Background: Operation planning in liver surgery depends on the precise understanding of the 3-dimensional (D) relation of the tumor to the intrahepatic vascular trees. To our knowledge, the impact of anatomical 3-D reconstructions on precision in operation planning has not yet been studied. Hypothesis: Three-dimensional reconstruction leads to an improvement of the ability to localize the tumor and an increased precision in operation planning in liver surgery. Design: We developed a new interactive computerbased quantitative 3-D operation planning system for liver surgery, which is being introduced to the clinical routine. To evaluate whether 3-D reconstruction leads to improved operation planning, we conducted a clinical trial. The data sets of 7 virtual patients were presented to a total of 81 surgeons in different levels of training. The tumors had to be assigned to a liver segment and subsequently drawn together with the operation proposal into a given liver model. The precision of the assignment to a liver segment according to Couinaud classification and the operation proposal were measured quantitatively for each surgeon and stratified concerning 2-D and different types of 3-D presentations. Results: The ability of correct tumor assignment to a liver segment was significantly correlated to the level of training (PϽ.05). Compared with 2-D computed tomography scans, 3-D reconstruction leads to a significant increase of precision in tumor localization by 37%. The target area of the resection proposal was improved by up to 31%. Conclusion: Three-dimensional reconstruction leads to a significant improvement of tumor localization ability and to an increased precision of operation planning in liver surgery.

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The purpose of this study was to assess the clinical feasibility of three-dimensional (3D) reconstruction of color Doppler signals in patients with mitral regurgitation. BACKGROUND Two-dimensional (2D) color Doppler has limited value in visualizing and quantifying asymmetric mitral regurgitation. Clinical studies on 3D reconstruction of Doppler signals in original color coding have not yet been performed in patients. We have developed a new procedure for 3D reconstruction of color Doppler. METHODS We studied 58 patients by transesophageal 3D echocardiography. The jet area was assessed by planimetry and the jet volumes by 3D Doppler. The regurgitant fractions, the volumes, and the angiographic degree of mitral regurgitation were assessed in 28 patients with central jets and compared with those of 30 patients with eccentric jets. RESULTS In all patients, jet areas and jet volumes significantly correlated with the angiographic grading (r ϭ 0.73 and r ϭ 0.90), the regurgitant fraction (r ϭ 0.68 and r ϭ 0.80) and the regurgitant volume (r ϭ 0.66 and r ϭ 0.90). In patients with central jets, significant correlations were found between jet area and angiography (r ϭ 0.86), regurgitant fraction (r ϭ 0.64) and regurgitant volume (r ϭ 0.78). No significant correlations were found between jet area and angiography (r ϭ 0.53), regurgitant fraction (r ϭ 0.52) and regurgitant volume (r ϭ 0.53) in the group of patients with eccentric jets. In contrast, jet volumes significantly correlated with angiography (r ϭ 0.90), regurgitant fraction (r ϭ 0.75) and regurgitant volume (r ϭ 0.88) in the group of patients with eccentric jets. CONCLUSIONS Three-dimensional Doppler revealed new images of the complex jet geometry. In addition, jet volumes, assessed by an automated voxel count, independent of manual planimetry or subjective estimation, showed that 3D Doppler is also capable of quantifying asymmetric jets.