In Vivo 16-Slice, Multidetector-Row Computed Tomography for the Assessment of Experimental Atherosclerosis

Abstract

Background-Noninvasive imaging can detect early atherosclerotic disease. Magnetic resonance imaging (MRI), because of its excellent spatial resolution, is already established as a tool for plaque characterization. Sixteen-slice, multidetector-row computed tomography (MDCT) was recently introduced into the field of cardiac imaging, with promising results for noninvasive angiography. We compared the capabilities of MDCT and MRI for the assessment of noncalcified, atherosclerotic plaques. Methods and Results-Six atherosclerotic rabbits underwent in vivo imaging by MDCT and 1.5-T MRI. MDCT parameters were 120 kV, 120 mA/s, collimation 12ϫ0.75, and spatial resolution 0.6ϫ0.6 mm. MRI parameters were as follows: for proton density, repetition time/echo time (TR/TE) 2300/5.6; for T2, TR/TE 2300/62; and for T1, TR/TE 800/5.6; slice thickness was 3 mm and spatial resolution, 0.3ϫ0.3 mm. Blinded analysis of 3-mm axial reconstructions from MDCT and the carefully matched MRI images (182 sections) showed excellent agreement between both modalities. MDCT yielded a slightly larger lumen area, anteroposterior diameters, and lateral diameters, with no significant differences in total vessel area. The sensitivity and specificity, respectively, to detect noncalcified, atherosclerotic plaques were 89% and 77% for MDCT and 97% and 94% for MRI. Fibrous-rich and lipid-rich plaque could not be differentiated visually, although they showed different attenuation properties (116Ϯ27 vs 51Ϯ25 Hounsfield units, PϽ0.01). Conclusions-Both techniques allow reliable detection of noncalcified, atherosclerotic plaques and accurate assessment of vessel areas and diameters. MDCT offers the additive value of a very short image acquisition time when compared with MRI. The subtle measurement differences found between modalities may be due to the better spatial resolution of MRI, which probably explains its superiority for tissue characterization.

Independent Association Between Obstructive Sleep Apnea and Noncalcified Coronary Plaque Demonstrated by Noninvasive Coronary Computed Tomography Angiography

“…When patients were divided by OSA severity into normal (AHI <10), mild (AHI [10][11][12][13][14][15][16][17][18][19][20], and severe (AHI >20) groups, the odds for any vessel involvement were 9.6 (95% CI: 1.1-85.3) for mild OSA and 42.1 (95% CI: 4.1-428.4) for moderate to severe OSA. These odds were adjusted for age, sex, race, hypercholesterolemia, and smoking history.…”

“…Overnight polysomnography was performed at nationally accredited sleep centers, and final diagnosis with apnea-hypopnea index (AHI; measure of the severity of disease) was available in all patients included in this study. Obstructive sleep apnea was further classified as no OSA (AHI <10), mild OSA (AHI [10][11][12][13][14][15][16][17][18][19][20], and severe OSA (AHI> 20). The number of vessels involved was defined as 0 if there was no stenosis and 1 if any stenosis or plaque was present.…”

“…Multidetector-row computed tomography (MDCT) recently has been demonstrated as a reliable noninvasive technique for detection and characterization of noncalcified atherosclerotic plaques. 17 We hypothesized that patients with OSA may have a higher burden of noncalcified and mixed plaques as determined by MDCT. We also looked at severity of stenosis and number of vessels involved as markers of increased atherosclerotic burden.…”

Angiografia coronariana minimamente invasiva através de tomografia com múltiplos detectores

“…Unfortunately a precise estimate of the histological characteristics of coronary atherosclerosis plaques remains controversial. Viles-Gonzales et al 16 did not fi nd a dependable relation between the radiological density of the lesion recorded by the angio-CT and the histological fi ndings. Once again, the question is raised regarding the methods used to conduct the test and the results obtained.…”

Avaliação anatômica de artérias coronárias humanas por ressonância magnética, ultra-som intravascular e anatomia patológica "in vitro"

“…As medidas obtidas nos 3 métodos foram comparadas através do teste de correlação de Pearson e método de Bland Altman Plot. As comparações entre os 3 métodos, pelas suas respectivas médias e desvios padrão, foram realizadas pela análise de variância para medidas repetidas.RESULTADOS: As médias das variáveis na RM,UIV e AP foram respectivamente: ATV 15,46 ± 4,83,13,86 ± 5,20 e 11,87 ± 4,57; MaDV 4,75 ± 0,84,4,40 ± 0,87 e 4,18 ± 0,87; MeDV 4,23 ± 0,73,3,75 ± 0,72 e 3,48 ± 0,70; AL 5,59 ± 2,93,6,86 ± 3,18 e 5,57 ± 2,46; DmiL 2,54 ± 0,64, 2,55 ± 0,57 e 2,32 ± 0,52; DmaxL 3,07 ± 0,65,3,34 ± 0,76 e 3,04 ± 0,83; EminP 0,76 ± 0,25, 0,38 ± 0,18 e 0,34 ± 0,17; EmaxP 1,11 ± 0,39, 0,88 ± 0,37 e 0,90 ± 0,48 For this, studies with cardiovascular magnetic resonance (CMR) and coronary intravascular ultrasound has been developed in an attempt to better measure and characterize coronary heart disease "in vivo". PURPOSE: To determine the capacity of CMR to detect changes in the lumen and the wall of the coronary arteries caused by atherosclerosis, using as references intravascular ultrasound (IVUS) and pathology measurements.…”