Yunyan Zhang MD, PhD, Presenter: Nothing to Disclose

Fiona Costello, Abstract Co-Author: Nothing to Disclose

James Norman Scott MD, MSc, Abstract Co-Author: Nothing to Disclose

Luanne M. Metz, Abstract Co-Author: Nothing to Disclose

Optic nerve function and structure can be reliably quantified, which makes it an ideal model to better understand mechanisms of central nervous system injury in multiple sclerosis. Preliminary data suggests that MRI texture analysis has the potential to evaluate tissue integrity. The goal was to correlate lesion texture with structural and functional measures of vision after optic neuritis (ON).

18 patients with ON (15 females; mean age of 36 years) within 15 days of symptom onset were followed in an ongoing prospective study. Optic nerve lesion length, gadolinium (Gd)-enhancing activity, and area ratio (ON to fellow eye) was evaluated on 3T MRI at baseline and month 6. Lesion texture was analyzed concurrently using a spatial-frequency method on the coronal STIR images showing maximal lesion area. Retinal nerve fiber layer (RNFL) thickness (Zeiss Stratus III) and logarithm of minimum angle resolution (logMAR) for visual acuity were assessed at the same time points.

Acute lesions were seen in all ON eye (mean length=14 mm) and two in a fellow eye (4 mm); 12/18 lesions had Gd-enhancement. Relative to the fellow eye, there was a tendency for texture to be coarser (0.46 vs 0.38, p=0.07) and RNFL to be thicker (148 μm vs 86 μm, p=0.09) in the ON eye at baseline. Visual acuity was markedly decreased (0.5 vs 0.05, p<0.01), which correlated only with acute lesion texture (p<0.01). Vision improved in the ON eye by 0.49 (p<0.01), RNFL thinned by 26 μm (p=0.03), and lesion length decreased by1.3 mm (p=0.09) at month 6 compared to baseline. Texture change was not significant (p>0.05). No variable correlated with vision at month 6.

These results suggest that MRI texture measured tissue integrity is a sensitive marker of visual function associated with an acute inflammatory event in the anterior visual pathway. Future work will test the differences from controls and the predictability of texture to visual outcome, which recovers despite residual structural damage in the optic nerve.

Texture analysis in optic neuritis may be a novel strategy to characterize consequences of neuroinflammation, which may serve as an assessing window for MS.

Zhang, Y, Costello, F, Scott, J, Metz, L, Measures of MRI Texture Analysis Correlate with Visual Acuity in Acute Optic Neuritis.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11016998.html