High-resolution MR Imaging For Carotid Plaque And A Comparative Study With Ultrasound

Objective: To evaluate the difference between ultrasound and high-resolution MRI(HR-MRI)in plaque load description.Methods:45 carotid artery plaques were detected by both ultrasound and HR-MRI,and were matched by two methods.There were 21 cases enrolled in this study,15 male cases,6 female cases,with a mean age of 61.3±9.9 years old.Among them,7 cases were smoking,drinking in 11 cases,hyperlipidemia in 10 cases,hypertension in 10 cases,diabetes in 8 cases,and cerebral infarction in 5 cases.The plaque number and distribution were described by two experienced physicians(the external carotid artery plaques were not included in this study).The maximum wall thickness(MWT),lumen area(LA),wall area(WA)and total vessel area(TVA)of the plaques were measured on both ultrasound and HR-MRI images.Normalized wall index(NWI)was calculated using the wall area divided by the total vessel area.Consistency analysis of those five morphological indexes were processed.Result: The position distribution of 45 plaques are: 7 at left common carotid artery,7 at right common carotid artery,9 at left bifurcation,10 at right bifurcation,5 at left internal carotid artery,7 at right internal carotid artery.The consistency ratio of the two methods was 93.3%(42/45).The average MWT,LA,WA,TVA and NWI were 2.88 mm,45.94mm2,40.5 mm2,86.66 mm2 and 0.50 by using HR-MRI?The average MWT,LA,WA,TVA and NWI were 2.56 mm,43.05 mm2,40.16 mm2,82.59 mm2 and 0.50 by using ultrasound.After statistical analysis,there was no significant difference in MWT,LA,WA,TVA and NWI detected by HR-MRI and ultrasound(P>0.05).Conclusion: There is a good consistency between HR-MRI and conventional ultrasound in the measurement of plaque load.The two methods can be used to evaluate the plaque load accurately.