Volume of White Matter Hyperintensities, and Cerebral Micro-Bleeds.

PURPOSE: In the past years the significance of white matter hyperintensities (WMH) has gained raising attention because it is considered a marker of severity of different pathologies. Another condition that in the last years has been assessed in the neuroradiology field is cerebral microbleeds (CMB). The purpose of this work was to evaluate the association between the volume of WMH and the presence and characteristics of CMB. MATERIAL AND METHODS: Sixty-five consecutive (males 45; median age 70) subjects were retrospectively analyzed with a 1.5 Tesla scanner. WMH volume was quantified with a semi-automated procedure considering the FLAIR MR sequences whereas the CMB were studied with the SWI technique and CMBs were classified as absent (grade 1), mild (grade 2; total number of CMBs: 1-2), moderate (grade 3; total number of CMBs: 3-10), and severe (grade 4; total number of CMBs: >10). Moreover, overall number of CMBs and the maximum diameter were registered. RESULTS: Prevalence of CMBs was 30.76% whereas WMH 81.5%. Mann-Whitney test showed a statistically significant difference in WMH volume between subjects with and without CMBs (p < 0.001). Pearson analysis showed significant correlation between CMB grade, number and maximum diameter and WMH. The better ROC area under the curve (Az) was obtained by the hemisphere volume with a 0.828 (95% CI from 0.752 to 0,888; SD = 0.0427; p value = 0.001). The only parameters that showed a statistically significant association in the logistic regression analysis were Hemisphere volume of WMH (p = 0.001) and Cholesterol LDL (p = 0.0292). CONCLUSION: In conclusion, the results of this study suggest the presence of a significant correlation between CMBs and volume of WMH. No differences were found between the different vascular territories.

Does Carotid Artery Tortuosity Play a Role in Stroke?

PURPOSE: To explore the association between carotid artery length and tortuosity, and the occurrence of stroke. MATERIAL AND METHODS: In this retrospective study, IRB approved, 411 consecutive patients (males: 245; median age: 56 ± 12 years, age range: 21-93 years) with anterior circulation ischemic stroke were included. Only patients that underwent CTA within 7 days were considered and stroke caused by cardiac embolism and thoracic aorta embolism were excluded. For each patient, both carotid arteries were considered, and the ICA, CCA-ICA length and tortuosity were calculated. Inter-observer analysis was quantified with the Bland-Altman test. Mann-Whitney test and logistic regression analysis were also calculated to test the association between length and tortuosity with the occurrence of stroke. RESULTS: In the final analysis, 166 patients (males: 72; median age: 54 ± 12 years, age range: 24-89 years) with anterior circulation ischemic stroke that were admitted to our hospital between February 2008 and December 2013 were included. The results showed a good concordance for the length of the vessels with a mean variation of 0.7% and 0.5% for CCA-ICA and ICA length respectively an for the tortuosity with a mean variation of 0.2% and -0.4% for CCA-ICA and ICA respectively. The analysis shows a statistically significant association between the tortuosity index of the ICA and CCA-ICA sides with stroke (P value = 0.0001 in both cases) and these findings were confirmed also with the logistic regression analysis. CONCLUSION: Results of this study suggest that tortuosity index is associated with the presence of stroke whereas the length of the carotid arteries does not play a significant role.

Carotid artery stenosis and brain connectivity: the role of white matter hyperintensities.

PURPOSE: It is under debate how white matter hyperintensities (WMH) affects the brain connectivity. The objective of this research study is to validate the hypothesis, if and how the WMH influences brain connectivity in a population with carotid artery stenosis (CAS), which are eligible for carotid endarterectomy (CEA). We used resting state functional connectivity (rs-fc) magnetic resonance (MR) to validate our hypothesis, focusing on the effects of the total number of WMH (TNWMH) and of the WMH Burden (WMHB). METHODS: Twenty-three patients (sixteen males and seven females, mean age 74.34 years) with mono or bilateral carotid stenosis eligible for carotid endarterectomy (CEA), underwent an MR examination on a 1.5-T scanner. The protocol included a morphologic T1-3D isotropic, an EPI functional sequence for rs-fc MR analysis, and a 3D isotropic FLAIR sequence. For each patient, the TNWMH and the WMHB were obtained using two online tools-volBrain and lesionBrain. The rs-fc region-of-interest to region-of-interest (ROI-to-ROI) analysis was performed with the CONN toolbox v18a: two different multiple regression analyses including both WMHB and TNWMH as second-level covariates evaluated the individual effects of WMHB (Analysis A) and TNWMH (Analysis B), adopting a p value corrected for false discovery rate (p-FDR) < 0.05 to identify statistically significant values. RESULTS: Both analyses A and B identified several statistically significant positive and negative correlations associated with WMHB and TNWMH. CONCLUSION: WMH influence functional connectivity in patients with carotid artery stenosis eligible for CEA; further, WMHB and TNWMH influence differently functional connectivity.

Association between carotid artery plaque inflammation and brain MRI.

PURPOSE: To explore the association between presence of inflammatory cells in the carotid plaques surgically treated and brain MRI findings. MATERIAL AND METHODS: Forty consecutive patients were prospectively analyzed. Brain MRI was performed with a 1.5 Tesla scanner and infacts (lacuna and non-lacunar) pertinence of the anterior circulation were recorded. All patients underwent carotid endarterectomy "en bloc"; carotid plaques histological sections were prepared and immuno-cytochemical analysis was performed to characterize and quantify the presence of inflammatory cells. ROC curve analysis, Pearson Rho correlation and Mann-Whitney test were applied. RESULTS: The immuno-cytochemical analysis demonstrated that plaques of symptomatic patients (stroke\TIA; n = 25) had more inflammatory cells, mainly macrophages (CD68) compared with plaques of patients without symptoms (Mann-Whitney = P < 0.001, ROC curve area = 0.901). Correlation analysis showed a statistically significant association between the number of brain non-lacunar infarcts and the entity of macrophages (P < 0.001); whereas no association with lacunar infarcts (P = 0.1934) was found. CONCLUSION: Results of this preliminary study suggest that the presence and amount of inflammatory cells within carotid artery plaque is associated with cerebrovascular events and with the number of MRI brain detectable infarct.

Carotid artery imaging: The study of intra-plaque vascularization and hemorrhage in the era of the "vulnerable" plaque.

Intraplaque hemorrhage (IPH) is one of the main factors involved in atherosclerotic plaque (AP) instability. Its recognition is crucial for the correct staging and management of patients with carotid artery plaques to limit ischemic stroke. Imaging plays a crucial role in identifying IPH, even if the great variability of intraplaque vascularization and the limitations of our current imaging technologies make it difficult. The intent of this review is to give a general overview of the main features of intraplaque vascularization and IPH on Ultrasound (US), Computed Tomography (CT), Magnetic Resonance (MR) and Nuclear Medicine, and a brief description on the future prospectives.

Volumetric Distribution of the White Matter Hyper-Intensities in Subject with Mild to Severe Carotid Artery Stenosis: Does the Side Play a Role?

PURPOSE: The purpose of this paper was to assess the difference in the distribution of white matter hyperintensities (WMHs) on left and right sides of the brain hemispheres of subjects with mild to severe carotid artery stenosis. MATERIAL AND METHODS: Eighty consecutive patients (mean age 71 ± 6 years, males 66) with carotid artery stenosis were prospectively recruited. FLAIR-WMH lesion volume was performed using a semiautomated segmentation technique (Jim, Xinapse System, Leicester, UK). The Wilcoxon test was applied to verify the differences in the volume of WMHs between the right and left hemispheres. RESULTS: A statistically significant difference was found in the middle cerebral artery (MCA) territory for the volume of the lesions (median volume of WMHs of the left side = 889.5 mm3; median volume of WMHs on the right side = 580.5 mm3; P = .0416); no statistically significant difference was found on the other territories by taking into considerations the lesions. By analyzing the degree of stenosis, we found a higher degree of stenosis of the left side (67.9%; 95% confidence interval [CI], 64.8%-70.9%) compared with the right side (65.7%; 95% CI, 62.4%-68.9%), but the Mann-Whitney test did not show a statistically significant difference (P = .3235). CONCLUSIONS: Results of our study suggest that there is a difference in the distribution of WMHs in the brain hemispheres according to the left/right side on the MCA territories and for the periventricular white matter in subjects with mild to severe carotid artery stenosis.

Relationship between Carotid Computed Tomography Dual-Energy and Brain Leukoaraiosis.

BACKGROUND: The purpose of this study was to assess if there is a correlation between the carotid computed tomography (CT) Hounsfield unit (HU)-based plaque attenuation values measured using dual-energy CT (DECT) scanner and brain leukoaraiosis (LA). METHODS: Fifty consecutive patients (34 males, 16 females; mean age, 69 years; age range, 46-84 years) who underwent carotid CT and brain magnetic resonance imaging were included in the study. CT examinations were performed with a DECT scanner, and LA lesion volume quantification was performed using a semiautomated segmentation technique. RESULTS: We found an inverse statistically significant correlation between the HU-based carotid artery plaque attenuation and the LA lesion volume. Because of the presence of calcified plaques, a second model was calculated at low kiloelectron volt levels from 66 to 100 and 100 kV by taking into consideration the fatty and mixed plaques, and this further led to the associations between HU-based attenuation and LA volume in brain and vascular territories. CONCLUSIONS: The results of our study suggest that the associations between HU attenuation of the carotid artery plaques (with the exclusion of calcified plaques) and the volume of LA are emphasized at low keV energy levels.

Volumetric Analysis of Carotid Plaque Components and Cerebral Microbleeds: A Correlative Study.

PURPOSE: The purpose of this work was to explore the association between carotid plaque volume (total and the subcomponents) and cerebral microbleeds (CMBs). MATERIALS AND METHODS: Seventy-two consecutive (male 53; median age 64) patients were retrospectively analyzed. Carotid arteries were studied by using a 16-detector-row computed tomography scanner whereas brain was explored with a 1.5 Tesla system. CMBs were studied using a T2*-weighted gradient-recalled echo sequence. CMBs were classified as from absent (grade 1) to severe (grade 4). Component types of the carotid plaque were defined according to the following Hounsfield unit (HU) ranges: lipid less than 60 HU; fibrous tissue from 60 to 130 HU; calcification greater than 130 HU, and plaque volumes of each component were calculated. Each carotid artery was analyzed by 2 observers. RESULTS: The prevalence of CMBs was 35.3%. A statistically significant difference was observed between symptomatic (40%) and asymptomatic (11%) patients (P value = .001; OR = 6.07). Linear regression analysis demonstrated an association between the number of CMBs and the symptoms (P = .0018). Receiver operating characteristics curve analysis found an association between the carotid plaque subcomponents and CMBs (Az = .608, .621, and .615 for calcified, lipid, and mixed components, respectively), and Mann-Whitney test confirmed this association in particular for the lipid components (P value = .0267). CONCLUSIONS: Results of this study confirm the association between CMBs and symptoms and that there is an increased number of CMBs in symptomatic patients. Moreover, we found that an increased volume of the fatty component is associated with the presence and number of CMBs.

Longitudinal assessment of carotid atherosclerosis after Radiation Therapy using Computed Tomography: A case control Study.

OBJECTIVES: To study the carotid artery plaque composition and its volume changes in a group of patients at baseline and 2 years after head and neck radiation therapy treatment (HNXRT). METHODS: In this retrospective study, 62 patients (41 males; mean age 63 years; range 52-81) who underwent HNXRT and 40 patients (24 males; mean age 65) who underwent surgical resection of neoplasm and did not undergo HNXRT were assessed, with 2-year follow-up. The carotid artery plaque volumes, as well as the volume of the sub-components (fatty-mixed-calcified), were semiautomatically quantified. Mann-Whitney and Wilcoxon tests were used to test the hypothesis. RESULTS: In the HNXRT group, there was a statistically significant increase in the total volume of the carotid artery plaques (from 533 to 746 mm(3); p = 0.001), in the fatty plaques (103 vs. 202 mm(3); p = 0.001) and mixed plaque component volume (328 vs. 419 mm(3); p = 0.034). A statistically significant variation (from 21.8 % to 27.6 %) in the percentage of the fatty tissue was found. CONCLUSIONS: Results of this preliminary study suggest that HNXRT promotes increased carotid artery plaque volume, particularly the fatty plaque component. KEY POINTS: HNXRT increases carotid plaque volume. Plaque volume increase is mainly due to increase.in fatty plaque component. Patients who undergo HNXRT have a progression of carotid artery disease.

Relationship between leukoaraiosis, carotid intima-media thickness and intima-media thickness variability: Preliminary results.

OBJECTIVE: To assess the relationship between the degree of leukoaraiosis (LA), carotid intima-media thickness (IMT) and intima-media thickness variability (IMTV). MATERIALS AND METHODS: Sixty-one consecutive patients, who underwent a brain MRI examination and a carotid artery ultrasound, were included in this retrospective study, which conformed with the Declaration of Helsinki. Written informed consent was waived. In each patient, right/left carotid arteries and brain hemispheres were assessed using automated software for IMT, IMTV and LA volume. RESULTS: The mean hemispheric LA volume was 2,224 mm3 (SD 2,702 mm3) and there was no statistically significant difference in LA volume between the right and left hemispheres (p value = 0.628). The mean IMT and IMTV values were 0.866 mm (SD 0.170) and 0.143 mm (SD 0.100), respectively, without significant differences between the right and left sides (p values 0.733 and 0.098, respectively). The correlation coefficient between IMTV and LA volume was 0.41 (p value = 0.0001), and 0.246 (p value = 0.074) between IMT and LA volume. CONCLUSIONS: IMTV significantly correlates with LA volume. Further studies are warranted to verify whether this parameter can be used clinically as a marker of cerebrovascular risk. KEY POINTS: • Intima-media thickness variability (IMTV) significantly correlates with leukoaraiosis volume. • IMTV could be used as a marker for cerebrovascular risk. • IMTV seems to be a better predictor of weighted mean difference than IMT.

Is there an association between leukoaraiosis volume and diabetes?

OBJECTIVES: The relation between white matter loss (WML) and diabetes is still debated. The aim of this study was to investigate the correlation between typical WML- and diabetes-related magnetic resonance imaging (MRI) findings in a cohort of patients scheduled for carotid endarterectomy (CEA). MATERIALS AND METHODS: Ninety-three consecutive patients (mean age 71±9years; male 71) were included in a single-centre retrospective study. All the patients underwent MRI as baseline evaluation prior to CEA. A neuroradiologist blinded to the presence of risk factors calculated WML volume and number of lesions on FLAIR images using a semi-automated segmentation technique. Receiver operating characteristics analysis was performed to search for any association between WML volume and the number of WML lesions. The Mann-Whitney tests were used to determine significant WML differences between diabetic and non-diabetic patients. Logistic regression analysis was performed to evaluate the potential association of other variables. RESULTS: The prevalence of diabetes was 20.4% (n=19). WML volume and number of WML lesions were significantly associated with diabetes (P=0.001). A statistically significant difference in WML volume was found between diabetic and non-diabetic patients (P<0.0001). Only diabetes, among all the investigated variables (WML volume, CAD status, age, smoking status, gender, hypertension, hyperlipidemia, diabetes) was significantly associated with WML (P=0.0001). CONCLUSION: Our results demonstrate a strong statistical correlation between diabetes and WML. Future scientific challenges could include the identification of potential therapeutic targets and the creation of dedicated screening protocols for WML in diabetic patients other than the simple measurement of leukoaraiosis total burden.

Quality of Life in Carotid Atherosclerosis: The Role of Co-morbid Mood Disorders.

INTRODUCTION/OBJECTIVE: To study in severe carotid atherosclerosis (CA): the frequency of mood disorders (MD); the impairment of quality of life (QoL); the role of co-morbid MD in such impairment. METHODS: Case-control study. CASES: consecutive in-patients with CA (stenosis ≥ 50%). CONTROLS: subjects with no diagnosis of CA randomized from a database of a community survey. Psychiatric diagnosis according to DSM-IV made by clinicians and semi-structured interview, QoL measured by the Short Form Health Survey (SF-12). RESULTS: This is the first study on comorbidity on CA disease and MD in which psychiatric diagnoses are conducted by clinicians according to DSM-IV diagnostic criteria. Major Depressive Disorder (MDD) (17.4% vs 2.72%, P <0.0001) but not Bipolar Disorders (BD) (4.3% vs 0.5%, P = 0.99) was higher in cases (N=46) than in controls (N= 184). SF-12 scores in cases were lower than in controls (30.56±8.12 vs 36.81±6:40; p <0.001) with QoL comparable to serious chronic diseases of the central nervous system. The burden of a concomitant MDD or BD amplifies QoL impairment. CONCLUSION: Comorbid MD aggravates the impairment of QoL in CA. Unlike autoimmune diseases or degenerative diseases of the Central Nervous System, CA shows a strong risk of MDD than BD.

Association between internal carotid artery dissection and arterial tortuosity.

INTRODUCTION: Carotid artery dissection is an important cause of ischemic stroke in all age groups, particularly in young patients. The purpose of this work was to assess whether there is an association between the presence of an internal carotid artery dissection (ICAD) and the arterial tortuosity. METHODS: This study considered 124 patients (72 males and 52 females; median age 57 years) with CT/MR diagnosis of ICAD of the internal carotid artery were considered in this multi-centric retrospective study. The arterial tortuosity was evaluated and, when present, was categorized as elongation, kinking, or coiling. For each patient, both the right and left sides were considered for a total number of 248 arteries in order to have the same number of cases and controls. Fisher's exact test was applied to test the association between elongation, kinking, coiling, dissection, and the side affected by CAD. RESULTS: Fisher's exact test showed a statistically significant association between the ICAD and kinking (p = 0.0089) and coiling (p = 0.0251) whereas no statistically significant difference was found with arterial vessel elongation (p = 0.444). ICAD was more often seen on the left side compared to the right (p = 0.0001). These results were confirmed using both carotid arteries of the same patient as dependent parameter with p = 0.0012, 0.0129, and 0.3323 for kinking, coiling, and elongation, respectively. CONCLUSION: The presence of kinking and coiling is associated with ICAD.

Patients with carotid atherosclerosis who underwent or did not undergo carotid endarterectomy: outcome on mood, cognition and quality of life.

BACKGROUND: To compare the six-month outcome on mood, cognition and quality of life (QoL) in patients with severe carotid atherosclerosis (CA) who underwent carotid endarterectomy (CEA) with subjects who refused treatment. METHODS: Cohort study on consecutive inpatients with CA (stenosis ≥ 50 %) (N = 46; age 72.56 ± 7.26; male 65.2 %). Intervention cohort: subjects who decided to undergo CEA (N = 35); Control cohort patients who refused CEA (N = 11). DSM-IV-Psychiatric diagnosis made by clinicians using interviews, QoL measured by Short Form Health Survey (SF-12); cognitive performance by WAIS Intelligent Coefficient (IC). RESULTS: The study showed a better improvement during six months in Overall IC, Performance IC and Verbal IC in the group that underwent CEA. QoL in the two cohorts did not reach statistical significance. Percentages of patients who improved in the CEA group were significantly higher with regard to Overall and Verbal IC scores, and at the limits of statistical significance in Performance IC. The differences of subject with improvement in SF-12 score in the two groups did not reach statistical significance. Ages below 68 were found to be determinant of a good outcome in Overall IC score. Limit: study conducted with a small sample size. CONCLUSIONS: Patients with severe carotid atherosclerosis who underwent CEA enhanced their cognitive performance.

Is there an association between asymmetry of carotid artery wall thickness (ACAWT) and cerebrovascular symptoms?

PURPOSE: Previous publications demonstrated that multi-detector-row computed tomography Angiography (MDCTA) can evaluate the carotid artery wall thickness (CAWT). The purpose of this work was to compare the asymmetry of CAWT between carotids in symptomatic and asymptomatic patients. MATERIAL AND METHODS: Sixty consecutive symptomatic (males 44; median age 64) and 60 asymptomatic sex- and age-matched patients were analysed by using a 40-detector-row CT system. CAWT was calculated for both carotids in each patient and the ratio between the thicker CAWT and the contra-lateral was calculated to obtain the ACAWT index. Bland-Altman, logistic regression and receiver operating characteristic (ROC) curve analysis were calculated. RESULTS: The Bland-Altman plot demonstrates a very good agreement between measurements with a mean difference value of 3.4% and 95% CI from -8% to 14.8%. The ACAWT was significantly different between symptomatic and asymptomatic patients (with a p value of 0.0001). The ROC area under the curve was 0.742 (p = 0.001). Logistic regression model indicated that ACAWT, CAWT, stenosis degree, and fatty plaques were independent variables associated with cerebrovascular symptoms (p value, respectively, 0.0108, 0.0231, 0.0002, and 0.013). CONCLUSION: Results of our study indicated that the index of asymmetry in the CAWT might be used as a further parameter to stratify the risk of symptoms related to carotid artery.

Association between the volume of carotid artery plaque and its subcomponents and the volume of white matter lesions in patients selected for endarterectomy.

OBJECTIVE: The amount of cerebral white matter lesions (WMLs) and the severity of carotid artery disease are correlated in this study. The association between the severity of WMLs and the volume of the different components of carotid artery plaque is also evaluated. MATERIALS AND METHODS: Fifty consecutive patients (39 men, 11 women; mean [SD] age, 71 ± 9 years) with carotid artery stenosis who underwent carotid endarterectomy were included in this study. On admission, patients underwent head and neck CT angiography (CTA) and brain MRI. The CTA-based plaque volume and the percentages of the three main plaque components (fatty, mixed, and calcified) were calculated according to the attenuation values. Leukoaraiosis lesion volume on FLAIR images was determined using a semiautomated segmentation technique. Pearson correlation was conducted between the leukoaraiosis lesion volume on FLAIR images and the volumes of the different plaque components. RESULTS: Pearson correlation analysis was performed to determine WML volume versus total carotid plaque volume (ρ = 0.2531; p = 0.0262), fatty plaque volume (ρ = 0.387; p = 0.0005), mixed plaque volume (ρ = 0.1709; p = 0.15), and calcified plaque volume (ρ = 0.0146; p = 0.899). The WML volume was also compared against fatty plaque percentage (ρ = 0.343; p = 0.0018), mixed plaque percentage (ρ = 0.181; p = 0.124), and calcified plaque percentage (ρ = -0.209; p = 0.068). CONCLUSION: The cerebral WML volume and the total volume of the plaque are correlated. The amount of fat within the plaque is an additional risk factor, whereas the calcified component seems to be protective.

Automated analysis of intima-media thickness: analysis and performance of CARES 3.0.

OBJECTIVES: In recent years, the use of computer-based techniques has been advocated to improve intima-media thickness (IMT) quantification and its reproducibility. The purpose of this study was to test the diagnostic performance of a new IMT automated algorithm, CARES 3.0, which is a patented class of IMT measurement systems called AtheroEdge (AtheroPoint, LLC, Roseville, CA). METHODS: From 2 different institutions, we analyzed the carotid arteries of 250 patients. The automated CARES 3.0 algorithm was tested versus 2 other automated algorithms, 1 semiautomated algorithm, and a reader reference to assess the IMT measurements. Bland-Altman analysis, regression analysis, and the Student t test were performed. RESULTS: CARES 3.0 showed an IMT measurement bias ± SD of -0.022 ± 0.288 mm compared with the expert reader. The average IMT by CARES 3.0 was 0.852 ± 0.248 mm, and that of the reader was 0.872 ± 0.325 mm. In the Bland-Altman plots, the CARES 3.0 IMT measurements showed accurate values, with about 80% of the images having an IMT measurement bias ranging between -50% and +50%. These values were better than those of the previous CARES releases and the semiautomated algorithm. Regression analysis showed that, among all techniques, the best t value was between CARES 3.0 and the reader. CONCLUSIONS: We have developed an improved fully automated technique for carotid IMT measurement on longitudinal ultrasound images. This new version, called CARES 3.0, consists of a new heuristic for lumen-intima and media-adventitia detection, which showed high accuracy and reproducibility for IMT measurement.

Association between carotid plaque enhancement shown by multidetector CT angiography and histologically validated microvessel density.

PURPOSE: Carotid plaques analysed by MDCTA can show contrast enhancement. The purpose of this study was to explore the association between carotid plaque enhancement (CPE) and microvessel density. MATERIALS AND METHODS: We obtained IRB approval. Twenty-nine consecutive (male, 20; median age, 63) symptomatic patients studied with 16-detector CT were prospectively analysed. Examinations were performed before and after intravenous contrast medium administration, and analysis of plaque enhancement was performed. Patients underwent "en bloc" carotid endarterectomy; histological sections were prepared and the presence of microvessels quantified. Logistic regression analysis as well as ROC curve and area under the curve was calculated. RESULTS: A statistically significant association between the degree of CPE and microvessel density (P = 0.009; rho = 0.553) was observed. The ROC curve analysis confirmed this association with an area under the curve of 0.906, 0.735, 0.644 and 0.546 for CPE of 10 HU, 15 HU, 20 HU and 25 HU respectively. There was a statistically significant difference between the CPE and the degree of neovascularisation (P = 0.0003). CONCLUSION: Results of this preliminary study suggest that CPE might be associated with the microvessel density. Histological analysis seems to demonstrate that the degree of intra-plaque neo-vascularisation is statistically associated with CPE. KEY POINTS: Carotid artery plaque enhancement at CT is associated with microvessel density. The degree of intra-plaque neo-vascularisation is statistically associated with carotid plaque enhancement. Plaque enhancement at CT should be considered when assessing vulnerable plaques.

Association between carotid artery plaque volume, composition, and ulceration: a retrospective assessment with MDCT.

OBJECTIVE: The purpose of this study was to evaluate the relationship between MDCT angiography-assessed carotid artery plaque volume and composition and the presence of ulceration. MATERIALS AND METHODS: Seventy consecutive patients (46 men and 24 women; mean age, 63 years; age range, 42-81 years) were studied using MDCT and were retrospectively analyzed. Component types of the carotid plaque were defined according to attenuation value ranges (lipid, < 60 HU; fibrous tissue, 60-130 HU; and calcification, > 130 HU). The plaque volumes of each component were calculated. Statistical analysis was performed using the receiver operating characteristic (ROC) statistic and Wilcoxon signed rank test to evaluate the association between the presence of ulceration and specific plaque components and their volume. RESULTS: Eighteen carotid arteries were excluded, and 16 ulcerated plaques were detected in the remaining 122 carotid arteries. Wilcoxon and ROC curve analysis showed a statistically significant association between increased relative lipid volume and ulceration (p = 0.0001; area under the ROC curve, 0.916). The total volume of the plaque did not show an association with the presence of ulceration (p = 0.0526). CONCLUSION: The results of our retrospective study suggest that there is no correlation between total carotid atherosclerotic plaque volume and ulcerations, whereas plaque relative lipid volume (using attenuation of < 60 HU) is associated with the presence of ulceration. This finding could indicate vulnerable plaques and increased risk for cerebrovascular events.

Comparison between postprocessing techniques in the analysis of hepatic arteries using multi-detector-row computed tomography angiography.

PURPOSE: Our purpose was to compare 4 different postprocessing techniques (maximum-intensity projection [MIP], multiplanar reconstruction, curved planar reconstruction, and volume rendering [VR]) for the study of hepatic arteries. METHODS: One hundred thirty-seven patients who underwent multi-detector-row computed tomography angiography between August 2009 and January 2010 were retrospectively analyzed. For each patient and for each reconstruction method, the image quality was evaluated and the interobserver and intraobserver agreement was calculated according to Cohen statistics. RESULTS: The Pearson r between the observers for the common hepatic artery measurement (Hounsfield unit) was good (r = 0.88). The VR showed a Cohen κ value of 0.78, and the highest image-quality score was obtained using MIP (total value, 384; mean value, 3.01) for observer 1 and using VR and MIP for observer 2 (mean value of 2.94). CONCLUSIONS: Maximum-intensity projection and VR showed the optimal interobserver and intraobserver agreement and the highest quality scores and therefore should be used as postprocessing techniques when analyzing the hepatic arteries.