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Purpose: The aim of the study is to explore the patient's and scan's parameters that affect the iodine concentration in the abdomen using dual energy computed tomography (DECT) in an oncologic population., Method: This is a retrospective study with consecutive patients with different cancers who underwent a single-source DECT (ssDECT) examinations at our institution between years 2015 and 2017. On axial IODINE images, the radiologist manually drew a circular ROI along the inner contour of the aorta. Mean iodine concentration and ROI areas were recorded. Body mass index for every patient was recorded. Descriptive statistics were summarized for iodine concentration and patient/scan characteristics. Linear regression was used to examine associations between iodine concentration in aorta and studied characteristics. Statistical significance was set at a p value < 0.05., Results: The univariate analysis, showed a statistically significant association between iodine concentration within the aorta and the area of ROI (Estimated Coefficient β: -0.013), the rate of injection (Estimated Coefficient β: 2.09), the acquisition time (Estimated Coefficient β: -0.195). In multivariable analysis iodine concentration in the aorta increased with higher rate of injection (4 ml/sec), smaller ROI area and lower BMI., Conclusion: Our results showed how iodine concentration is highly dependent on some intrinsic and extrinsic parameters of the examination. These parameters should be taken into account since lower concentration of iodine decrease contrast-to-noise ratio, and in longitudinal follow up studies, they would affect iodine quantitive assessments in cancer patients with frequent chemotherapy-induced variations in BMI and cardiac function., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: The aim of this study was to assess the potential of rest-stress DECT iodine quantification to discriminate between normal, ischemic, and infarcted myocardium., Methods: Patients who underwent rest-stress DECT on a 2nd generation dual-source system and cardiac magnetic resonance (CMR) were retrospectively included from a prospective study cohort. CMR was performed to identify ischemic and infarcted myocardium and categorize patients into ischemic, infarcted, and control groups. Controls were analyzed on a per-slice and per-segment basis. Regions of interest (ROIs) were placed in ischemic and infarcted areas based on CMR. Additionally, ROIs were placed in the septal area to assess normal and remote myocardium., Results: We included 42 patients: 10 ischemic, 17 infarcted, and 15 controls. Iodine concentrations showed no significant between segments in controls. Iodine concentrations for normal myocardium increased significantly from rest to stress (median 3.7 mg/mL (interquartile range 3.5-3.9) vs. 4.5 mg/mL (4.3-4.9)) (p < 0.001). Iodine concentrations in diseased myocardium were significantly lower than in normal myocardium; 1.3 mg/mL (0.9-1.8) and 0.6 mg/mL (0.4-0.8) at rest and stress in ischemic myocardium, and 0.3 mg/mL (0.3-0.5) and 0.5 mg/mL (0.5-0.7) at rest and stress in infarcted myocardium (p < 0.005 and p < 0.001). At rest only, iodine concentrations were significantly lower in infarcted vs. ischemic myocardium (p < 0.001). The optimal threshold for differentiating diseased from normal myocardium was 2.5 mg/mL and 2.1 mg/mL for rest and stress (AUC 1.00). To discriminate ischemic from infarcted myocardium, the optimal threshold was 1.0 mg/ml (AUC 0.944) at rest., Conclusion: DECT iodine concentration from rest-stress imaging can potentially differentiate between normal, ischemic, and infarcted myocardium., (Published by Elsevier B.V.)

Objectives: To evaluate whether iodine quantification with Dual-Energy Computed Tomography (DECT) improves the differentiation of accessory spleens (AS) from lymph nodes (LN) compared to CT number measurements., Methods: Abdominal DECT images of 75 patients with either AS (n=35) or LN (n=48) (benign entity) were retrospectively evaluated. Hounsfield Units (HU) and iodine concentrations of AS, LN and the main spleen were measured. Receiver operating characteristics (ROC) were performed to calculate an optimal threshold for distinguishing AS from LN. Sensitivity, specificity, and accuracy were calculated for distinguishing AS from LN by iodine concentration measurements., Results: Mean CT numbers and iodine concentrations were higher for AS (148±29 HU and 48.2±11×100μg/cc) than LN (83±19 HU and 31.5±6.2×100μg/cc, respectively, P<0.001 each). Mean CT numbers were lower for AS compared to the main spleen (161±29HU, P<0.01), whereas mean iodine concentrations (47.7±10×100μg/cc) were not significantly different (P=0.095). An iodine concentration greater than 38×100μg/cc suggested AS with a sensitivity, specificity and accuracy of 91%, 85%, and 88%, respectively (Area under ROC curve 0.941)., Conclusions: Iodine measurements might contribute to the differentiation of AS from LN. Iodine concentrations similar to that of the main spleen may help to confirm the diagnosis of AS., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Objectives: To compare iodine content (IC) of solitary lung cancer using dynamic measurements of CT attenuation (Hounsfield Units, HU) and to correlate their quantitative CT data with expressions of vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR) and hypoxia-inducible factor-1α (HIF-1α) using immunostaining methods., Methods: This study included 18 patients with adenocarcinoma, who undergone dual energy dynamic multiphase CT to examine solitary lung nodules (6 part-solid and 12 solid nodules). Tumor size was 21.1 mm±8.1 (9-39mm) [Mean±SD (range)]. Contrast volume was determined by weight (2ml/kg). Contrast volume and injection rate were 110.5 ml±17.2 (80-144ml) and 1.84ml/s±0.30 (1.3-2.4ml/s), respectively. Enhancement values ([CT value at each delayed scan-CT value at unenhanced scan]) and net enhancement values ([peak CT value-CT value at unenhanced scan]) were calculated in HU from 65keV monochromatic image. IC at each delayed scan was measured in mg/cm(3) from the iodine-water material decomposition pair on the advantage workstation VolumeShare4. Immunostaining using VEGF, EGFR, and HIF-1α was performed by two pathologists, who evaluated the expression level of them subjectively. Statistical analyses were performed with rank correlation tests and regression analysis., Results: IC at 2- and 3-minute delayed scan (x) and immunostaining score of HIF-1α (y) showed a significantly positive correlation (r=0.64 and 0.52, p=0.004 and 0.03): regression equation, y=1.34+0.58x and y=1.51+0.55x, respectively., Conclusions: Dual-energy dynamic multiphase CT can measure iodine content in lung adenocarcinoma. Iodine content at 2- and 3-minute delayed scan might correlate with the expression level of HIF-1α., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To investigate whether dual energy computed tomography (CT) with iodine quantification can characterize primary lesions and metastatic lymph nodes from non-metastatic ones in non-small cell lung cancer (NSCLC)., Materials and Methods: Sixty-one patients with NSCLC confirmed by pathology underwent chest contrast CT scan with dual energy computed tomography before surgery. The Iodine concentration (IC) and normalized iodine concentration (NIC) values of the primary lesions, 20 metastatic and 20 non-metastatic lymph nodes were measured, respectively. The differences between the primary lesions, metastatic and non-metastatic lymph nodes were statistically analyzed., Results: For the IC and NIC values of the primary lesions and their metastatic lymph nodes, there were no significant differences between lung squamous cell carcinomas and adenocarcinomas, respectively (P>0.05), while significant differences existed between metastatic and non-metastatic lymph nodes, respectively (P<0.05). The IC of 29.32 100μg/cm(3) and NIC value of 0.4328 of a lymph node represented the optimal threshold to discriminate metastatic from non-metastatic lymph nodes and yielded the following: sensitivity, 80% and 75%; specificity, 65% and 75%; PPV, 70% and 75%; NPV, 76% and 75%; accuracy, 73% and 75%, respectively., Conclusion: Although its value in distinguishing primary lesions and their metastatic lymph nodes in NSCLC needs to be verified in further studies, dual energy CT with iodine quantification may be used to differentiate metastatic from non-metastatic lymph nodes in NSCLC., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To determine the iodine load per body weight (ILPBW) that is minimally required for the detection of pancreatic adenocarcinoma for 80kVp CT imaging., Material and Methods: Institutional review board approval and written informed consent were obtained. Fifty-seven consecutive patients with histopathologically-proven pancreatic adenocarcinoma were assigned to three groups at random according to iodine load (0.5, 0.4, and 0.3gI/kg) and underwent CT at 80kVp. Enhancement of the pancreas and visualization of the tumor were assessed during the pancreatic parenchymal-phase and compared among the three groups. The relationship between the iodine load and tumor conspicuity was also analyzed., Results: The mean CT number of the pancreas (HUpancreas) was higher in the 0.5gI/kg group (158.8HU) than in the 0.4 (121.7HU) and 0.3 (106.6HU) gI/kg groups (P<0.05). Tumor-to-pancreas contrast (HUtumor-to-pancreas) was also higher in 0.5gI/kg group (88.9HU) than in 0.4 (62.2HU) and 0.3 (54.5HU) gI/kg groups (P<0.05). Linear regression between HUpancreas or HUtumor-to-pancreas and ILPBW were expressed as HUpancreas=23.3+263.9×ILPBW (r=0.74, P<0.0001) and HUtumor-to-pancreas=-1.24+174.3×ILPBW (r=0.56, P<0.0001), respectively. The iodine load estimated to achieve an acceptable HUpancreas (>100HU) and HUtumor-to-pancreas (>50HU) were 0.29 and 0.30gI/kg, respectively., Conclusion: An iodine load of 0.3gI/kg was the least amount required for the detection of pancreatic adenocarcinoma at 80kVp CT., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Aim: The aim of the study is to present the feasibility of using dual-energy CT and the evaluation of iodine and air distribution in differentiation of pathological conditions., Material and Method: We used the data of 50 CT examinations performed due to suspected pulmonary embolism with any pathological finding except consolidation of the parenchyma. The patients underwent CT angiography of the pulmonary arteries on a dual-source CT (DSCT), with the two tubes independently operated at 140 and 80 kV. By exploiting the dual-energy information, iodine distribution maps were obtained in addition to the conventional CT images which served as a marker of pulmonary perfusion. Minimum intensity projections (MinIP) were used as a marker of air content., Results: By comparing the iodine distribution maps and MinIP images, it was possible to differentiate between the following templates of lung parenchyma: A--normal iodine and air distribution; B--iodine content deficit with minimal or with no redistribution of air; C--reduced iodine content and increased content of air; D--deficit of iodine content and increased content of air; E--increased iodine content and normal content of air; F--increased iodine content and reduced content of air; G--reduced perfusion and reduced content of air. The type A (five cases) was typical for the pulmonary embolism with preserved normal conditions of perfusion and ventilation. Type B (18 cases) occurred in pulmonary embolism; type C was found in case of inflammation of small respiratory airways (five cases); emphysema was typical for type D (nine cases); increased perfusion was observed in the parenchyma preserved from emphysema or preserved from embolism in cases of emphysema or pulmonary embolism; type F occurred in pulmonary interstitial edema (four cases) both with pulmonary infection; finally type G was found in interstitial lung diseases (five cases)., Conclusion: Imaging of the pulmonary circulation by means of dual-energy CT opens the potential to study pathological changes of circulatory and pulmonary perfusion impairments, our presented work signs the important relations between iodine and air distribution which have to be thought in the interpretation of dual-energy perfusion imaging of the lungs., (Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.)