OSI Systems Inc. on Monday said its net income more than doubled in its third quarter as sales of airport security scanner overcame its slower medical imaging system business. However, shares fell in early trading Monday.

The Hawthorne company reported net income of $6.1 million (33 cents per share), compared with $2.6 million (15 cents) a year earlier. Revenue rose 1 percent to more than $145 million.

Excluding restructuring and other one-time costs, OSI earned 36 cents per share. Analysts surveyed by Thomson Reuters on average expected a per-share profit of 33 cents on higher revenue of $158 million.

The company said revenue from its security division rose 23 percent to $69.3 million. Revenue from its health care unit dropped 9 percent to $45.9 million.

“Macroeconomic factors have continued to result in a challenging environment for our health care division,” said Chief Executive Deepak Chopra in a press release, noting that its hospitals and providers continue to face difficulties in obtaining financing for equipment upgrades. “Our security division experienced an excellent third quarter and is poised for continued sales and operating profit growth.”

OSI said it should earn $1.30 to $1.36 per share for the fiscal year ending June 30. That’s higher than its previous guidance of $1.23 to $1.32; analysts were expecting $1.31. The company projects $153 million to $167 million in fourth quarter revenue, compared with average analyst forecast of more than $173 million.

Shares were down $2.26, or 7.5 percent, to $27.71 in midday trading on the Nasdaq.