Ultrasonic tissue characterization of vulnerable carotid plaque: correlation between videodensitometric method and histological examination

Abstract

BackgroundTo establish the correlation between quantitative analysis based on B-mode ultrasound images of vulnerable carotid plaque and histological examination of the surgically removed plaque, on the basis of a videodensitometric digital texture characterization.MethodsTwenty-five patients (18 males, mean age 67 ± 6.9 years) admitted for carotid endarterectomy for extracranial high-grade internal carotid artery stenosis (≥ 70% luminal narrowing) underwent to quantitative ultrasonic tissue characterization of carotid plaque before surgery. A computer software (Carotid Plaque Analysis Software) was developed to perform the videodensitometric analysis. The patients were divided into 2 groups according to symptomatology (group I, 15 symptomatic patients; and group II, 10 patients asymptomatic). Tissue specimens were analysed for lipid, fibromuscular tissue and calcium.ResultsThe first order statistic parameter mean gray level was able to distinguish the groups I and II (p = 0.04). The second order parameter energy also was able to distinguish the groups (p = 0,02). A histological correlation showed a tendency of mean gray level to have progressively greater values from specimens with < 50% to >75% of fibrosis.ConclusionVideodensitometric computer analysis of scan images may be used to identify vulnerable and potentially unstable lipid-rich carotid plaques, which are less echogenic in density than stable or asymptomatic, more densely fibrotic plaques.

Systematic review on the association between calcification in carotid plaques and clinical ischemic symptoms

“…The 95% CI of the pooled SMD did not cross the referent 0.0 (Fig 1), indicating that symptomatic plaques had lower calcification volume or weight than asymptomatic plaques. There was significant heterogeneity across studies measuring calcification percentage 14,42,45,[47][48][49][50]53 (I 2 ϭ 93.8%). Using a random-effects model, pooled SMD between symptomatic and asymptomatic plaques was Ϫ0.997 (95% CI, Ϫ1.793 to Ϫ0.200).…”

“…Of the remaining 20 studies, only 8 explicitly stated that they excluded patients with a possible cardiac source of embolism. 9,[40][41][42]46,49,51,55 Ten studies did not report whether they excluded patients with a possible cardiac source of embolism, 37,39,[43][44][45]50,[52][53][54]56,57 whereas one study reported to also include patients with atrial fibrillation. 37 It is debatable whether carotid plaques of patients with ipsilateral lacunar infarcts should be defined as symptomatic.…”

Juxtaluminal hypoechoic area in ultrasonic images of carotid plaques and hemispheric symptoms

“…Hypoechoic plaques with a low GSM have a high lipid core or recent hemorrhage on histologic examination, and increased GSM is associated with increased fibrous tissue. [26][27][28][29] The significance and reproducibility of GSM have been extensively discussed by other authors, [9][10][11] and a low GSM has been shown to be associated with the development of ipsilateral hemispheric symptoms in certain studies. 12,13 Because histologic examination of symptomatic and asymptomatic plaques has demonstrated that the proximity of necrotic core to lumen is associated with symptoms, it has been suggested that imaging techniques that resolve the position of necrotic core in relation to lumen should help identify high-risk plaques.…”

Common carotid intima–media features determine distal disease phenotype and vulnerability in asymptomatic patients

“…This is a measure of the random nature of the gray-tone values within the plaque [25], giving high values for heterogeneous composition, and low values for homogenous tissue. …”