Reader response: MRI predicts intracranial hemorrhage in patients who receive long-term oral anticoagulation
George K.Vilanilam, Research Fellow, Mayo Clinic, Florida
Mohammed K.Badi, Research Fellow, Mayo Clinic, Florida
NeethuGopal, Research Fellow, Mayo Clinic, Florida
KaneezZahra, Research Trainee, Mayo Clinic, Florida
Submitted May 28, 2019
We read, with interest, the impressive study by Martí-Fàbregas et al.1 As discussed, the HERO study and the CROMIS-2 study together have elaborated on the safety of oral anticoagulation (OA) in patients with cerebral microbleeds (CMBs).1,2
The nonuniformity of brain MRI protocols was discussed as a limitation in this study.1 This is of importance, as CMBs are radiologic constructs and pathologically represent perivascular hemorrhages.3 It is also well known that a higher magnetic strength and susceptibility-weighted imaging (SWI) sequence are associated with a higher burden of CMBs.4 Where unification of imaging protocols is impossible due to the retrospective nature of studies or due to technical constraints in prospective studies, a statistical correction for MRI field strength and specific blood-sensitive sequences will add novelty as well as increase confidence in the results. In this study,1 there were about 150 (16%) patients who underwent MRI with a 3T scanner and about 450 patients with an SWI sequence. It is unclear whether statistical adjustment for MRI field strength or blood-sensitive sequence were performed. To our knowledge, only 1 study to date has performed this correction for technical confounders.5
Disclosure
The authors report no relevant disclosures. Contact [email protected] for full disclosures.
References
Martí-Fàbregas J, Medrano-Martorell S, Merino E, et al. MRI predicts intracranial hemorrhage in patients who receive long-term oral anticoagulation. Neurology 2019;92:e2432–e2443.
Wilson D, Ambler G, Shakeshaft C, et al. Cerebral microbleeds and intracranial haemorrhage risk in patients anticoagulated for atrial fibrillation after acute ischaemic stroke or transient ischaemic attack (CROMIS-2): a multicentre observational cohort study. Lancet Neurol 2018;17:539–547.
Haller S, Vernooij MW, Kuijer JPA, et al. Cerebral Microbleeds: Imaging and Clinical Significance. Radiology 2018;287:11–28.
Nandigam RN, Viswanathan A, Delgado P, et al. MR imaging detection of cerebral microbleeds: effect of susceptibility-weighted imaging, section thickness, and field strength. AJNR Am J Neuroradiol 2009;30:338–343.
Badi MK, Vilanilam GK, Gupta V, et al. Pharmacotherapy for Patients With Atrial Fibrillation and Cerebral Microbleeds. J Stroke Cerebrovasc Dis Epub 2019 May 15.
We read, with interest, the impressive study by Martí-Fàbregas et al.1 As discussed, the HERO study and the CROMIS-2 study together have elaborated on the safety of oral anticoagulation (OA) in patients with cerebral microbleeds (CMBs).1,2
The nonuniformity of brain MRI protocols was discussed as a limitation in this study.1 This is of importance, as CMBs are radiologic constructs and pathologically represent perivascular hemorrhages.3 It is also well known that a higher magnetic strength and susceptibility-weighted imaging (SWI) sequence are associated with a higher burden of CMBs.4 Where unification of imaging protocols is impossible due to the retrospective nature of studies or due to technical constraints in prospective studies, a statistical correction for MRI field strength and specific blood-sensitive sequences will add novelty as well as increase confidence in the results. In this study,1 there were about 150 (16%) patients who underwent MRI with a 3T scanner and about 450 patients with an SWI sequence. It is unclear whether statistical adjustment for MRI field strength or blood-sensitive sequence were performed. To our knowledge, only 1 study to date has performed this correction for technical confounders.5
Disclosure
The authors report no relevant disclosures. Contact [email protected] for full disclosures.
References