A Critical Appraisal of the Performance, Reporting, and Interpretation of Studies Comparing Carotid Plaque Imaging With Histology

Abstract

Background and Purpose-Carotid plaque instability is an important determinant of stroke risk. There are now a number of different imaging techniques that provide information on carotid plaque morphology. However, it is unclear how they compare with one another or whether they can reliably assess plaque instability. Studies comparing imaging with pathology have shown highly variable results, even for similar imaging techniques. This may be because of variable pathology techniques rather than differences in imaging. Methods-We performed a systematic review of studies that compared carotid imaging with histology of the excised plaque published between January 1995 and September 2004. We assessed the quality and comparability of these studies. In particular, we determined which histology methods were used and whether observer reproducibility of the histology assessment was reported. Results-Among 73 eligible studies, histological methods were poorly reported and highly variable; 23% reported reproducibility data for imaging and only 12% reported reproducibility data for histology. Of 29 studies that reported quantitative results of blinded comparisons, there were methodological deficiencies and the results were highly variable.No study considered the extent to which the lack of reproducibility influenced the imaging-pathological correlations reported. Conclusions-Pathological correlation in studies of carotid plaque imaging cannot be reliably interpreted or compared because of incomparable and poorly reported histology methods. We make recommendations for the performance, reporting, and interpretation of imaging-pathological correlation studies and highlight the need for consensus guidelines.

Comparacoes preliminares entre a histologia virtual ultrassonografica in vivo e os achados histopatologicos da placa carotidea produto de endarterectomia

“…Because of that, several errors are introduced both in the removal and the preparation of the plaque and in the direction of the section under analysis. Lovett et al 13 suggested that the histological study of atheromas should be standardized. In this study, attempts were made to minimize these errors by removing the plaque with as minimal rupture as possible and using the image of the histological slide as the standard reference, choosing the area on the ultrasound image that had the same relation between the lumen and the wall, and studying a section of this region instead of the entire plaque.…”

“…Other complementary imaging tests, such as positron emission tomography (PET) and single photon emission CT (SPECT), may play an adjuvant role in follow-up. However, although promising, they are expensive, and access to them is limited 2,[13][14][15] .…”

“…In contrast, a high amount of fibrous contents and greater calcification may be associated with a lower risk of stroke (stable plaques). Therefore, plaque morphology and composition should be included in the evaluation of atherosclerotic diseases, which will further contribute to the knowledge about lumen narrowing 3,13,16,17 .…”

Investigations of Carotid Stenosis to Identify Vulnerable Atherosclerotic Plaque and Determine Individual Stroke Risk

“…16 The most commonly used method of MR plaque imaging consists of a series of images with different contrast weightings. In this 'multi-contrast' protocol (Figure 1 20 In recent years, many studies have investigated the association between MRI plaque characteristics and subsequent cerebrovascular events. IPH in particular is thought to be a crucial parameter related to plaque rupture and therefore studied extensively.…”

Carotid ultrasonography in the assessment of cardiovascular risk

“…In addition, irregularities of the carotid plaque surface may represent a good marker of its vulnerability, which translates into increased risk of thromboembolic cerebral events [11][12][13]. With regards to plaque echogenicity, several studies clearly showed that echolucent carotid plaques were more related to cardiovascular events (CVEs) than were echogenic ones [14][15][16]: in fact, echolucent plaques histologically demonstrate a higher lipid content and a reduced fibrous and calcium content, which represent important features of advanced and/or unstable atherosclerotic disease [17]. Different methods exist for the quantitative assessment of the ultrasonographic properties of Among healthy adults aged 20 to 79 years, risk scores classify 75% of the subjects as low or intermediate risk, but in these categories a substantial number of CVEs (about 60%) occurs [31].…”