Accuracy of Estimation of Graft Size for Living-Related Liver Transplantation: First Results of a Semi-Automated Interactive Software for CT-Volumetry

Abstract

ObjectivesTo evaluate accuracy of estimated graft size for living-related liver transplantation using a semi-automated interactive software for CT-volumetry.Materials and MethodsSixteen donors for living-related liver transplantation (11 male; mean age: 38.2±9.6 years) underwent contrast-enhanced CT prior to graft removal. CT-volumetry was performed using a semi-automated interactive software (P), and compared with a manual commercial software (TR). For P, liver volumes were provided either with or without vessels. For TR, liver volumes were provided always with vessels. Intraoperative weight served as reference standard. Major study goals included analyses of volumes using absolute numbers, linear regression analyses and inter-observer agreements. Minor study goals included the description of the software workflow: degree of manual correction, speed for completion, and overall intuitiveness using five-point Likert scales: 1–markedly lower/faster/higher for P compared with TR, 2–slightly lower/faster/higher for P compared with TR, 3–identical for P and TR, 4–slightly lower/faster/higher for TR compared with P, and 5–markedly lower/faster/higher for TR compared with P.ResultsLiver segments II/III, II–IV and V–VIII served in 6, 3, and 7 donors as transplanted liver segments. Volumes were 642.9±368.8 ml for TR with vessels, 623.8±349.1 ml for P with vessels, and 605.2±345.8 ml for P without vessels (P<0.01). Regression equations between intraoperative weights and volumes were y = 0.94x+30.1 (R2 = 0.92; P<0.001) for TR with vessels, y = 1.00x+12.0 (R2 = 0.92; P<0.001) for P with vessels, and y = 1.01x+28.0 (R2 = 0.92; P<0.001) for P without vessels. Inter-observer agreement showed a bias of 1.8 ml for TR with vessels, 5.4 ml for P with vessels, and 4.6 ml for P without vessels. For the degree of manual correction, speed for completion and overall intuitiveness, scale values were 2.6±0.8, 2.4±0.5 and 2.ConclusionsCT-volumetry performed with P can predict accurately graft size for living-related liver transplantation while improving workflow compared with TR.

The correlation between preoperative volumetry and real graft weight: comparison of two volumetry programs

“…Although we did not do an analysis of time duration needed for volumetry and surgical planning, we observed that it took only 10–15 minutes to use the Dr. Liver software. Our results were comparable to those reported in literature by other authors [102223]. …”

Impact of graft‐to‐recipient weight ratio on small‐for‐size syndrome following living donor liver transplantation

“…This can obviously have significant implications with the procurement of an SFS graft in the live donor setting. Currently, non‐automated computed tomography volumetry for graft size is generally considered to be the preoperative standard . However, recently, there has been increasing interest in computer‐assisted image analysis for calculating liver volume.…”

“…However, recently, there has been increasing interest in computer‐assisted image analysis for calculating liver volume. One recent study specific to preoperative volume prediction in the LDLT setting found that semi‐automated interactive software showed good prediction of graft size with a strong linear relationship and low error ratio with intraoperative volume and graft weight …”

Virtual monochromatic spectral imaging versus linearly blended dual-energy and single-energy imaging during CT-guided biopsy needle positioning: Optimization of keV settings and impact on image quality

“…Interreader-agreement. The interreader-agreement of the objective quantitative image analysis was performed with Bland-Altman analysis [21,22]. The interreader-agreement of the subjective qualitative image analysis was rated with Cohen's kappa coefficient and graded using the Landis and Koch classification [23,24].…”