Cross-sectional Area Values Research Articles

Cross-sectional area reference values of the median nerve at the palm using ultrasound.

The most common neuromuscular ultrasound abnormality in carpal tunnel syndrome is enlargement of the median nerve near the distal wrist crease, but sometimes the median nerve enlarges in the palm, just distal to the transverse carpal ligament. This study was conducted to devise a protocol for measuring the median nerve in the palm and to generate reference values for nerve cross-sectional area at this site. A systematic protocol was developed, 30 healthy individuals underwent ultrasound of the median nerve in the palm bilaterally, and cross-sectional area was recorded. The mean cross-sectional area of the median nerve at the palm was between 11.4 mm2 (95% confidence interval [CI] [10.4,12.4]) and 11.6 mm2 (95%CI [10.6,12.6]). The median nerve can be measured just distal to the hook of the hamate in the palm, and the mean cross-sectional area at this site is slightly larger than it is at the distal wrist crease.

Smaller cross-sectional areas of the hamstring tendon measured from preoperative ultrasonography are likely to need additional gracilis harvesting for double-bundle anterior cruciate ligament reconstructions

Background/PurposeHamstring tendon autografts are commonly used for double-bundle anterior cruciate ligament reconstruction (DB-ACLR). If the volume of the semitendinosus (ST) tendon is insufficient, the gracilis (G) tendon is also harvested. Additional harvesting of the G autograft can affect patients’ short-term postoperative outcome, such as muscle recovery; thus, preoperative information about whether an additional G autograft is needed would be useful. The purpose of this study was to investigate whether preoperative measurement of the ST tendon using ultrasonography could inform the intraoperative decision to harvest the G tendon.MethodsWe enrolled 20 patients (13 men and seven women) who underwent DB-ACLR between October 2017 and March 2019. The mean patient age was 28.5 years. The ipsilateral ST tendon was measured using ultrasonography before surgery. Measurements included the diameter and breadth of the short-axis image. The cross-sectional area (CSA) was calculated from these measurements. During surgery, when two grafts with diameters of ≥ 5.0 mm could not be made, the G tendon was also harvested. Patients were categorized into two groups: the ST group where only the ST tendon was harvested, and the semitendinosus gracilis tendon (STG) group where the ST and G tendons were both harvested. The CSA value was compared between the two groups, and the cutoff value was calculated.ResultsIn the ST group (n = 8), the mean diameter and breadth of the semitendinosus tendon were 4.21 and 2.34 mm, respectively. In the STG group (n = 12), the mean diameter and breadth of the ST tendon were 3.39 and 1.78 mm, respectively. The CSAs calculated for the ST group and the STG group were 7.74 mm2 and 4.79 mm2, respectively. A cutoff value of 7.0 mm2 was found to correspond to a specificity and sensitivity to harvest the G tendon of 87.5% and 75.0%, respectively.ConclusionsThe preoperative CSA of the ST tendon determined using ultrasonography can, therefore, be informative for deciding whether to harvest the G tendon for DB-ACLR. The results of this study provide valuable information for graft selection in anterior cruciate ligament reconstruction.Level of EvidenceIV (Retrospective case series design).

MRI Measurement of Upper Cervical Spinal Cord Cross-Sectional Area in Children.

Neurological and neurodegenerative diseases can affect the spinal cord (SC) of pediatric patients. Magnetic resonance imaging (MRI) allows for in vivo quantification of SC atrophy via cross-sectional area (CSA). The study of CSA values in the general population is important to disentangle disease-related changes from intersubject variability. This study aimed at providing normative values for cervical CSA in children, extending our previous work performed with adults. Seventy-eight children (age 7-17 years) were selected from a Developmental Dyslexia study. All subjects underwent a 3T brain MRI session and any incidental findings were reported on the scans. A sagittal 1 mm3 3-dimensional T1 -weighted brain acquisition extended to the upper cervical cord was used to measure CSA at C2-C3, as well as spinal canal area and skull volume (V-scale). These three metrics were linearly fitted as a function of age to extract trends and percentage annual changes. Sex differences of CSA were assessed using least squares regression analyses, adjusting for age. We tested normalization strategies proven to be effective in reducing the intersubject variability of adults' CSA. CSA changed as a function of age at a faster rate when compared with skull volume (CSA: 1.82% increase, V-scale: .60% reduction). Sex had a statistically significant effect on CSA. Normalization methods based on canal area and skull volume reduced the CSA intersubject variability up to 16.84%. We present CSA normative values in a large cohort of children, reporting on sources of intersubject variability and how to reduce them applying normalization methods previously developed.

Ultrasonography of cervical nerve roots: cross-sectional reference values according to age.

The aim of this study is to describe the normal cross-sectional area (CSA) and appearance of cervical nerve roots in ultrasound, correlating it to age and other patient somatic parameters. One hundred healthy volunteers were included. We aimed to achieve uniform representation throughout all age groups. Ultrasound of the cervical nerve roots was performed bilaterally. CSA and margins description were obtained. C5 nerve, 8.32 ± 2.30; C6 nerve, 11.88 ± 3.36; C7 nerve, 12.79 ± 3.85; C8 nerve, 11.20 ± 3.45. Significant correlation between CSA and age was demonstrated, but not for body mass index. Blurred margins were present in up to 23.71% cervical nerves, more frequently in older individuals and in C7 nerve. If ultrasound morphology of cervical nerve roots is used as a diagnostic parameter, the normal range of CSA values and percentage of blurred margins according to age should be considered.

Muscle Cross-sectional Area Improves With Home-based Training During Metastatic Castration-resistant Prostate Cancer

PURPOSE: Exercise training improves regional body composition in localized prostate cancer, but it is unknown if training has similar effects in advanced disease. Goals of this analysis were to determine changes in leg muscle cross-sectional area (CSA) and quality (MQ) values following home-based exercise training during metastatic castration-resistant prostate cancer (mCRPC) and to compare CSA values to healthy controls (CON). METHODS: Sedentary mCRPC patients undergoing androgen deprivation therapy (ADT) including next generation androgen receptor signaling inhibitors (n = 17, age = 71y ± 8, BMI = 32.0 kg/m2 ± 6.5) underwent CSA and MQ analyses using B-mode ultrasound for the vastus lateralis (VL) muscle before and after a 12-week home-based exercise protocol. Age- and BMI-matched CON (n = 17, age = 69y ± 2, BMI = 32.8kg/m2 ± 6.5) completed baseline scans only. RESULTS: At baseline, VL CSA was lower in mCRPC (9.12cm2+ 3.15) relative to CON (36.55cm2 ± 7.04, p<0.001, d=4.95). For mCRPC patients, the 12-week intervention did not change VL MQ, but increased CSA by 15.2% following the intervention (pre: 8.28cm2 ± 2.85, post: 9.54 ± 3.56, p<0.001, d= 0.39) with no change in MQ. CONCLUSIONS: Patients undergoing ADT for advanced prostate cancer exhibit lower muscle size compared to CON; however preliminary results suggest that home-based exercise training induces a moderate degree of regional muscle hypertrophy. The finding of regional hypertrophy is consistent with work conducted in patients with localized disease on ADT and may be an important outcome to monitor if increases in muscle CSA translate into improvements in physical function and quality of life. Supported by Physical Activity and Cancer Survivorship Pilot Funding.

Ultrasound analyses of hamstrings muscle morphology changes whit sport

Abstract Introduction Physical activities and sports can change muscle morphology. Changes caused by regular physical exercise can be assessed by ultrasound parameters such as the pennation angle, cross-sectional area, echo-intensity and muscle thickness. Objectives This study aims to characterise and evaluate the morphological changes of the hamstring muscles through ultrasound parameters such as the pennation angle, fascicle length, cross-sectional area, echo-intensity and muscle thickness, and verify the existence of morphological changes between the dominant and non-dominant limb. Methodology Twenty-two young female divided in two groups (control group=11; athletes group=11) were submitted to an ultrasound examination at 50% of the posterior region of the thigh, for the semimembranosus and long portion of the femoral biceps muscles in the longitudinal and in a panoramic view. Results 22 athletes with a mean age of 22.25 years were evaluated. There were significant differences between the two groups in muscle morphology. The athletes group showed a higher value for muscle thickness, cross-sectional area, pennation angle and fascicle length and a lower value for muscle echo-intensity. This group also showed higher values for these parameters when dominant limb is compared with non-dominant. Conclusion Physical exercise causes changes in muscle morphology and ultrasound is a good method for the musculoskeletal assessment of athlete’s performance, since it is an imaging modality that allows to carry out comparative bilateral studies for athletes performance follow up and for preventive strategies against the sedentarism.

Hamstring to quadriceps strength ratio and cross-sectional area of the quadriceps and hamstrings muscles assessed using extended field-of-view ultrasonography

ABSTRACT This study examined whether the association between hamstring (H) and quadriceps (Q) strength with size depends on the region and the muscle used to examined cross-sectional area (CSA). Maximum isometric contraction knee extension and flexion torque was obtained from 20 young participants while Q and H CSA was recorded using extended field of view ultrasonography at four sections along the thigh. Stepwise linear regression models using the maximum CSA of individual muscles showed a significant association of quadriceps (R2 = 0.793) and hamstring (R2 = 0.275) CSA with MVC torque (p < 0.05). The association was lower when maximum or section-specific muscle group CSAs were used as indices of size. The H:Q CSA ratio showed a significant association (R2 = 0.275, p < 0.05) and a moderate correlation (r = 0.48) with H:Q torque ratio. These results indicated that the association between muscle CSA and strength differs between the knee extensors and flexors. Amongst the various indices of muscle size, the combination of maximum CSA values of each muscle displayed the greatest relationship between strength and CSA. The H:Q CSA ratio can explain a significant but small part of the H:Q isometric strength ratio.

Prognostic Value of Ultrasound Imaging of the Median Nerve in Carpal Tunnel Syndrome.

Background: Ultrasound has been well established as a diagnostic modality for carpal tunnel syndrome, but its prognostic utility has not been deeply investigated. Few studies, showing contradictory results, exist investigating ultrasound results as a predictor of patient outcomes. Methods: Patients with ultrasound measurement of the cross-sectional area (CSA) of the median nerve who completed the Boston Carpal Tunnel Questionnaire (BCTQ) and followed up after surgery were included in the study. A total of 199 wrists from 172 patients met the inclusion criteria. Preoperative CSA of the median nerve at the wrist was compared with change in BCTQ at various follow-up times postoperatively. Results: The BCTQ score was found on average to decrease for patients after surgery at all 3 follow-up times. There was a larger decrease in the preoperative BCTQ with each progressive follow-up time, with the largest change of 1.43 points coming at 6+ months. The average change in BCTQ at each follow-up time was found to be greater than the minimal clinically important difference. The greatest R2 for preoperative CSA compared with change in BCTQ was 0.0552 for the 6+ month visits. No specific CSA value or range above or below which patients have better postoperative outcomes was found. Conclusions: Higher preoperative CSA, signifying worse carpal tunnel severity, showed almost no correlation with better outcomes after carpal tunnel release surgery as measured by improvement in patient-reported outcome scores.

Case-Control Study of Ultrasound Evaluation of Acute Median Nerve Response to Upper Extremity Circuit Training in Spinal Cord Injury

ObjectiveIndividuals with spinal cord injury (SCI) often present signs and symptoms of median nerve (MN) pathology. Preclinical signs identification of MN pathology might facilitate early intervention to prevent or delay carpal tunnel syndrome in SCI. We assessed if ultrasound parameters changed in response to upper extremity (UE) circuit training exercise in individuals with paraplegia and able-bodied individuals. DesignCase-control study. ParticipantsAdults (N=32) with paraplegia (n=16) and age- and sex-matched able-bodied controls (n=16). InterventionCircuit training exercise. Main Outcome MeasuresMN ultrasound evaluation at the pisiform and radius before and after UE exercise. Ultrasound parameters included cross-sectional area (CSA), and gray scale (GS). Data presented as mean ± SD. ResultsPre-exercise CSAs were larger in SCI at the radius (12.0±2.9 vs 9.0±2.1; P=.003), but not the pisiform (9.8±3.1 vs 9.1±1.7; P=.431). There were no statistical differences in MN response to exercise between groups (all P≥.293). Across participants, CSA changes were inversely associated with their pre-exercise values at the pisiform (r=–0.648; P<.001) and the radius (r=–0.366; P=.043). Participants with pre-exercise CSA values ≥10.00 mm2 at the pisiform responded to exercise with decreases in CSA (mean change ± SD, –2.0±1.5; P=.002) and GS (–2.8±6.2; P=.029). Participants with pre-exercise CSA ≤9.99 mm2 at the pisiform responded to exercise with no change in CSA (mean change ± SD, 0.7±2.5; P=.002) and increased GS (3.2±7.2; P=.029). ConclusionsCSA exercise response was more strongly related to pre-exercise MN values than presence or absence of SCI.

Which Ultrasound Parameter Is More Accurate in the Diagnosis of Carpal Tunnel Syndrome: Cross-Sectional Area, Resistive Index, or Strain Ratio?

The aim of this study was to compare the accuracy of cross-sectional area (CSA), resistive index (RI), and strain ratio (SR) in carpal tunnel syndrome (CTS). This prospective and case-control study included patients with a diagnosis of CTS and a healthy control group. The participants were examined with an ultrasound Doppler system equipped with a high-resolution (5-18 MHz) linear probe (Philips L18-5). CSA, RI, and SR values were compared. CSA, RI, and SR were found to be effective tools to detect the presence of CTS (regardless of severity). The cut-off value of 11.25 mm for CSA had a sensitivity and specificity of 97.2% and 88.0%, respectively. The cut-off value of 0.740 for RI had a sensitivity and specificity of 94.4% and 94.0%, respectively. The cut-off value of 1.95 for SR had a sensitivity and specificity of 97.2% and 84.0%, respectively. In respect of the severity of CTS, ultrasound was found to be an effective method to classify severe CTS cases only. The CSA, SR, and RI seem to have excellent accuracy in the diagnosis of CTS. When the grading of severity is considered, ultrasound seems to be sensitive and specific in differentiating severe CTS cases from mild or moderate CTS cases.

Evaluation of pre-operative neuroimaging characteristics in patients with primary hemifacial spasm as a prognostic factor of microvascular decompression

ObjectiveThe aim of this study was to explore the possible pathogenesis of primary hemifacial spasm (HFS) according to the performances of preoperative high-resolution magnetic resonance (MR) sequence and investigate the correlations between the neuroimaging parameters and the prognosis of microvascular decompression (MVD). Methods106 patients with HFS and 121 age-matched and gender-matched healthy controls (HCs) were included in this study. Electronic medical records and neuroimaging data were collected. The facial-nerve angle, cross-sectional area of CPA cistern and length of the cistern segment of the facial nerve were measured on affected side and unaffected as well as healthy individuals. The receiver operating characteristic curve was used for assessing the predictive performances. Results100 patients achieved complete relief postoperatively. 13 of the 100 complete relief patients developed a relapse in the follow-up. The preoperative facial-pontine angle and cross-sectional area of the CPA cistern on the affected side was significantly smaller than the unaffected side and HC. The facial-pontine angle and the cross-sectional area of the CPA cistern was significantly smaller in recurrent group than the non-recurrent group. The AUC value of both facial-pontine angle and cross-sectional area of the CPA cistern were over 0.7. ConclusionSmall facial-nerve angle and cross-sectional area of CPA cistern may be regarded as the possible pathogenesis of primary HFS. The measurement of facial-nerve angle and cross-sectional area of CPA cistern preoperatively might be used to predict the surgical effect of MVD.

Cross-sectional area in median and ulnar nerve ultrasound correlates with hand volume.

The influence of demographic and anthropometric factors on nerve cross-sectional area (CSA) reference values in high-resolution ultrasound was evaluated in a prospective observational study. We measured CSA of median, ulnar, radial, and sural nerves in 80 healthy adults from 18 to 98 years of age. Pearson's correlation and multiple linear regression with age, gender, body mass index, and hand volume were calculated. Ulnar and median nerve CSA showed a significant positive correlation with ipsilateral hand volume. Median nerve CSA in the left forearm (mean, 6.2 mm2 ; SD, 1.2) increased by 0.006 mm2 (SE = 0.002; P < .001) per cm3 of hand volume, resulting in a difference of 1.9 mm2 predictable by hand volume (mean, 326 cm3 ; SD, 81; range, 180-500). The observed correlation of CSA and hand volume may influence the interpretation of CSA values in patients with very large or small hands.

Shear Wave Velocity Measurements of the Median Nerve in Patients on Chronic Hemodialysis.

Chronic dialysis causes changes in the structure of median nerve. This is a risk for the development of carpal tunnel syndrome in patients on dialysis. The aim of the present study was to evaluate the diagnostic capacity of shear wave velocity (SWV) and the cross-sectional area (CSA) to detect the structural changes of the median nerve in patients with end-stage chronic kidney disease on hemodialysis. Twenty-five patients with chronic kidney disease undergoing hemodialysis 3 times per week and 26 healthy controls were included. None of the participants had any signs or symptoms of carpal tunnel syndrome specified according to the criteria of the American Academy of Neurology Practice Parameters. Both patients and controls underwent sonographic and elastographic examinations of the median nerves in both hands to evaluate CSA and SWV values, and they were compared regarding these parameters. The mean CSA of the median nerve in the chronic hemodialysis group was significantly higher than that in the control group (12.74 ± 1.88 mm2 versus 8.89 ± 1.45 mm2 ; P < .001). The mean longitudinal and axial SWV values in the hemodialysis group (3.86 ± 0.54 m/s and 3.92 ± 0.52 m/s, respectively) were significantly higher than those in the control group (2.98 ± 0.31 m/s and 3.04 ± 0.31 m/s, respectively; P < .001). Patients on chronic hemodialysis had higher mean CSA and SWV values of the median nerve compared with the healthy controls. Structural changes in the median nerve that occur in patients on chronic hemodialysis can be detected by shear-wave sonoelastography.

Effects of resistance training with controlled versus self-selected repetition duration on muscle mass and strength in untrained men.

The aim of this study was to compare the effect of self-selected repetition duration (SELF), with and without volume load (VL) equalized with controlled repetition duration (CON) on muscle strength and hypertrophy in untrained males. We used a within-subjects design in which 20 volunteers (age: 24.7 ± 2.9 years) had one leg randomly assigned to CON (i.e., 2 s concentric, 2 s eccentric) and the other to SELF or to self-selected repetition duration with equalized volume load (SELF-EV). One repetition maximum (1-RM) and muscle cross-sectional area (CSA) were measured at baseline (Pre) and after (Post) resistance training (RT; 2×/wk for 8 weeks). For the main study variables (1-RM and muscle CSA), a mixed-model analysis was performed, assuming repetition duration (SELF, SELF-EV and CON), and time (Pre and Post) as fixed factors and the subjects as random factor for each dependent variable (1-RM and CSA). All RT protocols showed significant increases in values of 1-RM from Pre (CON: 73.7 ± 17.6 kg; SELF: 75.9 ± 17.7 kg; and SELF-EV: 72.6 ± 16.9 kg) to Post (CON: 83.4 ± 19.9 kg, effect size (ES): 0.47; SELF: 84 ± 19.1 kg, ES: 0.43; and SELF-EV: 83.2 ± 19.9 kg, ES: 0.57, P < 0.0001). Muscle CSA values increased for all protocols from Pre (CON: 12.09 ± 3.14 cm2; SELF: 11.91 ± 3.71 cm2; and SELF-EV: 11.93 ± 2.32 cm2) to Post (CON: 13.03 ± 3.25 cm2, ES: 0.29; SELF: 13.2 ± 4.16 cm2, ES: 0.32; and SELF-EV: 13.2 ± 2.35 cm2, ES: 0.53, P < 0.0001). No significant differences between protocols were found for both 1-RM and CSA (P > 0.05). Performing RT with SELF, regardless of VL, was equally effective in inducing increases in muscle strength and hypertrophy compared to CON in untrained men.

Magnetic resonance imaging findings of redundant nerve roots of the cauda equina

BACKGROUNDRedundant nerve roots (RNRs) of the cauda equina are often a natural evolutionary part of lumbar spinal canal stenosis secondary to degenerative processes characterized by elongated, enlarged, and tortuous nerve roots in the superior and/or inferior of the stenotic segment. Although magnetic resonance imaging (MRI) findings have been defined more frequently in recent years, this condition has been relatively under-recognized in radiological practice. In this study, lumbar MRI findings of RNRs of the cauda equina were evaluated in spinal stenosis patients.AIMTo evaluate RNRs of the cauda equina in spinal stenosis patients.METHODSOne-hundred and thirty-one patients who underwent lumbar MRI and were found to have spinal stenosis between March 2010 and February 2019 were included in the study. On axial T2-weighted images (T2WI), the cross-sectional area (CSA) of the dural sac was measured at L2-3, L3-4, L4-5, and L5-S1 levels in the axial plane. CSA levels below 100 mm2 were considered stenosis. Elongation, expansion, and tortuosity in cauda equina fibers in the superior and/or inferior of the stenotic segment were evaluated as RNRs. The patients were divided into two groups: Those with RNRs and those without RNRs. The CSA cut-off value resulting in RNRs of cauda equina was calculated. Relative length (RL) of RNRs was calculated by dividing the length of RNRs at mid-sagittal T2WI by the height of the vertebral body superior to the stenosis level. The associations of CSA leading to RNRs with RL, disc herniation type, and spondylolisthesis were evaluated.RESULTSFifty-five patients (42%) with spinal stenosis had RNRs of the cauda equina. The average CSA was 40.99 ± 12.76 mm2 in patients with RNRs of the cauda equina and 66.83 ± 19.32 mm2 in patients without RNRs. A significant difference was found between the two groups for CSA values (P < 0.001). Using a cut-off value of 55.22 mm2 for RNRs of the cauda equina, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) values of 96.4%, 96.1%, 89.4%, and 98.7% were obtained, respectively. RL was 3.39 ± 1.31 (range: 0.93-6.01). When the extension of RNRs into the superior and/or inferior of the spinal canal stenosis level was evaluated, it was superior in 54.5%, both superior and inferior in 32.8%, and inferior in 12.7%. At stenosis levels leading to RNRs of the cauda equina, 29 disc herniations with soft margins and 26 with sharp margins were detected. Disc herniation type and spondylolisthesis had no significant relationship with RL or CSA of the dural sac with stenotic levels (P > 0.05). As the CSA of the dural sac decreased, the incidence of RNRs observed at the superior of the stenosis level increased (P < 0.001).CONCLUSIONRNRs of the cauda equina are frequently observed in patients with spinal stenosis. When the CSA of the dural sac is < 55 mm2, lumbar MRIs should be carefully examined for this condition.

Nerve ultrasound reference data in children from two to seven years

ObjectiveWe examined selected peripheral and spinal nerves of children aged between two and seven years. MethodHigh resolution ultrasound was performed in 116 children (2–7 years of age) at 19 predefined landmarks of median, ulnar, tibial, fibular, sural and radial nerves, the vagus as well as cervical spinal nerve 5 and 6. Further, side-to-side measuring and grey-scale analysis was done at selected nerve sites. ResultsNerves of children were on average smaller than those of adults. Nerve growth correlates significantly with age in all nerves, the mean values were similar in the age of two to four years and five to seven years. Body mass index (BMI) and gender showed moderate effect at some nerve sites, however not uniformly in all. A side-to-side difference of up to 30% in median, and up to 20% in tibial nerve can occur in healthy individuals. Grey-scale analysis for echointensity has been performed in median, ulnar and tibial nerves. ConclusionNerve size increases with age, BMI and gender have moderate effect. A side-to-side-difference of up to 30% can exist. SignificanceReference values of nerve cross-sectional area, side-to-side-difference and echo intensity are necessary to detect nerve pathology in children as well as in adults.

Using Impedance Planimetry (EndoFLIP) to Evaluate Myotomy and Predict Outcomes After Surgery for Achalasia

BackgroundThe functional lumen imaging probe (FLIP) is an innovative tool that uses impedance planimetry to assess esophageal geometry in real time. It has been used to diagnose achalasia and evaluate treatment failure after laparoscopic Heller myotomy (LHM) and peroral endoscopic myotomy (POEM). We hypothesize that impedance planimetry can be utilized intra-operatively to assess adequacy of myotomy and assist in predicting patient outcomes. MethodsA prospectively maintained patient database at a single center was queried. Seventy-seven patients with achalasia underwent POEM or LHM by a single surgeon. The FLIP was used to measure cross-sectional area (CSA), minimum diameter (Dmin), balloon pressure, and distensibility index (DI) of the lower esophageal sphincter (LES) before and after the procedure. Clinical outcomes were measured up to 2 years after treatment. ResultsPost-operative CSA, Dmin, balloon pressure, and DI values were significantly different from pre-operative values (p < 0.001). Patients with a post-operative Eckardt score ≥ 3 were significantly more likely to have a final DI ≤ 3.1 mm2/mmHg (p = 0.014) or a change in DI ≤ 3.0 mm2/mmHg (p = 0.010). Additionally, a final CSA > 96 mm2 or Dmin > 11.0mm was predictive of worse reflux at 2 years (p = 0.01). ConclusionImpedance planimetry using the FLIP can offer intra-operative feedback about the geometry of the LES. The most useful parameters in predicting patient outcomes have yet to be clearly defined, but our results demonstrate that final DI and CSA are predictive of post-operative treatment response.

Assessment of lumbar paraspinal muscle activation using fMRI BOLD imaging and T2 mapping.

Our study aimed to investigate the feasibility of functional magnetic resonance imaging [blood oxygen level-dependent (BOLD) imaging and T2 mapping] in monitoring the activation of lumbar paraspinal muscles before and after exercise. The ethics committee of the First Affiliated Hospital of Kunming Medical University approved our study. Both BOLD and T2 mapping of paraspinal muscles were performed in 50 healthy, young volunteers before and after upper-body extension exercises. The movement tasks included upper body flexion and extension using a simple Roman chair. Cross-sectional area (CSA), R2*, and T2 values were measured in various lower-back anatomical regions. The SPSS22.0 statistical software was used to analyze all the data. Post-exercise CSA and T2 values were higher than those recorded in the pre-exercise session for the three lower-back muscles that were evaluated (iliocostalis, longissimus, and multifidus) (P<0.01). However, R2* values of these muscles were significantly lower after exercise (P<0.01). A significant difference in the R2*, CSA, and T2 values of the iliocostalis occurred between males and females (P<0.05). No statistically significant differences were evident for R2*, CSA, and T2 of the lower-back muscles between L3 and L4 levels, or between the left and right sides. The total CSA of the iliocostalis was higher than that of the multifidus and longissimus (P<0.05). BOLD and T2 mapping are feasible non-invasive indirect assessments of lumbar paraspinal muscle activation before and after exercise.

Improvement of Auto Checking Hardness Machine using Several Material Series of Aluminum Structural Frame: Case Study on Mitutoyo HR-522 Hardness Tester

The hardness-checking tools are essential tools in engineering study, especially in the mechanical and manufacturing process. The field problem in Akebono Brake Astra Indonesia is the utilization of more manual tools to achieve product demands. Considering those issues, the development of a modified hardness checking tool from manual operation to automatic operation. For more effectively, it uses automatic operation in time and savings for other manual tools. The automated tool applies the 3-axes system mechanism using Festo linear actuator with the servo motor. The testing capacity of automatic devices is equal to more manual devices. The frame of the auto-checking hardness machine is assessed by applying load variations. This paper provides a comparison of various aluminum frame types based on different tensile strength and cross-sectional area values. The value of displacement and maximum stress depends on the ultimate tensile strength properties and cross-sectional area of the frame.

Relationship Between Cauda Equina Conduction Time and Type of Neurogenic Intermittent Claudication due to Lumbar Spinal Stenosis.

This study investigated whether the prolongation of the cauda equina conduction time (CECT) was related to the type of neurogenic intermittent claudication due to lumbar spinal stenosis. In total, 149 patients who underwent surgery due to lumbar spinal stenosis with neurogenic intermittent claudication were classified into three groups as follows: cauda equina-type(n = 67), radicular-type(n = 29), and mixed-type(n = 53). Cauda equina conduction time was measured by placing disc electrodes on the abductor hallucis muscle, electrically stimulating the tibial nerve of the ankle and recording the compound muscle action potentials and F-waves. Motor evoked potentials from the abductor hallucis muscle were measured after magnetically stimulating the lumbosacral spine. Cauda equina conduction time was calculated from the latencies of compound muscle action potentials, F-waves, and motor evoked potentials. The measurement of the dural sac cross-sectional area were assessed using computed tomography myelography or MRI. The values of CECT were as follows: cauda equina-type, 5.6 ± 1.1 ms; mixed-type, 5.1 ± 0.9 ms; and radicular-type, 4.0 ± 0.9 ms. The values of dural sac cross-sectional area were as follows: cauda equina-type, 42.8 ± 18.7 mm; mixed-type, 49.6 ± 20.9 mm; and radicular-type, 75.3 ± 19.1 mm. In the cauda equina-type and mixed-type patients, CECT was significantly prolonged and there were negative correlations between CECT and dural sac cross-sectional area. Cauda equina conduction time differed according to the type of lumbar spinal stenosis. The prolongation of CECT may be caused by the demyelination of the CE. Cauda equina conduction time may be a useful measure for evaluating the dysfunction of the CE rather than radiculopathy for patients with lumbar spinal stenosis.