Background: Indications to surgical intervention in patients with carotid artery stenosis is a topic under constant debate, above all in symptomatic patients. Recently, the use of [18F]NaF has been suggested to detect microcalcifiations in the arterial wall, a feature closely associated with macrophage accumulation and in ammation. In this small series of patients we want to perform a proof of concept study on the feasibility of [18F] NaF imaging in patients with symptomatic carotid stenosis. Therefore,we performed [18F]NaF-PET/CT just before carotid endarterectomy and correlate imaging and surgical findings. Methods: Between January-March2018 we evaluate four symptomatic patients(mean age 72.5±8years,range64-80,carot- id stenosis between 50-90%). Time from symptoms onset and surgery varied from 1to8weeks. Whole-body [18F]NaF-PET/CT was performed on Discovery710 General Electric. Images were assessed by visual analysis, semiquantitative parameters(MTV,- SUVmax, SUVmean, SUVsd, TLA). In addition, texture features to better characterized lesion heterogeneity as compared to the contralateral normal/subcritical site were extracted using the LIFEx package from semiautomatically segmented PET and CT images. Results: Intraoperative mean length of carotid plaque was3,12cm(range 2-4cm), three plaques had friable consistency and two of them presented a dual lumen with thrombus separated by a brotic septum. One plaque had brous and smooth consistency, even if preocclusive. All carotid stenosis between50-90% didn’t show signi cant di erences in [18F]NaF uptake compared to contralateral carotid. Comparing homolateral carotid artery stenosis to contralateral vessel we identified a pattern of features with consistent differences (SKEWNESS, COMPACITY, DISSIMILARITY,GLRLM-LRE/HGRE/SRHGE/LRHGE,GL- ZLM-LZE/LZLGE/LZHGE/GLNU,GLDM-CONTRAST). Considering the ultrasound and clinical characteristics of the plaques, in contralateral 50% asymptomatic carotid stenosis of the patient presenting the smooth brous plaque we observed a reversal trend of the following features:COMPACITY,GLZLM-LZE/LZLGE/ LZHGE. Therefore, contralateral 50% asymptomatic plaque and 50% symptomatic plaques share common features not present in the other asymptomatic plaques.This may prelude potential plaque evolution, therefore we are currently follow up the patient to test this possibility. Conclusions: These preliminary data suggest a possible use of [18F]NaF-PET/CT such as texture features, to characterize the heterogeneity of atheromatous lesions potentially predicting asymptomatic carotid plaque evolution causing unexpected cerebro-vascular accidents.

Evaluation of[F-18] NaF uptake in symptomatic and asymptomatic carotid artery plaques and determination of predictive pattern of vulnerable plaque : preliminary results

Belcari, N;Ferrari, M;Berchiolli, R;Erba, P
2018-01-01

Abstract

Background: Indications to surgical intervention in patients with carotid artery stenosis is a topic under constant debate, above all in symptomatic patients. Recently, the use of [18F]NaF has been suggested to detect microcalcifiations in the arterial wall, a feature closely associated with macrophage accumulation and in ammation. In this small series of patients we want to perform a proof of concept study on the feasibility of [18F] NaF imaging in patients with symptomatic carotid stenosis. Therefore,we performed [18F]NaF-PET/CT just before carotid endarterectomy and correlate imaging and surgical findings. Methods: Between January-March2018 we evaluate four symptomatic patients(mean age 72.5±8years,range64-80,carot- id stenosis between 50-90%). Time from symptoms onset and surgery varied from 1to8weeks. Whole-body [18F]NaF-PET/CT was performed on Discovery710 General Electric. Images were assessed by visual analysis, semiquantitative parameters(MTV,- SUVmax, SUVmean, SUVsd, TLA). In addition, texture features to better characterized lesion heterogeneity as compared to the contralateral normal/subcritical site were extracted using the LIFEx package from semiautomatically segmented PET and CT images. Results: Intraoperative mean length of carotid plaque was3,12cm(range 2-4cm), three plaques had friable consistency and two of them presented a dual lumen with thrombus separated by a brotic septum. One plaque had brous and smooth consistency, even if preocclusive. All carotid stenosis between50-90% didn’t show signi cant di erences in [18F]NaF uptake compared to contralateral carotid. Comparing homolateral carotid artery stenosis to contralateral vessel we identified a pattern of features with consistent differences (SKEWNESS, COMPACITY, DISSIMILARITY,GLRLM-LRE/HGRE/SRHGE/LRHGE,GL- ZLM-LZE/LZLGE/LZHGE/GLNU,GLDM-CONTRAST). Considering the ultrasound and clinical characteristics of the plaques, in contralateral 50% asymptomatic carotid stenosis of the patient presenting the smooth brous plaque we observed a reversal trend of the following features:COMPACITY,GLZLM-LZE/LZLGE/ LZHGE. Therefore, contralateral 50% asymptomatic plaque and 50% symptomatic plaques share common features not present in the other asymptomatic plaques.This may prelude potential plaque evolution, therefore we are currently follow up the patient to test this possibility. Conclusions: These preliminary data suggest a possible use of [18F]NaF-PET/CT such as texture features, to characterize the heterogeneity of atheromatous lesions potentially predicting asymptomatic carotid plaque evolution causing unexpected cerebro-vascular accidents.
2018
https://link.springer.com/article/10.1007/s00259-018-4148-3
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/938643
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