Whole-slide image analysis outperforms micrograph acquisition for adipocyte size quantification

Figures & data

Figure 1. Screenshots of adipocyte tissue images pre- and post-analysis

Each method successfully segmented adipocytes and calculated their areas, which are shown in yellow outlines (micrograph), blue outlines (QuPath), or as solid orange (Visiopharm). Magnification: Micrograph 4x, QuPath 5x, Visiopharm 5x. Insets: whole-slide subgross images when applicable.

Table 1. Number and average area of individual adipocytes by method

	Cells counted (n)		Average area (µm^2)
	Chow	High Fat Diet	Chow	High Fat Diet
Micrograph (manual)	208 ± 56	168 ± 35	N/A	N/A
Micrograph (Image J)	259 ± 129	155 ± 51	1280 ± 551	4987 ± 1450^a
QuPath	2502 ± 1272	4511 ± 2863	2223 ± 640^b	3320 ± 309^a
Visiopharm	4633 ± 2047 ^c	6370 ± 3496	2367 ± 462^b,c	3234 ± 373^a,b,c

^ap-value <0.0001 compared to Chow average area of same method.

^bp-value <0.05 compared to Micrograph analysis of same diet.

^cp-value <0.05 compared to QuPath analysis of same diet.

Values are mean ± SD

Figure 2. Population-level representations of adipocyte size

Histograms with absolute numbers of adipocytes of a given size were sorted by area with bin size of 500 µm² (a, c). Relative frequency plots: the number of counted cells of a given size per bin (size = 500 µm²) was normalized to the total number of cells counted per slide to generate a percentage (b, d). Slides from Chow-fed mice (n = 7) are shown in A and B, while slides from HFD-fed mice (n = 8) are shown in C and D.

Figure 3. Pairwise representations between image analysis methods

Bland-Altman plots of micrograph and QuPath (a), micrograph and Visiopharm (c) and QuPath and Visiopharm (e) emphasize the greater difference in method results between micrograph and whole-slide image analysis. Regression plots indicate a weak correlation between QuPath and micrograph methods (b), a weak but greater correlation between Visiopharm and micrograph methods (d) and a strong correlation between Visiopharm and QuPath, the two whole-slide image analysis methods (f).