Until now, we have been working to revamp our lineup of diagnostic imaging systems, which are the mainstay of the business unit. In 2018, we posted higher revenues, led by increased sales of new products such as the Alphenix series of next-generation diagnostic X-ray systems and the Vantage Orian, a high-resolution MRI system that incorporates cutting-edge technology.
Additionally, the addition of new compact and lightweight ultrasound diagnostic systems that inherit the ultra-high-resolution technology of premium models also contributed significantly to sales. In Japan, sales were negatively impacted by medical institutions deferring investment decisions amid revision of the NHI reimbursement schedule for diagnostic procedures. However, this was offset by higher sales in overseas markets.
As a result, overall sales for the business unit increased 0.3% year on year to ¥437.6 billion, while operating profit rose 31.4% year on year to ¥28.8 billion.
The diagnostic imaging equipment market is projected to grow steadily at around 3% per year, supported by rising demand for advanced healthcare in Western countries and the development of medical infrastructure in emerging markets.
At the end of 2018 we received regulatory approval in overseas markets for domestically successful new products, which is expected to contribute fully to sales in 2019. In 2019, we also expect to start introducing competitively priced CT systems for emerging markets that also offer high image quality.
We will also strengthen our sales structure by focusing on expanding our sales force overseas and converting local sales agents into subsidiaries.
We are also looking to improve profitability based on redoubling efforts to realize intra-Group synergies. For example, we have achieved cost reductions by making use of Canon production technologies, such as detecting faults before they occur through the detection of abnormal noises coming from production equipment during operation. What's more, we are utilizing our 3D simulation technologies to realize prototype-less product development that improves efficiency in R&D.