Johann Gruber

Carpal Tunnel Syndrome Assessment with US: Value of Additional Cross-sectional Area Measurements of the Median Nerve in Patients versus Healthy Volunteers

PURPOSE To improve accuracy in the diagnosis of carpal tunnel syndrome (CTS) by comparing cross-sectional area (CSA) measurements of the median nerve obtained at the level of the carpal tunnel (CSAc) with those obtained more proximally (CSAp), at the level of the pronator quadratus muscle. MATERIALS AND METHODS The study protocol was approved by the institutional review board, and all subjects gave written informed consent. One hundred wrists of 68 consecutive patients with CTS (16 men, 52 women; mean age, 57.9 years; range, 25-85 years) and 93 wrists of 58 healthy volunteers (16 male, 42 female; mean age, 55.1 years; range, 17-85 years) were examined with ultrasonography (US). Electrodiagnostic test results confirmed the diagnosis of CTS in all 68 patients. The US examiner was blinded to these test results. The CSA of the median nerve was measured at the carpal tunnel and proximal levels, and the difference between CSAc and CSAp (Delta CSA) was calculated for each wrist. RESULTS The mean CSAc in healthy volunteers (9.0 mm(2)) was smaller than that in patients (16.8 mm(2), P < .01). The mean Delta CSA was smaller in asymptomatic wrists (0.25 mm(2)) than in CTS-affected wrists (7.4 mm(2), P < .01). Receiver operating characteristic analysis revealed a diagnostic advantage to using the Delta CSA rather than the CSAc (P = .036). Use of a Delta CSA threshold of 2 mm(2) yielded the greatest sensitivity (99%) and specificity (100%) for the diagnosis of CTS. CONCLUSION Receiver operating characteristic analysis revealed improved accuracy in the diagnosis of CTS determined with the Delta CSA compared with the accuracy of the diagnosis determined with the CSAc.

Feasibility of ultrasound-guided sacroiliac joint injection considering sonoanatomic landmarks at two different levels in cadavers and patients.

OBJECTIVE Sacroiliitis is often caused by rheumatic diseases, and besides other therapeutic options, treatment consists of intraarticular injection of corticosteroids. The purpose of this study was to assess the feasibility of ultrasound (US)-guided sacroiliac joint (SI joint) injection at 2 different puncture levels in cadavers and patients when defined sonoanatomic landmarks were considered. METHODS After defining sonoanatomic landmarks, US-guided needle insertion was performed in 10 human cadavers (20 SI joints) at 2 different puncture sites. Upper level was defined at the level of the posterior sacral foramen 1 and lower level at the level of the posterior sacral foramen 2. In 10 patients with unilateral sacroiliitis, injection at the most feasible level was attempted. RESULTS Computed tomography confirmed correct intraarticular needle placement in cadavers by showing the tip of the needle in the joint and intraarticular diffusion of contrast media in 16 (80%) of 20 SI joints (upper level 7 [70%] of 10; lower level 9 [90%] of 10). In all 4 cases in which needle insertion failed, intraarticular SI joint injection at the other level was successful. In patients, 100% of US-guided injections were successful (8 lower level, 2 upper level), with a mean pain relief of 8.6 after 3 months. CONCLUSION US guidance of needle insertion into SI joints was feasible at both levels when defined sonoanatomic landmarks were used. If SI joint alterations do not allow for direct visualization of the dorsal joint space of the lower level, which is easier to access, the upper level might offer an appropriate alternative.

Feasibility of second‐generation ultrasound contrast media in the detection of active sacroiliitis

OBJECTIVE To determine whether a recently available contrast-enhanced ultrasound (CEUS) technique using second-generation microbubbles allows for the detection of active sacroiliitis, and to measure CEUS enhancement depth at the dorsocaudal part of the sacroiliac (SI) joints in healthy volunteers compared with patients with sacroiliitis. METHODS Forty-two consecutive patients (84 SI joints) presenting with a clinical diagnosis of sacroiliitis in 50 SI joints and 21 controls (42 SI joints) were investigated by CEUS using a standardized low mechanical index ultrasound protocol. Detected vascularity was used to retrospectively measure the enhancement depth in the dorsocaudal part of the SI joints. RESULTS CEUS detected enhancement in all clinically active SI joints, showing an enhancement depth into the dorsal SI joint cleft of 18.5 mm (range 16-22.1), which was significantly higher compared with both inactive joints of patients (3.6 mm, range 0-12; P < 0.001) and healthy controls (3.1 mm, range 0-7.8; P < 0.001). All inactive joints were correctly classified based on a lack of deep enhancement in patients with sacroiliitis and controls (42 of 42, 100% sensitivity, 100% specificity; Cohens kappa = 1). CONCLUSION CEUS allowed the differentiation of active sacroiliitis from inactive SI joints, and proved to be a feasible method for the detection of vascularity in clinically active sacroiliitis by showing deep contrast enhancement into the SI joints not detectable in inactive joints of patients or controls. If this technique might add information to the earlier detection of sacroiliitis, it should be addressed in further studies.

Detection of vascularity in wrist tenosynovitis: power doppler ultrasound compared with contrast-enhanced grey-scale ultrasound

IntroductionWe sought to assess vascularity in wrist tenosynovitis by using power Doppler ultrasound (PDUS) and to compare detection of intra- and peritendinous vascularity with that of contrast-enhanced grey-scale ultrasound (CEUS).MethodsTwenty-six tendons of 24 patients (nine men, 15 women; mean age ± SD, 54.4 ± 11.8 years) with a clinical diagnosis of tenosynovitis were examined with B-mode ultrasonography, PDUS, and CEUS by using a second-generation contrast agent, SonoVue (Bracco Diagnostics, Milan, Italy) and a low-mechanical-index ultrasound technique. Thickness of synovitis, extent of vascularized pannus, intensity of peritendinous vascularisation, and detection of intratendinous vessels was incorporated in a 3-score grading system (grade 0 to 2). Interobserver variability was calculated.ResultsWith CEUS, a significantly greater extent of vascularity could be detected than by using PDUS (P < 0.001). In terms of peri- and intratendinous vessels, CEUS was significantly more sensitive in the detection of vascularization compared with PDUS (P < 0.001). No significant correlation between synovial thickening and extent of vascularity could be found (P = 0.089 to 0.097). Interobserver reliability was calculated to be excellent when evaluating the grading score (κ = 0.811 to 1.00).ConclusionsCEUS is a promising tool to detect tendon vascularity with higher sensitivity than PDUS by improved detection of intra- and peritendinous vascularity.

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

ObjectivesThe 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.MethodsThis 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.ResultsThe 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%).ConclusionsSensitivity 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.

Response to: “Monosodium urate crystal deposition associated with the progress of radiographic grade at the sacroiliac joint in axial SpA: a dual-energy CT study”

We read with great interest the article by Zhu et al. [1] entitled “Monosodium urate crystal deposition associated with the progress of radiographic grade at the sacroiliac joint in axial SpA: a dual-energy CT study” which was published in Arthritis Research & Therapy in May 2017. We congratulate the authors on attempting to verify gouty deposits at the sacroiliac joint in axial SpA patients using dual-energy computed tomography (DECT), a relatively new imaging method to detect gouty deposits. Deposition of monosodium urate (MSU) in the spine is a rare manifestation of gout, and only case and series reports exist in the literature [2]. Axial SpA patients without gout and with no hyperuricemia were included in this study; however, a case–control group would be of interest to compare results with gout patients and with nonaxial SpA patients in order to elucidate the prevalence of spinal gout involvement, which is actually unknown [2]. In addition, matters of concern arise when considering the presented figures. DECT artifacts according to ACR/EULAR guidelines have to be differentiated from gouty deposits when submillimeter deposits, skin deposits, deposits obscured by motion, beam hardening, and vascular artifact are present [3, 4]. Submillimeter artifacts may be single or may form part of a diffuse pattern of the scatter. They are thought to occur as a result of and as a form of noise [4]. Furthermore, it has been shown recently using DECT that MSU crystal deposition is generally present within the joint, on the bone surface, and within bone erosion, but is not observed within bone in the absence of a cortical break [5]. Interestingly, the green DECT pixels presented in the figures (rated as MSU deposits) are mainly depicted inside the sacrum and the iliac bone, and not in the sacroiliac joint nor pronounced on the bone surface. This is contrary to the “bone cortex concept” where MSU crystals deposit outside bone and contribute to bone erosion through an “outside-in” mechanism [5].

Acute Gouty Knee Arthritis: Ultrasound Findings Compared With Dual-Energy CT Findings

OBJECTIVE The purpose of this study was to compare findings of ultrasound (US) with dual-energy CT (DECT) findings in patients presenting with suspected gouty knee arthritis. SUBJECTS AND METHODS This prospective study included 65 patients (52 men and 13 women; median age, 61.7 years [range, 38-87 years]) with an initial clinical diagnosis of acute gouty knee arthritis who underwent DECT performed using a 128-MDCT scanner and US performed using a 5-18-MHz transducer. Both intra- and extraarticular findings obtained using each modality were tabulated. RESULTS DECT identified gout as the final diagnosis for 52 of 65 patients (80.0%). An alternative diagnosis was confirmed for the remaining 13 patients. US detected gout in 31 of 52 patients (sensitivity, 59.6%) and produced findings negative for gout in seven of 13 patients (specificity, 53.8%). The double contour sign on US was positive for gout in 23 of 52 patients (44.2%) and negative in 12 of 13 patients (92.3%). Extraarticular urate deposition was identified by DECT in 44 of 52 patients, compared with identification by US in 11 of 52 patients (p < 0.001). CONCLUSION The sensitivity of US for the diagnosis of gouty knee arthritis is limited, particularly with respect to extraarticular urate deposition. The double contour sign is the single most valuable sign for the assessment of gouty knee arthritis by US.

Value of High Frequency Sonography in Rheumatoid Arthritis

Rheumatoid arthritis is a chronic inflammatory arthritis with the incidence reaching up to 1% of the population. The treatment of rheumatoid arthritis (RA) has improved dramatically over the last years with the introduction of TNF (tumor necrosis factor) alpha inhibitors. Joint damage and functional impairment are highly important adverse outcomes of rheumatoid arthritis. They have been repeatedly shown to be associated with clinical disease activity, in particular with swollen joint counts and acute-phase reactant levels, as well as composite measures of disease activity in which these variables are included as components. OMERACT outcome measures in rheumatology group published consensus US definitions for common pathologic lesions observed in patients affected by RA, each of them is discussed, effusion, synovitis, bone erosion, hypervascularity and tenosynovitis. The use of musculoskeletal ultrasound (MSK-US)is growing more and more between radiologists and rheumatologists for the early diagnosis and therapeutic follow up of rheumatoid arthritis and US scores are used for monitoring RA disease activity; US findings can be scored using quantitative or semiquantitative scoring systems to estimate the degree of synovial/tenosynovial and erosive processes.. New technologies such as elastography, three dimensional sonography, fusion imaging and contrast enhanced ultrasound can add further powerful information in the imaging of RA. [Egypt J Rheumatology & Clinical Immunology, 2015; 3(1): 23-32]