Low contrast media volume in pre-TAVI CT examinations.

Abstract

PurposeTo evaluate image quality using reduced contrast media (CM) volume in pre-TAVI assessment.MethodsForty-seven consecutive patients referred for pre-TAVI examination were evaluated. Patients were divided into two groups: group 1 BMI < 28 kg/m2 (n = 29); and group 2 BMI > 28 kg/m2 (n = 18). Patients received a combined scan protocol: retrospective ECG-gated helical CTA of the aortic root (80kVp) followed by a high-pitch spiral CTA (group 1: 70 kV; group 2: 80 kVp) from aortic arch to femoral arteries. All patients received one bolus of CM (300 mgI/ml): group 1: volume = 40 ml; flow rate = 3 ml/s, group 2: volume = 53 ml; flow rate = 4 ml/s. Attenuation values (HU) and contrast-to-noise ratio (CNR) were measured at the levels of the aortic root (helical) and peripheral arteries (high-pitch). Diagnostic image quality was considered sufficient at attenuation values > 250HU and CNR > 10.ResultsDiagnostic image quality for TAVI measurements was obtained in 46 patients. Mean attenuation values and CNR (HU ± SD) at the aortic root (helical) were: group 1: 381 ± 65HU and 13 ± 8; group 2: 442 ± 68HU and 10 ± 5. At the peripheral arteries (high-pitch), mean values were: group 1: 430 ± 117HU and 11 ± 6; group 2: 389 ± 102HU and 13 ± 6.ConclusionCM volume can be substantially reduced using low kVp protocols, while maintaining sufficient image quality for the evaluation of aortic root and peripheral access sites.Key points• Image quality could be maintained using low kVp scan protocols.• Low kVp protocols reduce contrast media volume by 34–67 %.• Less contrast media volume lowers the risk of contrast-induced nephropathy.