Assessment for Carotid Atherosclerotic Plaque Using Vessel Wall Magnetic Resonance Imaging: A Multireader ROC Study to Determine Optimal Sequence for Detecting Vessel Wall Calcification.

INTRODUCTION: We aimed to compare conventional vessel wall MR imaging techniques and quantitative susceptibility mapping (QSM) to determine the optimal sequence for detecting carotid artery calcification. METHODS: Twenty-two patients who underwent carotid vessel wall MR imaging and neck CT were enrolled. Four slices of 6-mm sections from the bilateral internal carotid bifurcation were subdivided into 4 segments according to clock position (0-3, 3-6, 6-9, and 9-12) and assessed for calcification. Two blinded radiologists independently reviewed a total of 704 segments and scored the likelihood of calcification using a 5-point scale on spin-echo imaging, FLASH, and QSM. The observer performance for detecting calcification was evaluated by a multireader, multiple-case receiver operating characteristic study. Weighted κ statistics were calculated to assess interobserver agreement. RESULTS: QSM had a mean area under the receiver operating characteristic curve of 0.85, which was significantly higher than that of any other sequence (p < 0.01) and showed substantial interreader agreement (κ = 0.68). A segment with a score of 3-5 was defined as positive, and a segment with a score of 1-2 was defined as negative; the sensitivity and specificity of QSM were 0.75 and 0.87, respectively. CONCLUSION: QSM was the most reliable MR sequence for the detection of plaque calcification.

Evaluación de un posible modelo experimental de aterosclerosis carotídea en conejos hipercolesterolémicos / Assessment of a possible experimental model of carotid atherosclerosis in hypercholesterolemic rabbits

Se evaluó la utilidad de un procedimiento experimental para desarrollar aterosclerosis carotídea en conejos. Se estudiaron 18 animales divididos en 3 grupos, con 6 animales cada uno. Los animales fueron alimentados mediante pienso suplementado con 0,5 y 1 porciento de colesterol (grupos I y II, respectivamente), en tanto el III (control) solo con pienso. Se hicieron determinaciones bioquímicas antes de comenzar el experimento y en las semanas 4, 8 y 12, posteriores a la dieta. Se observó un aumento significativo en el peso de los animales de los grupos I y II en la semana 8 para p < 0,05, se mantuvieron sin variaciones la hemoglobina y el hematócrito. El colesterol mostró un incremento significativo para los grupos I y II a partir de la semana 4 hasta el final. El estudio morfométrico dio como resultado que en los animales del grupo II en ambas carótidas había presencia de estrías adiposas, lo que demostró la utilidad de este modelo de aterosclerosis carotídea