Table 1 Anatomic severity grading score subcomponent descriptions
Attribute | Description | |
|---|---|---|
Proximal Landing Zone | Whole lumen cross-sectional area contour change (CC1) | The difference between the largest measured whole lumen cross-sectional area and the smallest, out of five measurements taken at standardized locations near the proximal landing zone. |
Maximum whole lumen cross-sectional area (mCSA1) | The largest whole lumen cross-sectional area out of five measurements taken at standardized locations near the proximal landing zone. | |
Left common carotid to left subclavian distance (L1) | The centerline distance between the left common carotid and the left subclavian arteries | |
Left common carotid to entry tear distance (L2) | The centerline distance between the left common carotid and the most proximal entry tear.b | |
Calcification and thrombus index (CT) | The volume of thrombus plus calcification divided by the volume of unthrombosed aorta lumen from the LCCA to a level 20 mm distal to the LSA. Thrombus = 51-150 HU; Calcium = > 150 HU | |
Curvature and Tortuosity | Thoracic aorta tortuosity index (TT) | Ratio of centerline distance between left common carotid and superior mesenteric arteries over the straight-line distance between the same two locations |
Intraaortic distance (ID) | Half the minimum distance between the inner curvature of the ascending aorta to the inner curvature of the descending aorta at the most superior level at which the bifurcation of the pulmonary artery can be observed. | |
Arch type | Vertical distance from the (middle of the) origin of the innominate artery to the top of the arch (Inn-Top). Type I: < 1 diameter of the LCCA. Type II: between 1 and 2 LCCA diameters. Type III: > 2 LCCA diameters. | |
Dissection | False lumen cross-sectional area index (FCI) | The ratio between the cross-sectional area of the false lumen and that of the sum of both the false and true lumens, measured 20 mm distal to the LSA. |
False lumen length (FLL) | Centerline measurement from proximal extent of false lumen to distal extent of false lumen, including thrombosed portions. | |
Tear length | Length of largest entry tear measured orthogonal to the centerline.b | |
Number of observable tears | ||
Tear circumferential location | Location of the tearb | |
Branch Vesselsa | Location (BVL) | Number of branch vessels whose ostia are located partially or entirely in the false lumen |
Patency (BVP) | BVP is based on an occlusion index (OI), where a branch vessel is assigned an index of 0 if the ostium is patent, 1 if partially occluded and 2 if completely occluded. BVP for each patient is then categorized based on the summed occlusion indices of all branch vessels. | |
Supraceliac Aorta Anatomy | Whole lumen cross-sectional area contour change (CC2) | The difference between the largest measured whole lumen cross-sectional area and the smallest, out of eight measurements taken at standardized locations on the supraceliac aorta. |
Maximum whole lumen cross-sectional area (mCSA2) | The largest whole lumen cross-sectional area out of eight measurements taken at standardized locations on the supraceliac aorta. |