Hepatic volumetry with PhotoShop in personal computer.

BACKGROUND: Convenient way to clarify liver volume or tumor volume in the liver is eagerly demanded by hepatobiliary surgeons, for so many aspects of clinical work need to know the liver volumetry. At present, some methods have been used to measure the liver volumetry, such as computed tomography (CT) scans, three-dimensional ultrasound volumetric system([1]) and 3-dimensional sonography([2,3]) et al. But enough volumetric information was failed to obtain by surgeons and a new way of measuring the liver volumetry that can be operated by themselves is exigent. Whereas we devise a new method of using PhotoShop in personal computer to measure the liver volumetry.
METHODS: A piece of whole CT film was transformed to a high quality digitized image by digital camera or scanner and then the digitized image was conducted as JPEG file into personal computer. The JPEG image file of CT film was opened by PhotoShop. Determining the edge of interested areas, and the data of pixel values of the interested areas divided by 1 cm2 pixel value will produce the actual area with the unit of square centimeter. If section thickness of CT scan is 1 cm, the sum of the areas of the liver or tumor in all sections naturally is the volume of the liver or tumor.
RESULTS: Comparison of 10 hepatic volumes gained by this method and those gained by the GE Prospeed CT set showed a good relativity between the two groups. The volumes of three right lobes were calculated by this method before lobectomy and their real volumes were obtained postoperatively by a volumenometer. Their variation was limited to 5%.
CONCLUSIONS: Hepatic volume obtained by PhotoShop is reliable. This method can be used to measure hepatic volume perfectly to meet clinical demand, and many parameters such as liver resection rate, graft volume can be achieved. The disadvantage of this method is the step of copying the pixel value from PhotoShop to Microsoft Excel.