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Table 1 Sites of measurement, measurement points and radiologic definitions for central lumbar spinal stenosis

From: Quantitative radiologic criteria for the diagnosis of lumbar spinal stenosis: a systematic literature review

Imaging method

Author

Site of measurement

Level, where measured (measurement points)

Definition of stenosis (cut-off values)

MRI

    
  

Antero-posterior diameter of spinal canal

  
 

Fukusaki [22]

 

Not reported

< 15 mm

 

Koc [23]

 

Not reported

< 12 mm

  

Mid-sagittal diameter of thecal sac

  
 

Herzog [15]

 

Midbody of each vertebra

Compression of thecal sac area in % of normal mid-sagittal diameter:

Grade 1: anterior < 15%

posterior < 10%

Grade 2: anterior 15 - 30%

posterior 10 - 20%

Grade 3: anterior > 30%

posterior > 20%

  

Cross-sectional area of dural tube or sac

  
 

Hamanishi [24]

 

Intervertebral levels: L2/3, L3/4, L4/5

< 100 mm2, at more than two of three intervertebral levels

 

Mariconda [25]

 

Not reported

< 130 mm2

 

Laurencin [26]

 

Motion segment: Intervertebral disc level coincident with flexible joint;

Stable segment:

Level coincident with the mid-pedicle unaffected by stenosis

Stenosis ratio:

Cross-sectional area of dural sac of motion segment divided by stable segment cross-sectional dural sac area:

Level: L3-L4 < 0.66

L4-L5 < 0.62

L5-S1 < 0.73

  

Ligamentous interfacet distance

  
 

Herzog [15]

 

Distance between the innner surface of flaval ligaments on a line connecting the joint space of facet joints at the level of the intervertebral disc

< 10 mm (L2 - L3)

< 10 mm (L3 - L4)

< 12 mm (L4 - L5)

< 13 mm (L5 - S1)

  

Transverse diameter of spinal canal

  
 

Koc [23]

 

Not reported

< 15 mm

 

Ullrich [27]

 

4 zones of measurement:

upper, middle, lower zone of vertebral body and disk space

< 16 mm

CT

    
  

Antero -posterior diameter of spinal canal

  
 

Bolender [28]

 

5 mm intervals from L2 to L5

< 13 mm

 

Haig [4]

 

Not reported

≤ 11.95 mm

 

Lee [29]

 

Not reported

< 15 mm (suggesting narrowing)

< 10 mm (usually diagnostic)

 

Ullrich [27]

 

Four zones of measurement:

Upper, middle, lower zone of vertebral body and disk space

< 11.5 mm

 

Verbiest [30]

 

Not reported

< 12 mm (relative)

< 10 mm (absolute)

  

Antero-posterior diameter of dural sac

  
 

Kalichman [3]

 

Midvertebral body level

10 - 12 mm (relative)

< 10 mm (absolute)

 

Herzog [15]

 

Midbody of each vertebra

Compression of thecal sac area in % of normal mid-saggital diameter:

Grade 1: anterior < 15%

posterior < 10%

Grade 2: anterior 15 - 30%

posterior 10 - 20%

Grade 3: anterior > 30%

posterior > 20%

 

Jönsson [31]

 

Disc level

≤ 10 mm

  

Cross-sectional area of dural sac

  
 

Bolender [28]

 

5 mm intervals from L2 to L5

100 - 130 mm2 (early stenosis)

< 100 mm2 (present stenosis)

 

Laurencin [26]

 

Motion segment: Intervertebral disc level coincident with flexible joint

stable segment:

Level coincident with the mid-pedicle unaffected by stenosis

Stenosis ratio:

Area of motion segment divided by stable segment area

Level: L3-L4 < 0.66

L4-L5 < 0.62

L5-S1 < 0.73

 

Schönström [32]

 

On each CT scan slice

< 100 mm2

 

Schönström [33]

 

Not reported

75 - 100 mm2 (moderate)

< 75 mm2 (severe)

 

Ullrich [27]

 

4 zones of measurement:

Upper, middle, lower zone of vertebral body and disk space

< 145 mm2

  

Ligamentous interfacet distance

  
 

Herzog [15]

 

Intervertebral disc level

< 10 mm (L2-L3)

< 10 mm (L3-L4)

< 12 mm (L4-L5)

< 13 mm (L5-S1)

 

Wilmink [34]

 

Pedicular, infrapedicular and/or disc level

< 11 mm (L4-L5)

Myelography

    

conventional

 

Antero-posterior diameter of contrast column

  
 

Airaksinen [35]

 

Narrowest point

> 12 mm

10 - 12 mm

< 10 mm

Subtotal block

Total block

 

Bolender [28]

 

Intervertebral level

< 13 mm

 

Herno [36]

 

Not reported

< 12 mm

 

Jönsson [31]

 

Disc level

≤ 10 mm

 

Sortland [37]

 

Disc level

< 10.5 mm (lower limit)

< 5.5 - 7 mm (considerable)

 

Verbiest [38]

 

Superior and inferior boarders of the laminae

10 - 12 mm (relative)

< 10 mm (absolute)

Myelo-CT

Mariconda [25]

 

Not reported

< 130 mm2