**4. Discussion**

The purpose of the present study using images from actual patients was to obtain initial data to indicate whether or not the newer tablet PCs with a 4K high‐resolution color display monitor could be deployed for mammographic imaging. Only one previous study has evaluated the display quality of tablet PCs [13]. This study represented the first attempt to evaluate the display quality of tablet PCs (iPad 2 and 3) with a dedicated 10‐MP LCD using a standardized CDMAM phantom. It was concluded that the evaluated iPads, especially version 3, would likely be adequate for display of diagnostic‐quality mammograms [13].

Our present study found no significant difference between the performances of the 5‐MP LCDs and the 4K tablet PCs for detecting breast cancers on mammograms. Moreover, in terms of the image quality, 4K tablet PCs were rated as having better brightness, contrast, and sharpness. This is the first confirmation that observer performance for detection of breast cancers using soft‐copy readings on digital mammograms is comparable between the current standard 5‐MP LCDs and 4K tablet PCs with a high‐resolution display monitor. The 4K tablet PC seems suitable for displaying mammograms in a variety of tasks such as patient consultation, clinical demon‐ strations, or educational and teaching purposes, and its large high‐resolution screen seems to meet the legal requirements. As many patients are interested in taking a look at their images, one of the most promising applications of tablet PC‐based mammographic display would be patient consultation. This would give patients a clearer idea of their disease and might have a positive impact on patient compliance.

The greatest benefits of the 4K tablet PC with a high‐resolution display monitor are its low cost and possible application for multiple purposes, such as reporting systems and referencing of color images including endoscopic, PET/CT, and SPECT/CT images. In addition, the performance of 4K high‐resolution color display monitors has recently improved, and they now have high‐ resolution (5‐MP or more) capability, as is the case for medical LCDs. However, the development of tablet PCs is progressing rapidly; the 4K display used in the present study might now be con‐ sidered a relatively old model. If the 4K display is suitable for medical display purposes, the cost would increase.
