1,721,076 research outputs found
Carotid plaque enhancement and symptom correlations: an evaluation by using multidetector row CT angiography
No full textBACKGROUND AND PURPOSE: The identification of plaque characteristics that determine its vulnerability is extremely important. The purpose of this work was to evaluate CPE after administration of contrast material and to assess whether there is a statistical association between CPE and cerebrovascular symptoms. MATERIALS AND METHODS: Ninety-seven consecutive patients (69 men, 28 women; mean age, 62 years; age range, 39-82 years), studied by using an MDCT scanner, were retrospectively analyzed. Examinations were performed before and after administration of contrast medium. Plaque enhancement was analyzed, and the obtained data were compared with the patient's symptoms. Patients were classified as symptomatic (TIA or stroke with a temporal window of 6 months) or asymptomatic according to neurologic assessment and the TOAST criteria. The ROC curve and Az were calculated, and multiple logistic regression analysis was performed. RESULTS: Thirty-nine patients were excluded because they had calcified plaques (40.2%). CPE was observed in 74% of the remaining 58 patients. A statistically significant difference was observed between symptomatic and asymptomatic patients for the presence of CPE (P = .0013; OR = 7.5). Moreover, we observed that CPE was higher in fatty plaques (P = .035) than in mixed ones and more frequent in the former (P = .0119). The ROC curve demonstrated that a threshold of 15 HU is associated with a specificity and sensitivity of 83.33% and 76.47%, respectively. Multiple logistic regression showed that CPE and symptoms are associated (P = .0315). CONCLUSIONS: The results of our study suggest that for noncalcified carotid plaques, the presence of CPE is associated with cerebrovascular symptoms. Fatty plaques are more likely to have CPE compared with mixed plaque
Differences between MIP and MPR techniques in the carotid artery stenosis degree measurement. Evaluation using multi-detector-row CT angiograph
No full textAIM:
Stroke is the third leading cause of mortality in the world and the stenosis degree is considered a fundamental parameter for the definition of the therapeutic approach. With the development of Multi-Detector-Row CT (MDCTA) scanner, computed tomography has become a widely used imaging technique for categorizing carotid artery stenosis degree. The purpose of this paper is to compare two CT post-processing procedures, maximum intensity projection (MIP) and multi planar reconstruction (MPR) in order to evaluate their sensitivity and inter-technique agreement.
METHODS:
For the purpose 45 patients (35 males and 10 females), that underwent MDCTA for carotid artery evaluation, have been retrospectively evaluated. Data set were processed with the study group's workstations, by using MPR and MIP algorithms. Each patient was assessed for stenosis degree by using North American Symptomatic Carotid Endarterectomy Trial method. Statistic analysis was performed to determine the sensitivity of the used procedure. The Cohen kappa test was applied to assess the level of intra-observer agreement. Image quality was also evaluated.
RESULTS:
MPR sensitivity was 87.8% (95% confidence interval [CI] 81-94.5%) and MIP sensitivity was 91.1% (95% CI 85.2-97%). Agreement in MPR was 0.792 with a standard error (SE) of 0.066, and agreement in MIP was 0.836, with a SE of 0.072.
CONCLUSION:
Results of the study indicate the MIP algorithm is more sensitive than MPR. Best intra-observer agreement and image quality results were also observed in the MIP. Data suggest also that MIP should be the post-processing procedure to be utilized in the evaluation of carotid artery stenosis degree, when using MDCTA. Presence of big calcified plaque can determine difficulties in MIP evaluation of stenosis degree
Comparison between quantification methods of carotid artery stenosis and computed tomographic angiography
No full textPurpose: The purpose of this study was to compare 3 percentage carotid artery measurement methods (the North American Symptomatic Carotid Endarterectomy Trial [NASCET], the European Carotid Surgery Trial [ECST], and the Carotid Stenosis Index [CSI]) and 1 millimeter method (direct millimeter measurement) to evaluate the difference and correlation between them. Materials and Methods: Seven hundred ninety-two patients (591 men; age: mean, 63 years; range, 32-91 years) studied by using a multi-detector row computed tomographic scanner for a total of 1584 carotid arteries were retrospectively analyzed. Each carotid stenosis was measured according to 4 measurement methods (the NASCET, the ECST, the CSI, and the direct millimeter measurement). Carotid arteries with near-occlusion condition were excluded. The Kolmogorov-Smirnov Z test was used to test the normality of continuous variable groups. Comparison of derived ratio-percent methods was performed by using the Bland-Altman plots, and receiver operating characteristic curves were calculated. Correlation coefficients were also calculated by using a nonparametric Spearman correlation. A P < 0.05 was considered to mean statistical significance. Results: Four hundred sixteen carotid arteries were excluded, and in the remaining 1168 ones, a strength correlation according to quadratic regression between the NASCET and ECST methods was observed (Spearman ρ coefficient, 0.948; P < 0.0001). An inverse correlation according to linear regression was observed between the NASCET and the direct millimeter measurement (Spearman ρ coefficient, -0.972; P < 0.0001); the CSI shows a quadratic regression with the NASCET, a linear regression with the ECST, and an inverse linear regression with the direct millimeter measurement (Spearman ρ coefficient, 0.946, 0.932, and -0.939 respectively). The cutoff values for 50% and 70% NASCET stenosis were 2.36 and 1.51, respectively. Conclusions: Our study results indicate that the direct millimeter measurement of stenosis, by using appropriate equations, can reliably predict NASCET-, ECST-, and CSI-type percent stenoses. The use of direct millimeter measurement may remove the pitfalls and the discrepancies deriving from the use of different ratio-percent method
A comparison between NASCET and ECST methods in the study of carotids: evaluation using Multi-Detector-Row CT angiography
No full textPurpose: NASCET and ECST systems to quantify carotid artery stenosis use percent diameter ratios from conventional angiography. With the use of Multi-Detector-Row CT scanners it is possible to easily measure plaque area and residual lumen in order to calculate carotid stenosis degree. Our purpose was to compare NASCET and ECST techniques in the measurement of carotid stenosis degree by using MDCTA. Methods and material: From February 2007 to October 2007, 83 non-consecutive patients (68 males; 15 females) were studied using Multi-Detector-Row CT. Each patient was assessed by two experienced radiologists for stenosis degree by using both NASCET and ECST methods. Statistic analysis was performed to determine the entity of correlation (method of Pearson) between NASCET and ECST. The Cohen kappa test and Bland-Altman analysis were applied to assess the level of inter- and intra-observer agreement. Results: The correlation Pearson coefficient between NASCET and ECST was 0.962 (p < 0.01). Intra-observer agreement in the NASCET evaluation, by using Cohen statistic was 0.844 and 0.825. Intra-observer agreement in the ECST evaluation was 0.871 and 0.836. Inter-observer agreement in the NASCET and ECTS were 0.822 and 0.834, respectively. Agreement analysis by using Bland-Altman plots showed a good intra-\inter-observer agreement for the NASCET and an optimal intra-\inter-observer agreement for the ECST. Conclusions: Results of our study suggest that NASCET and ECST methods show a strength correlation according to quadratic regression. Intra-observer agreement results high for both NASCET and ECS
A study of inferior vena cava anomaly: Evaluation using multi-detector-row CT angiography
No full textVenous malformations, especially absence of inferior vena cava (IVC), are unusual and occasional findings during complementary abdomen examinations or as a consequence of acute venous thrombosis of the vena cava. Absence of inferior vena cava, caused by aberrant development within the 6–8 weeks of gestation, is a rare congenital anomaly. However, it has been recently confirmed as a major risk factor for the development of deep venous thrombosis, especially in young patients. We report a case of a 34-year-old female patient with inferior vena cava agenesis and deep vein thrombosis
Fissured fibrous cap of vulnerable carotid plaques and symptomaticity: are they correlated? Preliminary results by using multi-detector-row CT angiography
No full textPURPOSE:
Carotid artery plaque with a disrupted fibrous cap is characterized by a higher tendency to rupture, resulting in a higher rate of transitory ischemic attack and stroke. The purpose of our study was to evaluate whether there is a statistically significant correlation between the presence of fissured fibrous cap (FFC) (assessed by using multi-detector-row CT angiography (MDCTA)) and ipsilateral symptomaticity. Material and
METHODS:
147 patients (105 males, 42 females; mean age 63 years, range 37-84) with a stenosis of at least 50% or a plaque alteration at sonography were retrospectively studied, yielding a total of 294 carotid arteries, by using a multi-detector-row CT (MDCT) scanner. A search for detection of FFC and a correlation with previously registered data about patients' symptomaticity by using statistical assessment were performed. Each examination was assessed independently by two readers and interobserver agreement was calculated.
RESULTS:
Among the 147 patients included in the study group, 15 were excluded because of inadequate quality images. In the 132 remaining patients, for a total of 264 carotids assessed, 30 FFCs were detected by using MDCTA and overall there were 36 symptomatic patients (12 ipsilateral symptomatic patients with FFC). A statistical correlation between the presence of FFC and symptomaticity (p = 0.0032) was found. The kappa value between readers was 0.781.
CONCLUSIONS:
MDCT may depict FFC and the results of our study suggest that FFC may be used as an indicator for prediction of potential cerebrovascular pathology. The interobserver agreement obtained was good
Correlation between kinking and coiling of the carotid arteries as assessed using MDCTA with symptoms and degree of stenosis
No full textAIM:
To evaluate whether the presence of kinking and coiling of the carotid arteries is associated with symptoms and an increased degree of carotid artery stenosis.
MATERIALS AND METHODS:
One hundred and fifty-three consecutive patients examined using multidetector-row computed tomography angiography (MDCTA) were studied retrospectively. The arterial phase was obtained by injecting 4-6ml/s of contrast material. A total of 306 carotid arteries were assessed for the presence of tortuosity. The degree of carotid artery stenosis was measured according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Logistic regression analysis was performed to determine whether an independent association existed between the presence of vessel tortuosity, symptoms, and the degree of carotid artery stenosis.
RESULTS:
Kinking was detected on 37 occasions (12.1%) and coiling on 20 occasions (6.5%). Using Yates's corrected chi-square test, an association between kinking and symptoms (p=0.002) was observed, but not between coiling and symptoms (p=0.31). Logistic regression confirmed that the strongest association was present between stenosis degree and symptoms (p=0.001), but kinking (p=0.009) and age (p=0.001) were also significantly associated with symptoms. A Mann-Whitney test did not demonstrate correlation between coiling (p=0.16) or kinking (p=0.22) and increased degree of carotid artery stenosis.
CONCLUSION:
The results suggest that kinking may be associated with symptoms, whereas coiling does not appear to be associated with symptoms. The degree of carotid artery stenosis severity is not related to the presence of vessel tortuosity
Spiral computed tomography imaging of bowel ischemia: a literature review.
No full textThe aim of this study was to evaluate the reported diagnostic efficacy of multidetector-row computed tomography (MDCT) for bowel ischemia and to identify the radiological signs that permit diagnosis. Based on a review of the literature, spiral CT sensitivity and specificity data were compared, as was the impact of last-generation CT scanner technology on the diagnosis of bowel ischemia. The data source was the PubMed database, from which 106 articles published in English from January 1998 to January 2006 were selected: 18 studies met the inclusion criteria. MDCT was reported to be more sensitive than CT for diagnosing bowel ischemia. The most frequent signs of disease were bowel wall thickening, intramural pneumatosis, mesenteric or portal venous gas, and mesenteric arterial or venous thromboembolism. The results of the literature review suggest that MDCT has high sensitivity for detecting bowel ischemia. Moreover, the use of MDCT angiography to evaluate abdominal vessels offers a better definition of vascular mapping and of the complications of bowel disease
Update on carotid artery imaging
No full textAtherosclerosis is a common systemic problem with multiple arterial sites affected. Some degree of carotid artery narrowing has been reported in up to 75% of men aged >65 years. Stroke is the third leading cause of severe disability in the Western World bringing about every year 4.5 millions of deaths. Extracranial carotid atherosclerotic disease is the major risk factor for the stroke. Nowadays, in the clinical practice, the therapeutical approach is still primary based on the luminal stenosis; however some morphological features of carotid plaques (intraplaque hemorrhage, plaque’s ulcerations, luminal thrombosis, fissured fibrous cap) are associated with and increased risk of stroke. Purpose of this review is to discuss the current state of the art non imaging diagnostic strategies to quantify the luminal stenosis and the to characterize the vulnerable plaques
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