ABSTRACT. Coronary angioplasties can be performed with either single-plane or biplane imaging techniques. The aim of this study was to determine whether biplane imaging, in comparison to single-plane imaging, reduces radiation dose and contrast load and shortens procedural time during (i) primary and elective coronary angioplasty procedures, (ii) angioplasty to the main vascular territories and (iii) procedures performed by operators with various levels of experience. This prospective observational study included a total of 504 primary and elective single-vessel coronary angioplasty procedures utilising either biplane or single-plane imaging. Radiographic and clinical parameters were collected from clinical reports and examination protocols. Radiation dose was measured by a dose-area-product (DAP) meter intrinsic to the angiography system. Our results showed that biplane imaging delivered a significantly greater radiation dose (181.4¡121.0 Gycm 2 ) than single-plane imaging (133.6¡92.8 Gycm 2 , p,0.0001). The difference was independent of case type (primary or elective) (p50.862), vascular territory (p50.519) and operator experience (p50.903). No significant difference was found in contrast load between biplane (166.8¡62.9 ml) and single-plane imaging (176.8¡66.0 ml) (p50.302). This non-significant difference was independent of case type (p50.551), vascular territory (p50.308) and operator experience (p50.304). Procedures performed with biplane imaging were significantly longer (55.3¡27.8 min) than those with single-plane (48.9¡24.2 min, p50.010) and, similarly, were not dependent on case type (p50.226), vascular territory (p50.642) or operator experience (p50.094). Biplane imaging resulted in a greater radiation dose and a longer procedural time and delivered a non-significant reduction in contrast load than single-plane imaging. These findings did not support the commonly perceived advantages of using biplane imaging in single-vessel coronary interventional procedures.

IntroductionDiagnostic coronary angiography utilises radiographic contrast media to delineate epicardial coronary lesions and assess left ventricular function. While contrast media is essential for the radiographic visualisation of coronary vessels, there are certain risks and complications associated with its use. One such complication is contrast-induced nephropathy (CIN). CIN is a life-threatening dose-dependent reaction and is commonly defined as a decrease in renal function 24-48 hours after contrast media administration, with a rise in serum creatinine levels of more than 25% from the baseline (or an absolute increase greater than 0.5 mg/dL) three to five days after the procedure. [1][2][3][4][5][6][7][8][9] Preventative measures for CIN in cardiovascular procedures include pre-hydration, prophylactic administration of N-acetylcysteine and utilisation of iso-osmolar/hypo-osmolar contrast media. However, reducing the volume of contrast media within the procedure was found to be the most effective. [10][11][12][13][14] Cigarroa, et al. 15 and Freeman, et al. 16 both investigated the significance of an adjusted volume of contrast media to patient's body weight and serum creatinine level (maximum radiographic contrast dose (MRCD)) in relation to the occurrence of CIN. CIN developed in 2% of cases when the calculated MRCD for a group of patients was not exceeded, and a 15-fold increase in incidence for a group where MRCD was exceeded. Similarly Rihal, et al. 12 reported a 12% increase in the risk of nephropathy with each 100 mL administered to the patient. As CIN has been found to be the third leading cause of acute renal failure in patients (10% of all admitted cases), it is essential that contrast load is kept to a minimum in any examinations requiring contrast media. 3,17 Coronary angiography can be performed using either singleplane or biplane imaging equipment. Single-plane imaging involves the use of one x-ray tube to acquire images at different angles and requires a separate injection of contrast for each cine angiography run. Biplane imaging utilises two x-ray tubes and is capable of acquiring two simultaneous projections with a single contrast injection. Therefore, it is assumed that contrast load will not only be reduced, but screening time and overall procedural time will be shorter.In biplane imaging, the screening time is inclusive of the total fluoroscopy and cine angiography time for both planes. The screening time should therefore be shorter for biplane imaging than single-plane imaging as it acquires two images simultaneously. Additionally, as the setup of the two C-arms require less movement throughout the procedure, the use of biplane equipment would accordingly assist in reducing procedural time when compared to single-plane imaging. Furthermore, because the runs are calculated from each individual plane, biplane should result in a slightly greater number of cine angiography runs than single-plane imaging. Where single-plane will complete the nine standard projections, biplane will produce ...