The physician dictation should confirm image documentation OR attempted documentation of the : Left and right atria, Left and right ventricles, aortic, tricuspid & mitral valves, pericardium if all of this are documented as looked at or attemped (could visual because of body habitus or the likes can still count) AND M-mode with color doppler are dictated you should use: 93306 (Complete study with M-mode and Color)
If Left and right atria, Left and right ventricles, aortic, tricuspid & mitral valves, pericardium if all of this are documented as looked at or attemped but only M-mode is dictated then you should only code: 93307 (Complete study with M-mode).
If not all of the areas are dictated (Left and right atria, Left and right ventricles, aortic, tricuspid & mitral valves, pericardium) then you would code: 93308 (Limited or F/U study only) since a complete study was not done. If M-mode is documented with the limited study then you can use add on code 93321(M-mode); If Color is performed with the limited study you may add on code 93325 (Color).