MRI findings of disc protrusion , nerve root displacement or compression , disc degeneration , and high intensity zone are all associated with LBP , but individually , none of these abnormalities provides a strong indication that LBP is attributable to underlying pathology .
This limits their value in refining epidemiological case definitions for LBP
OBJECTIVE to assess how confidently  low back pain ( LBP ) can be attributed to abnormalities on magnetic resonance imaging ( MRI ) , and thereby explore the potential value of MRI abnormalities in refining case definition for mechanical LBP in epidemiological research .
SUMMARY OF BACKGROUND DATA most epidemiological studies of mechanical LBP have defined cases only by reported symptoms , but it is possible that the potency of causes differs depending on whether there is demonstrable underlying spinal pathology .
Are first-time episodes of serious LBP associated with new MRI findings?
BACKGROUND Magnetic resonance ( MR ) imaging is frequently used to evaluate first-time episodes of serious low back pain ( LBP ) . Common degenerative findings are often interpreted as recent developments and the probable anatomic cause of the new symptoms . To date no prospect i ve study has established a baseline MR status of the lumbar spine in subjects without significant LBP problems and prospect ively surveyed these subjects for acute changes shortly after new and serious LBP episodes . This method can identify new versus old MR findings possibly associated with the acute symptomatic episode . PURPOSE To determine if new and serious episodes of LBP are associated with new and relevant findings on MRI . STUDY DESIGN Prospect i ve observational study with baseline and post-LBP MRI monitoring of 200 subjects over 5 years . OUTCOME MEASURES Clinical outcomes : LBP intensity ( visual analogue scale ) , Oswestry Disability Index , and work loss . MRI outcomes : disc degeneration , herniation , annular fissures , end plate changes , facet arthrosis , canal stenosis , spondylolisthesis , and root impingement . METHODS 200 subjects with a lifetime history of no significant LBP problems , and a high risk for new LBP episodes were studied at baseline with physical examination , plain radiographs , and MR imaging . Subjects were followed every 6 months for 5 years with a detailed telephone interview . Subjects with a new severe  LBP episode ( LBP > or=6/10,>1 week ) were assessed for new diagnostic tests . New MR imaging , taken within 6 to 12 weeks of the start of a new LBP episode , was compared with baseline ( asymptomatic ) images . Two independent and blinded readers evaluated each baseline and follow-up study . RESULTS During the 5-year observation period of 200 subjects , 51 ( 25 % ) subjects were evaluated with a lumbar MRI for clinical ly serious LBP episodes , and 3/51 ( 6 % ) had a primary radicular complaint . These 51 subjects had 67 MR scans . Of 51 subjects , 43 ( 84 % ) had either unchanged MR or showed regression of baseline changes . The most common progressive findings were disc signal loss ( 10 % ) , progressive facet arthrosis ( 10 % ) , or increased end plate changes ( 4 % ) . Only two subjects , both with primary radicular complaints , had new findings of probable clinical significance ( 4 % ) . Subjects having another MR were more likely to have had chronic pain at baseline ( odds ratio [OR]=3.19 ; 95 % confidence interval [ CI ] 1.61 - 6.32 ) , to smoke ( OR=5.81 ; 95 % CI 1.99 - 16.45 ) , have baseline psychological distress ( OR 2.27 ; 95 % CI 1.15 - 4.49 ) , and have previous disputed compensation cl aims ( OR=2.35 ; 95 % CI 0.97 - 5.69 ) . Subjects involved in current compensation cl aims were also more likely to have an MR scan to evaluate the LBP episode ( risk ratio=4.75 , p<.001 ) , but were unlikely to have significant new findings . New findings were not more frequent in subjects with LBP episodes developing after minor trauma than when LBP developed spontaneously . CONCLUSION Findings on MR imaging within 12 weeks of serious LBP inception are highly unlikely to represent any new structural change . Most new changes ( loss of disc signal , facet arthrosis , and end plate signal changes ) represent progressive age changes not associated with acute events . Primary radicular syndromes may have new root compression findings associated with root irritation
MRI findings of disc protrusion , nerve root displacement or compression , disc degeneration , and high intensity zone are all associated with LBP , but individually , none of these abnormalities provides a strong indication that LBP is attributable to underlying pathology .
This limits their value in refining epidemiological case definitions for LBP
OBJECTIVE to assess how confidently  low back pain ( LBP ) can be attributed to abnormalities on magnetic resonance imaging ( MRI ) , and thereby explore the potential value of MRI abnormalities in refining case definition for mechanical LBP in epidemiological research .
SUMMARY OF BACKGROUND DATA most epidemiological studies of mechanical LBP have defined cases only by reported symptoms , but it is possible that the potency of causes differs depending on whether there is demonstrable underlying spinal pathology .