Non-invasive characterisation of coronary lesion morphology and composition by multislice CT: first results in comparison with intracoronary ultrasound

Abstract

The reliable non-invasive detection of coronary artery disease (CAD) is a prime goal for future developments in clinical cardiology. In addition to the documentation of high-grade stenoses, the detection of vulnerable plaques is of major importance for risk stratification and early treatment to prevent plaque rupture. Recently, a new generation of fast spiral CT has been introduced using a multi-slice technique (MSCT), which is the first real quantum leap in CT since the introduction of spiral CT in the early 1990s. We report on non-invasive differentiation of coronary plaque morphology by MSCT in patients with lesions in the proximal left anterior descending artery (LAD). The results were compared with the findings of intracoronary ultrasound (ICUS). The ICUS and MSCT scans were analysed in 6 patients scheduled for ICUS-guided PTCA. One target lesion was selected in each patient. On ICUS, two lesions were classified as soft, two as intermediate and two as calcified according to established criteria based on echogenicity. By multislice CT, density measurements (expressed in Hounsfield Units, HU) were performed at 16 randomly selected areas within the plaques. The two soft plaques showed a mean density of 6+/-28 and -5+/-25 HU, the two intermediate plaques of 83+/-17 and 51+/-19 HU, and the two calcified plaques of 489+/-372 and 423+/-111 HU. To our knowledge, this is the first report on non-invasive characterisation of coronary lesions by MSCT. Plaque composition could be clearly differentiated and classified according to the ICUS results by determining tissue density within the lesions. Thus, this new technology holds promise for non-invasive risk assessment in patients with known or suspected CAD since also rupture-prone soft coronary lesions can be detected by use of this new technique.

Reclassification of Patients for Aggressive Cholesterol Treatment: Additive Value of Multislice Coronary Angiography to the National Cholesterol Education Program Guidelines

“…Although most patients had some degree of coronary calcifications, some had only noncalcified plaque that would have been missed by calcium scoring CT, a relevant finding as soft plaque may represent the more vulnerable lesion. 8 We found exclusively noncalcified plaque in 15% of nonhigh-risk patients, which is consistent with other studies. 5,6 In response to the MSCT results, statin drug use increased in all FRS categories with either initiation of drug use or an increase in the current drug dose.…”

Noninvasive Cardiac Imaging with Computed Tomography

“…25,28,[31][32][33][34][35][36][37][38] MSCT allows an accurate, non-invasive evaluation of the coronary vessels in those at intermediate risk for CAD. As stated previously, MSCT scanners also provide a coronary artery calcium score.…”

“…39 In addition to visualizing the coronary lumen, MSCT allows characterization of the coronary atherosclerotic plaque and has shown a good correlation with intravascular ultrasound. 31,32 A major goal of non-invasive imaging is to identify vulnerable plaques with the potential to rupture. 25,32 The accuracy of plaque characterization seems to vary with plaque size, as larger plaques tend to be overestimated and smaller plaques may be either underestimated or not detected.…”

“…31,32 A major goal of non-invasive imaging is to identify vulnerable plaques with the potential to rupture. 25,32 The accuracy of plaque characterization seems to vary with plaque size, as larger plaques tend to be overestimated and smaller plaques may be either underestimated or not detected. 32 Further technical improvements will likely enhance the ability of MSCT to characterize coronary plaques.…”

Predicting Breast Attenuation in Patients Undergoing Myocardial Perfusion Scintigraphy: A Digital X-Ray Study

“…The Hounsfield unit measurement is well known in medical and nonmedical fields, including the evaluation of coronary artery plaques and examination of fossil bone. 4,5 Therefore, the purpose of this study was to predict breast adverse attenuation by measuring breast tissue thickness and tissue Hounsfield density using digital x-ray. …”