Femoropatellar Joint Reaction Detected During a 4486 KM Ultramarathon with Mobile MRI.

Almost nothing is known about the condition of the knee joints of multistage ultra-marathon (MSUM) runner. This is first image-based investigation of the femoropatellar joint (FPJ) using a mobile 1.5T MRI accompanying the MSUM TransEurope Foot-Race (TEFR) 64 stages over 4486 km. Twenty-two (20 male) subjects got a knee MRI-protocol at defined measurement intervals during TEFR: T2*-mapping (FLASH T2*-GRE), TIRM, and fat saturated PD -sequence. In the FPJ 12 different regions were evaluated regarding cartilage T2* and thickness changes and cartilage lesions in course of TEFR and a test on possible compounding factors (running burden, BMI, age) was done if being appropriate. No significant changes in cartilage thickness- and T2*-values were found during TEFR. In 8 runners, at least one single cartilage lesion (Grade 2-3) was found at baseline, but no significant race-related adjacent T2*-changes or progress of the defects could be detected. Analyses on compounding factors were negative. In knees with MPP (5) significantly lower adjacent T2*-values were found. The extreme running burden of a MSUM seems not to have a relevant negative influence on the FPJ tissues, even if cartilage lesions are present.

Effect of short-term unloading on T2 relaxation time in the lumbar intervertebral disc--in vivo magnetic resonance imaging study at 3.0 tesla.

BACKGROUND CONTEXT: Diurnal changes in T2 values, indicative for changes in water content, have been reported in the lumbar intervertebral discs. However, data concerning short-term T2 changes are missing. PURPOSE: The purpose of this study was to investigate the short-term effects of unloading on T2 values in lumbar intervertebral discs in vivo. STUDY DESIGN: Experimental study with repeated measurements of lumbar discs T2 relaxation time during a period of 38 minutes of supine posture. PATIENT SAMPLE: Forty-one patients with acute or chronic low back pain (visual analog scale ≥3). OUTCOME MEASURES: T2 relaxation time in the intervertebral disc, lumbar lordosis angle, and intervertebral disc height. METHODS: Forty-one patients (mean age, 41.6 years) were investigated in the supine position using a 3-tesla magnetic resonance system. Sagittal T2 mapping was performed immediately after unloading and after a mean delay of 38 minutes. No patient movement was allowed between the measurements. One region of interest (ROI) was manually placed in both the anterior and the posterior annulus fibrosus (AF) and three ROIs in the nucleus pulposus (NP). RESULTS: There was a statistically significant decrease in the anterior NP (-2.7 ms; p<.05) and an increase in T2 values in the posterior AF (+3.5 ms; p<.001). Discs with initially low T2 values in the NP showed minor increase in the posterior AF (+1.6 ms; p<.05), whereas a major increase in the posterior AF was found in discs with initially high T2 values in the NP (+6.8 ms; p=.001). Patients examined in the morning showed no differences, but those investigated in the afternoon showed a decrease in the anterior NP (-5.3 ms; p<.05) and an increase in the posterior AF (+7.8 ms; p=.002). No significant differences were observed in other regions. Correlation analysis showed moderate correlations between the time of investigation and T2 changes in the posterior AF (r=0.46; p=.002). CONCLUSIONS: A shift of water from the anterior to the posterior disc regions seems to occur after unloading the lumbar spine in the supine position. The clinical relevance of these changes needs to be investigated.

Quantitative T2 evaluation at 3.0T compared to morphological grading of the lumbar intervertebral disc: a standardized evaluation approach in patients with low back pain.

BACKGROUND: The purpose of our investigation was to compare quantitative T2 relaxation time measurement evaluation of lumbar intervertebral discs with morphological grading in young to middle-aged patients with low back pain, using a standardized region-of-interest evaluation approach. PATIENTS AND METHODS: Three hundred thirty lumbar discs from 66 patients (mean age, 39 years) with low back pain were examined on a 3.0T MR unit. Sagittal T1-FSE, sagittal, coronal, and axial T2-weighted FSE for morphological MRI, as well as a multi-echo spin-echo sequence for T2 mapping, were performed. Morphologically, all discs were classified according to Pfirrmann et al. Equally sized rectangular regions of interest (ROIs) for the annulus fibrosus were selected anteriorly and posteriorly in the outermost 20% of the disc. The space between was defined as the nucleus pulposus. To assess the reproducibility of this evaluation, inter- and intraobserver statistics were performed. RESULTS: The Pfirrmann scoring of 330 discs showed the following results: grade I: six discs (1.8%); grade II: 189 (57.3%); grade III: 96 (29.1%); grade IV: 38 (11.5%); and grade V: one (0.3%). The mean T2 values (in milliseconds) for the anterior and the posterior annulus, and the nucleus pulposus for the respective Pfirrmann groups were: I: 57/30/239; II: 44/67/129; III: 42/51/82; and IV: 42/44/56. The nucleus pulposus T2 values showed a stepwise decrease from Pfirrmann grade I to IV. The posterior annulus showed the highest T2 values in Pfirrmann group II, while the anterior annulus showed relatively constant T2 values in all Pfirrmann groups. The inter- and intraobserver analysis yielded intraclass correlation coefficients (ICC) for average measures in a range from 0.82 (anterior annulus) to 0.99 (nucleus). CONCLUSIONS: Our standardized method of region-specific quantitative T2 relaxation time evaluation seems to be able to characterize different degrees of disc degeneration quantitatively. The reproducibility of our ROI measurements is sufficient to encourage the use of this method in future investigations, particularly for longitudinal studies.

Quantitative in vivo MRI evaluation of lumbar facet joints and intervertebral discs using axial T2 mapping.

OBJECTIVES: To assess the feasibility of T2 mapping of lumbar facet joints and intervertebral discs in a single imaging slab and to compare the findings with morphological grading. METHODS: Sixty lumbar spine segments from 10 low back pain patients and 5 healthy volunteers were examined by axial T2 mapping and morphological MRI at 3.0 Tesla. Regions of interest were drawn on a single slice for the facet joints and the intervertebral discs (nucleus pulposus, anterior and posterior annulus fibrosus). The Weishaupt grading was used for facet joints and the Pfirrmann score was used for morphological disc grading ("normal" vs. "abnormal" discs). RESULTS: The inter-rater agreement was excellent for the facet joint T2 evaluation (r = 0.85), but poor for the morphological Weishaupt grading (kappa = 0.15). The preliminary results show similar facet joint T2 values in segments with normal and abnormal Pfirrmann scores. There was no difference in mean T2 values between facet joints in different Weishaupt grading groups. Facet joint T2 values showed a weak correlation with T2 values of the posterior annulus (r = 0.32) CONCLUSIONS: This study demonstrates the feasibility of a combined T2 mapping approach for the facet joints and intervertebral discs using a single axial slab.

Parametric T2 and T2* mapping techniques to visualize intervertebral disc degeneration in patients with low back pain: initial results on the clinical use of 3.0 Tesla MRI.

OBJECTIVE: To assess, compare and correlate quantitative T2 and T2* relaxation time measurements of intervertebral discs (IVDs) in patients suffering from low back pain, with respect to the IVD degeneration as assessed by the morphological Pfirrmann Score. Special focus was on the spatial variation of T2 and T2* between the annulus fibrosus (AF) and the nucleus pulposus (NP). MATERIALS AND METHODS: Thirty patients (mean age: 38.1 ± 9.1 years; 20 female, 10 male) suffering from low back pain were included. Morphological (sagittal T1-FSE, sagittal and axial T2-FSE) and biochemical (sagittal T2- and T2* mapping) MRI was performed at 3 Tesla covering IVDs L1-L2 to L5-S1. All IVDs were morphologically classified using the Pfirrmann score. Region-of-interest (ROI) analysis was performed on midsagittal T2 and T2* maps at five ROIs from anterior to posterior to obtain information on spatial variation between the AF and the NP. Statistical analysis-of-variance and Pearson correlation was performed. RESULTS: The spatial variation as an increase in T2 and T2* values from the AF to the NP was highest at Pfirmann grade I and declined at higher Pfirmann grades II-IV (p < 0.05). With increased IVD degeneration, T2 and T2* revealed a clear differences in the NP, whereas T2* was additionally able to depict changes in the posterior AF. Correlation between T2 and T2* showed a medium Pearson's correlation (0.210 to 0.356 [p < 0.001]). CONCLUSION: The clear differentiation of IVD degeneration and the possible quantification by means of T2 and fast T2* mapping may provide a new tool for follow-up therapy protocols in patients with low back pain.

Lumbar intervertebral disc abnormalities: comparison of quantitative T2 mapping with conventional MR at 3.0 T.

OBJECTIVE: To assess the relationship of morphologically defined lumbar disc abnormalities with quantitative T2 mapping. METHODS: Fifty-three patients, mean age 39 years, with low back pain were examined by MRI at 3 T (sagittal T1-fast spin echo (FSE), three-plane T2-FSE for morphological MRI, multi-echo spin echo for T2 mapping). All discs were classified morphologically. Regions of interest (ROIs) for the annulus were drawn. The space in between was defined as the nucleus pulposus (NP). To evaluate differences between the classified groups, univariate ANOVA with post hoc Games-Howell and paired two-tailed t tests were used. RESULTS: In 265 discs we found 39 focal herniations, 10 annular tears, 123 bulging discs and 103 "normal discs". T2 values of the NP between discs with annular tear and all other groups were statistically significantly different (all p ≤ 0.01). Discs with annular tears showed markedly lower NP T2 values than discs without. The difference in NP T2 values between discs with focal herniation and normal discs (p = 0.005) was statistically significant. There was no difference in NP T2 values between bulging and herniated discs (p = 0.11) CONCLUSION: Quantitative T2 mapping of the nucleus pulposus of the intervertebral disc in the lumbar spine at 3 T reveals significant differences in discs with herniation and annular tears compared with discs without these abnormalities.