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Objective To investigate the clinical value of energy spectrum CT volume quantitative parameters in differentiating pathological types of colorectal cancer. Methods The clinical and imaging data of 66 patients (16 cases of mucinous adenocarcinoma and 50 cases of tubular adenocarcinoma) with colorectal cancer confirmed by pathology in our hospital from January 2019 to November 2021 were collected and retrospectively analyzed. The volume parameters and two-dimensional parameters of the tumor, including iodine (water) concentration, water (iodine) concentration and effective atomic number, were measured by different methods of region of interest (ROI) acquisition, and normalized iodine (water) concentration (NIC) was calculated. Student's t test or Mann-Whitney U test was used for comparison between groups, and receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic efficacy of statistically significant parameters for pathological types of colorectal cancer. Results In terms of energy spectrum volume parameters, iodine (water) concentration, NIC and Eff-Z in arterial and venous phases were significantly different (P < 0.01). The iodine (water) concentration, NIC and Eff-Z of mucinous adenocarcinoma were lower than those of tubular adenocarcinoma. However, in the two-dimensional parameters, only iodine (water) concentration, NIC and Eff-Z in venous phase had significant differences among groups (P < 0.05). The volumetric iodine (water) concentration and NIC in mucinous adenocarcinoma were lower than corresponding two-dimensional parameters. ROC curve showed that the area under the curve of energy spectrum volume parameters was higher than that of two-dimensional parameters. Among them, arterial volume NIC had the highest diagnostic efficiency, with a sensitivity of 82.0% and specificity of 87.5%. Conclusion The quantitative parameters of CT volume of energy spectrum may have greater potential clinical value in differentiating mucinous colorectal adenocarcinoma from tubular adenocarcinoma than two-dimensional parameters.

Objective To evaluate the effect of single-energy computed tomography (CT) combined with multi-artifact removal (MAR) for removing metal artifacts and optimizing blood vessel display in patients with coil embolization for intracranial aneurysms. Methods Thirty-two patients with intracranial aneurysms undergoing coil embolization under digital subtraction angiography (DSA) in our hospital between January and October in 2019 were enrolled in this study. After the surgery, the patients were scanned by gemstone spectral imaging (GSI) combined with MAR technique and post-processing with spectral monoenergy imaging technique. Two senior physicians scored the cranial vascular images acquired at a 10 KeV interval within 40 KeV to 140 KeV (the images acquired at 40 KeV and ≥100 KeV were excluded for poor quality). Nine single-energy images were reconstructed at 5 KeV intervals between 50 KeV and 90 KeV, and the noise level, signal-to-noise ratio (SNR) and artifact index (AI) of the images were evaluated. Results The SNR of the images tended to decrease with the increase of the energy level and showed significant differences between the energy levels 65 KeV and 70 KeV and between 75 KeV and 80 KeV (P < 0.05), but not between the other energy levels. The images acquired at 60~65 KeV had low AI indexes and the highest objective score for image quality with optimal display the blood vessels after coil embolization. Conclusion Energy spectral CT within the range of 60~65 KeV combined with MAR can effectively remove metal artifacts in patients after coil embolization for intracranial aneurysms.