Gout of hand and wrist: the value of US as compared with DECT.

OBJECTIVES: The purpose of this study was to compare findings of ultrasound (US) with dual-energy CT (DECT) in patients presenting with suspected gouty hand and wrist arthritis. METHODS: This prospective study included 180 patients (136 men and 44 women, age range, 31- 94 years; mean age, 65.9 years) with an initial clinical diagnosis of acute gouty arthritis who underwent DECT and US examination. Intra- and extra-articular findings of each modality were tabulated and calculated with DECT as gold standard. RESULTS: The final diagnosis of gout was positive in 97/180 patients (53.9%) by DECT, an alternative diagnosis confirmed in 83 patients. US showed a sensitivity of 70.1% (extra-articular: 42.5%, p < 0.0001; intra-articular: 80.3%, p = 0.14) and specificity of 51%. The double contour sign (DCS) was present in 58/61 patients with a positive US study for intra-articular gout (95.1%). CONCLUSIONS: Sensitivity of US for diagnosis of gouty arthritis in hand and wrist is limited, particularly with respect to extra-articular urate deposition. The DCS is the most sensitive sign for the assessment of gouty hand and wrist arthritis by US. KEY POINTS: • Sensitivity of US for diagnosis of gouty arthritis in hand and wrist is limited, particularly with respect to extra-articular gouty deposits. • The double contour sign is the most sensitive finding for the assessment of gouty hand and wrist arthritis by US. • Although the sensitivity of US for diagnosis of gouty hand and wrist arthritis is limited, it can be used as a first-line imaging modality in the presence of the DCS.

Sonoelastography of the Common Flexor Tendon of the Elbow with Histologic Agreement: A Cadaveric Study.

Purpose To determine the correlation of the results of conventional B-mode ultrasonography (US) and compression sonoelastography with histologic results in common flexor tendons of the elbow in human cadavers. Materials and Methods Twenty-five common flexor tendons were evaluated in 16 fresh, unembalmed cadavers of 11 women with a median age of 85 years (range, 71-101 years) and five men with a median age of 78 years (range, 70-88 years). Informed consent was provided according to the last will of the donors. B-mode US results were classified as grade 1, normal tendon with homogeneous fibrillar pattern; grade 2, tendon thickening or hypoechoic areas and/or calcifications in less than 30% of the tendon; or grade 3, hypoechoic areas and/or calcifications greater than 30% of the tendon. Sonoelastographic results were grade 1, blue (hardest) to green (hard); grade 2, yellow (soft); and grade 3, red (softest). The intraclass correlation coefficient was calculated to determine agreement with histologic findings for each B-mode US, sonoelastographic, and combined B-mode US and sonoelastographic examination. Histologic results were grade 1, normal, with parallel fibrillar pattern; grade 2, mild tendinopathy, with cellular infiltration, angiogenesis, or fatty vacuoles; or grade 3, severe tendinopathy, with loss of parallel collagen structure and necrosis. Results Histologic alterations were detected in 44% (11 of 25) of biopsy specimens. Intraclass correlation with histologic results was 0.57 for B-mode US, 0.68 for sonoelastography, and 0.84 for the combination of the two approaches. Conclusion The addition of sonoelastography to B-mode US provided statistically significant improvement in correlation with histologic results compared with the use of B-mode US alone (P < .02). © RSNA, 2016 Online supplemental material is available for this article.

Extensor tendinopathy of the elbow assessed with sonoelastography: histologic correlation.

PURPOSE: To compare agreement between conventional B-mode ultrasound (US) and compression sonoelastography (SEL) of the common extensor tendons of the elbow with histological evaluation. MATERIALS AND METHODS: Twenty-six common extensor tendons were evaluated in 17 cadavers (11 females, median age 85 years and 6 males, median age 80 years). B-mode US was graded into: Grade 1, homogeneous fibrillar pattern; grade 2, hypoechoic areas and/or calcifications <30%; and grade 3 > 30%. SEL was graded into: Grade 1 indicated blue (hardest) to green (hard); grade 2 yellow (soft); and grade 3 red (softest). B-mode US, SEL, and a combined grading score incorporating both were compared to histological findings in 76 biopsies. RESULTS: Histological alterations were detected in 55/76 biopsies. Both modalities showed similar results (sensitivity, specificity, and accuracy 84%, 81%, and 83% for B-mode US versus 85%, 86%, and 86% for SEL, respectively, P > 0.3). However, a combination of both resulted in significant improvement in sensitivity (96%, P < 0.02) without significant change in specificity (81%, P < 0.3), yielding an improved overall accuracy (92%). CONCLUSION: Combined imaging of the extensor tendons with both modalities is superior to either modality alone for predicting the presence of pathologic findings on histology. KEY POINTS: • Combination of B-mode US and SEL proved efficiency in diagnosing lateral epicondylitis. • Combination of B-mode US and SEL in lateral epicondylitis correlates to histology. • Combination of both modalities provides improved sensitivity without loss of specificity.

Meralgia paraesthetica: Ultrasound-guided injection at multiple levels with 12-month follow-up.

OBJECTIVES: To evaluate the efficacy of ultrasound (US)-guided injections around the lateral femoral cutaneous nerve (LFCN) at different levels in meralgia paraesthetica (MP) patients. METHODS: The study was approved by the university ethics committee and informed oral and written consent were obtained from all patients. Between June 2008 and August 2013, 20 patients with symptoms of MP, including nine men (mean age, 61.33 years) and 11 women (mean age 61.18 years), were treated with US-guided injection of steroids along the LFCN at three different levels in a mean of 2.25 sessions. A visual analogue scale (VAS) was used to measure symptoms before, immediately after and 12 months after treatment. RESULTS: Complete resolution of symptoms was documented in 15/20 patients (mean VAS decreased from 82 to 0), and partial resolution in the remaining five (mean VAS decreased from 92 to 42), which was confirmed at 12-month follow-up. By using the different levels of injection approach overall significantly better symptom relief was obtained (p < 0.05). CONCLUSION: The outcome of US-guided injection along the LFCN can be further improved by injections at different levels (p < 0.05), which was confirmed at 12-month long-term follow-up. KEY POINTS: Meralgia paraesthetica is an entrapment neuropathy of the lateral femoral cutaneous nerve. Ultrasound proved effective in diagnosis and in guiding injection therapy. Injection at the anterior superior iliac spine has been used previously. Multiple injections along the nerve course were used in this study. Long-term follow-up (12 months) confirmed the results.

Sonographic cross-sectional area measurement in carpal tunnel syndrome patients: can delta and ratio calculations predict severity compared to nerve conduction studies?

OBJECTIVE: To evaluate the accuracy of two different sonographic median nerve measurement calculations in predicting carpal tunnel syndrome (CTS) severity in a study population with clinically and electrophysiologically confirmed CTS. METHODS: 643 wrists of 427 patients (325 females and 102 males, age range: 17-90 years, mean ± SD: 57.9 ± 14.7) were included with CTS diagnosis based on clinical and nerve conduction studies (NCS). Cross-sectional area (CSA) measurement of the median nerve was performed at the carpal tunnel level (CSAc) and at the pronator quadratus muscle level (CSAp). Two parameters were calculated: delta (∆-CSA), which is the difference between proximal and distal measurements, and ratio (R-CSA), calculated by dividing distal over proximal measurements. RESULTS: Patients were classified into mild, moderate and severe CTS based upon NCS. The mean ∆-CSA (4.2 ± 2.6, 6.95 ± 2.2 and 10.7 ± 4.9 mm(2)) and mean R-CSA (1.5 ± 0.4, 1.95 ± 0.4 and 2.4 ± 0.7) values were significantly different between all groups (p < 0.001). Optimal cut-off values for ∆-CSA and R-CSA were 6 mm(2) and 1.7, respectively, to distinguish mild from moderate disease, and 9 mm(2) and 2.2, respectively, to distinguish moderate from severe disease. CONCLUSION: Threshold values for the calculated sonographic parameters ∆-CSA and R-CSA are useful in predicting CTS severity compared to NCS. KEY POINTS: • Two proposed parameters were calculated (∆-CSA, R-CSA) and compared to NCS. • A defined sonoanatomical proximal landmark was used for the calculation. • Both parameters showed ability to detect CTS severity comparable to NCS. • Cut-off values could be determined for both parameters.