Dual-energy computed tomography as a lower radiation dose alternative to perfusion computed tomography in tumor viability assessment.

To present the utility of dual-energy computed tomography (DECT) in the assessment of angiogenesis of focal lesions as an example of a solitary pulmonary nodule (SPN). This prospective study comprised 28 patients with SPN who underwent DECT and perfusion computed tomography (CTP), according to a proprietary protocol. Two radiologists independently analyzed four perfusion parameters, namely blood flow (BF), blood volume (BV), the time to maximum of the tissue residue function (Tmax), permeability surface area product (PS) from CTP, in addition to the iodine concentration (IC) and normalized iodine concentration (NIC) of the SPN from DECT. We used the Pearson R correlation and interclass correlation coefficients (ICCs). Statistical significance was assumed at p < 0.05. The mean tumor size was 23.5 ± 6.5 mm. We observed good correlations between IC and BF (r = 0.78, p < 0.000) and NIC and BF (r = 0.71, p < 0.000) as well as between IC and BV (r = 0.73, p < 0.000) and NIC and BV (r = 0.73, p < 0.000) and poor correlation between IC and PS (r = 0.38, p = 0.044).There was no correlation between NIC and PS (r = 0.35, p = 0.064), IC content and Tmax (r = - 0.28, p = 0.147) and NIC and Tmax (r = - 0.21, p = 0.266). Inter-reader agreement on quantitative parameters at CTP (ICCPS = 0.97, ICCTmax = 0.96, ICCBV = 0.98, and ICCBF = 0.99) and DECT (ICCIC = 0.98) were excellent. The radiation dose was significantly lower in DECT than that in CTP (4.84 mSv vs. 9.07 mSv, respectively). DECT is useful for the functional assessment of oncological lesions with less exposure to radiation compared to perfusion computed tomography.

A New Outlook on the Ability to Accumulate an Iodine Contrast Agent in Solid Lung Tumors Based on Virtual Monochromatic Images in Dual Energy Computed Tomography (DECT): Analysis in Two Phases of Contrast Enhancement.

For some time, dual energy computed tomography (DECT) has been an established method used in a vast array of clinical applications, including lung nodule assessment. The aim of this study was to analyze (using monochromatic DECT images) how the X-ray absorption of solitary pulmonary nodules (SPNs) depends on the iodine contrast agent and when X-ray absorption is no longer dependent on the accumulated contrast agent. Sixty-six patients with diagnosed solid lung tumors underwent DECT scans in the late arterial phase (AP) and venous phase (VP) between January 2017 and June 2018. Statistically significant correlations (p ≤ 0.001) of the iodine contrast concentration were found in the energy range of 40-90 keV in the AP phase and in the range of 40-80 keV in the VP phase. The strongest correlation was found between the concentrations of the contrast agent and the scanning energy of 40 keV. At the higher scanning energy, no significant correlations were found. We concluded that it is most useful to evaluate lung lesions in DECT virtual monochromatic images (VMIs) in the energy range of 40-80 keV. We recommend assessing SPNs in only one phase of contrast enhancement to reduce the absorbed radiation dose.

Assessment of Solitary Pulmonary Nodules Based on Virtual Monochrome Images and Iodine-Dependent Images Using a Single-Source Dual-Energy CT with Fast kVp Switching.

With lung cancer being the most common malignancy diagnosed worldwide, lung nodule assessment has proved to be one of big challenges of modern medicine. The aim of this study was to examine the usefulness of Dual Energy Computed Tomography (DECT) in solitary pulmonary nodule (SPN) assessment. Between January 2017 and June 2018; 65 patients (42 males and 23 females) underwent DECT scans in the late arterial phase (AP) and venous phase (VP). We concluded that imaging at an energy level of 65 keV was the most accurate in detecting malignancy in solitary pulmonary nodules (SPNs) measuring ≤30 mm in diameter on virtual monochromatic maps. Both virtual monochromatic images and iodine concentration maps prove to be highly useful in differentiating benign and malignant pulmonary nodules. As for iodine concentration maps, the analysis of venous phase images resulted in the highest clinical usefulness. To summarize, DECT may be a useful tool in the differentiation of benign and malignant SPNs. A single-phase DECT examination with scans acquired 90 s after contrast media injection is recommended.

Serum ADAMTS-13 Levels as an Indicator of Portal Vein Thrombosis.

BACKGROUND: Coagulation disorders in patients with liver cirrhosis are a common clinical problem. Cirrhosis should be considered a state of impaired blood clotting or an imbalance of the whole coagulation system. Cirrhosis-induced coagulopathy encompasses disturbances in both the procoagulant and anticoagulant systems. This mechanism may promote the development of thrombosis with portal vein thrombosis (PVT), which is considered an obstacle to orthotopic liver transplantation (OLT). We assessed serum ADAMTS-13 levels in patients with decompensated liver cirrhosis, with and without PVT. MATERIAL AND METHODS: Serum ADAMTS-13 levels, age, platelet count (PLT), and INR (international normalized ratio) were evaluated in (n = 64) patients with liver cirrhosis either with PVT (group 1, n = 31) or without PVT (group 2, n = 33). The results were compared with those from healthy volunteers (group 3, n = 37). Liver cirrhosis was based on Desmet's classification of chronic hepatitis in liver biopsy stage ≥ 3 or liver elastography F-score ≥ 3. Serum ADAMTS-13 levels were measured with Quantikine® ELISA Human ADAMTS13 Immunoassay, R&D Systems Inc. We used Welch's F-test, Games-Howell, one-way ANOVA, Bonferroni test, and logistic regression to determine whether ADAMTS-13 levels were a predictor that was independent of MELD and Child-Pugh scores. All results (P < 0.05) were considered statistically significant. RESULTS: The mean serum ADAMTS-13 level in patients with PVT was significantly lower than that in patients without PVT (P = 0.001) and controls (P = 0.001). The mean serum ADAMTS-13 level in patients without PVT was significantly lower than that in controls (P = 0.001). ADAMTS-13 levels were significantly associated with PVT accounting for the Child-Pugh or MELD score in the logistic regression model. CONCLUSIONS: Low serum ADAMTS-13 levels can be a useful indicator of portal thrombosis in patients with decompensated liver cirrhosis irrespective of Child-Pugh or MELD scores. Further research is needed to determine whether ADAMTS-13 levels will find use in everyday clinical practice.