PowerPoint Slides for: Comparison of Total Kidney Volume Quantification Methods in Autosomal Dominant Polycystic Disease for a Comprehensive Disease Assessment

Background: In recent times, the scientific community
has been showing increasing interest in the treatments aimed at slowing
the progression of the autosomal dominant polycystic kidney disease
(ADPKD). Therefore, in this paper, we test and evaluate the performance
of several available methods for total kidney volume (TKV) computation
in ADPKD patients - from echography to MRI - in order to optimize
patient classification. Methods: Two methods based on
geometric assumptions (mid-slice [MS], ellipsoid [EL]) and a third one
on true contour detection were tested on 40 ADPKD patients at different
disease stage using MRI. The EL method was also tested using ultrasound
images in a subset of 14 patients. Their performance was compared
against TKVs derived from reference manual segmentation of MR images.
Patient clinical classification was also performed based on computed
volumes. Results: Kidney volumes derived from echography
significantly underestimated reference volumes. Geometric-based methods
applied to MR images had similar acceptable results. The highly
automated method showed better performance. Volume assessment was
accurate and reproducible. Importantly, classification resulted in 79,
13, 10, and 2.5% of misclassification using kidney volumes obtained from
echo and MRI applying the EL, the MS and the highly automated method
respectively. Conclusion: Considering the fact that the
image-based technique is the only approach providing a 3D
patient-specific kidney model and allowing further analysis including
cyst volume computation and monitoring disease progression, we suggest
that geometric assumption (e.g., EL method) should be avoided. The
contour-detection approach should be used for a reproducible and precise
morphologic classification of the renal volume of ADPKD patients.