OSI Systems Inc. reported better-than-expected fiscal first quarter earnings, driven by strong sales growth in its security scanner division.

The Hawthorne company on Tuesday reported net income of $4.76 million (24 cents per share) compared with $3.39 million (18 cents) in the same period a year earlier. Net revenue rose 25 percent to more than $161 million.

Analysts surveyed by Thomson Reuters on average expected the company to report per-share profit of 22 cents on revenue of less than $152 million.

Revenue in the security division, which makes scanners for use at airports and military check-points, rose 42 percent to $72.6 million. Medical scanner revenue was up 1 percent to $46.5 million. Optoelectronics, which provides components for itself and other companies, rose 26 percent to $53 million before adjustments for intercompany sales.

“We had an exceptional first quarter of bookings leading to a record backlog of $413 million at quarter-end, which positions the company well for continued outstanding sales and earnings growth,” Chief Executive Deepak Chopra said in a statement.

OSI raised its fiscal 2012 sales guidance to between $740 million and $760 million, compared with its earlier range of $722 million to $740 million. It raised its adjusted earnings guidance range to $2.27 to $2.40 a share, compared with an earlier $2.21 to $2.32 range. The Wall Street consensus is for $2.26 per share profit on revenue of $731 million.

Shares on Wednesday were down 25 cents, or less than 1 percent, to $41.48 in midday trading on the Nasdaq.