Poster Author of 2 e-Posters
SE-019 - The efficacy of texture analysis using ZOOMit coronal diffusion-weighted imaging at 3T MRI for differentiating benign from malignant distal bile duct stricture
SE-131 - Dual-Layer Spectral CT of Pancreatic Adenocarcinoma: Can Virtual Monoenergetic Imaging of Portal Venous Phase Replace Pancreatic Phase?
Author of 2 Presentations
SE-019 - The efficacy of texture analysis using ZOOMit coronal diffusion-weighted imaging at 3T MRI for differentiating benign from malignant distal bile duct stricture
Abstract
Purpose
To investigate the diagnostic efficacy of ZOOMit coronal diffusion-weighted imaging (ZC-DWI) and MR texture analysis (MRTA) for differentiating benign from malignant distal bile duct strictures.
Material and methods
We retrospectively enrolled total 71 patients with distal bile duct stricture who underwent MRCP. ZC-DWI obtained along the bile duct course. MRTA features were extracted from the area of bile duct stricture on apparent diffusion coefficient (ADC) map of ZC-DWI before and after spatial filtration. For quantitative analysis, mean ADC value at sites suspected strictures were assessed on both ZC-DWI and conventional DWI (C-DWI). For qualitative analysis, two readers independently reviewed two image sets containing different DWIs, and ROC analysis was assessed.
Results
26 of 71 patients were confirmed as malignant stricture. Multiple MRTA parameters showed a statistically different distribution in benign and malignant strictures including mean, entropy, mean of positive pixels, and kurtosis at spatial filtration values 0, 5, and 6mm. Entropy showed the largest AUROC (0.915; 95% CI, 0.823 to 0.968; > 3.39, sensitivity of 84.62% and specificity of 95.45% for the diagnosis of malignant stricture). Average ADC value using ZC-DWI of malignant stricture (1.124 x 10–3 mm2/s) was lower than that of benign stricture (1.522 x 10–3 mm2/s) (p<0.001). AUC for differentiating benign from malignant stricture was higher in the image set with ZC-DWI than that of C-DWI (0.939, p=0.010).
Conclusion
High entropy using MRTA is potentially associated with a malignant distal bile duct stricture and the addition of ZC-DWI to conventional MRCP is more helpful for differentiating benign from malignant bile stricture.
SE-131 - Dual-Layer Spectral CT of Pancreatic Adenocarcinoma: Can Virtual Monoenergetic Imaging of Portal Venous Phase Replace Pancreatic Phase?
Abstract
Purpose
To evaluate diagnostic performance and optimal keV of virtual monoenergetic imaging (VMI) created from portal venous phase (PVP) in comparison with conventional 120kVp polychromatic imaging of pancreatic phase (PP) on dual-layer spectral CT when assessing pancreatic adenocarcinoma and peripancreatic vasculature
Material and methods
30 patients with pancreatic adenocarcinoma who underwent dual-layer spectral CT scan with nonenhanced phase, PP, and PVP were included. VMIs for 40 keV, 55 keV, and 70 keV of PVP were created, and each VMI was compared with conventional 120kVp polychromatic imaging of PP. In all four images, tumor-to-pancreas CNR and attenuation difference were compared for tumor conspicuity. CNR and SNR of the celiac trunk, superior mesenteric artery, portal vein, and superior mesenteric vein were compared for peripancreatic vasculature assessment. Effective radiation dose for standard triple-phase and dual-phase without pancreatic phase CT scan were compared
Results
VMI40 of PVP demonstrated significantly the greatest (P <0.001) tumor-to-pancreas CNR and attenuation difference, peripancreatic vascular CNR and SNR than those of conventional PP and VMI55, VMI70 of PVP. VMI55 of PVP demonstrated second greatest (P < 0.001) results in all measured values. VMI70 of PVP and conventional PP were equivalent in tumor-to-pancreas attenuation difference and CNR of arteries (celiac trunk and superior mesenteric artery). Mean effective dose was 12.8±3.9 mSv and 8.9±2.7 mSv for standard triple-phase CT scan and dual-phase CT scan without PP, respectively.
Conclusion
For assessing pancreatic adenocarcinoma, VMI40 of portal venous phase obtained on dual-layer spectral CT demonstrated superior tumor conspicuity, higher CNR and SNR for peripancreatic vasculature than those of conventional pancreatic phase.