Dual-energy CT angiography in peripheral arterial occlusive disease-accuracy of maximum intensity projections in clinical routine and subgroup analysis.

OBJECTIVE: To evaluate the accuracy of dual-energy CT angiography (DE-CTA) maximum intensity projections (MIPs) in symptomatic peripheral arterial occlusive disease (PAOD). METHODS: In 58 patients, DE-CTA of the lower extremities was performed on dual-source CT. In a maximum of 35 arterial segments, severity of the most stenotic lesion was graded (<10%, 10-49% and 50-99% luminal narrowing or occlusion) independently by two radiologists, with DSA serving as the reference standard. RESULTS: In DSA, 52.3% of segments were significantly stenosed or occluded. Agreement of DE-CTA MIPs with DSA was good in the aorto-iliac and femoro-popliteal regions (κ = 0.72; κ = 0.66), moderate in the crural region (κ = 0.55), slight in pedal arteries (κ = 0.10) and very good in bypass segments (κ = 0.81). Accuracy was 88%, 78%, 74%, 55% and 82% for the respective territories and moderate (75%) overall, with good sensitivity (84%) and moderate specificity (67%). Sensitivity and specificity was 82% and 76% in claudicants and 84% and 61% in patients with critical limb ischaemia. CONCLUSION: While correlating well with DSA above the knee, accuracy of DE-CTA MIPs appeared to be moderate in the calf and largely insufficient in calcified pedal arteries, especially in patients with critical limb ischaemia.

Impact of PVCs noted during coronary calcium scan on image quality and accuracy in subsequent coronary dual-source CT angiography.

The purpose of this study was to investigate the impact of the presence of one or more premature ventricular contractions (PVCs) during coronary calcium score scan (CS) on image quality and accuracy of subsequent dual-source coronary CT angiography (DS CCTA). Fifty-three out of 502 patients showed one or more PVCs during CS and built the study group. Sixty consecutively registered patients with sinus rhythm formed the control group. Two independent, blinded readers classified 1,723 coronary artery segments as being of diagnostic or non-diagnostic image quality. All segments with diagnostic image quality were assessed for the presence for significant coronary artery stenosis. Accuracy was calculated using conventional angiography as standard of reference. The percentage of DS CCTA data sets with diagnostic image quality was significantly lower in the study group (79.2%) compared to the control group (90.6%, P < 0.05). The rate of coronary segment with diagnostic image quality was highly significant lower in the study group (89.5%; n = 723/808) compared to the control group (99.4%; n = 908/915; P < 0.001). However, accuracy did not differ in both groups. Significant correlation between non-diagnostic image quality and mean HR was only found in the study group (P = 0.019). The presence of one or more PVCs during CS does not affect accuracy but impairs image quality of subsequent DS CCTA. Mean HR is a predictor of non-diagnostic data sets only in the study group, suggesting more aggressive HR control could be beneficial.