Single-source dual-energy computed tomography for the detection of bone marrow lesions: impact of iterative reconstruction and algorithms.

PURPOSE: To compare the diagnostic performance of different reconstruction algorithms of single-source dual-energy computed tomography (DECT) for the detection of bone marrow lesions (BML) in patients with vertebral compression fracture using MRI as the standard of reference. MATERIAL AND METHODS: Seventeen patients with an age over 50 who underwent single-source DECT of the spine were included. The raw data (RD) were reconstructed using filtered back-projection (FBP) and iterative reconstruction (IR) with three iteration levels (IR1-IR3). Bone marrow images were generated using a three-material decomposition (3MD) and a two-material decomposition (2MD) algorithm and an RD-based approach. Three blinded readers scored the images for image quality and the presence of bone marrow lesions (BML). Only vertebrae with height loss were included. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The different reconstructions were compared using Dunn's multiple comparison test. RESULTS: Thirty-nine vertebrae were included. IR(1-3) showed superior sensitivity (87.5%) compared to FBP (75%) using 3MD but was comparable to RD (83.3%). All 2MD images were inferior (sensitivity < 38%). The image quality score was significantly higher for 3MD-IR(1-3) compared to 3MD-FBP (p < 0.0001) and all 2MD data sets (p < 0.03). This pattern was also supported by the SNR and CNR measurements. RD showed no significant improvement compared to IR. CONCLUSION: The image quality of bone marrow images acquired with DECT can be improved by using IR compared with FBP. RD-based reconstruction does not offer significant improvement over image data-based reconstruction. 2MD algorithms are not suitable for BML detection.

[Rheumatoid arthritis-mimics : When appearances are deceptive]. / Rheumatoide Arthritis ­ Mimics : Wenn der Schein trügt.

Rheumatology represents a discipline full of differential diagnoses. Even for classical diseases, such as rheumatoid arthritis as the most frequent chronic inflammatory joint disease and described so clearly in many textbooks, it is not uncommon that it can be a diagnostic challenge in daily practice. This applies to arthritic joint involvement and also to frequently associated extra-articular manifestations. The patient history and results of the clinical examination are essential; however, laboratory and imaging findings often make a significant contribution to confirming the diagnosis, especially in early phases of the disease. This article, which makes no claims to completeness, focuses on diseases that in the opinion of the authors can imitate rheumatoid arthritis due to similar joint and other organ manifestations. These include metabolic, inflammatory infective and non-infective as well as tumorous diseases. A misinterpretation as rheumatoid arthritis as a rule leads to long-term and severe consequences for affected patients. Thus, the diagnosis of rheumatoid arthritis should be questioned and re-evaluated in cases of unusual accompanying symptoms, atypical course of disease and a lack of response to standard treatment approaches.

[Magnetic resonance imaging findings after shoulder surgery: What the radiologist needs to know]. / Besonderheiten der Magnetresonanztomographie nach operativer Schulterintervention.

Even primary diagnostic evaluation of the shoulder is a challenge for radiologists. Many imaging findings that definitely indicate abnormal findings in the untreated shoulder should be evaluated carefully in postoperative patients. Artifacts caused by implants or metal abrasion pose considerable problems in postoperative magnetic resonance imaging (MRI). Classic approaches to minimizing artifacts caused by foreign bodies include using turbo spin echo sequences, increasing bandwidth, and reducing voxel size. In recent years, several vendors have developed dedicated pulse sequences for reducing metal artifacts. Different postoperative imaging findings will be encountered, depending on the kind of surgery done. This review article describes typical postoperative MRI findings, focusing on subacromial decompression, reconstruction of the rotator cuff, labrum procedures, and biceps tenodesis.

Defining active sacroiliitis on MRI for classification of axial spondyloarthritis: update by the ASAS MRI working group.

OBJECTIVES: To review and update the existing definition of a positive MRI for classification of axial spondyloarthritis (SpA). METHODS: The Assessment in SpondyloArthritis International Society (ASAS) MRI working group conducted a consensus exercise to review the definition of a positive MRI for inclusion in the ASAS classification criteria of axial SpA. Existing definitions and new data relevant to the MRI diagnosis and classification of sacroiliitis and spondylitis in axial SpA, published since the ASAS definition first appeared in print in 2009, were reviewed and discussed. The precise wording of the existing definition was examined in detail and the data and a draft proposal were presented to and voted on by the ASAS membership. RESULTS: The clear presence of bone marrow oedema on MRI in subchondral bone is still considered to be the defining observation that determines the presence of active sacroiliitis. Structural damage lesions seen on MRI may contribute to a decision by the observer that inflammatory lesions are genuinely due to SpA but are not required to meet the definition. The existing definition was clarified adding guidelines and images to assist in the application of the definition. CONCLUSION: The definition of a positive MRI for classification of axial SpA should continue to primarily depend on the imaging features of 'active sacroiliitis' until more data are available regarding MRI features of structural damage in the sacroiliac joint and MRI features in the spine and their utility when used for classification purposes.

Acute vertebral fracture after spinal fusion: a case report illustrating the added value of single-source dual-energy computed tomography to magnetic resonance imaging in a patient with spinal Instrumentation.

Magnetic resonance imaging (MRI) is degraded by metal-implant-induced artifacts when used for the diagnostic assessment of vertebral compression fractures in patients with instrumented spinal fusion. Dual-energy computed tomography (DECT) offers a promising supplementary imaging tool in these patients. This case report describes an 85-year-old woman who presented with a suspected acute vertebral fracture after long posterior lumbar interbody fusion. This is the first report of a vertebral fracture that showed bone marrow edema on DECT; however, edema was missed by an MRI STIR sequence owing to metal artifacts. Bone marrow assessment using DECT is less susceptible to metal artifacts than MRI, resulting in improved visualization of vertebral edema in the vicinity of fused vertebral bodies.

[No exchange of information without technology : modern infrastructure in radiology]. / Kein Informationsaustausch ohne Technik : Moderne Infrastruktur einer Radiologie.

Modern radiology cannot accomplish the daily numbers of examinations without supportive technology. Even though technology seems to be becoming increasingly more indispensable, business continuity should be ensured at any time and if necessary even with a limited technical infrastructure by business continuity management. An efficient information security management system forms the basis. The early radiology information systems were islands of information processing. A modern radiology department must be able to be modularly integrated into an informational network of a bigger organization. The secondary use of stored data for clinical decision-making support poses new challenges for the integrity of the data or systems because medical knowledge is displayed and provided in a context of treatment. In terms of imaging the creation and distribution radiology services work in a fully digital manner which is often different for radiology reports. Legally secure electronic diagnostic reports require a complex technical infrastructure; therefore, diagnostic findings still need to be filed as a paper document. The internal exchange and an improved dose management can be simplified by systems which continuously and automatically record the doses and thus provide the possibility of permanent analysis and reporting. Communication between patient and radiologist will gain ongoing importance. Intelligent use of technology will convey this to the radiologist and it will facilitate the understanding of the information by the patient.

[Imaging modalities in psoriatic arthritis]. / Bildgebende Verfahren bei Psoriasisarthritis.

This review presents an overview of the range of imaging modalities used in the diagnostic evaluation of patients with psoriatic arthritis (PsA). Conventional radiography is used to detect structural changes of the joints and tendon attachments. These changes occur late in the course of PsA hence conventional radiography contributes little to the early detection of PsA; however, the detection of periosteal proliferations on radiographs allows a relatively specific diagnosis of PsA. Skeletal scintigraphy and computed tomography are rarely used in PsA. Arthrosonography (ultrasound of the joints) is gaining increasing importance in the early identification of inflammatory soft tissue signs of PsA in the peripheral joints. Sonography enables early detection of synovitis and tenosynovitis as well as superficial erosions and also inflammatory processes of the tendon attachments. Magnetic resonance imaging (MRI) is indispensable for identifying possible involvement of the axial skeleton. Moreover, it allows good visualization of periostitis and arthritis. High resolution microcomputed tomography is an interesting novel diagnostic tool which allows highly sensitive evaluation of the bone structure and can detect very tiny bone lesions where typical signs of PsA are omega-shaped erosions and small corona-like spikes. Another interesting new diagnostic technique is fluorescence optical imaging (FOI) with the Xiralite system which is highly sensitive for detecting inflammatory processes of the hands.

Quantification of periarticular demineralization and synovialitis of the hand in rheumatoid arthritis patients.

UNLABELLED: The bone mineral density (BMD) measurement of the hand in rheumatoid arthritis (RA) patients is no standard measurement method as yet. The aim was to contribute to the standardization of the hand BMD measurement, especially of periarticular regions. As results, we found best precision values for the wrist and a significant correlation between hand and spine/femur BMD depending on disease activity and disease duration. INTRODUCTION: This study was conducted to investigate (i) the precision of periarticular hand BMD measuring, (ii) the periarticular demineralization of the hand, (iii) the correlation between periarticular hand BMD and spine/femur BMD, and (iv) the correlation of hand BMD to hand synovitis. METHODS: A number of 52 RA patients were examined by BMD measurement of the femoral neck, spine, whole hand, metacarpophalangeal (MCP) joints II-V, personal identity profile (PIP) joints II-V, and wrist using dual-energy X-ray absorptiometry (DXA). Synovitis of the hand was examined by ultrasonography and magnetic resonance imaging (MRI). Three subgroups were further analyzed: early RA, established RA with moderate and with high disease activity. Early RA and established RA patients with high disease activity were Followed up after 12 months. RESULTS: We found (1) best precision of BMD measurement for the wrist, (2) BMD in RA significantly reduced if compared to normal controls, (3) a highly significant positive correlation between hand and spine/femur BMD and the power of correlation to depend on disease activity and disease duration (high correlation in RA with moderate disease activity and early RA, very high correlation in RA with high disease activity), (4) a negative correlation between hand BMD and hand synovitis in RA with high disease activity, and (5) a significant reduction of synovitis but no change in hand BMD after 12 months, respectively. CONCLUSIONS: This study shows a highly significant correlation between hand BMD and spine/femur BMD in RA patients depending on disease activity and disease duration. We conclude to measure BMD at different sites including hands in order to quantify bone loss in RA patients most properly.

[Imaging in rheumatic diseases. Rheumatoid arthritis and differential diagnostics]. / Bildgebung rheumatischer Erkrankungen. Rheumatoide Arthritis und Differenzialdiagnosen.

Differential diagnostics of arthritides is challenging even for experienced radiologists. Nevertheless, there are simple signs that can give important clues to make a diagnosis. Close cooperation with the attending clinicians is essential to get the most from imaging studies and to provide relevant information for patient management and therapy.

Relationship between active inflammatory lesions in the spine and sacroiliac joints and new development of chronic lesions on whole-body MRI in early axial spondyloarthritis: results of the ESTHER trial at week 48.

AIM: To investigate the relationship between active inflammatory lesions on whole-body MRI (wb-MRI) and new development of chronic lesions on T1 MRI in patients with early axial spondyloarthritis (SpA) treated either with etanercept (ETA) or sulfasalazine (SSZ). METHODS: Wb-MRIs of 65 patients treated either with ETA (n=35) or SSZ (n=30) over 1 year were scored for active inflammation, fatty lesions, erosions and ankylosis in the 23 vertebral units (VUs) of the spine and in the sacroiliac joints (SI joints). Scoring was performed by two blinded radiologists. RESULTS: If there was no previous inflammation in the bone no new fatty lesions occurred in SI joint quadrants and only a few (0.6%) in spine VUs. There was a significant relationship between disappearance of inflammation and the appearance of fatty lesions: if baseline inflammation resolved fatty lesions occurred in 10.5% of SI joint quadrants and 17.9% of VUs. If inflammation did not resolve over 1 year, fatty lesions occurred less frequently: 2.4% (SI joint quadrants) and 7.2% (VUs). There was a significantly higher increase of the mean fatty lesion score between baseline and week 48 in the ETA (4.0 vs 4.8 for the SI joints and 1.9 vs 2.7 for the spine) compared to the SSZ (3.0 vs 3.2 for the SI joints and 1.1 vs 1.2 for the spine, respectively) group (p=0.001 and p=0.020 for the differences). No significant changes in the erosion or ankylosis score were observed in any of the two groups during this time. CONCLUSIONS: These data indicate that there is a close interaction between inflammation, tumour necrosis factor blockade and the development of fatty lesions in subchondral bone marrow of patients with axial SpA.

Contrast-enhanced ultrasonography is more sensitive than grayscale and power Doppler ultrasonography compared to MRI in therapy monitoring of rheumatoid arthritis patients.

PURPOSE: To evaluate wrist and finger joints in patients with rheumatoid arthritis (RA) by grayscale, power Doppler (PD) and contrast-enhanced musculoskeletal ultrasonography (US) and to compare these findings with MRI, clinical (DAS28) and laboratory (ESR; CRP) data. MATERIALS AND METHODS: US was performed at baseline (t0) and after three, six and twelve (t12) months before and after a change of medical treatment. MRI was carried out at t0 and t12 and used as the reference method. Contrast-enhanced US was used to assess one clinically most affected joint region. Different semiquantitative synovitis scores were calculated by grayscale and PD US. RESULTS: Contrast-enhanced US results evaluated by enhancement, slope and semi-quantitative assessment significantly correlated to each other, to grayscale US, CRP, as well as to MRI with the highest correlation coefficients for the used contrast-enhanced US modes (r = 0.56, r = 0.55, r = 0.57; each p < 0.05). Sum scores evaluated by grayscale US showed that synovial inflammation in finger joints was detected significantly more frequently in the palmar aspect than on the dorsal side (p = 0.001). Using power Doppler US, the wrists were significantly more inflamed from dorsal than on the palmar side (p = 0.0004). Significant longitudinal correlations between grayscale and power Doppler US scores were detected. CONCLUSION: Grayscale, power Doppler and contrast-enhanced US are accurate tools for the detection and follow-up of synovitis in RA wrist and finger joints, with contrast-enhanced US being most sensitive compared to MRI. All imaging methods reflected a good response to TNFα blocking therapy.

Image-guided spinal injection procedures in open high-field MRI with vertical field orientation: feasibility and technical features.

OBJECTIVE: We prospectively evaluated the feasibility and technical features of MR-guided lumbosacral injection procedures in open high-field MRI at 1.0 T. METHODS: In a CuSO(4).5H(2)O phantom and five human cadaveric spines, fluoroscopy sequences (proton-density-weighted turbo spin-echo (PDw TSE), T1w TSE, T2w TSE; balanced steady-state free precession (bSSFP), T1w gradient echo (GE), T2w GE) were evaluated using two MRI-compatible 20-G Chiba-type needles. Artefacts were analysed by varying needle orientation to B(0), frequency-encoding direction and slice orientation. Image quality was described using the contrast-to-noise ratio (CNR). Subsequently, a total of 183 MR-guided nerve root (107), facet (53) and sacroiliac joint (23) injections were performed in 53 patients. RESULTS: In vitro, PDw TSE sequence yielded the best needle-tissue contrasts (CNR = 45, 18, 15, 9, and 8 for needle vs. fat, muscle, root, bone and sclerosis, respectively) and optimal artefact sizes (width and tip shift less than 5 mm). In vivo, PDw TSE sequence was sufficient in all cases. The acquisition time of 2 s facilitated near-real-time MRI guidance. Drug delivery was technically successful in 100% (107/107), 87% (46/53) and 87% (20/23) of nerve root, facet and sacroiliac joint injections, respectively. No major complications occurred. The mean procedure time was 29 min (range 19-67 min). CONCLUSION: MR-guided spinal injections in open high-field MRI are feasible and accurate using fast TSE sequence designs.

Contrast-enhanced ultrasound in monitoring the efficacy of a bradykinin receptor 2 antagonist in painful knee osteoarthritis compared with MRI.

OBJECTIVES: To evaluate contrast-enhanced ultrasound (CE-US) as a monitoring tool to assess hypervascularisation of synovial processes in knee osteoarthritis (OA) treated with intra-articular injections of the bradykinin-receptor 2 antagonist icatibant compared to contrast-enhanced magnetic resonance imaging (CE-MRI). PATIENTS AND METHODS: In a randomised, double-blind, placebo-controlled trial, 41 patients with painful knee OA underwent US (12.5 MHz for B-mode and 3-8 MHz for CE-US), and 36 of the patients underwent additional MRI (0.2T) at baseline and after 3 injections of the study drug (after a mean of 22.2 days). A total of 15 patients received placebo (group A), 12 patients 500 microg icatibant (group B) and 14 patients 2000 microg icatibant (group C). Pain and the synovial process (B-mode, power Doppler US (PD-US), CE-US, CE-MRI) were assessed at both time points. RESULTS: At baseline, the placebo group showed more activity in terms of effusion in the superior and lateral recess in ultrasound as well as in PD-US in the lateral recess. Pain improved significantly in all subgroups. Effect sizes were 0.43 (pain at rest) and 0.52 (pain during activity) in group B vs 0.48 and 1.11 in group C. There was no change of US and MRI parameters. We found moderate to good correlation (r) and kappa values (kappa) for effusion in the superior recess (r = 0.591, k = 0.453), effusion in the lateral recess (r = 0.304, k = 0.440) and contrast enhancement (r = 0.601, k = 0.242) between US and MRI. CONCLUSIONS: Our results show that CE-US and CE-MRI have good agreement in assessing inflammatory changes in knee OA. For the 41 patients with OA, an analgesic effect of icatibant could clearly be shown, especially for pain during activity in the high dose icatibant group. However, we could not find an anti-inflammatory effect of icatibant by CE-US compared to CE-MRI.

Defining active sacroiliitis on magnetic resonance imaging (MRI) for classification of axial spondyloarthritis: a consensual approach by the ASAS/OMERACT MRI group.

BACKGROUND: Magnetic resonance imaging (MRI) of sacroiliac joints has evolved as the most relevant imaging modality for diagnosis and classification of early axial spondyloarthritis (SpA) including early ankylosing spondylitis. OBJECTIVES: To identify and describe MRI findings in sacroiliitis and to reach consensus on which MRI findings are essential for the definition of sacroiliitis. METHODS: Ten doctors (two radiologists and eight rheumatologists) from the ASAS/OMERACT MRI working group reviewed and discussed in three workshops MR images depicting sacroiliitis associated with SpA and other conditions which may mimic SpA. Descriptions of the pathological findings and technical requirements for the appropriate acquisition were formulated. In a consensual approach MRI findings considered to be essential for sacroiliitis were defined. RESULTS: Active inflammatory lesions such as bone marrow oedema (BMO)/osteitis, synovitis, enthesitis and capsulitis associated with SpA can be detected by MRI. Among these, the clear presence of BMO/osteitis was considered essential for defining active sacroiliitis. Structural damage lesions such as sclerosis, erosions, fat deposition and ankylosis can also be detected by MRI. At present, however, the exact place of structural damage lesions for diagnosis and classification is less clear, particularly if these findings are minor. The ASAS group formally approved these proposals by voting at the annual assembly. CONCLUSIONS: For the first time, MRI findings relevant for sacroiliitis have been defined by consensus by a group of rheumatologists and radiologists. These definitions should help in applying correctly the imaging feature "active sacroiliitis by MRI" in the new ASAS classification criteria for axial SpA.

The Assessment of SpondyloArthritis international Society (ASAS) handbook: a guide to assess spondyloarthritis.

The field of spondyloarthritis (SpA) has experienced major progress in the last decade, especially with regard to new treatments, earlier diagnosis, imaging technology and a better definition of outcome parameters for clinical trials. In the present work, the Assessment in SpondyloArthritis international Society (ASAS) provides a comprehensive handbook on the most relevant aspects for the assessments of spondyloarthritis, covering classification criteria, MRI and x rays for sacroiliac joints and the spine, a complete set of all measurements relevant for clinical trials and international recommendations for the management of SpA. The handbook focuses at this time on axial SpA, with ankylosing spondylitis (AS) being the prototype disease, for which recent progress has been faster than in peripheral SpA. The target audience includes rheumatologists, trial methodologists and any doctor and/or medical student interested in SpA. The focus of this handbook is on practicality, with many examples of MRI and x ray images, which will help to standardise not only patient care but also the design of clinical studies.

[Vasculopathy in Sjögren's syndrome]. / Vaskulopathien bei Sjögren-Syndrom.

Sjögren's syndrome is a systemic autoimmune disease with a predominant involvement of exocrine glands leading to sicca symptoms. Extraglandular involvement occurs in about 40% of patients with skin, musculoskeletal, neurological and organ manifestations. Systemic vasculitic manifestations of Sjögren's syndrome can be assumed in approximately 5%-10% of patients. Leukocytoclastic or cryoglobulinemic vasculitis represent classic vasculitic manifestations of Sjögren's syndrome. In the pathogenesis of vasculitis, B-cell-driven autoimmune processes play a major role by producing autoantibodies against the Ro/SS-A and La/SS-B antigens and cryoglobulins. In patients with Sjögren's syndrome, manifestation of vasculitis, non-Hodgkin's lymphoma and glomerulonephritis, as well as positive cryoglobulins and decreased levels of complement factors, are considered negative prognostic markers. Various immunosuppressive strategies, usually in co-medication with glucocorticoids, are used for the treatment of vasculitis in Sjögren's syndrome. For refractory and severe manifestations, a B-cell-targeted therapy with Rituximab should be also considered.