Validation of a New Contrast Material Protocol Adapted to Body Surface Area for Optimized Low-Dose CT Coronary Angiography With Prospective ECG-Triggering

OBJECTIVES: In patients with large total blood volume contrast material (CM) dilution decreases coronary attenuation in CT coronary angiography (CTCA). As increased blood volume is well paralleled by body surface area (BSA) we assessed a BSA-adapted CM protocol to compensate for dilution effects.

METHODS: Low-dose CTCA with prospective ECG-triggering was performed in 80 patients with a BSA-adapted CM bolus ranging 40-105 ml and injection rate ranging 3.5-5.0 ml/s for a BSA of <1.70 to >2.5 m(2). Eighty control patients matched for BSA who had previously undergone routine CTCA with a fixed CM protocol of 80 ml at 5 ml/s served as reference group. The average vessel attenuation from the proximal right (RCA) and the left main coronary artery (LMA) was assessed. Correlation of BSA with vessel attenuation was assessed in both groups.

RESULTS: BSA-matching of all patients was successful (BSA-adapted group 1.98 +/- 0.15 m(2), range 1.66-2.39 m(2) versus reference group 1.98 +/- 0.17 m(2), range 1.59-2.38 m(2); P = 0.74). Mean CM bolus was significantly smaller in the BSA-adapted versus the reference group (70.9 +/- 14.1 vs. 80.0 +/- 0 ml, P < 0.001). There was no correlation in the BSA-adapted group (r = -0.07, P = 0.53, SEE = 0.15), while coronary attenuation was inversely related to BSA in the reference group (r = -0.59, P < 0.001, SEE = 0.14).

CONCLUSIONS: We have successfully validated a BSA-adapted contrast material protocol which results in a comparable coronary contrast enhancement independent of individual BSA. This was achieved despite a significant reduction in the overall contrast material amount. 

PMID: 20131006

Posted in Computed Tomography and tagged , , , , , , , , .

2 Comments

  1. Another focus in cardiac CT, in addition to reduction in radiation exposure, is the reduction of amount of contrast material used.This paper describes good and homogeneous vessel enhancement with a BSA adjusted protocol. Compare with paper from the same group:

    Determinants of vessel contrast in BMI-adapted low dose CT coronary angiography with prospective ECG-triggering.
    Herzog BA, Husmann L, Valenta I, Tay FM, Burkhard N, Gaemperli O, Wyss CA, Landmesser U, Kaufmann PA.
    Int J Cardiovasc Imaging. 2009 Aug;25(6):625-30.
    PMID:
    Reed Miller
    HeartWire; December 06, 2009

  2. Interesting study that underlines the capability of obtaining quality images with a small doses of contrast… even in the non-adapted group – 80cc of contrast material with a concentration of 320 mg/ml is actually a pretty low volume to be administered. I am still unsure of the clinical significance of a 10cc reduction.

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