Baseline parameters of spectral CT could predict tumor response to transcatheter arterial chemoembolization in hepatocellular carcinoma patients

Identifying metastatic lymph nodes (LNs) in patients with cervical cancer treated with definitive radiotherapy may inform treatment strategy and determine prognosis, but available methods have limitations, especially in developing regions. Herein, we aimed to evaluate the performance of quantitative parameters in spectral computed tomography (CT) scanning in this context, focusing on its complementary role alongside conventional diagnostic approaches like 18-fluorine-fuorodeoxyglucose positron emission tomography computed tomography (18F FDG-PET/CT). Patients with cervical cancer, who underwent pretreatment spectral CT simulation scanning and planned radiotherapy, were enrolled in this prospective study. The LNs were categorized as "metastatic" and "non-metastatic", based on a procedure that included 18F FDG-PET/CT as well as CT, magnetic resonance imaging, Node Reporting and Data System and follow-up results. Iodine concentrations (IC), normalized IC (NIC), effective atom number (effZ), and spectral curve slope (λHU) in the arterial (AP) and venous (VP) phases, were compared between metastatic and non-metastatic LNs. IC were derived from iodine-based material decomposition through manual delineation and normalized to the iodine concentration in the adjacent artery (NIC). effZ and λHU were calculated based on the effective atom number image and virtual monochromatic images. Univariate and multivariate logistic regression analyses were used to determine spectral CT factors independently associated with LNs metastasis, and their diagnostic efficacies were assessed using the area under the curve (AUC) analysis. The diagnostic efficiency of 18F FDG-PET/CT and spectral CT was compared. A total of 115 metastatic and 97 non-metastatic LNs were detected, and spectral CT parameters (IC, NIC, effZ, λHU) significantly differed between the two groups. In univariate and multivariable logistic regression analysis, λHU in the AP and NIC in the VP were independent predictors for metastatic LNs and their combination improved AUC to 0.923, with a sensitivity of 84.4%, and a specificity of 85.6%. Spectral CT could achieve similar sensitivity as 18FFDG-PET/CT in total LNs, and, more importantly, a higher sensitivity (95.5% vs. 59.1%) and diagnostic accuracy (92.9% vs. 67.9%) for para-aortic LNs. Quantitative spectral CT parameters can help distinguish metastatic from non-metastatic LNs in patients with cervical cancer treated with definitive radiotherapy. Combination of λHU in AP and NIC in VP further improves diagnostic performance. Spectral CT, while promising, complements rather than replaces PET/CT, especially for diagnosing para-aortic LNs, where PET/CT may have limitations. It could be a valuable adjunct to conventional imaging, particularly in settings with limited access to advanced tools.

Lung cancer is the leading cause of cancer-related mortality globally. The novel classification system for invasive lung adenocarcinoma (LUAD), which integrates predominant histologic and high-grade patterns, has been shown to correlate with prognosis. This study aimed to evaluate and compare the discriminative ability of spectral computed tomography (CT), 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT), and their combined model for identifying high-grade invasive non-mucinous adenocarcinoma (INMA) based on the 2021 World Health Organization (WHO)/International Association for the Study of Lung Cancer (IASLC) classification. A total of 135 patients with 144 lung nodules who underwent preoperative spectral CT were evaluated retrospectively. Of these, 55 patients with 60 lung nodules underwent additional PET/CT imaging. CT morphological features, spectral CT and PET/CT parameters of the tumors were compared between the high-grade group (grade 3) and the low-grade group (grade 1 and 2). Univariate and multivariate analyses were performed using binary logistic regression with spectral CT and PET/CT parameters. The diagnostic efficiencies of spectral CT parameters, PET metabolism parameters, and a combination of CT features were computed by receiver operating characteristic (ROC) curve analysis. The discriminative power and calibration of the nomogram were evaluated. There were significant differences in morphological CT (nodule attenuation), spectral CT parameters [iodine concentration of the lesion in arterial phase (ICLa), normalized iodine concentration in arterial phase (NICa), slope of spectral Hounsfield unit curve in arterial phase (λHUa), iodine concentration of the lesion in venous phase (ICLv), normalized iodine concentration in venous phase (NICv), slope of spectral Hounsfield unit curve in venous phase (λHUv)] and PET/CT parameters [maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), total lesion glycolysis (TLG)] between the grade 3 group and non-grade 3 group (P<0.05). According to the ROC analysis, the area under the curve (AUC) of the spectral CT, PET/CT, and comprehensive model was 0.930, 0.864, and 0.949, respectively. The performance of the comprehensive model was not superior to that of the spectral model [DeLong test, Z=0.819, P=0.413; integrated discrimination improvement (IDI) =0.042, 95% confidence interval (CI): -0.015 to 0.099, P=0.149]. Furthermore, our spectral CT and comprehensive model significantly outperformed the PET/CT model in predictive ability (IDI =0.148, 95% CI: 0.016-0.280, P<0.05; IDI =0.190, 95% CI: 0.085-0.295, P<0.001, respectively). The multivariate regression spectral CT model based on 144 lesions in 135 patients showed that ICLa [odds ratio (OR) =0.005, 95% CI: 0.001-0.027, P<0.001] and solid nodule (OR =26.757, 95% CI: 6.843-104.623, P<0.001] were independent predictors for grade 3 LUAD. The nomogram had good calibration power. The spectral CT model, including nodule attenuation type and ICLa, showed diagnostic performance comparable to that of the comprehensive model and superior to PET/CT, showing strong potential for histopathological high-grade INMA diagnosis.

BACKGROUNDRegional lymph node metastasis in patients with hepatocellular carcinoma (HCC) is not uncommon, and is often under- or misdiagnosed. Regional lymph node metastasis is associated with a negative prognosis in patients with HCC, and surgical resection of lymph node metastasis is considered feasible and efficacious in improving the survival and prognosis. It is critical to characterize lymph node preoperatively. There is currently no consensus regarding the optimal method for the assessment of regional lymph nodes in patients with HCC.AIMTo evaluate the diagnostic value of single source dual energy computed tomography (CT) in regional lymph node assessment for HCC patients.METHODSForty-three patients with pathologically confirmed HCC who underwent partial hepatectomy with lymphadenectomy were retrospectively enrolled. All patients underwent dual-energy CT preoperatively. Regional lymph nodes (n = 156) were divided into either a metastatic (group P, n = 52) or a non-metastasis group (group N, n = 104), and further, according to pathology, divided into an active hepatitis (group P1, n = 34; group N1, n = 73) and a non-active hepatitis group (group P2, n = 18; group N2, n = 31). The maximal short axis diameter (MSAD), iodine concentration (IC), normalized IC (NIC), and the slope of the spectral curve (λHU) of each group in the arterial phase (AP), portal phase (PP), and delayed phase (DP) were analyzed.RESULTSAnalysis of the MSAD, IC, NIC, and λHU showed statistical differences between groups P and N (P < 0.05) during all three phases. To distinguish benign from metastatic lymph nodes, the diagnostic efficacy of IC, NIC, and λHU in the PP was the best among the three phases (AP, PP, and DP), with a sensitivity up to 81.9%, 83.9%, and 81.8%, and a specificity up to 82.4%, 84.1% and 84.1%, respectively. The diagnostic value of combined analyses of MSAD with IC, NIC, or λHU in the PP was superior to the dual energy CT parameters alone, with a sensitivity up to 84.5%, 86.9%, and 86.2%, and a specificity up to 83.0%, 93.6% and 89.8%, respectively. Between groups P1 and P2 and groups N1 and N2, only IC, NIC, and λHU between groups N1 and N2 in the PP had a statistically significant difference (P < 0.05).CONCLUSIONDual-energy CT contributes beneficially to regional lymph node assessment in HCC patients. Combination of MSAD with IC, NIC, or λHU values in the PP is superior to using any single parameter alone. Active hepatitis does not deteriorate the capabilities for characterization of metastatic lymph nodes.

For investigating the correlation with spectral CT imaging parameters and occult lymph nodes metastasis in sufferers with isolated lung adenocarcinoma. The clinic cases data of 352 sufferers with isolated lung adenocarcinoma from January 2019 to January 2022 were assembled. In line with whether the sufferers had occult lymph nodes metastasis, they were taken as a part in the metastasis group (n = 172) and the nonmetastasis group. All sufferers were scanned by spectral CT with a dual-phase contrast-enhanced method, and the recording of spectral CT imaging parameters in arteriovenous phase, iodine concentration (IC), water concentration (WC), the slope rate of the spectral HU curve (λHU), the normalized iodine concentration(NIC), the normalized water concentration(NWC), the normalized effective atomic number (Neff-Z)], and receiver operating characteristic (ROC) were employed to analyze the spectral CT imaging parameters of the arteriovenous phase. Evaluation of occult lymph nodes metastases in sufferers with isolated lung adenocarcinoma. The IC, NIC, λHU, and Neff-Z in the arteriovenous phase spectral CT imaging parameters of the metastasis group were obviously smaller than that of the nonmetastasis group, and the discrepancies were statistically obvious (P < 0.05). The results of ROC curve analysis manifested that the area under the curve (AUC) of λHU, IC, NIC, and Neff-Z in the CT parameters of the arterial phase were 0. 840 (95%CI : 0. 796–0.883), 0.763 (95% CI : 0.708–0.818), 0.918 (95% CI : 0.888–0.948), 0.778 (95% CI : 0.731–0.826). The AUCs of λHU, IC, NIC, and Neff-Z in the venous phase spectral CT parameters were 0.909 (95% CI : 0.877–0.941), 0.837 (95% CI : 0.792–0.881), and 0.980 (95% CI : 0.968–0.968), respectively. 0.993), 0.792 (95% CI : 0.742∼0.842). Spectral CT imaging parameters have a certain value in evaluating occult lymph nodes metastasis in sufferers with isolated lung adenocarcinoma, which is helpful for doctors to judge the lymph nodes metastasis in sufferers with this disease before surgery.

Differentiating hepatocellular carcinoma from angiomyolipoma of the liver with CT spectral imaging: A preliminary study

To investigate the usefulness of computed tomographic (CT) spectral imaging parameters in differentiating small (≤3 cm) hepatic hemangioma (HH) from small hepatocellular carcinoma (HCC), with or without cirrhosis, during the late arterial phase (AP) and portal venous phase (PVP). This prospective study was institutional review board approved, and written informed consent was obtained from all patients. The authors examined 49 patients (39 men, 10 women; 65 lesions) with CT spectral imaging during the AP and the PVP. Twenty-one patients had HH; nine, HCC with cirrhosis; and 19, HCC without cirrhosis. Iodine concentrations were derived from iodine-based material-decomposition CT images and normalized to the iodine concentration in the aorta. The difference in iodine concentration between the AP and PVP (ie, iodine concentration difference [ICD]) and the lesion-to-normal parenchyma ratio (LNR) were calculated. Two readers qualitatively assessed lesion types on the basis of conventional CT characteristics. Sensitivity and specificity were compared between the qualitative and quantitative studies. The two-sample t test was performed to compare quantitative parameters between HH and HCC. Normalized iodine concentrations (NICs) and LNRs in patients with HH differed significantly from those in patients with HCC and cirrhosis and those in patients with HCC without cirrhosis: Mean NICs were 0.47 mg/mL ± 0.24 (standard deviation) versus 0.23 mg/mL ± 0.10 and 0.23 mg/mL ± 0.08, respectively, during the AP and 0.83 mg/mL ± 0.38 versus 0.47 mg/mL ± 0.86 and 0.52 mg/mL ± 0.11, respectively, during the PVP. Mean LNRs were 5.87 ± 3.36 versus 2.56 ± 1.10 and 2.29 ± 0.87, respectively, during the AP and 2.01 ± 1.33 versus 0.96 ± 0.16 and 0.93 ± 0.26, respectively, during the PVP. The mean ICD for the HH group (1.37 mg/mL ± 0.84) was significantly higher than the mean ICDs for the HCC-cirrhosis (0.33 mg/mL ± 0.29) (P < .001) and HCC-no cirrhosis (0.82 mg/mL ± 0.99) (P = .03) groups. The combination of NIC and LNR had higher sensitivity and specificity compared with those of conventional qualitative CT image analysis during individual and combined phases. Use of spectral CT with fast tube voltage switching may increase the sensitivity for differentiating small hemangiomas from small HCCs in two-phase scanning.

BackgroundTumor budding (TB) is an autonomous risk factor indicative of the invasiveness and prognosis of colorectal cancer (CRC). Dual-layer spectral detector computed tomography (SDCT) is a novel energy-resolved imaging technology that enables multiparametric tissue characterization through quantitative spectral analysis. Nevertheless, the efficacy of quantitative measures derived from SDCT in differentiating the TB grade of CRC remains ambiguous. This research aims to evaluate the efficacy of SDCT in preoperatively predicting TB grade in CRC.MethodsThis retrospective study enrolled 74 consecutive CRC patients who underwent surgical resection with confirmed TB grade at the First Hospital of Lanzhou University between July 2023 and July 2024. All patients received whole-abdomen spectral computed tomography (CT) scans within one week preoperatively. Based on postoperative pathology, patients were stratified into low-grade TB (Group A, Bd1) and high-grade TB (Group B, Bd2 + Bd3) groups. Using the IntelliSpace Portal workstation, radiologists manually delineated regions of interest (ROIs) on axial images to measure spectral CT quantitative parameters in both arterial and venous phases, encompassing CT values at 40 and 120 keV (CT40keV, CT120keV), iodine concentration (IC), effective atomic number (Zeff), the slope of the spectral Hounsfield unit (HU) curve (λHU), and to calculate normalized iodine concentration (NIC), normalized effective atomic number (NZeff), and arterial enhancement fraction (AEF). Statistically significant variables from univariate analysis were incorporated into multivariate logistic regression to construct a combined predictive model. Diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis.ResultsThe research included a total of 74 individuals with CRC (mean age: 61.16±13.08 years; male: 36, female: 38). Compared with the low-grade TB group, the high-grade TB group showed significantly higher proportions of both high-grade tumors (P=0.001) and elevated Ki-67 expression (P=0.009), along with a significantly increased likelihood of lymphovascular invasion (P=0.005). The CT40keV, CT120keV, IC, NIC, Zeff, NZeff, and λHU in the arterial phase and AEF of the low-grade TB group were elevated compared to the high-grade TB group (all P<0.05), but no significant differences in the spectral parameters were seen in the venous phase between the two groups (all P>0.05). Among the individual characteristics, NIC showed the highest area under the curve (AUC) value (0.723) in discriminating between low-grade and medium-high grade TB. The AUC of the combined model with each parameter in the arterial phase and AEF was 0.814, surpassing that of single spectral parameters, with a sensitivity of 84.62% and a specificity of 72.73%.ConclusionsQuantitative parameters of spectral CT may be associated with TB grade in CRC, and their potential value in preoperatively predicting different TB grades could be of great significance for guiding clinical treatment selection and prognostic evaluation.

Differentiation of liver abscess from liver metastasis using dual-energy spectral CT quantitative parameters

Objective: To investigate the value of spectral CT-based quantitative analysis in the differential diagnosis of liver cancer and liver abscess. Methods: A total of 70 patients with space-occupying lesions in the liver(45 with liver cancer and 25 with liver abscess)underwent spectral CT scans to obtain spectral images in the arterial phase and portal venous phase. The solid constituents of lesions and the iodine and water concentrations in necrotic or cystic parts of lesions, normal hepatic tissue, and abdominal aorta in the arterial phase and portal venous phase were measured, and the normalized iodine concentration(NIC)and lesion-to-normal hepatic tissue ratio(LNR)of iodine concentration were calculated. The two samples t-test and the receiver operating characteristic(ROC)curve analysis were performed for the quantitative indices above. Results: The patients with liver cancer had higher NIC and LNR in solid constituents in the arterial phase than those with liver abscess(NIC: 0.15±0.06 mg/ml vs 0.14±0.02 mg/ml, P > 0.05; LNR: 2.78±0.65 vs 1.45±0.88, P < 0.001). The patients with liver abscess had significantly higher NIC and LNR in solid constituents in the portal venous phase than those with liver cancer(NIC: 0.65±0.08 mg/ml vs 0.52±0.08 mg/ml, P≤0.001; LNR: 1.22±0.23 vs 0.95±0.15, P≤0.001). There were no significant differences in NIC in the arterial phase or NIC and LNR in the portal venous phase in necrotic or cystic parts of lesions between the patients with liver cancer and liver abscess(P > 0.05). The optimal quantitative value for the differential diagnosis of liver cancer and liver abscess was LNR in arterial phase, and the cut-off value of 1.53 had a sensitivity of 100% and a specificity of 92%. Conclusion: Quantitative iodine concentration analysis in spectral CT imaging has a certain value in the differential diagnosis of liver cancer and liver abscess and can improve the accuracy of diagnosis.

Ki-67 is a pivotal biomarker for evaluating the prognosis of hepatocellular carcinoma (HCC). This study aimed to investigate the utility of qualitative and quantitative parameters derived from spectral computed tomography (CT) in assessing Ki-67 expression in HCC. This prospective, single-center study included 89 patients (94 lesions) with pathologically confirmed HCC from February 2023 to February 2024. Participants underwent enhanced abdominal spectral CT scans within one week prior to surgery. The patients were divided into the following two groups based on the positive rate of Ki-67 (Ki-67%): a high-expression group (Ki-67 >20%, n=42); and a low-expression group (Ki-67 ≤20%, n=52). The spectral parameters assessed included CT values at 40 and 70 keV, iodine concentration (IC), the slope of the spectral Hounsfield unit (HU) curve (λHU), normalized iodine concentration (NIC) during the arterial phase (AP) and portal venous phase (PVP), and extracellular volume (ECV) fraction. Statistical significance of spectral CT parameters related to Ki-67 expression status was compared across different groups, and correlations between spectral CT parameters and Ki-67 expression levels were analyzed. Significant differences were observed between the low and high Ki-67 expression groups concerning age, alpha-fetoprotein (AFP) levels, and capsule integrity (P=0.002, P=0.013, and P=0.005, respectively). Notable differences were also found in intratumoral NIC-AP, NIC-PVP, AP slope, PVP slope, and ECV fraction (P=0.017, P=0.005, P=0.001, P<0.001, and P=0.001, respectively). Meanwhile, in the comparative analysis between the low and high expression group of Ki-67, there were no statistically significant differences in the peritumoral <1 cm NIC-AP and NIC-PVP, as well as transtumoral NIC-AP and NIC-PVP levels (P>0.05). Ki-67 expression in HCC exhibited negative correlations with intratumoral NIC-AP (r=-0.248; P=0.016), NIC-PVP (r=-0.291; P=0.004), AP slope (r=-0.330; P=0.001), PVP slope (r=-0.367; P<0.001), and ECV fraction (r=-0.339; P=0.001). Qualitative and quantitative parameters from spectral CT provide valuable information for distinguishing between low and high Ki-67 expression in HCC.

Objective To explore the application value of spectral CT multi-parameter imaging in the differential diagnosis of hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH). Methods Forty-eight patients with hepatic lesions underwent gemstone spectral imaging (GSI) scans,including 32 HCC and 16 FNH,to obtain spectral serial images for the arterial phase and portal venous phase (PVP).The spectral parameters of lesions,normal hepatic tissue and the aorta were measured.Then,the lesion-liver contrast-to-noise ratio (CNR) in the different energy levels,normalized iodine concentration (NIC),the lesion-normal parenchyma iodine concentration ratio (LNR) and iodine concentration difference (ICD) between the arterial phase and the portal venous phase were calculated.The above measurement results were analyzed with two samples t test and ROC curve. Results The CNR of HCC and FNH in the different energy levels showed a certain regularity.In general,with the single photon energy increased,the CNR decreased except for some energy points.For HCC and FNH,the optimal CNR were 3.59±2.13 and 8.29±2.65,respectively,during the arterial phase and 1.80±0.42 and 1.06±0.34,respectively,during the portal venous phase.The NIC were 0.25±0.08 and 0.42±0.22,respectively,during the arterial phase and 0.52±0.14 and 0.86±0.18,respectively,during the portal venous phase.The LNR were 2.97±0.50 and 6.15±0.97,respectively,during the arterial phase and 0.99±0.19 and 1.22±0.26,respectively, during the portal venous phase.The ICD were (0.35±0.14) and (1.17±0.28) g/L,respectively.The NIC,LNR and ICD for HCC were less than FNH during the arterial phase and the portal venous phase.There were significant differences in NIC (t=-3.196,the arterial phase;t=-6.518,the portal venous phase),LNR (t=-12.911,the arterial phase; t=-3.260,the portal venous phase),and ICD (t=-2.754) between HCC and FNH (P<0.05).LNR in the arterial phase had the highest sensitivity and specificity of 100% and 100% in differentiating HCC from FNH. Conclusion The use of spectral CT with the quantitative analysis of iodine concentration might be helpful for increasing the efficiency of the detection and accuracy of diagnosis of HCC and FNH. Key words: Liver neoplasms; Tomography,X-ray computed; Diagnosis,differential

The Lauren classification (intestinal versus diffuse type) is pivotal for prognosing gastric cancer and guiding treatment selection. This study developed an integrated preoperative prediction model that merges preoperatively available clinicopathological characteristics with spectral CT parameters to distinguish Lauren subtypes and predict disease-free survival (DFS). This single-centre, retrospective diagnostic-accuracy study included 224 chemotherapy-treated gastric cancer patients with histopathologically confirmed intestinal or diffuse-type Lauren classification and two-year disease-free survival outcomes. Portal-venous phase spectral computed tomography (CT) parameters (CT₇₀ₖₑv, iodine concentration, and normalized iodine concentration) and clinicopathological variables (tumor differentiation and Borrmann type) were assessed. Independent predictors were identified using multivariate logistic regression, and three models were constructed: clinicopathological, spectral CT, and combined. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis, calibration curves, decision curve analysis, and 1000-bootstrap internal validation. Disease-free survival was further analysed using Kaplan-Meier curves, the log-rank test, and Cox proportional hazards regression. Multivariate analysis identified poor differentiation (OR = 9.80, P < < 0.001) and Borrmann type III/IV (OR = 2.65, P = 0.004) as clinicopathological predictors, while portal-venous phase CT at 70keV (OR = 1.34, P < < 0.001), iodine concentration (OR = 2.08, P = 0.001), and normalized iodine concentration (OR = 2.09, P < < 0.001) were significant spectral CT predictors of diffuse-type histology. The combined model demonstrated an area under the curve (AUC) of 0.901 (95% CI: 0.859-0.944) for Lauren classification, outperforming both the pathological model (AUC = 0.810) and the spectral CT model (AUC = 0.861). The optimism-corrected AUC was 0.901 (95% CI: 0.857-0.943) based on 1000-bootstrap validation. For disease-free survival (DFS) prediction, the model achieved an AUC of 0.896 (95% CI: 0.851-0.941) at a cut-off value of 0.646, with an optimism-corrected AUC of 0.895 (95% CI: 0.850-0.939). Calibration curves and decision curve analysis indicated satisfactory agreement and a superior net benefit. Kaplan-Meier analysis revealed significant separation between high-risk and low-risk groups (2-year DFS rates: 7.2% versus 84.4%; log-rank chi2 = 158.88, P < < 0.001), and Cox regression analysis confirmed a substantially increased recurrence risk in the high-risk group (HR = 10.97, 95% CI: 6.68-17.99, P < < 0.001). The integrated model provides accurate preoperative Lauren classification and robust DFS prediction, serving as a multimodal tool for gastric cancer risk stratification and treatment planning.

Whole-lesion iodine map histogram analysis versus single-slice spectral CT parameters for determining novel International Association for the Study of Lung Cancer grade of invasive non-mucinous pulmonary adenocarcinomas

Objective The objective is to assess the value of spatial distribution difference in iodine concentration between malignant and benign solitary pulmonary nodules (SPNs) by analyzing multiple parameters of spectral CT. Methods Sixty patients with 39 malignant nodules and 21 benign nodules underwent chest contrast CT scans using spectral imaging mode during pulmonary arterial phase (PP), arterial phase (AP), and venous phase (VP). Iodine concentrations of proximal and distal regions in pulmonary nodules on iodine-based material decomposition images were recorded. Normalized iodine concentration (NIC) and the differences in NIC between the proximal and the distal regions (dNIC) were calculated. The two-sample t-test and Mann–Whitney U-test were performed to compare the multiple parameters generated from spectral CT between malignant and benign nodules. Receiver operating characteristic (ROC) curves were generated to calculate sensitivity and specificity. Results NIC in the proximal region (NICpro) and NIC in the distal region (NICdis) between malignant and benign nodules at AP (NICpro, P=0.012; NICdis, P=0.024), and VP (NICpro, P=0.005; NICdis, P =0.004) were significantly different. NICpro at PP (P = 0.037) was also found significantly different between malignant and benign nodules; however, no significant differences were found in NICdis at PP (P = 0.093). In addition, the dNIC of malignant nodules was significantly higher than that of benign ones at PP (median and interquartiles (0.31, 0.11, 0.57 versus -0.26, -0.5, -0.1); p≤0.001), AP (mean dNIC, 0.093 ±0.094 versus -0.075±0.060; p≤0.001), and VP (mean dNIC, 0.171±0.137 versus -0.183±0.127; p≤0.001). The sensitivity and specificity (93%, 95%, respectively) of dNIC during VP were higher than other parameters, with a threshold value of -0.07. Conclusions Spectral CT imaging with multiple parameters such as NICpro, NICdis, and dNIC may be a new method for differentiating malignant SPNs from benign ones.

Spectral CT imaging in the differential diagnosis of necrotic hepatocellular carcinoma and hepatic abscess