Assessment of the carpal tunnel and associated neural structures with superb microvascular imaging: a scoping review.

INTRODUCTION: Superb microvascular imaging (SMI) is an advanced ultrasound technique that portrays microcirculation. Its clinical applications have been studied in various diseases, including carpal tunnel syndrome (CTS) i.e. the most common entrapment neuropathy. This scoping review explores the role of SMI in diagnosing CTS or the assessment of relevant neural structures. METHODS: We conducted a comprehensive search of electronic databases (PubMed, Embase and Web of Science) up to 26 September 2023. Two independent authors conducted the literature search, quality assessment, and data extraction. RESULTS: This review includes seven studies comprising 385 wrists. SMI consistently revealed increased intraneural vascularity in the median nerves of patients with CTS compared to healthy individuals. While SMI demonstrated higher sensitivity than traditional Doppler methods for detecting CTS, its specificity was somewhat lower. Combining SMI with B-mode ultrasound appears to enhance the diagnostic accuracy for CTS. However, the relationship between SMI findings and CTS severity remains unclear. CONCLUSIONS: This review highlighted the ability of SMI to provide detailed vascular structures in both healthy wrists and those with CTS. Additional research is crucial to determine the typical SMI findings of the carpal tunnel and within that context, tailor more precise diagnostic/therapeutic applications for the CTS population.

Repeatability, Reproducibility and Sources of Variability in the Assessment of Backscatter Coefficient and Texture Parameters from High-Frequency Ultrasound Acquisitions in Human Median Nerve.

Ultrasound (US) is an increasingly prevalent and effective diagnostic modality for neuromuscular imaging. Gray-scale B-mode imaging has been the dominant US approach to evaluating nerves qualitatively or making morphometric measurements of nerves, providing important insights into pathological changes for conditions such as carpal tunnel syndrome. Among more recent ultrasound strategies, high-frequency ultrasound (often defined as >15 MHz for clinical applications), quantitative ultrasound and image textural analysis offer promising enhancements for improved and more objective approaches to nerve imaging. In this study, we evaluated the repeatability and reproducibility of backscatter coefficient (BSC) and imaging texture features extracted by gray-level co-occurrence matrices (GLCMs) in homogeneous tissue-mimicking reference phantoms and in median nerves in the wrists of healthy participants. We also investigated several practical sources of variability in the assessment of quantitative parameters, including influences of operators, and participant-to-participant variability. Overall, BSC- and GLCM-based outcomes are highly repeatable and reproducible after operator training, based on measurement of descriptive statistics, repeatability coefficient (RC) and reproducibility coefficient recommended by Quantitative Imaging Biomarker Alliance (QIBA RDC). GLCM parameters appear more reproducible and repeatable than BSC-based parameters in healthy participants in vivo. However, such variability noted here must be compared with the value ranges and variability of the results in pathological nerves, including median nerves afflicted by trauma, overuse syndromes such as carpal tunnel syndrome and after surgical repair.

Assessment Of Carpal Tunnel Syndrome With Ultrasonography.

BACKGROUND: Carpal tunnel syndrome (CTS) is the most common nerve entrapment neuropathy caused by compression of median nerve at wrist as it passes through Osseo fibrous canal known as carpal tunnel. Epidemiological statistics shows one in every ten people develops the disease at any stage of life. CTS mostly affect females than males with mean age of 50. Clinical features are considered to be enough for establishing the diagnosis of carpal tunnel syndrome. However, nerve conduction studies give quantitative information regarding median nerve function therefore good at predicting outcome of intervention. Ultrasound being easily available, cost effective and real time is a promising modality for diagnosis and grading carpal tunnel syndrome. METHODS: This correlational study was conducted in collaboration of Neurology and Radiology Department of Pakistan Institute of Medical Sciences, Islamabad from January 2018 to January 2019. Total 50 patients with 85 wrists involved were included in the study. All patients with positive nerve conduction study were included. Patient with history of wrist trauma were not included. Detailed history and clinical features were recorded. All patients with positive result on nerve conduction studies underwent ultrasound examinations. Fifty control wrists were also included to establish the normal median nerve cross sectional area value in our study population. Results were recorded. Data was analyzed and appropriate statistical tests were applied by using SPSS v20. RESULTS: Mean cross sectional area of median nerve for controls was 6.34±1.23. Mean cross sectional area of median nerve for mild CTS was 8.05±1.72, moderate CTS was 11.15±2.32, severe was 17.49±4.93. Strong correlation was found between (r=0.76, p-value <0.0001) between increased cross-sectional area on Ultrasonography and severity of CTS on NCS. Other finding on Ultrasonography included flattening in 4 and fluid in 10 affected wrists. CONCLUSIONS: Increased cross-sectional area on Ultrasonography and severity of carpal tunnel syndrome on nerve conduction studies are very strongly correlated.

Use of Ultrasound in Patients With Carpal Tunnel Syndrome: A Cost-Effective Solution to Reduce Delays in Surgical Care.

PURPOSE: Currently, electrodiagnostic testing, which comprises electromyogram (EMG) and nerve conduction studies (NCS), is the most commonly used method for confirming the clinical diagnosis of carpal tunnel syndrome (CTS). Electromyogram and NCS can be costly, can require multiple visits, may induce anxiety, and may be painful for patients. The purpose of this study was to determine whether replacing EMG/NCS with ultrasound (US), performed by the treating surgeon, to diagnose CTS decreases time to surgery and the number of office visits. METHODS: We retrospectively reviewed a database that consisted of patients who presented to our department with numbness and/or tingling in the hand(s). We assessed the patients' histories for any subsequent carpal tunnel release, dates of diagnosis, dates of surgery, the number of CTS-related medical visits, and diagnostic methods employed. A fellowship-trained hand surgeon performed US examination, and the patients were referred for EMG/NCS testing. We collected data prior to surgery using the Boston Carpal Tunnel Questionnaire to evaluate symptom severity scale and functional status scale scores. We performed linear regression to assess differences in the time to surgery and the number of medical visits prior to carpal tunnel release. RESULTS: Patients who had the diagnosis confirmed by the surgeon using US (n = 34) underwent surgical intervention 3-4 weeks earlier, with 1.8 fewer medical visits on average than the number of medical visits for those who had their diagnosis confirmed using EMG/NCS (n = 98). CONCLUSIONS: If a confirmatory method for the diagnosis of CTS is required or desired by the treating surgeon, surgeon-conducted US might have an impact on the efficiency of care for patients with CTS. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

Accurate automated diagnosis of carpal tunnel syndrome using radiomics features with ultrasound images: A comparison with radiologists' assessment.

PURPOSE: Ultrasonography is the most common imaging modality used to diagnose carpal tunnel syndrome (CTS). Recently artificial intelligence algorithms have been used to diagnose musculoskeletal diseases accurately without human errors using medical images. In this work, a computer-aided diagnosis (CAD) system is developed using radiomics features extracted from median nerves (MN) to diagnose CTS accurately. METHOD: This study is performed on 228 wrists from 65 patients and 57 controls, with an equal number of control and CTS wrists. Nerve conduction study (NCS) is considered as the gold standard in this study. Two radiologists used two guides to evaluate and categorize the pattern and echogenicity of MNs. Radiomics features are extracted from B-mode ultrasound images (Ultrasomics), and the robust features are fed into support vector machine classifier for automated classification. The diagnostic performances of two radiologists and the CAD system are evaluated using ROC analysis. RESULTS: The agreement of two radiologists was excellent for both guide 1 and 2. The honey-comb pattern clearly appeared in control wrists (based on guide 1). In addition, CTS wrists indicated significantly lower number of fascicles in MNs (based on guide 2). The area under ROC curve (AUC) of the radiologist 1 and 2 are 0.658 and 0.667 based on guide 1 and 0.736 and 0.721 based on guide 2, respectively. The CAD system indicated higher performance than two radiologists with AUC of 0.926. CONCLUSION: The proposed CAD system shows the benefit of using ultrasomics features and can assist radiologists to diagnose CTS accurately.

Ultrasound assessment of carpal tunnel in rheumatoid arthritis and idiopathic carpal tunnel syndrome.

OBJECTIVES: To comparatively assess the sonographic spectrum of carpal tunnel syndrome (CTS) in patients with rheumatoid arthritis (RA) and in patients with idiopathic CTS. METHODS: Fifty-seven RA patients and 25 idiopathic CTS patients were consecutively enrolled. The diagnosis of CTS in RA patients was made according to clinical history and examination. The following sonographic findings were assessed at carpal tunnel level: median nerve cross-sectional area (CSA) at the carpal tunnel proximal inlet, finger flexor tendons tenosynovitis, radio-carpal synovitis and intraneural power Doppler (PD) signal. RESULTS: CTS was diagnosed in 15/57 RA patients (26.3%). Twenty-three RA wrists with CTS, 84 RA wrists without CTS and 34 idiopathic CTS wrists were evaluated. The average CSA of the median nerve was higher in idiopathic CTS than in RA wrists with CTS (17.7 mm2 vs 10.6 mm2, p < 0.01). A higher rate of inflammation of synovial structures (flexor tendons sheath and/or radio-carpal joint) was found in RA wrists with CTS compared with those without CTS (p = 0.04) and idiopathic CTS (p = 0.02). Intraneural PD signal was more common in CTS (in both RA and idiopathic CTS) wrists compared with wrists without CTS (p < 0.01). CONCLUSION: The sonographic spectrum of CTS in RA patients is characterized by an inflammatory pattern, defined by the presence of finger flexor tendons tenosynovitis and/or radio-carpal joint synovitis. Conversely, a marked median nerve swelling is the dominant feature in idiopathic CTS. Intraneural PD signal is a frequent finding in both conditions. Key Points • Carpal tunnel syndrome (CTS) associated with rheumatoid arthritis (RA) and idiopathic CTS have distinct ultrasound patterns. • The most characteristic sonographic features of CTS in RA patients are those indicative of synovial tissue inflammation at carpal tunnel level. Conversely, marked median nerve swelling is the dominant finding in idiopathic CTS. • Intraneural power Doppler signal is a frequent finding in both conditions. • In patients with CTS, differently from electrophysiology, US can provide clues prompting a rheumatology referral in case of prominent inflammatory findings at carpal tunnel level.

Value of Grayscale and Power Doppler High-Resolution Ultrasound in Assessment of Patients with Clinically Suspected Carpal Tunnel Syndrome.

OBJECTIVES: To determine the value of grayscale and power Doppler ultrasound (PDUS) in the evaluation of carpal tunnel syndrome (CTS) in clinically suspected patients. METHODS: Eighty-seven wrists of 61 patients with clinically suspected CTS and 57 wrists of 30 healthy control participants were included in our study. Median nerve (MN) cross-sectional area (CSA) measurements were performed at the tunnel inlet level (wCSA) and proximal pronator quadratus muscle level (fCSA). Two parameters were calculated: CSA absolute difference (ΔCSA), which was the difference between the two measurements; and CSA ratio (RCSA), calculated by dividing wCSA over fCSA. The MN at the wrist level was evaluated for hypervascularity with PDUS. RESULTS: The mean wCSA, R-CSA, and ΔCSA values were significantly higher in patients (17 mm2 , 2.45, and 9.9 mm2 , respectively) than in control participants (8 mm2 , 1.29, and 1.65 mm2 ; (P < .0001). At their corresponding cutoff values, the wCSA yielded higher sensitivity (95%) and lower specificity (88%) compared to the RCSA and ΔCSA (89% and 93% sensitivity and 93% and 89% specificity). Power Doppler US was the most specific US parameter (100%) but the least sensitive (76%). A multivariate logistic regression model including the wCSA, RCSA, and PDUS yielded 97% diagnostic accuracy at their optimal cutoffs, which increased to 99% after eliminating age and body mass index confounding effects. CONCLUSIONS: The combination of MN swelling measurements and PDUS increases the diagnostic accuracy of US in patients with clinically suspected CTS.

Ultrasonographic Assessment of Carpal Tunnel Syndrome Severity: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of the study was to investigate the overall estimates of cross-sectional areas of the median nerve measured by ultrasonography in accordance with the electrodiagnostic classification of carpal tunnel syndrome severity. DESIGN: MEDLINE (PubMed), Embase (Ovid), and Web of Science were searched for studies reporting the median nerve cross-sectional area measured by ultrasonography for mild, moderate, and severe carpal tunnel syndrome based on electrodiagnostic study. Cross-sectional area values measured at the carpal tunnel inlet were included in the analyses. RESULTS: Overall, 866 citations were retrieved and checked for eligibility. Finally, 16 articles were included for meta-analysis. These studies included a total sample of 2292 wrists including 776 mild, 823 moderate, and 693 severe carpal tunnel syndrome. The pooled analysis revealed a mean cross-sectional area of 11.64 mm (95% confidence interval = 11.23-12.05 mm, P < 0.001) for mild carpal tunnel syndrome, a mean cross-sectional area of 13.74 mm (95% confidence interval = 12.59-14.89 mm, P < 0.001) for moderate carpal tunnel syndrome, and a mean cross-sectional area of 16.80 mm (95% confidence interval = 14.50-19.1 mm, P < 0.001) for severe carpal tunnel syndrome. CONCLUSIONS: This is the first meta-analysis that provides the pooled median nerve cross-sectional area values in accordance with the electrodiagnostic classification of carpal tunnel syndrome severity. The values obtained in this study have clinical utility in ultrasonographic assessment of patients with carpal tunnel syndrome.

Principles of Billing for Diagnostic Ultrasound in the Office and Operating Room.

Ultrasound is becoming more prevalent as physicians gain comfort in its diagnostic and therapeutic uses. It allows for both static and dynamic evaluation of conditions and assists in therapeutic injections of joints and tendons. Proper technique is necessary for successful use of this modality. Appropriate coding for physician reimbursement is required. We discuss common wrist and hand pathology for which ultrasound may be useful as an adjunct to diagnosis and treatment and provide an overview of technique and reimbursement codes when using ultrasound in a variety of situations.

The diagnostic accuracy of median nerve ultrasonography in elderly patients with carpal tunnel syndrome: sensitivity and specificity assessment.

BACKGROUND: Accurate diagnosis of carpal tunnel syndrome (CTS), the most common entrapment neuropathy, and its differentiation from other diseases are essential, especially in older individuals with advanced symptoms and modified electrophysiological abnormalities. The current study was conducted to evaluate the diagnostic accuracy of ultrasonography (US), regarding sensitivity and specificity in the diagnosis of CTS in elderly patients. METHODS: Individuals with upper limb complaints and reference subjects were recruited from the Rofaydeh Hospital, Tehran, Iran, from June 2013 to October 2014 - (15 months). We evaluate case and control subjects for health status, demographics, clinical characteristics of CTS, median nerve physiology by electrodiagnostic tests, and anatomy by US. Median nerve cross-sectional area (CSA) at precanal, tunnel inlet, midcanal, tunnel outlet, and antecubital levels was measured applying US examination. RESULTS: Of the 723 complaining patients, we assessed 380 patients with CTS symptoms. Electrodiagnostic studies (EDX) confirmed the CTS diagnosis in 203 of these clinically diseased patients. A total of 103 patients (of the 113 reference subjects) had normal EDX in the reference group. Comparisons of wrists between the afflicted and reference subjects demonstrated the CSA at precanal, tunnel inlet, midcanal, and tunnel outlet levels being significantly more abundant in the diseased hands than in the nondiseased hands. CSA at the tunnel inlet and the inlet-to-antecubital CSA ratio with a threshold of 8.5 mm2 and 0.65 gave the best diagnostic accuracy with a sensitivity and specificity of 96.9 and 93.6% for the inlet CSA and 99 and 28% for the CSA ratio, respectively. CONCLUSION: The US as a noninvasive diagnostic method may serve for the investigation of CTS in elderly patients with excellent sensitivity and specificity.

Sonographic assessment of carpal tunnel syndrome in diabetic patients with and without polyneuropathy.

The objective of this study is to determine whether the cross sectional area (CSA) measurement of the median nerve at the wrist differ between carpal tunnel syndrome (CTS) in diabetic patients with and without diabetic polyneuropathy (DPN).This study included 44 patients with type II diabete millitus (DM) with CTS, 32 patients with CTS and DPN, 46 patients with idiopathic CTS, and 42 healthy subjects. Ultrasonographic measurement of the CSA of the median nerve was made at the level of the wrist, together with nerve conduction studies.The median CSA at the wrist was significantly larger in all patient groups compared with healthy subjects. The median nerve CSA was significantly larger in diabetic patients with CTS than patients with idiopathic CTS. The median nerve CSA at wrist was significantly smaller in patients with CTS and DPN compared with diabetic patients with CTS only.The median nerve CSA at the wrist was larger in diabetic patients with CTS than patients with idiopathic CTS and CTS with DPN. Median nerve CSA can help to differentiate between diabetic patients with CTS with and without DPN.

Usefulness of ultrasound assessment of median nerve mobility in carpal tunnel syndrome.

BACKGROUND: Carpal tunnel syndrome (CTS) is the most common peripheral compression neuropathy of the upper extremity. Recently, dynamic ultrasound (US) imaging has shown differences in median nerve mobility between the affected and unaffected sides in CTS. PURPOSE: The present study was performed to compare the median nerve mobility between patients with CTS and healthy individuals, and to correlate median nerve mobility with the severity of CTS. MATERIAL AND METHODS: A total of 101 patients (128 wrists) with CTS and 43 healthy individuals (70 wrists) were evaluated. Electrodiagnostic studies were initially conducted to determine the neurophysiological grading scale (NGS). The cross-sectional area (CSA) of the median nerve and the grade of median nerve mobility were measured using US. RESULTS: The mean grade of median nerve mobility in the CTS group (1.9) was significantly lower than that in the control group (2.6; P < 0.001). There were significant negative correlations between the grade of median nerve mobility and distal motor latency of the median nerve (r = -0.218, P = 0.015), NGS (r = -0.207, P = 0.020) and CSA of the median nerve (r = -0.196, P = 0.028). CONCLUSION: The grade of median nerve mobility was negatively correlated with the severity of CTS. US assessment of median nerve mobility may be useful in diagnosing and determining the severity of CTS.

Carpal tunnel syndrome assessment with diffusion tensor imaging: Value of fractional anisotropy and apparent diffusion coefficient.

OBJECTIVES: To quantitatively assess carpal tunnel syndrome (CTS) with DTI by evaluating two approaches to determine cut-off values. METHODS: In forty patients with CTS diagnosis confirmed by nerve conduction studies (NCs) and 14 healthy subjects (mean age 58.54 and 57.8 years), cross-sectional area (CSA), apparent diffusion coefficient (ADC) and fractional anisotropy (FA) at single and multiple levels with intraobserver agreement were evaluated. RESULTS: Maximum and mean CSA and FA showed significant differences between healthy subjects and patients (12.85 mm2 vs. 28.18 mm2, p < 0.001, and 0.613 vs. 0.524, p=0.007, respectively) (10.12 mm2 vs. 19.9 mm2, p<0.001 and 0.617 vs. 0.54, p=0.003, respectively), but not maximum and mean ADC (p > 0.05). For cut-off values, mean and maximum CSA showed the same sensitivity and specificity (93.3 %). However, mean FA showed better sensitivity than maximum FA (82.6 % vs. 73.9 %), but lower specificity (66.7 % vs. 80 %), and significant correlation for maximum CSA, 97 % (p < 0.01), with good correlation for maximum ADC and FA, 84.5 % (p < 0.01) and 62 % (p=0.056), respectively. CONCLUSIONS: CSA and FA showed significant differences between healthy subjects and patients. Single measurement at maximum CSA is suitable for FA determination. Key Points • DTI showed that FA is stronger than ADC for CTS diagnosis. • Single- and multiple-level approaches were compared to determine FA and ADC. • Single-level evaluation at the thickest MN cross-sectional area is sufficient.

High-Resolution Axonal Bundle (Fascicle) Assessment and Triple-Echo Steady-State T2 Mapping of the Median Nerve at 7 T: Preliminary Experience.

OBJECTIVES: The aims of this preliminary study were to determine the number of axonal bundles (fascicles) in the median nerve, using a high-resolution, proton density (PD)-turbo spin echo (TSE) fat suppression sequence, and to determine normative T2 values, measured by triple-echo steady state, of the median nerve in healthy volunteers and in patients with idiopathic carpal tunnel syndrome (CTS), at 7 T. MATERIALS AND METHODS: This prospective study was approved by the local ethics committee and conducted between March 2014 and January 2015. All study participants gave written informed consent. Six healthy volunteers (30 ± 12 years) and 5 patients with CTS (44 ± 16 years) were included. Measurements were performed on both wrists in all volunteers and on the affected wrist in patients (3 right, 2 left). Based on 5-point scales, 2 readers assessed image quality (1, very poor; 5, very good) and the presence of artifacts that might have a possible influence on fascicle determination (1, severe artifacts; 5, no artifacts) and counted the number of fascicles independently on the PD-TSE sequences. Furthermore, T2 values by region of interest analysis were assessed. Student t tests, a hierarchic linear model, and intraclass correlation coefficients (ICCs) were used for statistical analysis. RESULTS: Proton density-TSE image quality and artifacts revealed a median of 5 in healthy volunteers and 4 in patients with CTS for both readers. Fascicle count of the median nerve ranged from 13 to 23 in all subjects, with an ICC of 0.87 (95% confidence interval [CI], 0.67-0.95). T2 values were significantly higher (P = 0.023) in patients (24.27 ± 0.97 milliseconds [95% CI, 22.19-26.38]) compared with healthy volunteers (21.01 ± 0.65 milliseconds [95% CI, 19.61-22.41]). The ICC for all T2 values was 0.97 (95% CI, 0.96-0.98). CONCLUSIONS: This study shows the possibility of fascicle determination of the median nerve in healthy volunteers and patients with CTS (although probably less accurately) with high-resolution 7 T magnetic resonance imaging, as well as significantly higher T2 values in patients with CTS, which seems to be associated with pathophysiological nerve changes.

Assessment of Median Nerve Mobility by Ultrasound Dynamic Imaging for Diagnosing Carpal Tunnel Syndrome.

Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy and is characterized by median nerve entrapment at the wrist and the resulting median nerve dysfunction. CTS is diagnosed clinically as the gold standard and confirmed with nerve conduction studies (NCS). Complementing NCS, ultrasound imaging could provide additional anatomical information on pathological and motion changes of the median nerve. The purpose of this study was to estimate the transverse sliding patterns of the median nerve during finger movements by analyzing ultrasound dynamic images to distinguish between normal subjects and CTS patients. Transverse ultrasound images were acquired, and a speckle-tracking algorithm was used to determine the lateral displacements of the median nerve in radial-ulnar plane in B-mode images utilizing the multilevel block-sum pyramid algorithm and averaging. All of the averaged lateral displacements at separate acquisition times within a single flexion-extension cycle were accumulated to obtain the cumulative lateral displacements, which were curve-fitted with a second-order polynomial function. The fitted curve was regarded as the transverse sliding pattern of the median nerve. The R2 value, curvature, and amplitude of the fitted curves were computed to evaluate the goodness, variation and maximum value of the fit, respectively. Box plots, the receiver operating characteristic (ROC) curve, and a fuzzy c-means clustering algorithm were utilized for statistical analysis. The transverse sliding of the median nerve during finger movements was greater and had a steeper fitted curve in the normal subjects than in the patients with mild or severe CTS. The temporal changes in transverse sliding of the median nerve within the carpal tunnel were found to be correlated with the presence of CTS and its severity. The representative transverse sliding patterns of the median nerve during finger movements were demonstrated to be useful for quantitatively estimating median nerve dysfunction in CTS patients.

A comparison between ultrasonographic, surgical and histological assessment of tenosynovits in a cohort of idiopathic carpal tunnel syndrome patients.

Carpal tunnel syndrome (CTS) may be caused by subclinical tenosynovitis which may be detected by ultrasonography (US). The objective of this study is to investigate whether ultrasonography has a place in the workup of idiopathic CTS patients. Therefore, we investigated the prevalence of tenosynovitis and its association with the clinical outcome of surgery. A cohort of 31 consecutive idiopathic CTS patients (33 wrists) who were a candidate for carpal tunnel release (CTR) surgery was assessed using greyscale ultrasonography (GSUS) and power Doppler ultrasonography (PDUS). Peroperatively, tenosynovitis was evaluated macroscopically by the surgeon. Tissue samples from areas macroscopically suspected for tenosynovitis were taken for histological evaluation. The clinical outcome of the operation was assessed after 6 months and if applicable alternative diagnoses for the CTS were proposed. US tenosynovitis (OMERACT) was detected preoperatively in 58 % of the wrists. Peroperatively, macroscopic tenosynovitis was detected visually in 88 % of the wrists. Histological evaluation demonstrated a limited influx of lymphocytes indicative of a mild chronic inflammatory response in 19 %. Non-specific reactive changes were observed in 78 % of the cases. Ultrasonographically defined tenosynovitis was associated with an OR of 2.81 (95 % CI 0.61-13) for responding well to surgery. Most cases of ultrasonographic and peroperatively defined tenosynovitis were classified by histology as reactive changes. The presence of ultrasonographic tenosynovitis might be associated with a better clinical outcome of surgery.

Reliability Assessment of Various Sonographic Techniques for Evaluating Carpal Tunnel Syndrome.

Objectives-The aim of this study was to determine the intra- and inter-rater reliability of sonographic measurements of the median nerve cross-sectional area in individuals with carpal tunnel syndrome and healthy control participants.Methods-The median nerve cross-sectional area was evaluated by sonography in 18 participants with carpal tunnel syndrome (18 upper extremities) and 9 control participants (18 upper extremities) at 2 visits 1 week apart. Two examiners, both blinded to the presence or absence of carpal tunnel syndrome, captured independent sonograms of the median nerve at the levels of the carpal tunnel inlet, pronator quadratus, and mid-forearm. The cross-sectional area was later measured by each examiner independently. Each also traced images that were captured by the other examiner.Results-Both the intra- and inter-rater reliability rates were highest for images taken at the carpal tunnel inlet (radiologist, r = 0.86; sonographer, r = 0.87; inter-rater, r = 0.95; all P < .0001), whereas they was lowest for the pronator quadratus (r = 0.49, 0.29, and 0.72, respectively; all P < .0001). At the mid-forearm, the intra-rater reliability was lower for both the radiologist and sonographer, whereas the inter-rater reliability was relatively high (r = 0.54, 0.55, and 0.81; all P < .0001). Tracing of captured images by different examiners showed high concordance for the median cross-sectional area at the carpal tunnel inlet (r = 0.96-0.98; P < .0001).Conclusions-The highest intra- and inter-rater reliability was found at the carpal tunnel inlet. The results also demonstrate that tracing of the median nerve cross-sectional area from captured images by different examiners does not contribute significantly to measurement variability.

Transverse Ultrasound Assessment of the Displacement of the Median Nerve in the Carpal Tunnel during Wrist and Finger Motion in Healthy Volunteers.

PURPOSE: The purpose of this study was to investigate the displacement of the median nerve in the carpal tunnel during finger motion at varied wrist positions using transverse ultrasound in healthy volunteers, in order to clarify the appropriate position of a wrist splint in treating carpal tunnel syndrome. METHODS: Fifty wrists of 25 asymptomatic volunteers were evaluated by transverse ultrasound. The location of the median nerve in the carpal tunnel was examined at 5 wrist positions (neutral, 60° dorsiflexion, 60° palmar flexion, 40° ulnar flexion, 10° radial flexion) with all 5 fingers in full extension, all 5 fingers in full flexion, and isolated thumb in full flexion, respectively. RESULTS: The median nerve was located significantly (p<0.05) more dorsally at the wrist dorsal flexion position, more ulnopalmarly at the wrist palmar flexion position, more radially at the wrist radial flexion position, and more radially at the wrist ulnar flexion position than at the wrist neutral position in all 5 fingers at full extension. The median nerve moved the most significantly dorsally among all wrist positions during finger motion at the wrist dorsal flexion position (p<0.05). Conversely, the median nerve moved the most significantly ulnopalmarly at the wrist palmar flexion position with all 5 fingers in full flexion among all wrist positions during finger motion (p<0.05). This latter wrist and finger position induced significant displacement of the median nerve toward the transverse carpal ligament, and compressed it between the flexor tendons and the transverse carpal ligament. CONCLUSIONS: This study showed that there is a significant relationship between the median nerve displacement in the carpal tunnel and the motion of the wrist and fingers. This finding suggests that the compression or the shearing stress of the median nerve caused by the movement of the flexor tendons is reduced in the wrist dorsal flexion position compared with other wrist positions. This wrist dorsal flexion position could be the appropriate position for a wrist splint in the treatment for carpal tunnel syndrome. This ultrasound information provides further knowledge and understanding of the biomechanics and pathophysiology of the carpal tunnel. It could also help in the accurate analysis and assessment of diagnostic images and treatment for carpal tunnel syndrome.