Liver Volumetry Plug and Play: Do It Yourself with ImageJ

Abstract

Background A small remnant liver volume is an important risk factor for posthepatectomy liver failure and can be predicted accurately by computed tomography (CT) volumetry using radiologic image analysis software. Unfortunately, this software is expensive and usually requires support by a radiologist. ImageJ is a freely downloadable image analysis software package developed by the National Institute of Health (NIH) and brings liver volumetry to the surgeon's desktop. We aimed to assess the accuracy of ImageJ for hepatic CT volumetry. Methods ImageJ was downloaded from http://www.rsb. info.nih.gov/ij/. Preoperative CT scans of 15 patients who underwent liver resection for colorectal cancer liver metastases were retrospectively analyzed. Scans were opened in ImageJ; and the liver, all metastases, and the intended parenchymal transection line were manually outlined on each slice. The area of each selected region, metastasis, resection specimen, and remnant liver was multiplied by the slice thickness to calculate volume. Volumes of virtual liver resection specimens measured with ImageJ were compared with specimen weights and calculated volumes obtained during pathology examination after resection. Results There was an excellent correlation between the volumes calculated with ImageJ and the actual measured weights of the resection specimens (r 2 = 0.98, p \ 0.0001). The weight/volume ratio amounted to 0.88 AE 0.04 (standard error) and was in agreement with our earlier findings using CT-linked radiologic software. Conclusion ImageJ can be used for accurate hepatic CT volumetry on a personal computer. This application brings CT volumetry to the surgeon's desktop at no expense and is particularly useful in cases of tertiary referred patients, who already have a proper CT scan on CD-ROM from the referring institution. Most likely the discrepancy between volume and weight results from exsanguination of the liver after resection.

Fast and accurate liver volumetry prior to hepatectomy

“…Manual outlining of liver borders for preoperative volumetric evaluation of the liver is time-consuming and has been performed in recent years with specific post-processing software such as OsiriX ® or Image J ® . [4][5][6] The present study showed that volumetry of the liver using Terarecon Aquarius iNtuition ® auto-segmentation was three times faster than manual outlining of the liver with OsiriX ® , while maintaining accuracy.…”

“…The future role of post-processing open source software such as Osirix ® is unclear as the time needed for volumetric assessment of the liver by nonradiologists was almost 20 min in our and sometimes more in previous studies. [4][5][6]11,13 To our knowledge, there is no 'liver plugin' available in OsiriX ® or other open source post-processing software that allows for automated liver segmentation.…”

“…[1][2][3] Prevention of this severe and often lethal complication is attempted through pre-operative CT-based volumetric liver assessment in patients undergoing major liver resections. [4][5][6] In patients with healthy livers approximately 25% of the liver parenchyma needs to be preserved to prevent PLF. 7 In damaged or cirrhotic livers up to 50% liver parenchyma needs to be spared.…”

“…This volumetric assessment is relatively time-consuming. [4][5][6] Additionally, with traditional software, the total liver volume, future remnant liver volume and tumour volume all need to be outlined separately in order to make a proper risk-assessment prior to large liver resections, further increasing the time required for complete analysis. 4,6 With specialised software, auto-segmentation of organs is possible.…”

Using bimodal MRI/fluorescence imaging to identify host angiogenic response to implants

“…In recent years, MRI has become one of the most universal techniques aimed at visualizing detailed internal structures in the body. The use of contrast agents for MRI provides comparable spatial resolution with far better contrast resolution than CT imaging (21,22). Furthermore, the use of both MRI and fluorescent labeling (i.e., bimodal imaging) to track proteins, cells, and angiogenesis was recently reported (23)(24)(25).…”