Ultrasound transducer shape has no effect on measurements of lumbar multifidus muscle size

ObjectiveEvidence is currently lacking for guidance on ultrasound transducer configuration (shape) when imaging muscle to measure its size. This study compared measurements made of lumbar multifidus on images obtained using curvilinear and linear transducers.MethodFifteen asymptomatic males (aged 21–32 years) had their right lumbar multifidus imaged at L3. Two transverse images were taken with two transducers (5 MHz curvilinear and 6 MHz linear), and linear and cross-sectional area (CSA) measurements were made off-line. Reliability of image interpretation was shown using intra-class correlation coefficients (0.78–0.99). Muscle measurements were compared between transducers using Bland and Altman plots and paired t-tests. Relationships between CSA and linear measurements were examined using Pearson's Correlation Coefficients.ResultsThere were no significant differences (p > 0.05) in the measurements of the two transducers. Thickness and CSA measurements had small differences between transducers, with mean differences of 0.01 cm (SDdiff = 0.21 cm) and 0.03 cm² (SDdiff = 0.58 cm²) respectively. Width measures had a mean difference of 0.14 cm, with the linear transducer giving larger measures. Significant correlations (p < 0.001) were found between all linear measures and CSA, with both transducers (r = 0.78–0.89).ConclusionMeasurements of multifidus at L3 were not influenced by the configuration of transducers of similar frequency. For the purposes of image interpretation, the curvilinear transducer produced better definition of the lateral muscle border, suggesting it as the preferable transducer for imaging lumbar multifidus.     

Measurement of lumbar multifidus muscle contraction with rehabilitative ultrasound imaging

Rehabilitative Ultrasound Imaging (RUSI) has been validated as a noninvasive method to measure activation of selected muscles. The purpose of this study was to determine the relationship between muscle thickness change, as measured by ultrasonography, and electromyography (EMG) activity of the lumbar multifidus (LM) muscle in normal subjects. Bipolar fine wire electrodes were inserted into the LM at the L4 level of five subjects. Simultaneous EMG and RUSI data (muscle thickness) were collected while subjects performed increasingly demanding postural response tasks thought to activate the LM muscle. To determine the relationship between muscle thickness change and EMG activity, the normalized EMG data were correlated to normalized RUSI data. To determine if the tasks increased the demand on the LM, the mean EMG data were compared over each of the four tasks. Muscle thickness change as measured by RUSI was highly correlated with EMG activity of LM in asymptomatic subjects (r=.79,P<.001). Mean EMG data showed increasing levels of activation across tasks (19-34% of maximum voluntary isometric contraction (MVIC)). The results of the repeated measures ANOVA demonstrated theses differences were significant (F(3,12)=25.39,P<.001). Measurement of muscle thickness change utilizing RUSI is a valid and potentially useful method to measure activation of the LM muscle in a narrow range (19-34% of MVIC) in an asymptomatic population.     

Electromyographic technique for lumbar multifidus examination: comparison of previous techniques used to localize the multifidus

OBJECTIVES: To verify and compare established techniques for needle localization in the multifidus muscle and to explore more practical techniques. DESIGN: Human cadaver study. SETTING: Anatomy laboratory in a university setting. CADAVERS: Six fresh human cadavers. INTERVENTION: A 22-gauge needle was inserted into the multifidus muscle fascicle of 6 cadavers using 2 different techniques described previously in the electrodiagnostic literature by Haig and Stein and colleagues. A mixture of colored latex and contrast dyes (0.1 mL) was injected bilaterally into each fascicle at levels L1 to L5. Two electromyographers performed injections into 60 targeted muscles, affording 120 total insertions. Separate investigators dissected the muscles to determine dye position. MAIN OUTCOME MEASURES: Not applicable. RESULTS: A total of 88 (73%) and 79 (66%) injections were successfully delivered to the targeted multifidus muscles using the Haig and the Stein techniques, respectively. With the Haig method, 22 injections (18%) were delivered to different superficial muscles. With the Stein method, 24 injections were delivered to a common tendon and 3 injections were delivered to the spinal canal. CONCLUSIONS: This study highlights the nonoptimizing accuracy of previous techniques for multifidus needle electromyography. A modified Haig method involving less acute needle angulation relative to the skin surface and closer insertion from the midline may increase accuracy and safety.     

The lumbar multifidus muscle and patterns of pain

This paper describes the patterns of pain induced by injecting hypertonic saline into the lumbar multifidus muscle opposite the L5 spinous process in 15 healthy adult volunteers. All subjects experienced local pain while referred pain was reported by 13 subjects in one of two regions of the thigh; anterior (n=5) or posterior (n=8). These results confirm that the multifidus muscle may be a source of local and referred pain. Comparison of these maps with pain maps following stimulation of the L4 medial dorsal rami and L4-5 interspinous ligaments shows that pain arising from the band of multifidus innervated by the L4 dorsal ramus has a segmental distribution. In addition patterns of pain arising from multifidus clearly overlap those reported for other lumbar structures. These findings highlight the difficulty of using pain distribution to accurately identify specific lumbar structures as the source of pain.     

Ultrasound imaging distinguishes between normal and weak muscle

OBJECTIVE: To determine whether real-time ultrasound imaging can provide quantitative data that distinguish pathologic from healthy muscle and that correlate with strength measures. DESIGN: Nonrandomized matched-pair, repeated-measures design. SETTING: Ultrasound imaging laboratory, rehabilitation medicine department, government research hospital. PARTICIPANTS: Nine patients with stable active or inactive myositis, stratified into 3 groups based on their 10-point manual muscle test (MMT) scores, and 9 age- and gender-matched controls. INTERVENTIONS: Maximal isometric contraction of the rectus femoris muscle in 2 knee-flexion positions (60 degrees, 90 degrees ) during simultaneous ultrasound imaging and muscle force dynamometry. MAIN OUTCOME MEASURES: Changes of the rectus femoris muscle in horizontal (X) and vertical (Y) diameters between relaxed and contracted states, and muscle force measurements. RESULTS: The X diameters decreased and the Y diameters increased during isometric contraction in all participants. For each group, average changes in cross-sectional diameters were consistently higher in controls than in patients. Patients with MMT less than 8 differed significantly from controls in both X and Y dimensions. A moderately strong correlation was found between muscle force and the Y diameter during contraction at 60 degrees (r =.78) and 90 degrees (r =.67) knee-flexion angles. CONCLUSIONS: Ultrasonography provided a quantitative measure of change between relaxed and contracted state of muscle, which correlated with muscle force. Ultrasound identified significant differences in cross-sectional diameters between the myopathic and normal muscles sampled and may be useful for measuring muscle response to drug and exercise therapy.     

Muscle activity onset in the lumbar multifidus muscle recorded simultaneously by ultrasound imaging and intramuscular electromyography

BACKGROUND: Delayed anticipatory muscle activity response in deep abdominal and back muscles has been observed in patients with low back pain, indicative of a pathological condition. Muscle activity onset is traditionally recorded by intramuscular electromyography, but there is a need for a non-invasive and less cumbersome recording method in large clinical studies. An experimental study was carried out to explore whether high-frame rate m-mode ultrasound could measure anticipatory muscle responses ("onset") in the lumbar multifidus muscle reliably and comparably accurate to intramuscular electromyography. METHODS: Muscle activity onset was recorded by ultrasound m-mode and intramuscular electromyography. Ultrasound m-mode with a temporal resolution of 500 s(-1) (frames per second) was used to record rapid movements caused by muscle deformations in multifidus. In ultrasound m-mode, the frequency of each echo signal from 0.15 mm incremental depth levels is analysed. The frequency of these signals is proportional to the velocity of the interrogated tissue. The mean amplitude of the high-pass filtered echo signals within a pre-set depth range was plotted against time, and used to indicate onset. The results were compared to muscle activity onset in the multifidus recorded simultaneously by intramuscular electromyography. FINDINGS: High inter-rater agreement was found for visual determination of onset within both methods. The smallest detectable difference was 21 and 24 ms for electromyography and the ultrasound methods, respectively. The ultrasound m-mode method recorded muscle activity onset in the deep multifidus on average 16 ms (SD 21) later than intramuscular electromyography. For single trials, large variation and thus unacceptable method agreement was found. INTERPRETATION: Ultrasound m-mode imaging at high time resolution can detect onset of muscle activity comparably accurate to intramuscular electromyography, but with a small systematic delay that should be corrected for in onset determination by m-mode ultrasound. Regardless of recording method, onset estimates should be based on averaged values of repeated trials. Further studies are needed to explore the applicability of the ultrasound method in clinical settings.     

超声引导下臂丛、腰丛神经阻滞

近年来，介入超声特别是术中超声技术飞速发展，超声引导下神经阻滞麻醉作为一个超声应用的新兴领域正逐渐被临床所重视。超声引导下神经阻滞不仅仅是在可视条件下直接阻滞神经，而且有利于观察神经周围结构和动态观察局麻药的扩散情况。超声引导的优势不仅仅是提高麻醉的成功率、减少并发症，更重要的是超声引导下麻醉将导致传统麻醉领域技术革新。     

The effect of chronic low back pain on size and contraction of the lumbar multifidus muscle

Decreases in the size of the multifidus muscle have been consistently documented in people with low back pain. Recently, ultrasound imaging techniques have been used to measure contraction size of the multifidus muscle, via comparison of the thickness of the muscle at rest and on contraction. The aim of this study was to compare both the size (cross-sectional area, CSA) and the ability to voluntarily perform an isometric contraction of the multifidus muscle at four vertebral levels in 34 subjects with and without chronic low back pain (CLBP). Ultrasound imaging was used for assessments, conducted by independent examiners. Results showed a significantly smaller CSA of the multifidus muscle for the subjects in the CLBP group compared with subjects from the healthy group at the L5 vertebral level (F = 29.1, p = 0.001) and a significantly smaller percent thickness contraction for subjects of the CLBP group at the same vertebral level (F = 6.6, p = 0.02). This result was not present at other vertebral levels (p > 0.05). The results of this study support previous findings that the pattern of multifidus muscle atrophy in CLBP patients is localized rather than generalized but also provided evidence of a corresponding reduced ability to voluntarily contract the atrophied muscle.     

建立不同孕周胎儿胆囊的正常参考值范围

目的探讨胎儿胆囊的正常值,为产前检查提供评价胎儿生长发育的新的指标。方法收集在徐州市妇幼保健院接受产前检查且发育正常的1345胎15～40孕周胎儿,测量不同孕周胎儿胆囊的各项参数,评估胆囊的生长发育情况。结果①胆囊各项参数与孕周呈正相关(P均<0.01))。胆囊长径及周长与孕周的相关性最显著(长径:r=0.806,周长:r=0.788)。②经腹超声探查最早可在14周显示胎儿胆囊,但显示率仅为17.00%;16～35周胎儿的胆囊超声显示率均可达90%以上,最高可达100%;36周后显示率明显下降,至38周时显示率为64.71%。结论提供不同孕周胎儿胆囊的正常参考值范围及显示率,可为评估胎儿生长发育提供新的指标。     

Influence of feedback schedule in motor performance and learning of a lumbar multifidus muscle task using rehabilitative ultrasound imaging: a randomized clinical trial

BACKGROUND AND PURPOSE: Low back pain (LBP) may be associated with inadequate multifidus muscle function. Varying the frequency and timing of feedback may enhance acquisition and retention of multifidus muscle recruitment during exercise. SUBJECTS: Subjects without LBP (n=30) were randomly assigned to a constant (CON) or variable (VAR) feedback group. Twenty-eight subjects (mean age=28 years, SD=8.0; mean body mass index=24 kg/m(2), SD=0.70) completed training, and 23 completed retention testing. METHODS: Eight training sessions over 4 weeks included multifidus muscle exercise with rehabilitative ultrasound imaging (RUSI) feedback. Retention was assessed at 1 week and >or=1 month. RESULTS: At the start, both groups had similar performances of multifidus muscle recruitment (Fisher exact test, P=.26). Early in training, the CON group had good success (mean=80%) that was maintained at session 8 (mean=84%), with no difference between sessions 1 and 8 (Wilcoxon signed rank test, P=.19, 95% confidence interval [CI]=-9%, 42%). The VAR group gradually increased success (Wilcoxon signed rank test, P=.002, 95% CI=17%, 59%) between sessions 1 and 8. Both groups sustained their session 8 success when tested for short-term retention at 1 week (CON group: Wilcoxon signed rank test, P=.79; VAR group: Wilcoxon signed rank test, P=.36). At the long-term retention test, the VAR group outperformed the CON group (Wilcoxon score test, P=.04), indicating superior motor learning. DISCUSSION AND CONCLUSION: Variable feedback provided by RUSI resulted in greater success in lumbar multifidus muscle recruitment up to 3 to 4 months after training.     

Intermittent isometric fatigue study of the lumbar multifidus muscle in four-point kneeling: an intra-rater reliability investigation.

Back muscle endurance is considered important in low back pain (LBP) rehabilitation. Specific training of multifidus may also be necessary to restore normal low back function. The reliability of surface electromyogram (EMG) to assess endurance of the multifidus muscle during intermittent isometric exercise was evaluated. Multifidus endurance was monitored in the four-point kneeling exercise position using the power spectral analysis method. Twenty healthy volunteers were tested on three separate occasions. Subjects performed repeat 10 s high-intensity voluntary contractions of multifidus for 3 min. The median frequency (MF) and the integrated-rectified (I-R) EMG signal displayed the fatigue pattern of multifidus. Intraclass correlation coefficients indicated fair-good reproducibility for MF (0.48-0.67) but poor reliability for IR-EMG. In conclusion, problems concerning functional testing protocols for the back muscles remain and careful development is necessary for more realistic rehabilitation monitoring.     

Ultrasound of tibialis anterior muscle and tendon: anatomy,technique of examination,normal and pathologic appearance

Lesions of the tibialis anterior muscle and tendon are not frequently reported in international literature although pathology is not rare. Pathology can be spontaneous, associated with arthropathy or more generalized conditions. Clinical assessment may not be sufficient for distinguishing conditions like tendinopathy, tears, bursitis, etc. Therefore, imaging studies are necessary to plan appropriate therapy. US has a number of advantages, including widespread availability, absence of contraindications and low cost. It can also be used for dynamic studies of the muscle during contraction and relaxation. This article reviews the anatomy of the tibialis anterior, normal variants, the technique used for standard US examination of this muscle and tendon, its normal appearance on US and the sonographic characteristics of the most common lesions that affect it including tips on US-guided injections used for treatment.     

Ultrasound guidance for transforaminal percutaneous endoscopic lumbar discectomy may prevent radiation exposure: A case report

BACKGROUND Percutaneous endoscopic lumbar discectomy(PELD)has become a mature and mainstream minimally invasive surgical technique for treating lumbar disc herniation(LDH).Repeated fluoroscopy,with more than 30 shots on average,is inevitable to ensure its accuracy and safety.However,exposure to X-rays may pose a threat to human health.We herein report a case of ultrasound(US)-assisted PELD in two levels of LDH to explore a new possibility that can reduce the radiation dose during puncture and cannulation in PELD.CASE SUMMARY A 38-year-old man with low back pain and left leg pain for more than 7 years came to our clinic,his symptoms had aggravated for 1 month,and he was diagnosed with L3-4 and L4-5 disc herniations.He received US-guided PELD with good results:His straight leg elevation increased from 40 to 90 degrees after PELD,and his visual analog scale(VAS)and Oswestry Disability Index scores both significantly decreased immediately and 6 mo after PELD.With the guidance of US,he received only two shots of fluoroscopy(fluoroscopic time:4.4 s;radiation dose:3.98 mGy).To our knowledge,this is the first case of US-guided puncture and cannulation of PELD for LDH at two levels.CONCLUSION US could be used to guide PELD and has the potential to largely reduce radiation than traditional X-ray guidance.     

Nasal bone length throughout gestation: normal ranges based on 3537 fetal ultrasound measurements.

OBJECTIVE: To establish normal ranges for nasal bone length measurements throughout gestation and to compare measurements in two subsets of patients of different race (African-American vs. Caucasian) to determine whether a different normal range should be used in these populations. METHOD: Normal nasal bone length reference ranges were generated using prenatal measurements by a standardized technique in 3537 fetuses. RESULTS: The nasal bone lengths were found to correlate positively with advancing gestation (R(2) = 0.77, second-order polynomial). No statistical difference was found between African-American and Caucasian subjects. CONCLUSION: These reference ranges may prove to be useful in prenatal screening and diagnosis of syndromes known to be associated with nasal hypoplasia. Different normal ranges for African-American and Caucasian women are not required.     

Ultrasound imaging of residual limbs: new use for an old technique

The use of ultrasound for diagnosing problems in the residual limb of an individual with an amputation has not been documented in the literature. We present a case where this modality was particularly useful in the diagnosis of an extensive abscess in the distal stump. Ultrasound imaging of compromised residual limbs is useful in the diagnosis of stump infections with infected muscle tissue and deep fluid collection. This technique can help shorten the course of intravenous antibiotics by clarifying the need for surgical intervention.     

The effect of unilateral muscle pain on recruitment of the lumbar multifidus during automatic contraction. An experimental pain study

Changes in control of the multifidus muscle are a likely contributor to low back pain (LBP), however, the underlying mechanisms of these changes are not well understood. To date it remains uncertain if pain has a selective effect on the multifidus muscles, in line with the observations of the selective changes in structure in acute LBP, or a more generalized effect.The objective of this study is to help to elucidate whether acute unilateral muscle pain alters the activation of the multifidus specific at the level and side of the pain or has a more widespread effect.An experimental pain protocol using hypertonic saline was applied to induce unilateral low back muscle pain. Automatic activity of the multifidus muscle during arm lifts was evaluated with dynamic ultrasound measurement, by assessing muscle thickness change during contraction. Multifidus activity of 15 healthy subjects was compared in a non-pain and in a pain condition, at different spinal levels (L3–L4–L5) and at both body sides.Unilateral induced pain at one segmental level reduced muscle thickness increase during contraction, at both body sides and at different lumbar levels.These results do suggest that unilateral pain may have a more widespread effect on multifidus muscle recruitment, affecting the left and right muscles, at different lumbar levels.     

Color Doppler imaging of the eye: normal ranges,reproducibility, and observer variation.

Color Doppler ultrasonography has numerous potential applications in the diagnosis and monitoring of many ocular disease processes. One of its advantages over other investigative and diagnostic tests is its safety and repeatability. To be able to fully assess this technique it is important to have good control data and to know the reproducibility of the technique for each of the retrobulbar vessels. Color Doppler ultrasonography was performed on 80 volunteers, and normal ranges of blood velocity were calculated for the ophthalmic artery and for the central retinal artery and vein. Reduction in the peak systolic and end diastolic velocities in the ophthalmic artery and an increase in resistive index in the central retinal artery and vein were noted with advancing age. With regard to reproducibility of the retrobulbar vessels, 15 healthy persons were chosen at random and intra- and interobserver studies performed. The most reliable and reproducible vessels were the ophthalmic artery and central retinal artery and vein. Greater variation was noted in the posterior ciliary vessels, whereas the superior ophthalmic and vortex veins were unreliable in both detection and velocity measurement. The results provide normal ranges for future studies and demonstrate that reproducible results can be obtained for the orbital vasculature using color Doppler imaging.     

产前超声建立胎儿甲状腺正常参考值

目的 利用超声观察胎儿甲状腺大小与孕周（GA）的关系,建立胎儿发育过程中甲状腺大小的正常参考值范围。方法 应用二维及三维超声计算机辅助虚拟脏器分析技术测量306胎胎龄20~40周正常单胎胎儿甲状腺长径、前后径、横径、周长、面积、体积,并分析各测量值与GA的关系。结果 超声声像图中,胎儿甲状腺呈中等回声,甲状腺大小随GA增加而增大,其与GA的回归方程分别为：长径=0.059GA+0.055（r=0.813,P<0.05）,前后径=0.025GA+0.16（r=0.747,P<0.05）,横径=0.036GA+0.275（r=0.752,P<0.05）,周长=0.159GA-0.135（r=0.744,P<0.05）,面积=0.045GA-0.358（r=0.689,P<0.05）,体积=0.067GA-1.083（r=0.755,P<0.05）。同一医师和不同医师测量甲状腺大小的重复性均较高,且不同医师测量甲状腺大小的一致性较好。结论 产前超声建立胎儿甲状腺大小的正常参考值范围,有助于评估其发育情况及早期诊断甲状腺异常。