynthesis for women with dense breasts. However, as tomosynthesis offers a benefit in both fatty and dense breasts, the eventual goal should be to screen all women using tomosynthesis imaging. These types of scenarios are illustrated in Figure 2, and represent a hypotheti- cal clinic that switches, in the current year, some but not all of their screening systems to tomosynthesis. – Prior Year(s): 2D mammograms were acquired. – Current Year: Combo-mode exam acquired. The radiologist can diag- nose from the 2D and Tomo dataset, and uses the current year’s 2D to compare to prior years’ 2D images. – Next Year: A 2D only exam or a combo-mode exam may be acquired, depending upon whether the patient is triaged to a 2D or Tomo-capable system. · If a combo-mode exam is acquired, the radiologist has both 2D and Tomo currents and priors. · If a 2D only exam is acquired, the radiologist can compare the current year 2D to the next year 2D and also to the current year Tomo, if desired. (continue next page) Patient Selection Some facilities offer tomosynthesis using the ‘next available free system’ model. In this scenario, if the room with the tomo- synthesis system is free, the next patient will be triaged to the room, regardless of their breast density. Some facilities also offer full access to a tomosynthesis exam for any woman who requests the proce- dure. This is accomplished through the use of special after-hours or otherwise scheduled blocks of time to assure access to the system. Figure 1 shows some of the possible implementation scenarios for tomosyn- thesis. All of these scenarios are reason- able implementation strategies. Handling Priors Standard mammography practice in- volves the comparison of current images to images from a previous exam (pri- ors). The use of combo-mode imaging gives the radiologist access to a 2D cur- rent for comparison to 2D priors. This combo-mode procedure also offers some advantages in the scenarios mentioned above where a patient this year might get a tomosynthesis study and in the next year receive only a 2D study because of scheduling constraints or equipment ac- cess. In such a situation, the radiologist reading the study in the following year would have access to the 2D exams from previous combo-mode studies. 2D Prior Year Current Year Next Year 2D 2D + Tomo Complete Partial 2D + Tomo 2D Prior Year Current Year Next Year 2D 2D + Tomo Complete conversion to tomosynthesis All screening and diagnostic patients receive tomo exams Use for some screening patient subgroups, such as women with dense breasts Use for some screening patients, as the tomosynthesis system(s) are available Use for diagnostic exams only Partial conversion to tomosynthesis 2D + Tomo The tomosynthesis reconstructed slice shown on the right reveals a definitive spiculated mass that is only faintly revealed in the 2D im- age shown on the left. (Diagnosis: invasive ductal carcinoma) Figure 1: Various Implementation Strategies for Tomosynthesis Figure 2: Represents a hypothetical clinic that switches in the current year to some but not all of their screening systems to tomosynthesis