title: Coronary artery calcium score on low-dose computed tomography for lung cancer screening.
abstract: OBJECTIVE
  To evaluate the feasibility of coronary artery calcium score (CACS) on low-dose non-gated chest CT (ngCCT).
  
  
  METHODS
  Sixty consecutive individuals (30 males; 73 ± 7 years) scheduled for risk stratification by means of unenhanced ECG-triggered cardiac computed tomography (gCCT) underwent additional unenhanced ngCCT. All CT scans were performed on a 64-slice CT scanner (Somatom Sensation 64 Cardiac, Siemens, Germany). CACS was calculated using conventional methods/scores (Volume, Mass, Agatston) as previously described in literature. The CACS value obtained were compared. The Mayo Clinic classification was used to stratify cardiovascular risk based on Agatston CACS. Differences and correlations between the two methods were compared. A P-value < 0.05 was considered significant.
  
  
  RESULTS
  Mean CACS values were significantly higher for gCCT as compared to ngCCT (Volume: 418 ± 747 vs 332 ± 597; Mass: 89 ± 151 vs 78 ± 141; Agatston: 481 ± 854 vs 428 ± 776; P < 0.05). The correlation between the two values was always very high (Volume: r = 0.95; Mass: r = 0.97; Agatston: r = 0.98). Of the 6 patients with 0 Agatston score on gCCT, 2 (33%) showed an Agatston score > 0 in the ngCCT. Of the 3 patients with 1-10 Agatston score on gCCT, 1 (33%) showed an Agatston score of 0 in the ngCCT. Overall, 23 (38%) patients were reclassified in a different cardiovascular risk category, mostly (18/23; 78%) shifting to a lower risk in the ngCCT. The estimated radiation dose was significantly higher for gCCT (DLP 115.8 ± 50.7 vs 83.8 ± 16.3; Effective dose 1.6 ± 0.7 mSv vs 1.2 ± 0.2 mSv; P < 0.01).
  
  
  CONCLUSIONS
  CACS assessment is feasible on ngCCT; the variability of CACS values and the associated re-stratification of patients in cardiovascular risk groups should be taken into account.
authors: Teresa Arcadi, Department of Radiology, SDN Foundation, IRCCS, 80131 Naples, Italy.
authors: Teresa
authors: T
authors: Arcadi
authors: Teresa Arcadi, Department of Radiology, SDN Foundation, IRCCS, 80131 Naples, Italy.
authors: Erica
authors: E
authors: Maffei
authors: Teresa Arcadi, Department of Radiology, SDN Foundation, IRCCS, 80131 Naples, Italy.
authors: Nicola
authors: N
authors: Sverzellati
authors: Teresa Arcadi, Department of Radiology, SDN Foundation, IRCCS, 80131 Naples, Italy.
authors: Cesare
authors: C
authors: Mantini
authors: Teresa Arcadi, Department of Radiology, SDN Foundation, IRCCS, 80131 Naples, Italy.
authors: Andrea I
authors: AI
authors: Guaricci
authors: Teresa Arcadi, Department of Radiology, SDN Foundation, IRCCS, 80131 Naples, Italy.
authors: Carlo
authors: C
authors: Tedeschi
authors: Teresa Arcadi, Department of Radiology, SDN Foundation, IRCCS, 80131 Naples, Italy.
authors: Chiara
authors: C
authors: Martini
authors: Teresa Arcadi, Department of Radiology, SDN Foundation, IRCCS, 80131 Naples, Italy.
authors: Ludovico
authors: L
authors: La Grutta
authors: Teresa Arcadi, Department of Radiology, SDN Foundation, IRCCS, 80131 Naples, Italy.
authors: Filippo
authors: F
authors: Cademartiri
keywords: Cardiovascular risk stratification; Coronary artery calcium score; High-resolution computed tomography; Lung cancer screening; Unenhanced chest computed tomography