Time Course and Clinical Correlates of Retinal Diffusion Restrictions in Acute Central Retinal Artery Occlusion

Abstract

BACKGROUND AND PURPOSE: Retinal diffusion restrictions were recently identified as a regular finding in acute central retinal artery occlusion. We sought to investigate the influence of technical MR imaging and clinical parameters on the detection rate of retinal diffusion restrictions on standard brain DWI. MATERIALS AND METHODS:In this retrospective cohort study, MR imaging scans of patients with central retinal artery occlusion were assessed by 2 readers for retinal diffusion restrictions on DWI performed within 2 weeks after vision loss. The influence of clinical and technical MR imaging parameters and the time interval between symptom onset and DWI on the presence of retinal diffusion restrictions were evaluated. RESULTS:One hundred twenty-seven patients (mean age, 69.6 [SD 13.9] years; 59 women) and 131 DWI scans were included. Overall, the MR imaging sensitivity of retinal diffusion restrictions in acute central retinal artery occlusion was 62.6%-67.2%. Interrater and intrarater agreement for retinal diffusion restrictions was "substantial" with k inter ¼ 0.70 (95% CI, 0.57-0.83) and k intra ¼ 0.75 (95% CI, 0.63-0.88). Detection of retinal diffusion restrictions did not differ with differences in field strengths (1.5 versus 3T, P ¼ .35) or sequence type (P ¼ .22). Retinal diffusion restrictions were consistently identified within the first week with a peak sensitivity of 79% in DWI performed within 24 hours after symptom onset. Sensitivity of retinal diffusion restrictions declined in the second week (10.0%, P , .001). Absence of retinal diffusion restrictions was more prevalent in patients without fundoscopic retinal edema (60% versus 27.1%, P ¼ .004) and with restitution of visual acuity at discharge (75% versus 28.4%, P ¼ .006).CONCLUSIONS: Retinal diffusion restrictions in acute central retinal artery occlusion can be reliably identified on DWI performed within 24 hours and 1 week after onset of visual impairment. Detectability of retinal diffusion restrictions is dependent on the clinical course of the disease.ABBREVIATIONS: CRAO ¼ central retinal artery occlusion; logMAR ¼ Logarithm of the Minimum Angle of Resolution; RDR ¼ retinal diffusion restrictions; VA ¼ visual acuity S udden and painless monocular visual impairment is the characteristic clinical feature of nonarteritic acute central retinal artery occlusion (CRAO), which is mainly caused by proximal embolism originating from the heart or atherosclerotic lesions of the aortic arch and carotid arteries. 1 Patients with CRAO develop persistent and debilitating central scotoma if the blood supply to

Retinal diffusion restrictions in acute branch retinal arteriolar occlusion

“…This retrospective investigation of 85 patients is the first to confirm the presence of RDR in patients with BRAO on routine stroke DWI–MRI, although overall sensitivity, as well as interrater and intrarater reliability were lower than previously reported for complete CRAO 5 , 9 . The findings of our study are well conceivable, because the area of retinal ischemia in BRAO is generally smaller when compared to complete CRAO and may show considerable variability ranging from hemicentral RAO (caused by occlusion of one of the two main divisions of the CRA at the optic disc) to small, circumscribed lesions, e. g. in peripapillary BRAO.…”

“…In ischemic stroke, a high signal on DWI with low ADC is generally observed within the first week after symptom onset 14 . Interestingly, Danyel et al reported decreased detection of RDR for complete CRAO in DWI performed after the first week 9 . Our study did not find differences in RDR detection rates among time interval groups in BRAO patients.…”

“…Recently, retinal diffusion restrictions (RDR) were identified as a characteristic finding on standard brain diffusion-weighted magnetic resonance imaging (DWI MRI) in CRAO patients 5 – 9 , which may aid in the diagnosis of retinal ischemia. However, no studies assessing the diagnostic utility of retinal DWI in BRAO exist as of today.…”

Utility of standard diffusion-weighted magnetic resonance imaging for the identification of ischemic optic neuropathy in giant cell arteritis

“…Finally, the fourth patient presented with vision loss of the right eye with fundoscopic examination revealing retinal edema with cherry red spot sign indicative of central retinal artery occlusion. Although retinal restricted diffusion of the right eye was in accordance with a diagnosis of CRAO 32,33 , DWI further revealed right-sided optic nerve restricted diffusion of the intraorbital portion suggesting concurrent PION (Fig. 3D).…”

“…Cerebral DWI has long been an established method to identify ischemic stroke, which is a feared complication in GCA patients with cranial artery involvement 48 . However, a growing number of case reports [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]49 and systematic studies 26,32,33,50,51 substantiate the presence of DWI abnormalities in non-arteritic ischemic lesions of the optic nerve and retina. Additionally, DTI studies by Fang and Wang et al have observed changes in ON fractional anisotropy in subacute AION of unspecified etiology 52,53 .…”