Mengiardi Bernard, Schmid Marius R, Boos Norbert, Pfirrmann Christian W A, Brunner Florian, Elfering Achim, Hodler Juerg
Department of Radiology, Orthopedic University Hospital Balgrist, Forchstrasse 340, CH-8008 Zurich, Switzerland.
Radiology. 2006 Sep;240(3):786-92. doi: 10.1148/radiol.2403050820.
To prospectively evaluate the fat content of paraspinal muscles by using proton magnetic resonance (MR) spectroscopy in patients with chronic low back pain (LBP) and in asymptomatic volunteers matched with regard to age, sex, and body mass index.
The study was approved by the responsible institutional review board. Informed consent was obtained from each patient and each volunteer. Single-voxel proton MR spectroscopy was used to measure the fat content of the lumbar multifidus and longissimus muscles in 25 patients (13 women, 12 men; mean age, 40.5 years) with chronic LBP and in 25 matched asymptomatic volunteers (13 women, 12 men; mean age, 39.8 years). The fat content was also graded semiquantitatively (grades 0-4). The relationship between fat content and LBP duration, LBP intensity, and self-rated disability was assessed (Pearson correlation).
The mean percentage fat content of the multifidus muscle was 23.6% (95% confidence interval [CI]: 17.5%, 29.7%) in patients with chronic LBP and 14.5% (95% CI: 10.8%, 18.3%) in the volunteers (P = .014). The corresponding values for the longissimus muscle were 29.3% (95% CI: 23.4%, 35.3%) in patients with LBP and 26.0% (95% CI: 21.9%, 30.0%) in the volunteers (P = .66). The semiquantitative grading of the fat content of the multifidus muscle was 0 in 12 (48%) of 25 patients and in 14 (56%) of 25 volunteers, 1 in 11 (44%) patients and in eight (32%) volunteers, and 2 in two (8%) patients and three (12%) volunteers. The semiquantitative grading of the fat content of the longissimus muscle was 0 in nine (36%) of 25 patients and 15 (60%) of 25 volunteers, 1 in 13 (52%) patients and nine (36%) volunteers, and 2 in three (12%) patients and one (4%) volunteer. Neither grade 3 nor grade 4 was assigned to any muscle. The grading differences were not significant between patients and volunteers. No significant correlation was found between fat content and pain intensity, pain duration, or self-rated disability.
Proton MR spectroscopy demonstrates a significantly higher fat content in the multifidus muscle in patients with chronic LBP than in asymptomatic volunteers. No difference was detected with a semiquantitative grading system.
通过质子磁共振（MR）波谱法前瞻性评估慢性下腰痛（LBP）患者以及在年龄、性别和体重指数相匹配的无症状志愿者中椎旁肌的脂肪含量。
本研究经负责的机构审查委员会批准。获得了每位患者和每位志愿者的知情同意。采用单体素质子MR波谱法测量25例慢性LBP患者（13名女性，12名男性；平均年龄40.5岁）和25名匹配的无症状志愿者（13名女性，12名男性；平均年龄39.8岁）的腰多裂肌和最长肌的脂肪含量。脂肪含量也进行了半定量分级（0 - 4级）。评估了脂肪含量与LBP持续时间、LBP强度和自我评定残疾之间的关系（Pearson相关性）。
慢性LBP患者多裂肌的平均脂肪含量百分比为23.6%（95%置信区间[CI]：17.5%，29.7%），志愿者为14.5%（95%CI：10.8%，18.3%）（P = 0.014）。LBP患者最长肌的相应值为29.3%（95%CI：23.4%，35.3%），志愿者为26.0%（95%CI：21.9%，30.0%）（P = 0.66）。25例患者中有12例（48%）和25例志愿者中有14例（56%）多裂肌脂肪含量半定量分级为0级，11例（44%）患者和8例（32%）志愿者为1级，2例（8%）患者和3例（12%）志愿者为2级。最长肌脂肪含量半定量分级为0级的25例患者中有9例（36%）和25例志愿者中有15例（60%），1级的13例（52%）患者和9例（36%）志愿者，2级的3例（12%）患者和1例（4%）志愿者。没有任何肌肉被评为3级或4级。患者和志愿者之间的分级差异不显著。未发现脂肪含量与疼痛强度、疼痛持续时间或自我评定残疾之间存在显著相关性。
质子MR波谱法显示慢性LBP患者多裂肌的脂肪含量明显高于无症状志愿者。半定量分级系统未检测到差异。
