The Placental Distal Villous Hypoplasia Pattern: Interobserver Agreement and Automated Fractal Dimension as an Objective Metric

TY - JOUR

T1 - The Placental Distal Villous Hypoplasia Pattern

T2 - Interobserver Agreement and Automated Fractal Dimension as an Objective Metric

AU - Mukherjee, Anika

AU - Chan, Adrian D.C.

AU - Keating, Sarah

AU - Redline, Raymond W.

AU - Fritsch, Michael K.

AU - Machin, Geoffrey A.

AU - Cornejo-Palma, Daniel

AU - Nanassy, Joseph de

AU - El-Demellawy, Dina

AU - Dadelszen, Peter von

AU - Benton, Samantha J.

AU - Grynspan, David

N1 - doi: 10.2350/15-03-1619-OA.1

PY - 2016/1/1

Y1 - 2016/1/1

N2 - The distal villous hypoplasia (DVH) pattern is a placental correlate of fetal growth restriction. Because the pattern seems to involve less complexity than do appropriately developed placental villi, we postulated that it may be associated with lower fractal dimension?a mathematical measure of complexity. Our study objectives were to evaluate interobserver agreement related to the DVH pattern among expert pathologists and to determine whether pathologist classification of DVH correlates with fractal dimension. A study set of 30 images of placental parenchyma at ?4 magnification was created by a single pathologist from a digital slide archive. The images were graded for the DVH pattern according to pre-specified definitions and included 10 images graded as ?no DVH? (grade = 0), 10 with mild to moderate DVH (grade = 1), and 10 with severe DVH (grade = 2). The images were randomly sorted and shown to a panel of 4 international experts who similarly graded the images for DVH. Weighted kappas were calculated. For each image, fractal dimension was calculated by the Box Counting method. The correlation coefficient between (1) the averaged DVH scores obtained by the 5 pathologists and (2) fractal dimension was calculated. The mean weighted kappa score among the observers was 0.59 (range: 0.42?0.70). The correlation coefficient between fractal dimension and the averaged DVH score was ?0.915 (P <0.001). Expert pathologists achieve fair to substantial agreement in grading DVH, indicating consensus on the definition of DVH. Distal villous hypoplasia correlates extremely well with fractal dimension and represents an objective measure for DVH.

AB - The distal villous hypoplasia (DVH) pattern is a placental correlate of fetal growth restriction. Because the pattern seems to involve less complexity than do appropriately developed placental villi, we postulated that it may be associated with lower fractal dimension?a mathematical measure of complexity. Our study objectives were to evaluate interobserver agreement related to the DVH pattern among expert pathologists and to determine whether pathologist classification of DVH correlates with fractal dimension. A study set of 30 images of placental parenchyma at ?4 magnification was created by a single pathologist from a digital slide archive. The images were graded for the DVH pattern according to pre-specified definitions and included 10 images graded as ?no DVH? (grade = 0), 10 with mild to moderate DVH (grade = 1), and 10 with severe DVH (grade = 2). The images were randomly sorted and shown to a panel of 4 international experts who similarly graded the images for DVH. Weighted kappas were calculated. For each image, fractal dimension was calculated by the Box Counting method. The correlation coefficient between (1) the averaged DVH scores obtained by the 5 pathologists and (2) fractal dimension was calculated. The mean weighted kappa score among the observers was 0.59 (range: 0.42?0.70). The correlation coefficient between fractal dimension and the averaged DVH score was ?0.915 (P <0.001). Expert pathologists achieve fair to substantial agreement in grading DVH, indicating consensus on the definition of DVH. Distal villous hypoplasia correlates extremely well with fractal dimension and represents an objective measure for DVH.

U2 - 10.2350/15-03-1619-OA.1

DO - 10.2350/15-03-1619-OA.1

M3 - Article

SN - 1093-5266

VL - 19

SP - 31

EP - 36

JO - PEDIATRIC AND DEVELOPMENTAL PATHOLOGY

JF - PEDIATRIC AND DEVELOPMENTAL PATHOLOGY

IS - 1

ER -