Fried-Breadstick sign: A novel marker for healthy vasculature in magnetic resonance angiography

The Fried-Breadstick sign is characterized as a continuous signal loss at the center of the intracranial internal carotid artery (ICA) on time-of-flight magnetic resonance angiography (TOF-MRA). In this study, we present a novel imaging marker on TOF-MRA and investigate its potential association with ICA-middle cerebral artery (ICA-MCA) atherosclerosis and ischemic stroke. Vessel wall magnetic resonance imaging data were obtained from patients with recent clinical stroke or asymptomatic patients with suspected middle cerebral artery (MCA) atherosclerosis, covering the period from January 2007 to August 2015. We conducted a comparative analysis of ICA stenosis, MCA atherosclerosis and stenosis degree, and the terminal ICA bifurcation angle between ICA-MCAs with and without the Fried-Breadstick sign, involving a total of 1,005 ICA-MCAs from 553 patients. The Fried-Breadstick sign exhibited a higher prevalence in non-to-mild stenotic ICAs (57.5% vs. 9.8% in severely stenotic ICA, P < 0.001) and plaque-free MCAs (53.2% vs. 26.6% in MCAs with plaque, P < 0.001). Factors independently associated with the presence of the Fried-Breadstick sign included MCA stenosis degree (odds ratio [OR]: 0.85/10% increase, 95% confidence interval [CI]: 0.80 – 0.90), ICA stenosis (compared to non-to-mild stenosis, moderate stenosis: OR: 0.39, 95% CI: 0.28 – 0.54, severe stenosis: OR: 0.10, 95% CI: 0.06 – 0.17), and terminal ICA bifurcation angle (OR: 0.86/10° increase, 95% CI: 0.79 – 0.93). In atherosclerotic MCAs without luminal narrowing, the Fried-Breadstick sign was also less frequently observed than in plaque-free MCAs (34.6% vs. 53.2%, P = 0.012). In conclusion, the presence of the Fried-Breadstick sign is associated with healthier ICA-MCAs devoid of stenosis or plaque. The Fried-Breadstick sign may signify healthy ICA-MCA hemodynamics, serving as a potential screening tool for intracranial atherosclerosis without incurring additional cost or risk.