Yoshihisa Hatakeyama MD, Abstract Co-Author: Nothing to Disclose

Shingo Kakeda MD, Presenter: Nothing to Disclose

Yukunori Korogi MD, Abstract Co-Author: Nothing to Disclose

Nobuhiro Oda MS, RN, Abstract Co-Author: Nothing to Disclose

Kazuyoshi Nishino, Abstract Co-Author: Nothing to Disclose

Wataru Miyamoto, Abstract Co-Author: Nothing to Disclose

Norihiro Ohnari, Abstract Co-Author: Nothing to Disclose

Junji Moriya, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To compare an angiography system using the flat panel detector (FPD) of direct conversion type with an image intensifier (I.I.)-TV system for the detection of the simulated aneurysmal bleb, as well as for evaluation of dose reduction.

An anthropomorphic vascular phantom was designed to simulate the various intracranial aneurysms with and without bleb, and this vascular phantom consisting of tubes was filled with three kinds of contrast material concentration (300, 150, 100mgI/ml). 2D-DSAs generated at low dose mode of FPD system were compared with 2D-DSAs generated at a standard dose mode of FPD system and a conventional mode of I.I.-TV system. Data analysis was based on 738 observations (82 aneurysms [21 with bleb and 61 without bleb] ×3 DSA modes×3 contrast material concentrations) by each of five radiologists, and the detection performances of five radiologists were compared by using a receiver operating characteristic (ROC) analysis.

The mean dose measurements with a phantom during 2D-DSA were 0.4 mGy/frame with low dose mode of FPD system, 1.20 mGy/frame with standard dose mode of FPD system and 1.36 mGy/frame with I.I.-TV system. Between the low dose mode and standard dose mode of FPD system, the significant difference was not accepted regarding the detection performance (mean area under the ROC curve [Az]) of aneurismal bleb with any contrast material concentrations. Az with low dose mode of FPD system obtained with a contrast material concentration of 100mgI/ml was significantly superior to that with I.I.-TV system (P<.05), although differences was not significant with 150 and 300 mgI/ml between both systems.

Use of our angiography system using the FPD of direct conversion type allows a considerable dose reduction during 2D-DSA without loss of the detection performance for small intracranial vascular lesions, such as aneurysmal bleb.

Hatakeyama, Y, Kakeda, S, Korogi, Y, Oda, N, Nishino, K, Miyamoto, W, Ohnari, N, Moriya, J, et al, , Flat Panel Detector of Direct Conversion Type versus Conventional Image Intensifier: TV System for Angiography of Cerebral Aneurysms—A Vascular Phantom Study.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4414237.html