R Faschingbauer

Real-Time Sonoelastography: Findings in Patients with Symptomatic Achilles Tendons and Comparison to Healthy Volunteers

PURPOSE Real-time sonoelastography (SE), a newly introduced ultrasound technique, has already shown conclusive results in breast, prostate, and thyroid tumor diagnostics. This study investigated the performance of SE for the differentiation of Achilles tendon alterations of tendinopathy compared to clinical examination and conventional ultrasound (US). MATERIALS AND METHODS Achilles tendons in 25 consecutive patients with chronic Achilles tendinopathy and 25 healthy volunteers were examined clinically by US and by SE. RESULTS In the healthy volunteers, SE showed the tendon to be hard (93 %), while distinct softening was found in 57 % of the patients. SE showed more frequent involvement of the distal (64 %) and middle third (80 %) than the proximal third (28 %) of the Achilles tendon. Using SE a mean sensitivity of 94 %, specificity of 99 %, and accuracy of 97 % were found when clinical examination was used as the reference standard. The correlation to US was 0.89. Mild softening was found in 7 % of the healthy volunteers and in 11 % of the patients. CONCLUSION Our results emphasize that only distinct softening of Achilles tendons is comparable to clinical examination and US findings. However, mild softening might be explained by very early changes in tissue elasticity in the case of Achilles tendinopathy, which should be assessed in follow-up studies.

Achilles Tendon Assessed with Sonoelastography: Histologic Agreement

PURPOSE To compare and determine the level of agreement of findings at conventional B-mode ultrasonography (US) and sonoelastography of the Achilles tendon with findings at histologic assessment. MATERIALS AND METHODS This study was conducted with the approval of the institutional review boards, and all cadavers were in legal custody of the study institution. Thirteen Achilles tendons in 10 cadavers (four male, six female; age range, 70-90 years) were examined with B-mode US and sonoelastography. B-mode US grading was as follows: Grade 1 indicated a normal-appearing tendon with homogeneous fibrillar echotexture; grade 2, a focal fusiform or diffuse enlarged tendon; and grade 3, a hypoechoic area with or without tendon enlargement. Sonoelastography grading was as follows: Grade 1 indicated blue (hardest) to green (hard); grade 2, yellow (soft); and grade 3, red (softest). Twenty-five biopsy specimens from representative lesions of the middle and distal thirds of the Achilles tendons were evaluated histologically. The concordance of B-mode US grading compared with sonoelastographic grading was assessed by using κ analysis. RESULTS With B-mode US and sonoelastography, all 11 tendon thirds of histologically normal tendons were verified as normal (grade 1). Sonoelastography depicted 14 of 14 (100%) tendon thirds with histologic degeneration (grade 2 or 3), whereas B-mode US could depict only 12 of 14 (86%) lesions (grade 2 or 3). Only moderate agreement between B-mode US and sonoelastography was seen (κ = 0.52, P < .001). CONCLUSION Sonoelastography might help predict signs of histopathologic degeneration of Achilles tendinosis, potentially more sensitively than B-mode US.

Is Sonoelastography of Value in Assessing Tendons

Sonoelastography is a newly introduced ultrasound technique that evaluates tissue elasticity and thus provides additional information to that offered by conventional ultrasound images. In the musculoskeletal field, sonoelastography can help improve estimation of tendon stiffness. In this article, the principles and future developments of sonoelastography are discussed using the strongest and thickest tendon of the human body, the Achilles tendon, for illustrative purposes. Preliminary findings of sonoelastography in healthy and pathological Achilles tendons, technical considerations, examination technique and several limitations are addressed. The usefulness of elastography can be expected to increase rapidly in the musculoskeletal field, as soon as we learn to interpret elastographic artifacts as well as to take advantage of the new information provided by sonoelastography.

Fusion of real-time US with CT images to guide sacroiliac joint injection in vitro and in vivo.

PURPOSE To evaluate if image fusion, a technology matching real-time ultrasonography (US) and a previously obtained computed tomographic (CT) scan, is a feasible aid for sacroiliac (SI) joint injections in cadavers and patients. MATERIALS AND METHODS This study was approved by institutional review board, and written informed consent was obtained from each patient. In five human cadavers (10 joints) and seven consecutive patients (10 joints; four male, three female patients; mean age, 33.6 years; range, 22-44 years), SI joint injections were performed by using image fusion guidance technology. Registration errors were calculated automatically by the software and reported as mean registration error. In cadavers, needle placement was confirmed by means of CT, while in patients, a subjective rating of pain (score of 0-10) was recorded before and 3 months after injection. Procedure time was calculated. RESULTS Matching of real-time US and CT images by image fusion software was reliable in all tests (mean registration error, 0.3 mm). In all cadavers, correct intraarticular needle positioning by using image fusion guidance was confirmed on CT scans. In patients, no intraprocedural complications were noted, and 3 months after injection pain score decreased (mean pain score before procedure, 8.05; after, 0.3). In patients, mean time for the whole procedure was 20.4 minutes (range, 17-22 minutes), with a mean duration of 15.4 minutes (range, 14-17 minutes) for image matching and 5 minutes (range, 3-7 minutes) for needle placement. CONCLUSION Image fusion of real-time US and previously obtained CT scans is feasible to guide needle insertion into the SI joint.

Bifid Median Nerve in Carpal Tunnel Syndrome: Assessment with US Cross-sectional Area Measurement

PURPOSE To evaluate the accuracy of ultrasonography (US) in the diagnosis of carpal tunnel syndrome (CTS) in patients with a bifid median nerve on the basis of cross-sectional area (CSA) measurements of the median nerve at the level of the carpal tunnel (CSAc), with additional measurements obtained more proximally (CSAp) at the level of the pronator quadratus muscle. MATERIALS AND METHODS This HIPAA-compliant study was approved by the local institutional review board; informed oral and written consent were obtained. Fifty-three wrists in 49 consecutive patients with a bifid median nerve and CTS symptoms and 28 wrists in 27 healthy volunteers with a bifid median nerve were examined by using US. Two independent US examiners who were blinded to prior test results measured median nerve CSA at two levels, CSAc and CSAp. The difference between CSAc and CSAp (ΔCSA) was calculated for each wrist. Receiver operating characteristic (ROC) analysis was performed. RESULTS The study population included 17 men and 32 women (mean age, 55.1 years; age range, 24-78 years). The control population included 13 men and 14 women (mean age, 52.6 years; age range, 24-86 years). Mean CSAc was approximately 5 mm(2) greater in patients with CTS than in healthy volunteers (P < .0001), while mean ΔCSA was 5.8-5.9 mm(2) greater in patients with CTS (P < .0001). A CSAc threshold of 12 mm(2) provided sensitivity and specificity of 84.9% and 46.5%, respectively, while a ΔCSA threshold of 4 mm(2) provided sensitivity and specificity of 92.5% and 94.6%, respectively. ROC analysis demonstrated a significant advantage of ΔCSA (area under ROC curve [A(z)] = 0.95-0.96) compared with CSAc (A(z) = 0.84-0.85) for the diagnosis of CTS (P < .003). CONCLUSION The use of a ΔCSA parameter improves the diagnostic accuracy of US for the presence of CTS in patients with a bifid median nerve.

Entrapment Neuropathies II: Carpal Tunnel Syndrome

Diagnostic tests in patients complaining of carpal tunnel syndrome (CTS) are based on physical examination, electrodiagnostic tests (EDTs), and diagnostic imaging. Timely diagnosis helps prevent permanent nerve damage and its sequelae in terms of functional impairment. Imaging provides additional information to that obtained from clinical tests and EDTs. By allowing direct visualization of the compressed median nerve (MN), ultrasound (US) and magnetic resonance imaging can depict the causes for secondary CTS and describe anatomical variants, such as a bifid MN or a persistent median artery of the forearm, as well as space-occupying lesions including tenosynovitis and ganglion cysts. In addition, diagnostic imaging is of value for postoperative patients presenting with persistent symptoms. Finally, US is able to add information for EDT-negative symptomatic patients. Over time, US has increased in its sensitivity and specificity so it can be used as the initial test in patients presenting with clinical symptoms of CTS because it is now equivalent to EDT. The use of US as a screening test may reduce the number of EDT examinations in patients with suspected CTS, providing additional valuable anatomical information.

Sonographic criteria for therapy follow-up in the course of ultrasound-guided intra-articular injections of hyaluronic acid in hand osteoarthritis

OBJECTIVE To assess the value of sonographic criteria, based on measurements of joint capsule distension and synovial hyperemia, during the course of repeated ultrasound (US)-guided intra-articular injections of hyaluronic acid (HA) in hand osteoarthritis (OA). MATERIALS AND METHODS Thirty-three patients (28 females/5 males), with hand OA in 78 joints, were included in this study. Patients underwent sonographic evaluation at baseline and consecutively for 4 weeks at weekly US-guided intra-articular injections of HA (Hyalgan(®)). Measurements of joint thickening and joint inflammation were performed with Grey-scale and semi-quantitative Power-Doppler US (PDUS). Sonographic values were correlated with weekly patients self-assessment of pain for each treated joint. RESULTS The mean (SD) patients self-assessment of pain statistically significantly (p<0.0001) decreased from the first [68.3(22.3)] to the last week [37.3(30.34)]. A steady pain relief could be noticed in 67 (86%) of all treated joints. Over the whole observation period, the mean (SD) joint thickening of all joints markedly decreased from 15.6mm (5.3) to 13.1mm (6.4) (p<0.0001). The PDUS-score before initiation of HA treatment was statistically significantly higher than at the end of therapy (p<0.0001). The decrease in pain statistically significantly correlated with the decrease of joint thickening and PDUS-score between baseline and the end of therapy (p<0.001). CONCLUSION In this study, we demonstrate the meaningfulness of sonographic evaluation criteria including measurements of joint capsule distension and PDUS vascularization, both significantly correlating with the decrease of pain, during the therapy follow-up of US-guided intra-articular HA-injections in patients with hand OA.