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Angiography syngo iFlow Objective Assessment of Transcatheter Arterial Chemoembolization Supported by syngo iFlow Courtesy of Xue-bin Zhang, MD Department of Interventional Radiology, Renji Hospital, Shanghai, China Contact qi_sun@siemens.com Data Analysis syngo iFlow images were generated for both pre- and post-procedural DSA sequences. The maximum enhancement and the time to peak (TTP) were measured respectively at several homologous anatomic landmarks: (A) The origin of the tumor feeding artery (TFA), (B) the embolized site of the TFA and (C) the parenchyma of the tumor (Fig. 1). The difference of TTP between landmarks (A) and (B) was defined as the tumor blood supply time (TBST). The pre- and post-syngo iFlow images illustrate that the TTP of the embolized site of the TFA was delayed from 5.07 sec. to 6.93 sec., and the TBST after embolization (2.66 sec.) was also greatly delayed compared to that before embolization (0 sec.), which quantitatively measured the deterioration of the hemodynamic condition of the lesion. In addition, a circular region of interest (ROI) was selected in the proximal and distal TFA for measurements of pre- and post-DSA sequences (Fig. 2), which visualized the ROI time intensity curve (TIC) and calculated the ratio of area under the curve (AUC), Peak Intensity (PI) between the origin (ROI Ref) and distal end (ROI 2) of the TFA (Fig. 3) in addition to the pixel measurements. The pre- and post-procedural TIC of proximal TFA both rose steeply, they presented a quick-in and quick-out pattern; the post-procedural TIC of the distal TFA changed from a quick-in and quick-out to a slow-in and slow-out pattern. TTP for proximal and distal TFA were the same (5.07 sec.) before the interventional treatment. After the treatment the Patient History A 53-year-old male patient was diagnosed with cholangiocellular carcinoma three years ago and has already received transcatheter chemoembolization (TACE) ten times, at an interval between one and a half and three months. Now he has been admitted to the hospital for further treatment. Diagnosis Upper abdominal MR scan showed multiple intra-hepatic metastases. Compared to previous MR images the lesions have clearly increased in size and proliferated in number. Treatment A pre-procedural DSA was performed with the catheter tip at the common hepatic artery. Embolization was performed selectively using iodized oil (Lipiodol Ultrafluide; Guerbet, France) mixed with mitomycin. Gelatin sponge particles (Alicon, Hangzhou, China) with a size of 1 μm were utilized to enhance the embolic effect. A post-treatment angiogram was obtained with the same acquisition parameters. TFA delayed from 5.33 sec. to 6.93 sec., which corresponded with the result of the pixel measurement. Ratio of AUC (ROI 2 AUC/ROI REF AUC) decreased from 1.28 to 1.05 after the embolization. Comments syngo iFlow offers a new way to represent DSA series and provides an objective evaluation measurement. All measured values such as TTP, AUC, PI, and TIC curve pattern can be analyzed to detect the physiological changes induced by the embolization. It may serve as a functional biomarker to help to determine the optimal end point for TACE procedures. A preliminary study regarding this topic has been performed and the results were presented at RSNA 2012 1. 1 Zhang XB, Zhuang ZG; Ye H; Beilner J; Kowarschik M, Cheng J. A quantitative assessment for the endpoint of transcatheter arterial chemoembolization: preliminary study of color-coded digital subtraction angiography. RSNA. 2012. Contact kaiyi.huang@siemens.com Xue-bin Zhang, MD 24  AXIOM Innovations | December 2013 | www.siemens.com/angiography


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