Preoperative contrast-enhanced CT imaging and clinicopathological characteristics analysis of mismatch repair-deficient colorectal cancer

Fig. 1. Flow chart of the patient enrolment

Fig. 2. a, b The tumour is denoted by green. Green represents the homogeneous portion. The inhomogeneous part of the tumour is denoted by yellow. a Homogeneous. b Inhomogeneous; c, d, e The tumour is denoted by green. Hypoattenuation-within-tumour is denoted by yellow. 2 Hypoattenuation-within-tumour ratio < 1/3; d Hypoattenuation-within-tumour ratio 1/3–2/3; e Hypoattenuation-within-tumour ratio > 2/3

Fig. 3. a Preoperative model: Nomogram, calibration plot and DCA. b Postoperative model: Nomogram, calibration plot and DCA. Note: LN = Lymph node; HR = Hypoattenuation-within-tumour ratio

Fig. 4. One pMMR CRC case (a-f). Male patient, 65 years old. The CEA status was negative. Postoperative pathologic results showed moderately differentiated adenocarcinoma in the left-hemi colon at stage pT4N1M0, with two lymph nodes metastasis. a In unenhanced CT images, the tumour appeared as an isoattenuation thickened bowel wall (green arrow). b In the venous phase, the tumour as a whole appeared as homogeneous hyperenhancement without hypoattenuation-within-tumour (green arrow). c In venous phase MPR images, there was an enhanced lymph node in the local region, with short diameter of 7 mm and long diameter of 8 mm. Only one lymph node had long diameter ≥ 8 mm. d After HE staining, the tumour specimen was assessed as moderately differentiated adenocarcinoma. e, f The pictures show the prediction results of the preoperative model and postoperative model. One dMMR CRC case (g-l). Male patient, 49 years old. The CEA status was negative. Postoperative pathologic results showed mucinous adenocarcinoma in the right-hemi colon at stage pT4N0M1, with peritoneal metastasis and no lymph node metastasis. g In unenhanced CT images, the majority of the tumour appeared as hypoattenuation with 25HU…

Fig. 5. Feature correlation coefficient plot. Note: Categorical variables were treated as dummy variables. Cross marks indicate no statistical significance between the two variables (p > .05); LN = Lymph node; 5 mm = Number of lymph nodes with long diameter ≥ 5 mm; 8 mm = Number of lymph nodes with long diameter ≥ 8 mm; 10 mm = Number of lymph nodes with long diameter ≥ 10 mm. Enhancement degree: Hyperenhancement or isoenhancement = 1; Hypoenhancement = 0. Hypoattenuation-within-tumour ratio: < 1/3 = 1; 1/3–2/3 = 2; > 2/3 = 3. Enhancement pattern: Inhomogenous = 1; Homogenous = 0. CEA status: Positive = 1; Negative = 0. Tumour deposit: Positive = 1; Negative = 0. Peritoneal metastasis: Positive = 1; Negative = 0. Lympho-vascular invasion: Positive = 1; Negative = 0. Perineural invasion: Positive = 1; Negative = 0. Mucinous component: Yes = 1; No = 0. Stage: I = 1; II = 2; III = 3; IV = 4. M stage: M1 = 1; M0 = 0. N stage: N1 + N2 = 1; N0 = 0. T stage: T1 = 1; T2 = 2; T3 = 3; T4 = 4. Sex: Male = 1; Female = 2. Tumour location: Right-hemi colon = 1; Left-hemi colon = 2