Small Coronary Calcifications Are Not Detectable by 64-Slice Contrast Enhanced Computed Tomography

OBJECTIVES: Recently, small calcifications have been associated with unstable plaques. Plaque calcifications are both in intravascular ultrasound (IVUS) and multi-slice computed tomography (MSCT) easily recognized. However, smaller calcifications might be missed on MSCT due to its lower resolution.

METHODS: Because it is unknown to which extent calcifications can be detected with MSCT, we compared calcification detection on contrast enhanced MSCT with IVUS. The coronary arteries of patients with myocardial infarction or unstable angina were imaged by 64-slice MSCT angiography and IVUS. The IVUS and MSCT images were registered and the arteries were inspected on the presence of calcifications on both modalities independently. We measured the length and the maximum circumferential angle of each calcification on IVUS.

RESULTS: In 31 arteries, we found 99 calcifications on IVUS, of which only 47 were also detected on MSCT. The calcifications missed on MSCT (n = 52) were significantly smaller in angle (27° ± 16° vs. 59° ± 31°) and length (1.4 ± 0.8 vs. 3.7 ± 2.2 mm) than those detected on MSCT. Calcifications could only be detected reliably on MSCT if they were larger than 2.1 mm in length or 36° in angle.

CONCLUSIONS: Half of the calcifications seen on the IVUS images cannot be detected on contrast enhanced 64-slice MSCT angiography images because of their size. The limited resolution of MSCT is the main reason for missing small calcifications.

PMID: 20602171

Schoenhagen Paul

Cardiovascular Imaging
Imaging Institute and
Heart&Vascular Institite
Cleveland Clinic
Cleveland, OH
Posted in Computed Tomography, Invasive Imaging and tagged , , , , .

2 Comments

  1. See associated editorial:
    IVUS detects more coronary calcifications than MSCT; matter of both resolution and cross-sectional assessment?
    E. E. van der Wall, F. R. de Graaf, J. E. van Velzen, J. W. Jukema, J. J. Bax and J. D. Schuijf .
    Cardiovasc Imaging. 2010 Jul 11.
    PMID: 20623370

    Measurements of soft-plaque volumes calculated on different software platforms following cardiac CT angiography (CCTA) exams can vary widely, according to a study presented this week at the Society of Cardiovascular Computed Tomography (SCCT) meeting in Las Vegas.

  2. See also:

    Small calcified coronary atherosclerotic plaque simulation model: minimal size and attenuation detectable by 64-MDCT and MicroCT.
    Kristanto W, van Ooijen PM, Groen JM, Vliegenthart R, Oudkerk M.
    Int J Cardiovasc Imaging. 2011 Apr 21.
    PMID: 21509430

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>