Table 2 Descriptions and frequency distributions of the categorical parameters
From: Reliability of preoperative MRI findings in patients with lumbar spinal stenosis
Parameter | Severity of degenerative changes | Examined parameters by all observers (%)a |
|---|---|---|
Foraminal stenosis according to Lee et al. [20] | Category 0 (Lee grade 0 and 1): no obliteration of perineural fat, or obliteration only horizontally or vertically | 2019 (88) |
Category 1 (Lee grade 2 and 3): obliteration of perineural fat both horizontally and vertically, with or without structural changes in the nerve | 277 (12) | |
Central canal stenosis according to Schizas et al. [21] | Category 0 (Schizas grade A and B): inhomogeneous or grey fluid signal, recognisable rootlets, posterior epidural fat is present | 605 (63) |
Category 1 (Schizas grade C and D): grey or black signal from the central canal, no recognisable rootlets, posterior epidural fat may or may not be present | 363 (37) | |
Facet joint osteoarthritis according to Weishaupt et al. [22] | Category 0 (Weishaupt grade 0 and 1): normal, or mild joint space reduction and hypertrophy of the articular process, small osteophytes | 681 (34) |
Category 1: (Weishaupt grade 2 and 3): moderate or marked joint space reduction and hypertrophy of the articular process with osteophytes, erosions or cysts | 1335 (66) | |
Redundant nerve roots (RNR) | Category 0: normal appearance of the cauda equina | 941 (79) |
Category 1: tortuous nerves of the cauda equina | 243 (21) | |
Intraspinal cysts | Category 0: no synovial cysts | 1959 (99) |
Category 1: presence of intraspinal synovial cyst | 25 (1) |