Application of dual-layer spectral detector computed tomography to evaluate the expression of Ki-67 in colorectal cancer

Abstract

Background: Compared with traditional computed tomography (CT), dual-layer spectral detector CT (SDCT) shows significant improvement in imaging soft tissues of the digestive tract. This work aimed to explore the application of SDCT to evaluate the expression of the molecular marker Ki-67 in colorectal cancer. Methods: We retrospectively analyzed the imaging data of the SDCT (IQon Spectral CT; Philips Healthcare) of 45 patients with colorectal cancer in our centre. We used Spearman’s test for the imaging parameters (reconstruction of 40, 70, and 100 keV virtual monoenergetic images [VMIs] and the slope of the Hounsfield unit attenuation plot [VMI Slope] based on venous phase CT images, the arterial phase iodine concentration [AP-IC] and venous phase iodine concentration [VP-IC], and the effective atomic number [Z effect]) and correlation analysis for the Ki-67 index. Multivariate logistic regression was used to eliminate confounding factors. We evaluated the expression level of Ki-67 and drew the receiver operating characteristic curve. Results: The 40-keV VMI, VMI Slope, and AP-IC were found to better reflect the Ki-67 index in patients with colorectal cancer with statistical significance. The 40-keV VMI (r = −0.612, p < 0.001) and VMI Slope (r = −0.523, p < 0.001) were negatively correlated with the Ki-67 index, and AP-IC (r = 0.378, p = 0.010) was positively correlated with the Ki-67 index. The other indexes (p > 0.05) were not statistically significant. The SDCT parameters demonstrated good performance, with area under curves of 0.785 for 40-keV VMI and 0.752 for AP-IC. Conclusion: The SDCT parameters 40-keV VMI and AP-IC can be used for preliminary evaluation of the Ki-67 index in colorectal cancer.

Dual-energy spectral detector computed tomography differential diagnosis of adrenal adenoma and pheochromocytoma: Changes in the energy level curve, a phenomenon caused by lipid components?

“…Obviously, the low-level VMI of SDCT has a more refined effect on the scanned object than the high-level VMI, which is similar to an amplification effect (16). At the same time, the slope of the Hounsfield unit attenuation plot (VMI-Slope) plotted in combination with high and low energy levels is even an extreme case where the curve is inverted (Figure 2).…”

“…In particular, the key component that distinguishes adrenal adenomas from pheochromocytoma is lipid-containing components because pheochromocytoma often has necrosis and haemorrhage and rarely contains lipidcontaining components (14,15). At present, SDCT is widely used in the assessment of digestive, urinary and cardiovascular diseases (16)(17)(18). Compared with conventional CT to delineate the area of interest (ROI) and measure the Hounsfield unit (HU) value, SDCT can evaluate whether there is lipid in the lesion through virtual monoenergetic images (VMIs) and plotting Hounsfield unit attenuation plots (19).…”

Quantitative parameters of dual-layer spectral detector computed tomography for evaluating Ki-67 and human epidermal growth factor receptor 2 expression in colorectal adenocarcinoma

“…Nuclear-associated antigen Ki-67, a nuclear proliferation antigen, exists in all cycles of cell mitosis except G0 phase. Ki-67 can be used to evaluate the activity of cell proliferation and is an indicator of tumor malignancy ( 3 ). The high expression of Ki-67 is significantly associated with poor overall survival and poor prognosis in patients with CRAC ( 4 ).…”

The Evaluation of Quantitative Parameters of Dual-layer spectral detector CT for Discrimination of Differentiation grade, T Stage, and Lymph Node Metastasis stage of Colorectal Adenocarcinoma

“…The prognosis of CRC patients varies greatly between patients with a 5-year survival rate of 90-10%, depending mainly on other factors such as differentiation grade, T-stage, and lymph node metastasis stage [3]. The development of individualized treatment options for patients with CRC relies heavily on preoperative imaging to assess the degree of tumor malignancy [4]. Dual-layer spectral detector CT (SDCT) extends the single parameter scanning mode of traditional CT and is a new energy spectrum imaging method.…”

“…Currently, there are few studies on SDCT for CRC, mainly including evaluating the expression of Ki-67 [4]; the application of nomograms in preoperative histological classi cation of CRAC [7]; enhancing the visualization of colorectal lesions [8]; distinguish between intraluminal and extraluminal iodine or calcium [9]; improve CT virtual colonography via electronic cleansing [10].…”