Browsing by Author "Pesko, P. (57204298089)"

Purpose: To estimate if CT perfusion parameter values of the esophageal cancer, which were obtained with the deconvolution-based software and maximum slope algorithm are in agreement, or at least interchangeable. Methods: 278 esophageal tumor ROIs, derived from 35 CT perfusion studies that were performed with a 64-MDCT, were analyzed. "Slice-by-slice" and average "whole-covered-tumor-volume" analysis was performed. Tumor blood flow and blood volume were manually calculated from the arterial tumortime- density graphs, according to the maximum slope methodology (BFms and BV ms), and compared with the corresponding perfusion values, which were automatically computed by commercial deconvolutionbased software (BF deconvolution and BVdeconvolution), for the same tumor ROIs. Statistical analysis was performed using Wilcoxon matched-pairs test, paired-samples t-test, Spearman and Pearson correlation coefficients, and Bland-Altman agreement plots. Results: BFdeconvolution (median: 74.75 ml/min/100 g, range, 18.00-230.5) significantly exceeded the BF ms(25.39 ml/min/100 g, range, 7.13-96.41) (Z = -14.390, p < 0.001), while BVdeconvolution (median: 5.70 ml/100 g, range: 2.10-15.90) descended the BVms(9.37 ml/100 g, range: 3.44-19.40) (Z = -13.868, p < 0.001). Both pairs of perfusion measurements significantly correlated with each other: BFdeconvolution, versus BFms (rS = 0.585, p < 0.001), and BVdeconvolution, versus BV ms (rS = 0.602, p < 0.001). Geometric mean BF deconvolution/BFms ratio was 2.8 (range, 1.1-6.8), while geometric mean BVdeconvolution/BVms ratio was 0.6 (range, 0.3-1.1), within 95% limits of agreement. Conclusions: Significantly different CT perfusion values of the esophageal cancer blood flow and blood volume were obtained by deconvolution-based and maximum slope-based algorithms, although they correlated significantly with each other. Two perfusion-measuring algorithms are not interchangeable because too wide ranges of the conversion factors were found. © 2013 Elsevier Ireland Ltd.

INTRODUCTION: Determination of borders of the postcricoid tumors is of great significance during preoperative analysis, because it can be of considerable influence on operative treatment and its planning. Therefore, exact demarcation, delineation and opacification of tumor zone on CT analysis is crucial. MATERIAL AND METHOD: Late CT scan delay of 150 sec and slow vein flow of contrast agents of 1 ml/sec is radiological method of choice in preoperative evaluation of carcinoma of the post-cricoid region. For our purposes we used modern MSCT Light Speed GE 64, with slice thick of 2.5 mm (retro recon of 0.625) with software postprocesing. RESULTS AND DISCUSSION: In our study, we have detaily analized 25 patients with clinically proved carcinoma of hypopharynx, of which 8 had the hardest form of tumor. Control group were patients to whom CT scan was done by standard protocol and CT time scan of 50 sec. With all 8 of them, scanned by protocol of delay time of 150 sec, was proved a statistically important validity of interpretation and demarcation of tumors. CONCLUSION: Delay time on CT scanning is proved to be efficient protocol for visualization of neck soft tissues which includes the walls of hypopharynx.

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