Volume 14, Issue 2, Pages 98-104 (May 2008) Diagnostic efficacy for coronary in-stent patency with parameters defined on Hounsfield CT value-spatial profile curves  Tadashi Yamazaki, Jun-ichi Suzuki, Ryoichi Shimamoto, Taeko Tsuji, Yuki Ohmoto-Sekine, Toshihiro Morita, Hiroshi Yamashita, Junko Honye, Ryozo Nagai, Shuhei Komatsu, Masaaki Akahane, Kuni Ohtomo  Radiography  Volume 14, Issue 2, Pages 98-104 (May 2008) DOI: 10.1016/j.radi.2006.12.004 Copyright © 2007 The College of Radiographers Terms and Conditions

Figure 1 In-stent coronary CT angiograms and Hounsfield CT value-spatial profile curve. (A) Line cursor for Hounsfield CT value-spatial profile curves superimposed on in-stent coronary short-axis CT angiogram reproduced with multi-planar reconstruction. Line cursor defining the direction of CT profile curve is set across coronary CT angiogram to accord with the direction of IVUS measurements. (B) Hounsfield CT value-spatial profile curve. Twine peaks represent stent materials and valley indicates central flow across cross-section of coronary in-stent lumen. Vertical axis and horizontal axis are CT values in Hounsfield units and distance (mm) from start-point of cursor, respectively. Radiography 2008 14, 98-104DOI: (10.1016/j.radi.2006.12.004) Copyright © 2007 The College of Radiographers Terms and Conditions

Figure 2 Schematic representation of IVUS parameters. (A) In-stent cross-sectional area of patent lumen cavity [Area (patent)]. (B) In-stent cross-sectional area surrounded by media [Area (native)]. [Area (patent)]/[Area (native)] represents percent cross-sectional patency. (C) In-stent intravascular diameter by IVUS. Direction of IVUS diameter coincides with direction of cursor for CT value-spatial profile curve. Radiography 2008 14, 98-104DOI: (10.1016/j.radi.2006.12.004) Copyright © 2007 The College of Radiographers Terms and Conditions

Figure 3 CT parameters. Scheme of in-stent Hounsfield CT value-spatial profile curve is represented. Minimum extreme values are measured with three kinds of backgrounds. Correlations between each measurement and IVUS references are tested. Radiography 2008 14, 98-104DOI: (10.1016/j.radi.2006.12.004) Copyright © 2007 The College of Radiographers Terms and Conditions

Figure 4 Scheme of out-stent Hounsfield CT value-spatial profile curve for standardization of CT measurements. Maximum value of out-stent CT value-spatial profile curve with a background of water, myocardium, and sub-epicardial fat is used for standardization of CT parameters. Radiography 2008 14, 98-104DOI: (10.1016/j.radi.2006.12.004) Copyright © 2007 The College of Radiographers Terms and Conditions

Figure 5 Scheme of ideal Hounsfield CT value-spatial profile curve with ideal spatial resolution. Radiography 2008 14, 98-104DOI: (10.1016/j.radi.2006.12.004) Copyright © 2007 The College of Radiographers Terms and Conditions