Phase-contrast CT: qualitative and quantitative evaluation of atherosclerotic carotid artery plaque

TY - JOUR

T1 - Phase-contrast CT: qualitative and quantitative evaluation of atherosclerotic carotid artery plaque

AU - Hetterich, Holger

AU - Willner, Marian

AU - Fill, Sandra

AU - Herzen, Julia

AU - Bamberg, Fabian

AU - Hipp, Alexander

AU - Schüller, Ulrich

AU - Adam-Neumair, Silvia

AU - Wirth, Stefan

AU - Reiser, Maximilian

AU - Pfeiffer, Franz

AU - Saam, Tobias

PY - 2014/6

Y1 - 2014/6

N2 - PURPOSE: To evaluate the potential of phase-contrast computed tomography (CT) for atherosclerotic plaque imaging in human carotid arteries in an experimental ex vivo study.MATERIALS AND METHODS: The study was approved by the institutional review board, and informed consent was obtained from the patients' relatives. Seven postmortem human carotid artery specimens were imaged at a laboratory setup by using a conventional x-ray tube and grating interferometer. After histologic processing, phase-contrast imaging and histopathologic data were matched. Characteristics of the necrotic core (NC) covered by a fibrous cap (FC), intraplaque hemorrhage (IPH), and calcifications (CAs) were established, and sensitivity, specificity, and accuracy of phase-contrast CT for plaque detection and the potential for accurate quantification were assessed. The Cohen κ and Pearson correlation coefficient R were used to determine the agreement between phase-contrast imaging and histopathologic findings for plaque characterization and correlation of quantitative plaque measurements, respectively. A difference with a P value of less than .05 was considered significant.RESULTS: Characteristic criteria were found in all analyzed plaque components. Applying these criteria, phase-contrast CT had a good sensitivity for the detection of the FC and NC, IPH, and CAs (all, >80%) and excellent specificity and accuracy (all, >90%), with good interreader agreement (κ ≥ 0.72, P < .0001). There were excellent correlations for quantitative measurements of FC, NC, and CAs between phase-contrast imaging and histopathologic findings (R ≥ 0.92). Interreader reproducibility was excellent, with an intraclass correlation coefficient of 0.98 or higher for all measurements.CONCLUSION: The results of this study indicate that ex vivo phase-contrast CT can help identify and quantify atherosclerotic plaque components, with excellent correlation to histopathologic findings. Although not yet applicable in vivo, phase-contrast CT may become a valuable tool to monitor atherosclerotic disease process noninvasively.

AB - PURPOSE: To evaluate the potential of phase-contrast computed tomography (CT) for atherosclerotic plaque imaging in human carotid arteries in an experimental ex vivo study.MATERIALS AND METHODS: The study was approved by the institutional review board, and informed consent was obtained from the patients' relatives. Seven postmortem human carotid artery specimens were imaged at a laboratory setup by using a conventional x-ray tube and grating interferometer. After histologic processing, phase-contrast imaging and histopathologic data were matched. Characteristics of the necrotic core (NC) covered by a fibrous cap (FC), intraplaque hemorrhage (IPH), and calcifications (CAs) were established, and sensitivity, specificity, and accuracy of phase-contrast CT for plaque detection and the potential for accurate quantification were assessed. The Cohen κ and Pearson correlation coefficient R were used to determine the agreement between phase-contrast imaging and histopathologic findings for plaque characterization and correlation of quantitative plaque measurements, respectively. A difference with a P value of less than .05 was considered significant.RESULTS: Characteristic criteria were found in all analyzed plaque components. Applying these criteria, phase-contrast CT had a good sensitivity for the detection of the FC and NC, IPH, and CAs (all, >80%) and excellent specificity and accuracy (all, >90%), with good interreader agreement (κ ≥ 0.72, P < .0001). There were excellent correlations for quantitative measurements of FC, NC, and CAs between phase-contrast imaging and histopathologic findings (R ≥ 0.92). Interreader reproducibility was excellent, with an intraclass correlation coefficient of 0.98 or higher for all measurements.CONCLUSION: The results of this study indicate that ex vivo phase-contrast CT can help identify and quantify atherosclerotic plaque components, with excellent correlation to histopathologic findings. Although not yet applicable in vivo, phase-contrast CT may become a valuable tool to monitor atherosclerotic disease process noninvasively.

KW - Aged

KW - Aged, 80 and over

KW - Carotid Artery Diseases

KW - Female

KW - Humans

KW - Male

KW - Middle Aged

KW - Plaque, Atherosclerotic

KW - Radiographic Image Interpretation, Computer-Assisted

KW - Reproducibility of Results

KW - Sensitivity and Specificity

KW - Tomography, X-Ray Computed

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1148/radiol.14131554

DO - 10.1148/radiol.14131554

M3 - SCORING: Journal article

C2 - 24588675

VL - 271

SP - 870

EP - 878

JO - RADIOLOGY

JF - RADIOLOGY

SN - 0033-8419

IS - 3

ER -