Initial experience of correlating diffusion spectral parameters with histopathologic indexes in murine colorectal tumor homografts

Figures & data

Figure 1 From left to right are HCT-116 cells in the logarithmic growth phase at 800× magnification, stable HCT-116 cell lines expressing GFP at 800× magnification, and the BALB/c nu/nu mouse implanted with HCT-116 cells expressing GFP by subcutaneous injection into the iliac region.

Abbreviation: GFP, green fluorescent protein.

Figure 2 From left to right are the coronal, axial T2WI, and DWI images using 10 b values of 0, 10, 20, 50, 100, 200, 400, 600, 800, 1,000, 1,200, and 1,500 s/mm².

Abbreviations: DWI, diffusion-weighted image; T2WI, T2 weighted image.

Figure 3 ROI was drawn on the b0 image with a homogenous area of tumor, consistent with minimal contamination from unintended tissues; moreover, signal intensities were measured for each b value with a copy–paste operation.

Note: Pink circle represents homogenous area of tumor.
Abbreviation: ROI, region of interest.

Figure 4 Time-dependent dynamic changes of DWI parameters and photon numbers between radiotherapy and control groups. (A) D_max, (B) FWHM, (C) ADC, and (D) photon numbers.

Abbreviations: DWI, diffusion-weighted image; FWHM, full width half maximum; ADC, apparent diffusion coefficient.

Table 1 Comparisons of percentage changes of DWI and optical parameters between radiotherapy and control groups

		24 h	P-value	48 h	P-value	72 h	P-value	7 d	P-value	14 d	P-value	28 d	P-value
D_max	Radiotherapy	33.4±49.23	0.004	61.98±82.98	0.002	48±71.06	0.065	116.58±71.06	0.015	90.48±44	0.31	16.19±14.41	0.065
	Control	−10.56±14.41		−1.19±18.85		21.49±21.08		41.24±21.51		60.38±48.5		42.35±21.14
FWHM	Radiotherapy	33.69±45.28	0.032	52.31±51.17	0.017	71.83±45.72	0.18	36.77±42.69	0.041	101.35±59.4	0.132	53.23±41.87	0.485
	Control	−2.93±17.76		−1.06±14.3		33.69±43.61		101.35±51.4		58.4±32.21		92.32±91
ADC	Radiotherapy	35.1±61	0.004	97.31±182.19	0.009	79.82±39.68	0.009	124.89±22.03	0.002	101.58±41.95	0.041	27.46±21.08	0.31
	Control	−16.02±18.5		−13.85±11.9		14.48±30.87		39.92±46.62		45.13±35.66		19.81±9.68
Photon Number	Radiotherapy	−18.46±34.26	0.199	−12±37.52	0.177	−13.99±46.28	0.24	−13.77±56.21	0.41	−54.63±18.91	0.18	−76.3±8.13	0.041
	Control	8.37±14.68		18.75±28.11		21.57±14.7		29.56±56.13		−25.27±38.23		−62.11±13.42

Abbreviation: DWI, diffusion-weighted image.

Figure 5 The change of pathological indices between radiotherapy and control groups at different time points. (A) Ki67, (B) cyclin D1, and (C) survivin.

Abbreviation: IOD, integrated optical density.

Figure 6 Histopathologic comparisons between radiotherapy and control groups using slides at 400× magnification. Scale bar: 50 μm. (A) 24 h cyclin D1 expression in the control group; (B) 24 h cyclin D1 expression in the radiotherapy group; (C) 24 h survivin expression in the control group; (D) 24 h suivivin expression in the radiotherapy group; (E) 24 h Ki67 expression in the control group; and (F) 24 h Ki67 expression in the radiotherapy group.

Figure 7 Correlations between pathological indexes (Ki67, survivin and cyclin D1) and percentage changes of DWI parameters (D_max, FWHM, and ADC values).

Abbreviations: DWI, diffusion-weighted image; FWHM, full width half maximum; ADC, apparent diffusion coefficient; IOD, integrated optical density.