** 4Dmedical 4DX.AX surges as much as 40.4% to A$0.800, highest since March 12, 2024
** Stock top gainer on ASX All Ordinaries index .AORD
** Medical tech co receives U.S. FDA clearance for its ventilation-perfusion scan CT:VQ
** VQ scan evaluates both airflow and blood flow in the lungs and is primarily used to diagnose pulmonary embolism
** Co's CT:VQ test capable of extracting VQ data from routine CT scans without contrast dyes
** YTD, 4DX gains more than 61%
(Reporting by Komal Pooja Asokan)
((KomalPooja.Asokan@thomsonreuters.com;))