title: Determinants of vessel contrast in BMI-adapted low dose CT coronary angiography with prospective ECG-triggering.
abstract: We evaluated the determinants of vessel contrast in prospectively ECG-triggered CT coronary angiography (CTCA). Seventy patients underwent low-dose CTCA using body mass index (BMI)-adapted tube parameters and a fixed contrast material bolus. Contrast to noise ratio (CNR) was calculated from contrast (between coronaries and perivascular tissue) and image noise (standard deviation of aortic attenuation). Cardiac output (CO) was calculated from gated (99m)Tc-tetrofosmin-SPECT. Mean radiation dose was 2.13 +/- 0.69 mSv. Image noise was not affected by BMI (r = 0.1, P = 0.36), while CNR was inversely related to body surface area (BSA) (r = -0.5, P < 0.001) and CO (r = -0.45, P < 0.001). After successfully overcoming the impact of BMI on image noise by adapting tube parameters, CNR mainly depends on coronary vessel contrast. The latter reflects the dilution of the contrast material by blood volume and CO, which are both correlated to BSA. Therefore, BSA adapted contrast administration may help to compensate for this effect.
authors.affiliation: Cardiac Imaging, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Bernhard A
authors.initials: BA
authors.lastname: Herzog
authors.forename: Lars
authors.initials: L
authors.lastname: Husmann
authors.forename: Ines
authors.initials: I
authors.lastname: Valenta
authors.forename: Fabian M
authors.initials: FM
authors.lastname: Tay
authors.forename: Nina
authors.initials: N
authors.lastname: Burkhard
authors.forename: Oliver
authors.initials: O
authors.lastname: Gaemperli
authors.forename: Christophe A
authors.initials: CA
authors.lastname: Wyss
authors.forename: Ulf
authors.initials: U
authors.lastname: Landmesser
authors.forename: Philipp A
authors.initials: PA
authors.lastname: Kaufmann
mesh_terms: D016477:Artifacts; D001810:Blood Volume; D015992:Body Mass Index; D001830:Body Surface Area; D002302:Cardiac Output; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004562:Electrocardiography; D006801:Humans; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011829:Radiation Dosage; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D014283:Triiodobenzoic Acids
chemical_list: D003287:Contrast Media; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D014283:Triiodobenzoic Acids; C078700:technetium tc-99m tetrofosmin; C044834:iodixanol