Article Figures & Data
Figures
- Fig 1.
Non-diffusion-weighted (B0) image and FA, ADC, and eigenvector maps of DTI. Three ROIs are placed over each intraorbital nerve on the b=0 image (A). ROIs on the b=0–averaged image (A) are then transferred onto the FA (B), ADC (C), and eigenvector (D) maps.
- Fig 2.
Routine orbital MR imaging of patients with RP together with DTI maps. Axial T1WI (A), axial fat-saturated T2WI (B), coronal fat-saturated T2WI (C), and the corresponding FA (D), ADC (E), and eigenvector maps (F) of DTI in a 48-year-old patient with RP.
- Fig 3.
The DTI measures of both right and left ONs of patients are compared with corresponding normal ONs of controls. Bar graphs of mean FA, ADC, principal eigenvalue, and orthogonal eigenvalue averaged across the right and left optic nerves are shown in 38 patients with RP compared with the homolateral optic nerves of 35 controls. The error bars denote the SDs across subjects. The units of the ADC, λ//, and λ⊥ measures are in ×10−3 mm2 per second−1. The asterisk indicates a significant difference compared with the homolateral nerves of controls (*P < .01; **P < .001).
- Fig 4.
Correlation of DTI data with visual function. Plot of FA and orthogonal eigenvalue versus mean deviation of the visual field, respectively, averaged across the pixels inside the ROIs along the optic nerves of 38 patients with RP (76 affected eyes).
Tables
Patients (n = 38) Controls (n = 35) P Value Sex (male/female) 24:14 22:13 .979 Age (yr)a 37 ± 15 (6∼62) 36 ± 14 (9∼60) .921 Eyes (NR/NL) 76 (38:38) 70 (35:35) / MDVF (dB)b R −30.26 ± 8.94 (−37.00∼−4.68) −0.69 ± 0.98 (−2.00∼1.23) .000c L −29.41 ± 9.73 (−35.68∼−3.85) −0.54 ± 1.15 (−2.71∼1.45) .000c VA (LogMAR)b R 0.52 ± 0.70 (0∼2) −0.067 ± 0.08 (−0.2∼0.1) .000c L 0.52 ± 0.68 (0∼2) −0.065 ± 0.072 (−0.2∼0.1) .000c Note:—LogMAR indicates logarithm of minimal angle of resolution; NR, number of right eyes; NL, number of left eyes; R, right eye; L, left eye; /, not available.
↵a Values are mean ± SD (range).
↵b Values from patient group are median ± interquartile range (range), and values from control group are mean ± SD (range).
↵c Significant difference is noted between patients and controls.
Patients (n = 38) Controls (n = 35) t Value P Value FA R 0.442 ± 0.077 0.572 ± 0.046 −8.840 .000b L 0.447 ± 0.067 0.581 ± 0.044 −10.083 .000b ADC (×10−3mm2s−1) R 1.367 ± 0.250 1.099 ± 0.166 5.417 .000b L 1.343 ± 0.218 1.068 ± 0.122 6.667 .000b λ// (×10−3mm2s−1) R 5.548 ± 0.288 5.361 ± 0.231 3.030 .003b L 5.521 ± 0.250 5.333 ± 0.191 3.609 .001b λ⊥ (×10−3mm2s−1) R 4.526 ± 0.249 4.218 ± 0.146 6.511 .000b L 4.503 ± 0.213 4.187 ± 0.106 8.041 .000b
