Novel three-dimensional imaging technique improves the accuracy of hepatic volumetric assessment.

Department of Surgery, Washington University in Saint Louis, Saint Louis, MO 63110, USA.
HPB (Impact Factor: 2.05). 09/2011; 13(9):670-4.
Source: PubMed

ABSTRACT With pre-operative prediction of liver volume becoming increasingly important to safely carry out complex hepatic resections, the aim of the present study was to validate the accuracy of a three-dimensional (3-D) liver surgery operative planning software in performing hepatic volumetry.
Between 1999 and 2007, we performed 29 live donor liver resections for transplantation. Eleven patients had pre-operative volumetry performed by radiologists from either computed tomography (CT) or magnetic resonance (MR) imaging with documentation of the corresponding specimen weight. Retrospectively, images were uploaded into Scout™ where 3-D models of each case were generated to perform volumetry. A correlational analysis was performed followed by an accuracy comparison.
Estimations by both radiologists and Scout™ were significantly correlated with the specimen weights, P ≤ 0.0001. Compared with radiologists' volumetry, Scout™ significantly improved overall accuracy [per cent error (PE) 20.0% ± 5.3 vs. 32.9% ± 5.7, P=0.005], accuracy of CT-based estimations (PE 23.2% ± 6.7 vs. 37.2% ± 6.9, P=0.023) and accuracy of the left lateral section (PE 11.1% ± 3.9 vs. 26.6% ± 6.8, P=0.027).
This 3-D planning software is a valid tool for use in volumetry. Significance is greatest for CT-based models of the left lateral section. This approach gives surgeons the ability to assess volumetrics and actively plan resections.

  • [Show abstract] [Hide abstract]
    ABSTRACT: An interactive liver surgery planning system has been developed to construct and optimize the resection plan. With this system, the segmentation results of the liver and its components (such as tumors and vessels) are comprehensively visualized for surgeons to have an intuitive understanding of the internal anatomical structure of the liver. This system will also allow surgeons to interactively create and modify a resection plan on the virtual liver model. The resection surface, whose boundary is a closed curve, will be automatically constructed with the safe resection margins of tumors. Different from other systems, our developed system is able to generate the safety margins to all tumors. During surgery, a larger resection surface may cause potentially more bleeding and other complications. Therefore, area minimization is applied during the resection surface construction by adopting the minimal area mesh, which is a smooth surface with minimal area. After these virtual modifications, the resultant resection surface indicates the route to cut the liver for tumor removal. The volumes for both resected liver and residual liver are calculated for clinical decision making.
    Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 07/2013; 2013:1286-1289.
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study aimed to evaluate a novel segmentation software for automated liver volumetry and segmentation regarding segmentation speed and interobserver variability. Computed tomographic scans of 20 patients without underlying liver disease and 10 patients with liver metastasis from colorectal cancer were analyzed by a novel segmentation software. Liver segmentation was performed after manual placement of specific landmarks into 9 segments according to the Couinaud model as well as into 4 segments, the latter being import for surgery planning. Time for segmentation was measured and the obtained segmental and total liver volumes between the different readers were compared calculating intraclass correlations (ICCs). Volumes of liver tumor burden were evaluated similarly. Liver segmentation could be performed rapidly 3 minutes or less. Comparison of total liver volumes revealed a perfect ICC of greater than 0.997. Segmental liver volumes within the 9-part segmentation provided fair to moderate correlation for the left lobe and good to excellent correlations for the right lobe. When applying a 4-part segmentation relevant to clinical practice, strong to perfect agreement was observed. Similarly tumor volumes showed perfect ICC (>0.998). Rapid determination of total and segmental liver volumes can be obtained using a novel segmentation software suitable for daily clinical practice.
    Journal of computer assisted tomography 01/2013; 37(4):577-82. · 1.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to evaluate the effect of a low tube voltage technique and hybrid iterative reconstruction (HIR) on image quality at 3-dimensional computed tomographic angiography (3D-CTA) of the liver. Before hepatic surgery, we randomly assigned 60 patients (17 women, 43 men; mean ± SD age, 68.9 ± 10.1 years) who had undergone 3D-CTA to 1 of 2 protocols; 30 patients underwent scanning under the conventional 120-kilovolt (peak) protocol with filtered back projection (P1); and 30 patients, under an 80-kilovolt (peak) protocol with HIR (P2). The estimated effective radiation dose, computed tomographic attenuation, image noise, contrast-to-noise ratio, and figure of merit were calculated, and the visual image quality of 3D-CTA was scored on a 4-point scale. The mean effective radiation dose was significantly lower under P2 than P1 (4.8 ± 1.2 vs 7.2 ± 1.5 mSv, P < 0.01). P1 and P2 did not significantly differ with respect to the image noise (10.5 ± 2.3 vs 9.9 ± 1.6 Hounsfield units; P = 0.46). Computed tomographic attenuation, contrast-to-noise ratio, figure of merit, and the visual scores for image quality were higher under P2 than P1 (P < 0.01). The use of low tube voltage and HIR can yield significantly improved image quality at 3D-CTA of the liver.
    Journal of computer assisted tomography 01/2014; 38(1):131-6. · 1.38 Impact Factor

Full-text (2 Sources)

Available from
Jan 26, 2015