Cartilage Imaging: Techniques and Developments.

Cartilage degeneration is one of the most common chronic age-related joint disorders leading to pain and reduced joint motion. The increasing prevalence of osteoarthritis requires accurate cartilage imaging, both clinically and in research. Detailed cartilage imaging is also necessary for traumatic cartilage lesions and for pre- and postoperative assessment of cartilage repair procedures. Although still widely used, conventional radiography bears significant limitations because it assesses cartilage indirectly by joint space width. Magnetic resonance imaging (MRI) enables direct visualization of cartilage damage along with other concomitantly affected joint tissues. Several semiquantitative grading systems and volumetric analysis methods exist to assess cartilage damage and cartilage repair on MRI. Quantification of hyaline and fibrocartilage biochemical composition is possible with novel MRI methods such as T2- and T1ρ-mapping, delayed gadolinium-enhanced MRI of cartilage, glycosaminoglycan chemical exchange saturation transfer, and sodium imaging, along with quantitative computed tomography arthrography. These techniques provide promising quantitative imaging biomarkers that can detect early cartilage changes before morphological alterations occur.

Good clinical and radiographic outcome of cementless metal metaphyseal sleeves in total knee arthroplasty.

Background and purpose - The number of revision total knee arthroplasties (TKA) is continuously increasing, leading to a growing need for reliable management of metaphyseal bone loss. We evaluated patients operated with a TKA using metal metaphyseal sleeves for bone defects with a minimum 5-year follow-up. Patients and methods - 37 patients had been operated on. 3 patients died and 3 patients were lost during follow-up. Of the 31 remainders (20 women), 9 had been operated on with a primary TKA and 22 with a revision TKA at the index surgery. The mean age at surgery was 69 (54-89) years and the mean follow-up time was 7.4 (5-12) years. Bone defects were classified according to the Anderson Orthopaedic Research Institute classification (tibia: type I n = 9, type II n = 5 and type III n = 17; femur: type I n = 12, type II n = 3 and type III n = 16). Results - At final follow-up one-third experienced an improvement concerning walking aids and walking distance. Except for 1 patient, all had full extension and a mean knee flexion of 110 (90-140) degrees. VAS pain at rest was 13 (SD 25) and on movement 30 (SD 31). 7 patients were reoperated due to: infection (n = 4), periprosthetic fracture (n = 1), skin necrosis (n = 1), and wound rupture (n = 1). The cumulative 5-year survival rate for reoperation was 77% (CI 63-92) and for revision 97% (CI 91-100). At the time of final follow-up, the sleeves showed good osseointegration with no signs of progressive radiolucency or migration. Interpretation - Titanium sleeves are a promising option in managing difficult cases with metaphyseal bone defects in TKA, providing a stable construct with good medium-term radiographic outcome.

A new low-dose multi-phase trauma CT protocol and its impact on diagnostic assessment and radiation dose in multi-trauma patients.

PURPOSE: Computed tomography (CT) examinations, often using high-radiation dosages, are increasingly used in the acute management of polytrauma patients. This study compares a low-dose polytrauma multi-phase whole-body CT (WBCT) protocol on a latest generation of 16-cm detector 258-slice multi-detector CT (MDCT) scanner with advanced dose reduction techniques to a single-phase polytrauma WBCT protocol on a 64-slice MDCT scanner. METHODS: Between March and September 2015, 109 polytrauma patients (group A) underwent acute WBCT with a low-dose multi-phase WBCT protocol on a 258-slice MDCT whereas 110 polytrauma patients (group B) underwent single-phase trauma CT on a 64-slice MDCT. The diagnostic accuracy to trauma-related injuries, radiation dose, quantitative and semiquantitative image quality parameters, subjective image quality scorings, and workflow time parameters were compared. RESULTS: In group A, statistically significantly more arterial injuries (p = 0.04) and arterial dissections (p = 0.002) were detected. In group A, the mean (±SD) dose length product value was 1681 ± 183 mGy*cm and markedly lower when compared to group B (p < 0.001). The SDs of the mean Houndsfield unit values of the brain, liver, and abdominal aorta were lower in group A (p < 0.001). Mean signal-to-noise ratios (SNRs) for the brain, liver, and abdominal aorta were significantly higher in group A (p < 0.001). Group A had significantly higher image quality scores for all analyzed anatomical locations (p < 0.02). However, the mean time from patient registration until completion of examination was significantly longer for group A (p < 0.001). CONCLUSIONS: The low-dose multi-phase CT protocol improves diagnostic accuracy and image quality at markedly reduced radiation. However, due to technical complexities and surplus electronic data provided by the newer low-dose technique, examination time increases, which reduces workflow in acute emergency situations.

Comparison of metal ion concentrations and implant survival after total hip arthroplasty with metal-on-metal versus metal-on-polyethylene articulations.

Background and purpose - Large metal-on-metal (MoM) articulations are associated with metal wear and corrosion, leading to increased metal ion concentrations and unacceptable revision rates. There are few comparative studies of 28-mm MoM articulations with conventional metal-on-polyethylene (MoP) couplings. We present a long-term follow-up of a randomized controlled trial comparing MoM versus MoP 28-mm articulations, focused on metal ions and implant survival. Patients and methods - 85 patients with a mean age of 65 years at surgery were randomized to a MoM (Metasul) or a MoP (Protasul) bearing. After 16 years, 38 patients had died and 4 had undergone revision surgery. 13 patients were unavailable for clinical follow-up, leaving 30 patients (n = 14 MoM and n = 16 MoP) for analysis of metal ion concentrations and clinical outcome. Results - 15-year implant survival was similar in both groups (MoM 96% [95% CI 88-100] versus MoP 97% [95% CI 91-100]). The mean serum cobalt concentration was 4-fold higher in the MoM (1.5 µg/L) compared with the MoP cohort (0.4 µg/L, p < 0.001) and the mean chromium concentration was double in the MoM (2.2 µg/L) compared with the MoP cohort (1.0 µg/L, p = 0.05). Mean creatinine levels were similar in both groups (MoM 93 µmol/L versus MoP 92 µmol/L). Harris hip scores differed only marginally between the MoM and MoP cohorts. Interpretation - This is the longest follow-up of a randomized trial on 28-mm MoM articulations, and although implant survival in the 2 groups was similar, metal ion concentrations remained elevated in the MoM cohort even in the long term.

Early treatment intensification induces favourable radiographic outcomes according to predicted versus observed radiographic progression in early rheumatoid arthritis: a subanalysis of the randomised FIN-RACo and NEO-RACo trials.

OBJECTIVES: Predicted versus observed radiographic progression in early rheumatoid arthritis (POPeRA) was applied to demonstrate how various treatment modalities affect and potentially minimise radiographic progression over time. METHODS: The POPeRA method utilises the baseline radiographic score and patient-reported symptom duration to predict radiographic outcomes. It was applied at baseline, 2, and 5 years to patients with eRA from the randomised Finnish RA Combination trial (FIN-RACo) (n=144) and New Finnish RA Combination Therapy (NEO-RACo) (n=90) trials. For FIN-RACo, patients were randomised either to a single DMARD (sulfasalazine, with or without prednisolone) or to combination therapy (methotrexate+sulfasalazine+hydroxychloroquine, i.e. triple therapy, with prednisolone). In NEO-RACo, all patients were assigned intensified combination therapy (including 7.5 mg prednisolone/day) plus a randomised 6-month induction of either placebo or anti-TNF treatment (infliximab). RESULTS: In FIN-RACo, combination versus monotherapy resulted in superior outcomes in the change from predicted progression over 2 and 5 years (mean 35.7% reduction vs. -32.9%, a worsening from predicted, p=0.001; 34.2% vs. -17.8%, p=0.003, respectively). In NEO-RACo, combination+anti-TNF induction led to significantly greater reductions from predicted progression than combination+placebo, both at 2 and 5 years of follow-up (98.5% vs. 83.4%, p=0.005; 92.4% vs. 82.5%, p=0.027, respectively). Importantly, anti-TNF add-on led to superior reductions from predicted among RF-positive patients (2 years: 97.4% vs. 80.4%, p=0.009; 5 years: 90.2% vs. 80.1%, p=0.030), but not among RF-negative patients. CONCLUSIONS: These results confirm that conventional combination therapy in eRA has a long-term radiographic benefit versus monotherapy. Through POPeRA, it was made evident that anti-TNF induction therapy for 6 months further increases the long-term radiographic benefit of combination therapy in RF-positive patients.

Recommendations of the ESSR Arthritis Subcommittee on Ultrasonography in Inflammatory Joint Disease.

This article presents the recommendations of the European Society of Musculoskeletal Radiology Arthritis Subcommittee on the use of ultrasonography (US) in rheumatic disease, focused on the examination of joints in the adult population. The recommended examination technique and protocols used in a radiologic work-up are discussed. The main US features that can lead to a final diagnosis in the most common rheumatic diseases are addressed. The differential diagnosis that should be considered at image interpretation is presented. The role of US in interventional procedures and clinically important recent developments is also discussed.

Recommendations of the ESSR Arthritis Subcommittee for the Use of Magnetic Resonance Imaging in Musculoskeletal Rheumatic Diseases.

This article presents the recommendations of the European Society of Musculoskeletal Radiology Arthritis Subcommittee regarding the standards of the use of MRI in the diagnosis of musculoskeletal rheumatic diseases. The recommendations discuss (1) the role of MRI in current classification criteria of musculoskeletal rheumatic diseases (including early diagnosis of inflammation, disease follow-up, and identification of disease complications); (2) the impact of MRI on the diagnosis of axial and peripheral spondyloarthritis, rheumatoid arthritis, and juvenile spondyloarthritis; (3) MRI protocols for the axial and peripheral joints; (4) MRI interpretation and reporting for axial and peripheral joints; and finally, (5) methods for assessing MR images including quantitative, semiquantitative, and dynamic contrast-enhanced MRI studies.

Sonoelastography: musculoskeletal applications.

All participants for image samplings provided written informed consent. Conventional B-mode ultrasonography (US) has been widely utilized for musculoskeletal problems as a first-line approach because of the advantages of real-time access and the relatively low cost. The biomechanical properties of soft tissues reflect to some degree the pathophysiology of the musculoskeletal disorder. Sonoelastography is an in situ method that can be used to assess the mechanical properties of soft tissue qualitatively and quantitatively through US imaging techniques. Sonoelastography has demonstrated feasibility in the diagnosis of cancers of the breast and liver, and in some preliminary work, in several musculoskeletal disorders. The main types of sonoelastography are compression elastography, shear-wave elastography, and transient elastography. In this article, the current knowledge of sonoelastographic techniques and their use in musculoskeletal imaging will be reviewed.

Clinical imaging assessments of knee osteoarthritis in the elderly: a mini-review.

Knee osteoarthritis (OA) in the elderly is one of the most common degenerative age-related joint diseases leading to typical degradation of articular cartilage with severe pain and limitation of joint motion. Its increasing prevalence due to the demographic development of the society has major implications for individual and public healthcare with the increasing necessity for clinical imaging assessment in a high number of individuals. Although conventional X-ray radiographs are widely considered as gold standard for the assessment of knee OA, in clinical and scientific settings they increasingly bare significant limitations in situations when high resolution and detailed assessment of cartilage is demanded. New imaging modalities are broadening the possibilities in knee OA clinical practice and are offering new insights to help for a better understanding of the disease. X-ray analysis in OA of the knee is associated with many technical limitations and increasingly is replaced by high-quality assessment using magnetic resonance imaging or ultrasonography both in clinical routine and scientific situations. These novel imaging modalities enable an in vivo visualization of the quality of the cartilaginous structure and bone as well as all articular and periarticular tissues. Therefore, the limitations of radiographs in knee OA assessment could be overcome by these techniques. This review article should provide an insight into the most important radiological features of knee OA and their systematic visualization with different imaging approaches that can be used in clinical routine.

Transcatheter embolization for the management of acute active inferior epigastric artery hemorrhages.

PURPOSE: To report a retrospective review of all patients who were admitted to the interventional radiology unit at our hospital for transcatheter arterial embolization (TAE) of an acute active hemorrhage of the inferior epigastric artery. METHODS: From 1996 to 2012, 52 consecutive patients (26 men; mean age 63±15 years) with hemodynamically relevant active abdominal wall hematoma were admitted for TAE of the inferior epigastric artery. Of these, 19 patients had spontaneous hemorrhage due to use of anticoagulants, 18 due to abdominal trauma, and 15 due to an iatrogenic complication. All superselective embolizations were performed using a coaxial catheter technique with a 0.018-inch microcatheter introduced through the diagnostic macrocatheter. Various embolization methods, alone or in combination, were applied, including primarily microcoils and polyvinyl alcohol particles. RESULTS: Primary technical success was achieved in 47/52 (90%) patients; the remainder needed a second embolization session (secondary success 100%). The mean puncture-to-hemostasis time was 65.4±35 minutes. No patient developed a large hematoma or pseudoaneurysm at the puncture site. The 30-day mortality was 19% (n=10) and the total cumulative mortality rate was 23% (n=12). Over a mean 67-month follow-up of 39/40 survivors (1 lost to follow-up), no complications from the embolization procedure, such as abdominal wall ischemia, were observed. There were no differences in outcomes based on etiology of the hemorrhage. CONCLUSION: In selected patients with acute active hemorrhage of the IEA in the anterior abdominal wall, TAE is a fast, safe, minimally invasive, and reliable method with a high technical success rate and no long-term complications.

Very high levels of anti-citrullinated protein antibodies are associated with HLA-DRB1*15 non-shared epitope allele in patients with rheumatoid arthritis.

OBJECTIVE: Production of anti-citrullinated protein antibodies (ACPAs) is an important biomarker for rheumatoid arthritis (RA). We undertook this study to determine whether genetic factors (HLA-DRB1 alleles) are associated with extreme ACPA levels in individuals with ACPA-positive RA, and to ascertain whether there are any phenotypic characteristics associated with these subgroups of RA. METHODS: HLA-DRB1 allelic groups were genotyped in 1,073 ACPA-positive RA patients from the Swedish Epidemiological Investigation of Rheumatoid Arthritis study. We found that 283 patients (26.4%) had high ACPA levels (defined as >1,500 units/ml using the Euro-Diagnostica anti-CCP2 test), while the rest of the patients had moderate ACPA levels and served as the comparison group. A replication group consisted of 235 RA patients. RESULTS: No significant differences in baseline disease activity were observed between patients with high and those with moderate ACPA levels. However, the HLA-DRB1*15 allele was associated with high ACPA levels (P=0.0002). A similar trend was detected in HLA-DRB1*15-positive patients in the replication cohort, with meta-analysis of the discovery and replication cohorts demonstrating an overall effect of HLA-DRB1*15 on development of high ACPA levels in both the discovery and replication cohorts (P<0.0001 by Mantel-Haenszel test with a fixed-effects model). CONCLUSION: Our data indicate that HLA-DRB1*15 may promote the production of high ACPA levels. Due to the high value of ACPA level scores in the 2010 American College of Rheumatology/European League Against Rheumatism classification criteria for RA, the presence of HLA-DRB1*15 may, at least in part, contribute to fulfilling the criteria for RA. This illustrates the complex nature of the genetic regulation of ACPA levels. Additional mechanistic studies of the regulation of ACPAs and ACPA-positive RA are pending.

The pattern of acute injuries in patients from alpine skiing accidents has changed during 2000-2011: analysis of clinical and radiological data at a level I trauma center.

OBJECTIVES: During the last decade, many educational efforts and technological improvements have been made to protect skiing athletes from injuries. Whether these efforts have changed the pattern of acute injuries from skiing casualties has not yet been shown on a medical basis, which this longitudinal study examines. METHODS: All patients transferred to the Department of Radiology of our level I trauma center for acute emergency computed tomography (CT) after alpine skiing accidents from 2000 to 2011 were included. We hypothesized that only patients with clinical suspicion for injuries were admitted for acute CT. RESULTS: Of all acute patients after skiing accidents, 2,252 could be included. From 2000 to 2011, all cerebral injuries and vascular arterial injuries statistically significantly decreased (p < 0.05, respectively). However, extremity fractures, facial fractures, and vertebral fractures increased (p < 0.04, respectively). The number of cerebral hemorrhages, thoracic injuries, and abdominal injuries remained unchanged (p = NS). The mean (SD) number of all initial radiological examinations per victim statistically significantly decreased from 2.3 (0.7) in 2000 to 1.5 (0.6) in 2011, whereas the admissions for acute CT have significantly increased (p < 0.02; respectively). CONCLUSIONS: Acute radiological evaluation in skiing accidents has changed during the last decade. The decrease in overall cerebral injuries might be a function of the increasing use of skiing helmets. A protection of the extremities, trunk, spine, and face, however, needs further improvements and their radiological assessment with CT warrants attention in skiing casualties.

Endovascular popliteal thrombectomy using the self-expanding, retrievable Solitaire recanalization device.

PURPOSE: To present an initial peripheral application of the self-expanding, detachable, fully-retrievable Solitaire FR Recanalization Device for endovascular thrombectomy in the lower leg of a patient with acute peripheral limb ischemia. CASE REPORT: A 79-year-old woman with a long history of peripheral arterial occlusive disease and a femoropopliteal bypass graft presented with sudden grade IIb ischemia of the left lower leg. Conventional antegrade angiography identified total thrombotic occlusion of the tibioperoneal trunk below the distal femoropopliteal bypass anastomosis; the bypass itself was not occluded. When suction thrombectomy was unsuccessful, a 4×20-mm self-expanding, retrievable Solitaire stent was deployed. The thrombus was retrieved, with immediate recanalization of the tibioperoneal trunk and no sequela. Clinical signs of ischemia resolved, and after 6 months of follow-up, no reocclusion had occurred. CONCLUSION: Developed as a tool to retrieve clots causing acute ischemic stroke, the Solitaire FR Recanalization Device may also have a place in treating patients with acute below-the-knee thrombotic arterial occlusion in whom suction thrombectomy had failed. The Solitaire stent may be an additional endovascular option that can result in successful treatment of acute limb ischemia and avoid more expensive surgical procedures in selected cases.

Heat shock protein 60 and immune inflammatory responses in atherosclerosis.

Hallmarks of inflammation in various cardiovascular diseases, notably atherosclerosis, have been observed for a long time. However, evidence for an (auto)antigen-driven process at these sites of inflammation has come forward only recently. Heat shock proteins (HSPs) have been identified as playing either immunologically mediated disease promoting or protective roles. HSP60 has been shown to trigger innate and adaptive immune responses that initiate the earliest still reversible inflammatory stage of atherosclerosis. HSP60 is structurally highly conserved and abundantly expressed by prokaryotic and eukaryotic cells under stressful conditions. Beneficial protective immunity to microbial HSP60 acquired by infection or vaccination and bona fide autoimmunity to biochemically altered autologous HSP60 is present in all humans. In vitro and in vivo experiments have demonstrated that classical atherosclerosis risk factors can act as endothelial stressors that provoke the simultaneous expression of adhesion molecules and of HSP60 in mitochondria, in cytoplasm, and on the cell surface, where it acts as a "danger signal" for cellular and humoral immune reactions. Hence, protective, preexisting anti-HSP60 immunity may have to be "paid for" by harmful (auto)immune cross-reactive attack on arterial endothelial cells maltreated by atherosclerosis risk factors. These experimentally and clinically proven findings are the basis for the autoimmune concept of atherosclerosis.

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.

The "Innsbruck Emergency Algorithm" avoids the underdiagnosis of blunt cervical vascular injuries.

OBJECTIVES: Blunt cervical vascular injuries (BCVI) from alpine sports accidents bear an increased risk for being underdiagnosed during initial radiological evaluation. At our hospital, the "Innsbruck Emergency Algorithm", which includes assessment of the neck as a computed tomography (CT) angiography during initial whole-body CT, has been introduced to avoid misdiagnoses and optimizes emergency radiology management. METHODS: Critically injured patients who were admitted for emergency CT after trauma from alpine skiing and mountain-biking accidents and who were reported with BCVI were included in this retrospective study. RESULTS: During 2003-2009, 36 victims were eligible for inclusion. They presented with a mean (SD) of 4.6 (2.1) diagnoses per patient, of which 3.5 (2.3) were perceptible on radiology examinations only. The "Innsbruck Emergency Algorithm" was performed in 15 individuals while 21 underwent another CT protocol including a native scan of the neck or during a parenchymatous contrast-medium phase only. In addition to BCVI, most patients (71%) were diagnosed with fractures followed by unspecific contusion/s (54%), head injuries (43%), and injuries of parenchymatous organs (19%). In five (14%), BCVI was underdiagnosed during the initial radiological examination. All of the latter had CT during a parenchymatous contrast-medium phase and not according to the "Innsbruck Emergency Algorithm". Four of those patients died during their hospital stay. In 11, cerebral follow-up examinations showed cerebral pathologies considered as results from BCVI. CONCLUSIONS: The "Innsbruck Emergency Algorithm" in patients with clinically unapparent BCVI after skiing and mountain-biking accidents avoided overlooking vascular injuries, which significantly improved their long-term outcome.

In vivo molecular imaging of vascular stress.

Noninvasive in vivo imaging is an emerging specialty in experimental radiology aiming at developing hardware and appropriate contrast agents to visualize the molecular basis and pathophysiological processes of many pathological conditions, including atherosclerosis. The list of potentially useful tracers and targets for in vivo molecular imaging in the cascade of early atherosclerotic events has been narrowed down to some very promising endothelial factors, i.e., cell adhesion molecules, macrophages, apoptosis, lipoproteins, heat shock proteins, and others. In this review, we will update on the progress of recent developments in the field of noninvasive molecular imaging in experimental atherosclerosis.

In vivo imaging of the effect of LPS on arterial endothelial cells: molecular imaging of heat shock protein 60 expression.

Bacterial endotoxins are known as stress factors for endothelial cells. In 20 normocholesterolemic New Zealand White (NZW) rabbits, endothelial stress was induced by intravenous (i.v.) injection of lipopolysaccharide (LPS), while eight NZW rabbits were sham-treated or served as untreated controls. In vivo molecular imaging was performed using co-registered computer tomography and positron emission tomography 24 h after i.v. injection of (124)I-labeled monoclonal anti-HSP60 or (124)I-radiolabelled isotype control antibodies. Compared to control animals, in vivo images of rabbit aortae revealed significantly increased endothelial binding of (124)I-labeled anti-HSP60 antibodies upon LPS, especially at sites of aortal branching. This was confirmed by immunohistochemistry and autoradiography data. Our results showed, as proof-of-principle, that HSP60-expression in normocholesterolemic rabbits is significantly increased after induction of endothelial stress and that non-invasive in vivo molecular imaging of early aortal HSP60-expression using (124)I-labeled anti-HSP60 monoclonal antibodies is possible.