Assessment of vascular calcification in ESRD patients using spiral CT

Dialysis patients have increased vascular calcification of the coronary arteries and aorta by electron beam CT scan. The purpose of the present study was to utilize an alternative machine, spiral CT, to assess calcification in end-stage renal disease (ESRD) patients.

Two groups of patients with ESRD were evaluated: group 1, those receiving a renal transplant (n=38); and group 2, those remaining on dialysis (n=33). All patients underwent quad-slice spiral CT with retrospective gating to evaluate coronary artery and aorta calcification scores. Both area (Agatston method) and volume calculations were utilized, with retrospective gating in all but 16 subjects. Laboratory tests, medications and clinical characteristics were analysed.

Using spiral CT, the intra-reader variability for coronary artery calcification (after correction for very low scores) was 0.9% mean / 0% median using the area (Agatston method) and 2.9% mean / 0% median using volume calculations. Group 1 patients were younger, more likely to be Caucasian and on peritoneal dialysis, had lower serum calcium and higher C-reactive protein levels than group 2. In patients without vs those with coronary artery calcification, only longer duration of dialysis (34+/-64 vs 55+/-50 months, P=0.004; r=0.39, P=0.005) and increasing age (39+/-13 vs 54+/-10 years, P<0.001; r=0.29, P=0.039) were associated, whereas only increasing age was associated with aorta calcification.

In ESRD patients, the factors correlating with coronary calcification were duration of dialysis and advancing age, whereas only age correlated with aorta calcification. Spiral CT offers an alternative technique for the assessment of these changes.