Article Figures & Data
Figures
- Fig 1.
A, An original image. B, Image generated by rotating A and deforming the tip of the hat (dashed circle). C, An ordinary subtracted image that was obtained by subtracting image B from A. This step causes misregistration in which a large amount of the white or black area is seen. D and E, Subtracted images that were obtained by subtracting image A from the warped image of image B created by rigid and nonrigid registration, respectively. D, Deformation of the hat remains and leads to misregistration around the tip of the hat. E, Perfect subtraction by restoring the rotation and deformation.
- Fig 2.
First, warped images of the late arterial phase were obtained by using nonrigid registration (SyN–cross-correlation) adjusted to the arterial phase images. The subtracted spinal CTA by using nonrigid registration was then obtained by subtracting warped images that were multiplied by 1.1 from the arterial phase images. R-CTA and conventional spinal CTA were analyzed with digital subtraction angiography results as a reference standard, and the difference in diagnostic performance was assessed.
- Fig 4.
Images of an illustrative case of a 53-year-old man (case 5). Spinal digital subtraction angiography of the right ninth ICA (A) shows a feeder and enlarged vein. C-CTA image (B) and R-CTA (C) at the T9 level can detect the feeder (black arrowhead) from the right ninth ICA. In R-CTA with thin-slab maximum-intensity-projection images, assessing the feeder and continuity is easier than with C-CTA. The window level and width of R-CTA are set to 120 and 240, respectively.
- Fig 5.
Images of an illustrative case of a 57-year-old man (case 10). Spinal digital subtraction angiography of the right second lumbar artery (A) shows a feeder and enlarged vein. In the C-CTA image (B), the right T12 was misread as the feeder (black arrowhead). Furthermore, in C-CTA at the L2 level, the true feeder from the right second lumbar artery was difficult to differentiate from the blooming artifacts of the neighboring bone. However, in R-CTA (C), the true feeder from the right second lumbar artery was easily detected (white arrow). The window level and width of R-CTA are set to 120 and 240, respectively.
- Fig 3.
In an ordinary subtraction image (left), determining the level of the vertebra is difficult because the background is totally equaled. However, in a weighted subtraction image (right), the bone is displayed as a darker structure than background attenuation.
Tables
- Table 1:
Subject characteristics and the level of feeders as shown by spinal digital subtraction angiography results
Case Age (yr) Sex Clinical Manifestation Feeder Type Side and Level Origin 1 60 F Paraplegia – – No AVF 2 83 M Claudication Lt. L1 LA D 3 71 M Paraplegia Rt. L2 LA D 4 78 M Paraplegia Rt. T7, Lt. T11 ICA D 5 53 M Paraplegia Rt. T9 ICA D 6 74 M Paraparesis – – No AVF 7 49 M Paraplegia Lt. T6 ICA PM 8 66 M Paraplegia Lt. T6, Lt. T7 ICA D 9 39 M Paraplegia Lt.T5, Lt. T6 ICA D 10 57 M Paraplegia Rt. L2 LA D 11 67 F Paraplegia Lt. L3 LA PM 12 80 M Paraplegia Rt. T4, Rt. T5 ICA D 13 45 M Paraplegia Rt. T4 ICA D 14 71 M Paraplegia Lt. T3, Rt. T5 ICA PM 15 87 M Paraplegia Lt. T4 ICA D Note:—D indicates dural AVF; LA, lumber artery; PM, perimedullary AVF; –, data not available; ICA, intercostal artery; T, thoracic spine; L, lumbar spine; Rt., right; Lt, left.
Variables C-CTA R-CTA ORa P Values Subject-based analysis Feeder detection accuracy (%) Observer 1 47 (7/15) 80 (12/15) .025b Observer 2 40 (6/15) 73 (11/15) .025b Time required for diagnosis (sec) Observer 1 97.1 ± 37.4 45.1 ± 23.6 .002b Observer 2 89.5 ± 60.0 45.6 ± 24.1 .020b Intervertebral foramen–based analysis Sensitivity (%)c 44.4 (22.2–66.7) 72.2 (50.0–94.4) 3.26 (0.82–13.0) .095 Specificity (%)c 98.1 (97.8–99.5) 99.5 (98.7–100) 3.55 (0.87–14.5) .077 Accuracy (%)c 95.6 (93.8–97.2) 98.2 (96.9–99.2) 2.49 (1.04–6.00) .041b
