BACKGROUNDMagnetic resonance imaging (MRI) is the most sensitive technique for evaluating the healing process and should be performed before the patients return to their exercise routines. The aim of this research was to diagnose chronic lumbago associated with lumbar muscle strain and to monitor healing process by MRI.

METHODSSixty-fve symptomatic cases of chronic lumbago caused by lumbar muscle strain were collected from March 2009 to October 2011. MRI was used to examine, diagnose and monitor the healing process. The control group included 65 random cases of asymptomatic volunteers. MRI methods included routine sequences of GRE T1WI, TSE T2WI and special sequences of T2-STIR-FS, combined with DWI. We compared the MRI characteristics of symptomatic cases before and after healing and with asymptomatic controls.

RESULTSThe important MRI characteristics of chronic lumbago with lumbar muscle strain included: (1) The low back muscle showed edema. (2) The low back intermuscular spaces showed edema and/or fluid. (3) The low back spaces beside the spinous process showed edema and/or fluid. (4) The low back vertebral articular process fossae or transverse process fossae showed fluid. Of these image characteristics, the intermuscular space edema provided the best diagnostic sensitivity, Se = 83%, with YI = 0.63, p = 74%. The low back muscle edema provided the best diagnostic specificity, Sp = 100%, with YI = 0.66, Π = 83%. And the spaces edema beside the spinous process provided the best diangnostic accuracy, Π = 86%, with YI = 0.71, Se = 80%, Sp = 91%. The diagnosis accurate could be improved by combining multiple MRI characteristics. The diagnostic accuracy could achieve Π = 93%, with YI = 0.86, Se = 100% and Sp = 86% when two characteristics were combined. After rehabilitation care, the edema disappeared on the repeated MRI.

CONCLUSIONSMRI may well be a useful diagnostic method for lumbago with lumbar muscle strain. Combining routine sequences with T2-STIR-FS and DWI sequences could demonstrate the pathological changes of lumbar muscle strain and monitor the healing.

Adult ; Chronic Disease ; Diffusion Magnetic Resonance Imaging ; Female ; Humans ; Low Back Pain ; diagnosis ; etiology ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Sprains and Strains ; complications ; Wound Healing

Objective To explore the establishment of the mimetic aging effect in guinea pigs induced by D-galactose, and to detect the biological indicatrix associated with hearing loss and provide a new tool for molecular pathogenesis of hearing loss.Methods Total of 51 guinea pigs were randomly divided into three groups: group A ( model aging group , n = 25) , which were injected with D-galactose (200 mg ·kg-1·d-1 ) by intra peritoneum for 6 weeks, group B ( model control group , n = 18), which were given the same amount of saline only, and group C(vacant group, n = 15) were not treated.Then, The guinea pigs in group A and B were exposed in noise for 8 days, 8 hours once a day.Auditory brainstem response (ABR) was used to test the hearing threshold of guinea pigs thrice, first before the drug administered, then after 6 weeks the drug used, third after noise exposure.And colorimetry was used to analyze the activity of superoxide dismutase (SOD) and malon dialdehyde (MDA) in brain and liver tissue.The DNA of inner ear tissue was harvested and amplified fragment length polymorphism (AFLP) was used to detect the differential polymorphic markers.Results After injection, there was no significant difference in elevation of ABR threshold between the group A and group B ( t = 1.14, P>0.05 ).However, exposure of noise later, elevation in ABR threshold of ( 22.97±10.56) dB PeSPL was observed in group A, and ( 14.16±7.36) dB peSPL in group B.The was significant difference in variation of hearing threshold between group A and group B ( t = 2.78 ,P<0.05 ).The activity of SOD in brain and liver tissue in group A was lower than that in group B.the level of MDA was opposite between group A and group B.The difference between group A and group B was significant ( P<0.01 ) .A differential polymorphic marker was observed by AFLP. Conclusions The mimetic aging effect of the guinea pigs can be induced by D-galactose, and this model can not directly induce the hearing loss.The differential polymorphic marker possibly act as a predisposing factor which can greatly enhance the sensitivity of the ear to the noise.