Radiology 2006; 238:1022-1035.
Remy-Jardin M, Bahepar J, Lafitte JJ, Dequiedt P, Ertzbischoff O, Bruzzi J, Delannoy-Deken V, Duhamel A, Remy J.
PURPOSE: To prospectively evaluate gadolinium dose safety and effectiveness for 16-detector pulmonary computed tomographic (CT) angiography.
MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. Sixty patients with contraindications to iodine underwent CT of the pulmonary circulation with 0.5 mmol/L gadolinium chelate given at either 0.3 (n = 29, group A) or 0.4 (n = 31, group B) mmol/kg; clinical and biologic tolerances were evaluated. Enhancement of central and segmental pulmonary arteries was measured (poor enhancement, <100 HU; good, 100-150 HU; excellent, >150 HU). Subsegmental artery enhancement was assessed as similar or inferior to that of segmental arteries. Confidence in analysis of the pulmonary arterial bed was graded according to arterial enhancement: Grades 1-3, diagnostic images; grade 4, nondiagnostic. The main effectiveness parameter for comparison between groups A and B was diagnostic value of CT angiograms. Nonpara-metric statistics were used to analyze results.
RESULTS: The mean (± standard deviation) contrast material volume was 50.09 mL ± 8.45 (all patients: range, 30-64 mL; group A: 46.54 mL ± 8.59; group B: 53.42 mL ± 6.92). Diagnostic images were obtained in 55 (92%) patients, and confident analysis of pulmonary arteries to the subsegmental level was achieved in 26 (grade 1, 44%) and to the segmental level, in 21 (grade 2, 35%). Mean attenuation was higher in group B than in group A in central (180.61 HU ± 53.85 vs 148.14 HU ± 52.61; P = .04) and segmental (201.59 HU ± 54.70 vs 164.73 HU ± 59.26; P = .03) arteries. Number of diagnostic CT angiograms was higher (P = .02) in group B (n = 31 [100%]) than in group A (n = 24 [83%]). In both groups, mean enhancement of pulmonary arteries was significantly higher at 80 or 100 kV than at 120 kV. Renal function was impaired in two group A patients.
CONCLUSION: Gadolinium chelates may be used as an alternative CT contrast agent in patients who cannot receive iodine.