Diagnostic Accuracy of High-Pitch Dual-Source CT for the Assessment of Coronary Stenoses: First Experience

OBJECTIVES: The objective was to prospectively investigate the diagnostic accuracy of high-pitch (HP) dual-source computed tomography coronary angiography (CTCA) compared with catheter coronary angiography (CCA) for the diagnosis of significant coronary stenoses.

METHODS: Thirty-five patients (seven women; mean age 62 +/- 8 years) underwent both CTCA and CCA. CTCA was performed with a second-generation dual-source CT system permitting data acquisition at an HP of 3.4. Patients with heart rates >60 bpm were excluded from study enrolment. All coronary segments were evaluated by two blinded and independent observers with regard to image quality on a four-point scale (1: excellent to 4: non-diagnostic) and for the presence of significant coronary stenoses (defined as diameter narrowing exceeding 50%). CCA served as the standard of reference. Radiation dose values were calculated using the dose-length product.

RESULTS: Diagnostic image quality was found in 99% of all segments (455/459). Non-diagnostic image quality occurred in a single patient with a sudden increase in heart rate immediately before and during CTCA. Taking segments with non-evaluative image quality as positive for disease, the sensitivity, specificity and positive and negative predictive values were 94, 96, 80 and 99% per segment and 100, 91, 88 and 100% per patient. The effective radiation dose was on average 0.9 +/- 0.1 mSv.

CONCLUSIONS: In patients with heart rates </=60 bpm, CTCA using the HP mode of the dual-source CT system is associated with high diagnostic accuracy for the assessment of coronary artery stenoses at sub-milliSievert doses.

PMID: 19760229

Posted in Computed Tomography and tagged , , , , .

2 Comments

  1. This and the posted article by Lell et al. report initial results with a new dual-source scanner generation with high-pitch mode.
    In selected patient coronary CTA is performed at sub-miliSievert doses.

  2. As mentioned in my comment attached to the related post, one relevant result in these 2 studies is that this technology allows obtaining high-quality images using only 60cc of contrast! (concentration of 370 mg/mL in this study).
    Future studies should be able to determine how much more this dose can be reduced without compromising the diagnostic capacity of the exam.

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