(Yicai) April 7 -- Shares of American medical device suppliers GE HealthCare Technologies and Varex Imaging plunged after China launched an anti-dumping investigation into X-ray tubes used in CT scanners imported from the United States and India, following US tariff hikes.

GE HealthCare [NASDAQ: GEHC] dropped 1.8 percent in pre-market trading in New York today as of 4.52 a.m. after closing 16 percent lower at USD60.51 on April 4. Meanwhile, Varex [NASDAQ: VREX] plummeted 19.1 percent in pre-market hours, following a 19.7 percent plunge to close at USD8.28 during the previous trading day.

The anti-dumping investigation, initiated at the request of domestic suppliers, targets certain ball-bearing CT tubes originating from the US and India, a Chinese commerce ministry official said on April 4.

The official added that preliminary evidence from local suppliers shows that from 2022 to 2024, the volume of dumped imports from the US and India increased by 13 percent, while prices continued to decline -- causing operating difficulties and financial losses for Chinese manufacturers.

After US President Donald Trump announced at least 10 percent tariffs on global imports on April 2, China responded on April 4 with reciprocal 34 percent tariffs on US-origin goods. Additionally, China added 11 American firms to its "unreliable entity list" and imposed export controls on 16 companies. China now faces a cumulative tariff rate of 54 percent on exports to the US, comprising 34 percent in new duties on top of existing 20 percent tariffs.

X-ray tubes are core components of medical imaging systems. Industry insiders told Yicai that GE HealthCare, Siemens Healthineers from Germany, and Philips from the Netherlands all manufacture their own X-ray tubes. Chinese CT scanner manufacturers, by contrast, depend heavily on imported components due to their relatively recent market entry. More than 80 percent of these parts are supplied by Varex and Dunlee, a subsidiary of Philips, according to insiders.

Industry estimates suggest that China's annual demand for CT tubes exceeds 5,000 units for new machines and 100,000 units for replacements in existing systems.

If anti-dumping measures are implemented, domestic manufacturers could face increased costs for imported CT tubes, an analyst noted. However, Varex operates a manufacturing facility in Wuxi, Jiangsu Province, which may help mitigate the impact, the source added.

Editors: Dou Shicong, Emmi Laine