COMPARISON OF CAROTID STENOSIS GRADING BY CT ANGIOGRAPHY AND DOPPLER ULTRASONOGRAPHY: HOW THE STATISTICAL METHODS APPLIED INFLUENCE THE RESULTS.

In this study, we compared the measurement of carotid stenosis by computed tomography angiography (CTA) based on the narrowest diameter versus cross sectional area (CSA) with the measurement by color Doppler ultrasonography (CDUS) as a reference standard, and analyzed how the application of different statistical methods affected the result. On 113 carotid arteries with ≥50% stenosis, we quantified the level of correlation among the three measurements, sensitivity, specificity, and differences in the estimated stenosis level. Correlation between both CTA measurements was good with Pearson's ρ between 0.87 and 0.91 (p<0.001). Correlation between CDUS and CTA measurements was only modest with Pearson's ρ between 0.2 (p=0.075) and 0.4 (p=0,007) for CDUS CTA (CSA), and between 0.23 (p=0.062) and 0.39 (p=0.008) for CDUS CTA (diameter). Differences in stenosis between CTA (CSA) and CDUS were centered around 0%, and between CTA (diameter) and CDUS around 20%. Sensitivity and specificity for CTA (CSA) method were 81% and 77%, and for CTA (diameter) 23% and 100%, respectively. A good correlation between CSA and diameter measurement just means that these are two related features of stenosis, it does not mean good agreement. CTA (CSA) method better detected surgical stenoses, whereas CTA (diameter) systematically underestimated stenosis level. The study of differences between the measurements indicated agreement better than the calculation of correlation coefficients.

Association of the imaging characteristics of desmoplasia on digital breast tomosynthesis and the Ki-67 proliferation index in invasive breast cancer.

AIM: To evaluate the imaging characteristics of desmoplasia on digital breast tomosynthesis (DBT) and their association with the Ki-67 index. METHODS: Seventy-seven malignant spiculated breast masses were analyzed in terms of tumor size, length and width of spicules, coverage of tumor margin with spicules, and the number of spicules. The Ki-67 index was obtained from surgically removed tumor specimens. RESULTS: The average spicule length was significantly negatively associated with a high Ki-67 (P=0.005, odds ratio [OR] 0.252, 95% confidence interval [CI] 0.094-0.676), ie, the lesions with longer spicules had a 3.968 times lower odds of having a high Ki-67 than the lesions with shorter spicules. The average spicule width at the base was significantly positively associated with Ki-67 (P=0.004, OR 3.939, 95% CI 1.520-10.209), ie, the lesions with thick spicules had a 3.939 times higher odds of having a high Ki-67 than the lesions with thin spicules. The lesions with more than 20 spicules and those with partially spiculated margins more frequently had a high Ki-67 than those with fewer spicules and fully spiculated margins, but the differences were not significant. CONCLUSION: The spiculation analysis could be used as a non-invasive method providing information about malignant lesions. The tumor proliferative activity, and therefore the patient's prognosis, might be predicted before biopsy directly from DBT images.

Grading of carotid artery stenosis with computed tomography angiography: whether to use the narrowest diameter or the cross-sectional area.

OBJECTIVES: To compare the estimation of carotid artery stenosis by computed tomography angiography (CTA) based on cross-sectional area versus the smallest diameter measurement, and test the accuracy of both CTA measurements using color Doppler ultrasonography (CDUS) as a reference method. METHODS: For 113 carotid arteries with stenosis ≥50% we analysed the differences in the estimated stenosis level between both CTA methods and CDUS using the Bland-Altman approach. Further, we calculated sensitivity, specificity and plotted receiver operating characteristic (ROC) curves for both CTA methods. RESULTS: The mean difference between CDUS and CTA (area) measurements was -0.4% (p = 0.68); between CDUS and CTA (diameter), 20.7% (p < 0.001); and between CTA (area) and CTA (diameter), 21.2% (p < 0.001). Sensitivity and specificity for the CTA (area) method were 81% and 77%, and for CTA (diameter) were 23% and 100%. The area under the curve (AUC) for CTA (diameter) was 0.62 (0.57, 0.66), and for CTA (area) 0.79 (0.71-0.87). The equality test for the two AUCs was <0.0001. CONCLUSIONS: CTA (diameter)-based measurements significantly underestimated the degree of carotid stenosis. We recommend the CTA (area) method because of its higher predictive power for a correct stenosis classification and a lack of significant difference in the estimated stenosis level, compared to CDUS. MAIN MESSAGES: • Cross-sectional area measurement considers asymmetric shape of the residual vessel lumen. • CTA (diameter) method on average significantly underestimates the true level of stenosis. • CTA (area) method correctly classifies vessels needing surgical intervention.