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.

EULAR recommendations for the use of imaging in the clinical management of peripheral joint osteoarthritis.

The increased information provided by modern imaging has led to its more extensive use. Our aim was to develop evidence-based recommendations for the use of imaging in the clinical management of the most common arthropathy, osteoarthritis (OA). A task force (including rheumatologists, radiologists, methodologists, primary care doctors and patients) from nine countries defined 10 questions on the role of imaging in OA to support a systematic literature review (SLR). Joints of interest were the knee, hip, hand and foot; imaging modalities included conventional radiography (CR), MRI, ultrasonography, CT and nuclear medicine. PubMed and EMBASE were searched. The evidence was presented to the task force who subsequently developed the recommendations. The strength of agreement for each recommendation was assessed. 17 011 references were identified from which 390 studies were included in the SLR. Seven recommendations were produced, covering the lack of need for diagnostic imaging in patients with typical symptoms; the role of imaging in differential diagnosis; the lack of benefit in monitoring when no therapeutic modification is related, though consideration is required when unexpected clinical deterioration occurs; CR as the first-choice imaging modality; consideration of how to correctly acquire images and the role of imaging in guiding local injections. Recommendations for future research were also developed based on gaps in evidence, such as the use of imaging in identifying therapeutic targets, and demonstrating the added value of imaging. These evidence-based recommendations and related research agenda provide the basis for sensible use of imaging in routine clinical assessment of people with OA.

Silent progression in patients with rheumatoid arthritis: is DAS28 remission an insufficient goal in RA? Results from the German Remission-plus cohort.

BACKGROUND: Remission is arguably the ultimate therapeutic goal in rheumatoid arthritis (RA). Applying modern strategies, clinical remission can be achieved in a substantial number of patients with early RA (ERA). Even in those patients, the number and scope of erosions can increase. We, therefore, investigated the value of MRI for the detection of radiological progression in patients with DAS28 improvement and/or clinical remission of the German Remission-plus cohort. METHODS: Data-sets of 80 RA patients (according to 2010 ACR/EULAR criteria) from the Remission-plus study cohort, who fulfilled the following criteria, were retrospectively analysed: availability of two consecutive MRI scans (low-field MRI, follow-up interval 1 year) of the clinically dominant hand and wrist, and the presence of DAS28 (CRP) scores at both time points, which was used to assess disease activity. RESULTS: Seventy-one of the 80 investigated patients presented a numerical improvement of the DAS28 (CRP) after 12 months (DAS28(CRP) T0 average (Ø) 4.96, SD 1.2; DAS28 T4 (12 month) Ø 2.6, SD 1.0), 73% of them also improved in the RAMRIS-Score, while 24% demonstrated an increase despite DAS28 improvement and 3% showed equal values. 48% of patients who improved in the DAS28 reached EULAR remission. 41% of these patients had an increase in the RAMRIS Erosion-subscore after 12 months. When considering EULAR response criteria (non-response (n = 7), moderate response (n = 19), good response (n = 45)), an increase of erosions was found in 71.4% of non-responders, 52.6% of moderate responders, and 31.1% of good responders after 12 months, all compared to baseline. CONCLUSION: Up to 40% of patients in this study demonstrated a progressive erosive disease detected by MRI despite DAS28 improvement or EULAR remission. Future studies are needed to determine the prognostic clinical impact of disease progression in MRI despite clinical remission, and to investigate if DAS28 remission may be an insufficient therapeutic goal and should be accompanied by MRI remission criteria.

Optimizing radiation exposure in screening of body packing: image quality and diagnostic acceptability of an 80 kVp protocol with automated tube current modulation.

The aim of this study was to evaluate the objective and subjective image quality of a novel computed tomography (CT) protocol with reduced radiation dose for body packing with 80 kVp and automated tube current modulation (ATCM) compared to a standard body packing CT protocol. 80 individuals who were examined between March 2012 and July 2015 in suspicion of ingested drug packets were retrospectively included in this study. Thirty-one CT examinations were performed using ATCM and a fixed tube voltage of 80 kVp (group A). Forty-nine CT examinations were performed using a standard protocol with a tube voltage of 120 kVp and a fixed tube current time product of 40 mAs (group B). Subjective and objective image quality and visibility of drug packets were assessed. Radiation exposure of both protocols was compared. Contrast-to-noise ratio (group A: 0.56 ± 0.36; group B: 1.13 ± 0.91) and Signal-to-noise ratio (group A: 3.69 ± 0.98; group B: 7.08 ± 2.67) were significantly lower for group A compared to group B (p < 0.001). Subjectively, image quality was decreased for group A compared to group B (2.5 ± 0.8 vs. 1.2 ± 0.4; p < 0.001). Attenuation of body packets was higher with the new protocol (group A: 362.2 ± 70.3 Hounsfield Units (HU); group B: 210.6 ± 60.2 HU; p = 0.005). Volumetric Computed Tomography Dose Index (CTDIvol) and Dose Length Product (DLP) were significantly lower in group A (CTDIvol 2.2 ± 0.9 mGy, DLP 105.7 ± 52.3 mGycm) as compared to group B (CTDIvol 2.7 ± 0.1 mGy, DLP 126.0 ± 9.7 mGycm, p = 0.002 and p = 0.01). The novel 80 kVp CT protocol with ATCM leads to a significant dose reduction compared to a standard CT body packing protocol. The novel protocol led to a diagnostic image quality and cocaine body packets were reliably detected due to the high attenuation.

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.

Glycosaminoglycan chemical exchange saturation transfer at 3T MRI in asymptomatic knee joints.

BACKGROUND: Biochemical alterations such as glycosaminoglycan (GAG) depletion occur early in the course of osteoarthritis, but cannot be detected with standard magnetic resonance techniques. With glycosaminoglycan chemical exchange saturation transfer (gagCEST), a biochemical imaging technique, it is feasible to detect biochemical components in knee joint cartilage. PURPOSE: To establish baseline values for gagCEST magnetic resonance imaging (MRI) in knee joint cartilage at 3 Tesla (T). MATERIAL AND METHODS: Twenty volunteers (8 women, 12 men; mean age, 24.55 ± 2.35 years;age range, 21-29 years) with no history or clinical findings indicative of knee joint pathologies underwent MRI at 3T. The imaging protocol included three-dimensional (3D) double-echo steady-state sequence for morphological cartilage assessment and a prototype 3D CEST pulse sequence to evaluate the CEST effects in six cartilage regions of the knee joint: (i) lateral femoral condyle; (ii) medial femoral condyle; (iii) lateral tibial plateau; (iv) medial tibial plateau; (v) patella; and (vi) trochlea. We used the asymmetry of the magnetization transfer ratio (MTRasym) parameter to quantify the gagCEST effects in these regions. RESULTS: Regional differences revealed high MTRasym values in the patellar (1.62% ± 1.19%) and the trochlear (1.17% ± 1.29%) cartilages, and low MTRasym values in the medial femoral condyle (0.41% ± 0.58%) and the lateral tibial plateau (0.52% ± 0.53%) cartilages. CONCLUSION: Regional differences in the gagCEST values must be considered when conducting gagCEST imaging of knee joint cartilage. In the future gagCEST imaging may be an additional feature in the evaluation of the biochemical composition of knee joint cartilage.

Biochemical imaging of cervical intervertebral discs with glycosaminoglycan chemical exchange saturation transfer magnetic resonance imaging: feasibility and initial results.

OBJECTIVE: To evaluate glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging at 3T in the assessment of the GAG content of cervical IVDs in healthy volunteers. MATERIALS AND METHODS: Forty-two cervical intervertebral discs of seven healthy volunteers (four females, three males; mean age: 21.4 ± 1.4 years; range: 19-24 years) were examined at a 3T MRI scanner in this prospective study. The MRI protocol comprised standard morphological, sagittal T2 weighted (T2w) images to assess the magnetic resonance imaging (MRI) based grading system for cervical intervertebral disc degeneration (IVD) and biochemical imaging with gagCEST to calculate a region-of-interest analysis of nucleus pulposus (NP) and annulus fibrosus (AF). RESULTS: GagCEST of cervical IVDs was technically successful at 3T with significant higher gagCEST values in NP compared to AF (1.17% ± 1.03% vs. 0.79% ± 1.75%; p = 0.005). We found topological differences of gagCEST values of the cervical spine with significant higher gagCEST effects in lower IVDs (r = 1; p = 0). We could demonstrate a significant, negative correlation between gagCEST values and cervical disc degeneration of NP (r = -0.360; p = 0.019). Non-degenerated IVDs had significantly higher gagCEST effects compared to degenerated IVDs in NP (1.76% ± 0.92% vs. 0.52% ± 1.17%; p < 0.001). CONCLUSION: Biochemical imaging of cervical IVDs is feasible at 3T. GagCEST analysis demonstrated a topological GAG distribution of the cervical spine. The depletion of GAG in the NP with increasing level of morphological degeneration can be assessed using gagCEST imaging.

Age-dependency of glycosaminoglycan content in lumbar discs: A 3t gagcEST study.

PURPOSE: To analyze age-dependency of glycosaminoglycan content using gagCEST (glycosaminoglycan chemical exchange saturation transfer) imaging in lumbar intervertebral discs of healthy volunteers. MATERIALS AND METHODS: In all, 70 volunteers without low back pain (mean age 44 ± 14 years, range: 21-69 years) were examined with T2 -weighted and gagCEST imaging with a 3T MR scanner, with approval of the local Ethics Committee after written informed consent was obtained. Pfirrmann grading and classification into discs without bulging and herniation, discs with bulging, and discs with herniation were performed. Only intervertebral discs without bulging and herniation were analyzed. A region-of-interest-based gagCEST analysis of nucleus pulposus (NP) and annulus fibrosus (AF) was performed. Correlation between age and gagCEST was tested within groups of equal Pfirrmann score. RESULTS: GagCEST effects decreased significantly from 3.09 ± 1.12% in 20-29 years old volunteers to -0.24 ± 1.36% in 50-59 years old volunteers (P < 0.001). In the case of Pfirrmann scores 2 and 3, a significant correlation was observed between gagCEST effect and age (Pfirrmann score 2, NP: ρ = -0.558, P < 0.001; Pfirrmann score 3, NP: ρ = -0.337, P = 0.048). For Pfirrmann scores 1 and 4, no significant correlation was obtained (Pfirrmann score 1, NP: ρ = -0.046, P = 0.824; Pfirrmann score 4, NP: ρ = -0.316, P = 0.188). CONCLUSION: We show a decreased gagCEST effect likely corresponding to decreasing glycosaminoglycans with aging. Hence, age-matched analysis of gagCEST imaging may be necessary in future studies.

Glycosaminoglycan chemical exchange saturation transfer of lumbar intervertebral discs in patients with spondyloarthritis.

PURPOSE: To assess glycosaminoglycan (GAG) content of lumbar intervertebral discs (IVD) in patients with spondyloarthritis (SpA) using glycosaminoglycan chemical exchange saturation transfer (gagCEST). MATERIALS AND METHODS: Ninety lumbar intervertebral discs of nine patients with SpA and nine age-matched healthy controls (eight patients with ankylosing spondylitis; one patient with spondylitis related to inflammatory bowel disease; mean age: 44.1 ± 14.0 years; range: 27-72 years) were examined with a 3T magnetic resonance imaging (MRI) scanner in this prospective study. The MRI protocol included standard morphological, sagittal T2 -weighted (T2 w) images to assess Pfirrmann score of the five lumbar IVDs (L1 to S1) and biochemical imaging with gagCEST to calculate a region of interest analysis of nucleus pulposus (NP) and annulus fibrosus (AF). Prior to statistical testing of gagCEST effects (MTRasym values in percent) in patients and controls, IVDs were classified according to the Pfirrmann score. RESULTS: Significantly lower gagCEST values of NP and AF were found in SpA patients compared with healthy volunteers (NP: 1.41% ± 0.41%, P = 0.001; 95% confidence interval, CI [0.600%-2.226%]; AF: 1.19% ± 0.32%, P < 0.001; CI [0.560%-1.822%]) by comparing the differences of the means. Pooled nondegenerative IVDs (Pfirrmann 1 and 2) had significantly lower gagCEST effects in patients suffering from SpA compared with healthy controls in NP (P < 0.001; CI [1.176%-2.337%]) and AF (P < 0.001; CI [0.858%-1.779%]). No significant difference of MTRasym values was found in degenerative IVDs between patients and controls in NP (P = 0.204; CI [-0.504%-2.170%]). CONCLUSION: GagCEST analysis of morphologically nondegenerative IVDs (Pfirrmann score 1 and 2) in T2 w images demonstrated significantly lower GAG values in patients with spondyloarthritis in NP and AF, possibly representing a depletion of GAG in spondyloarthritis in the absence of morphologic degeneration.

Evaluation of a simplified version of the Rheumatoid Arthritis Magnetic Resonance Imaging Score (RAMRIS) comprising 5 joints (RAMRIS5).

OBJECTIVES: The objective of this study was to evaluate a simplified version of the Rheumatoid Arthritis Magnetic Resonance Imaging Score (RAMRIS) reduced to five joints of the hand (RAMRIS5). METHODS: 94 patients with rheumatoid arthritis (62 female; age 59±12 years, range 25-83 years; disease duration 60±90 months (median: 22 months, first quartile: 7 months, third quartile: 66 months) from the REMISSION PLUS study cohort who had complete files on C-reactive protein (CRP) levels and Disease Activity Score of 28 joints (DAS28) and complete MRI of the clinical dominant hand at baseline and after one year under anti-rheumatic therapy (follow-up time 12.5±1.1 months) in a dedicated extremity MRI scanner at 0.2T were included in this retrospective study. RESULTS: There was a strong correlation between RAMRIS5 and the RAMRIS sum-score for all patients (r=0.87, p<0.001) at baseline and follow-up (r=0.87, p<0.001). Among the subscores there was a significant correlation between RAMRIS5 and RAMRIS-MCP (baseline: r=0.66, p<0.001; follow-up: r=0.74, p<0.001) as well as between RAMRIS5 and RAMRIS-wrist (baseline: r=0.72, p<0.001, follow-up: r=0.69, p<0.001) at baseline and follow-up. CONCLUSIONS: RAMRIS5, a modified shorter RAMRIS score based on five joints of the hand is a viable tool for semi-quantitative assessment of joint damage in RA. This abbreviated score might reduce the time needed for image analysis in MRI-controlled studies in RA and might facilitate the use of MRI in studies on therapy response assessment in RA.

Comparison of quantitative and semiquantitative dynamic contrast-enhanced MRI with respect to their correlation to delayed gadolinium-enhanced MRI of the cartilage in patients with early rheumatoid arthritis.

OBJECTIVE: The objective of this study was to investigate the correlation between semiquantitative and quantitative dynamic contrast-enhanced (DCE) parameters with delayed gadolinium-enhanced magnetic resonance imaging (MRI) of the cartilage (dGEMRIC). METHODS: Fifteen patients with early rheumatoid arthritis (RA) from the ArthroMark cohort were investigated at a 3-T MRI scanner. The metacarpophalangeal (MCP) joint of the index finger was examined with DCE-MRI and dGEMRIC. Semiquantitative and quantitative DCE perfusion parameters were calculated. The RA MRI score of the second MCP joint and the joint space width were measured. RESULTS: Significant correlations were noted between both semiquantitative and quantitative DCE parameters and the RA MRI score of the second MCP joint. There was a significant negative correlation between DCE parameters and dGEMRIC. No association between joint space width and DCE parameters was observed. CONCLUSIONS: Semiquantitative and quantitative analyses of perfusion are applicable to show that cartilage damage correlates with the inflammation activity despite the absence of joint space narrowing.

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.

Low-tube voltage 100 kVp MDCT in screening of cocaine body packing: image quality and radiation dose compared to 120 kVp MDCT.

PURPOSE: The aim of this study was to evaluate the impact of a reduced tube potential (100 kVp) for non-enhanced abdominal low-dose CT on radiation dose and image quality (IQ) in the detection of body packing. METHODS: This retrospective study was approved by the local research ethics committee of our clinic. From March 2012 to July 2014, 99 subjects were referred to our institute with suspected body packing. 50 CT scans were performed using a 120 kVp protocol (group A), and 49 CTs were performed using a low-dose protocol with a tube voltage of 100 kVp (group B). Subjective and objective IQ were assessed. DLP and CTDIvol were analyzed. RESULTS: All examinations were of diagnostic IQ. Objective IQ was not significantly different between the 120 kVp and 100 kVp protocol. Mean density of solid and liquid body packets was 210 ± 60.2 HU at 120 kVp and 250.6 ± 29.7 HU at 100 kVp. Radiation dose was significantly lower in group B as compared to group A (p < 0.05). In group A, body packs were detected in 16 (32%) of the 50 patients. In group B, packets were observed in 15 (31%) of 49 patients. Laboratory analysis detected cocaine in all smuggled body packs. CONCLUSIONS: Low-tube voltage 100 kVp MDCT with automated tube current modulation in screening of illegal drugs leads to a diagnostic IQ and significant dose reduction compared to 120 kVp low-tube voltage protocols. Despite lower radiation dose, liquid and solid cocaine containers retain high attenuation and are easily detected.

Improvement of gagCEST imaging in the human lumbar intervertebral disc by motion correction.

OBJECTIVE: To investigate whether motion correction improves glycosaminoglycan chemical exchange saturation transfer imaging (gagCEST imaging) of intervertebral discs (IVDs). MATERIALS AND METHODS: Magnetic resonance gagCEST imaging of 12 volunteers was obtained in lumbar IVDs at 3 T using a prototype pulse sequence. The data were motion-corrected using a prototype diffeomorphism-based motion compensation technique. For both the data with and that without motion correction (datac, datauc), CEST evaluation was performed using the magnetisation transfer ratio asymmetry (MTRasym) as a means of quantifying CEST effects. MTRasym and the signal-to-noise ratio (SNR) of the MTRasym map in the nucleus pulposus (NP) were compared for datac and datauc. A visual grading analysis was performed by a radiologist in order to subjectively quantify the quality of the MTRasym analysis (score 1: best quality, score 5: worst quality). Furthermore, a landmark analysis was performed in order to objectively quantify the motion between CEST images using the mean landmark distance dmean. RESULTS: MTRasym and SNR were significantly higher for the motion-corrected data than for the uncorrected CEST data (MTRasym(datac) = 3.77 % ± 0.95 %, MTRasym(datauc) = 3.41 % ± 1.54 %, p value = 0.001; SNR(datac) = 3.88 ± 2.04, SNR(datauc) = 2.77 ± 1.55, p value < 0.001, number of IVDs = 48). The visual grading analysis revealed a higher reliability for datac (maximum score = 2) compared with datauc (maximum score = 5). The landmark analysis demonstrated the superiority of the motion-corrected data (dmean(datac) = 0.08 mm ± 0.09 mm, dmean(datauc) = 0.36 mm ± 0.09 mm, p value = 0.001). CONCLUSION: Our study showed significant improvements in the ability to quantify CEST imaging in IVDs after the application of motion correction compared with uncorrected datasets.

T2* mapping and delayed gadolinium-enhanced magnetic resonance imaging in cartilage (dGEMRIC) of humeral articular cartilage--a histologically controlled study.

BACKGROUND: Cartilage biochemical imaging modalities that include the magnetic resonance imaging (MRI) techniques of T2* mapping (sensitive to water content and collagen fiber network) and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC, sensitive to the glycosaminoglycan content) can be effective instruments for early diagnosis and reliable follow-up of cartilage damage. The purpose of this study was to provide T2* mapping and dGEMRIC values in various histologic grades of cartilage degeneration in humeral articular cartilage. METHODS: A histologically controlled in vitro study was conducted that included human humeral head cartilage specimens with various histologic grades of cartilage degeneration. High-resolution, 3-dimensional (3D) T2* mapping and dGEMRIC were performed that enabled the correlation of MRI and histology data. Cartilage degeneration was graded according to the Mankin score, which evaluates surface morphology, cellularity, toluidine blue staining, and tidemark integrity. SPSS software was used for statistical analyses. RESULTS: Both MRI mapping values decreased significantly (P < .001) with increasing cartilage degeneration. Spearman rank analysis revealed a significant correlation (correlation coefficients ranging from -0.315 to 0.784; P < .001) between the various histologic parameters and the T2* and T1Gd mapping values. CONCLUSION: This study demonstrates the feasibility of 3D T2* and dGEMRIC to identify various histologic grades of cartilage damage of humeral articular cartilage. With regard to the advantages of these mapping techniques with high image resolution and the ability to accomplish a 3D biochemically sensitive imaging, we consider that these imaging techniques can make a positive contribution to the currently evolving science and practice of cartilage biochemical imaging.

Direct comparison of intra-articular versus intravenous delayed gadolinium-enhanced MRI of hip joint cartilage.

PURPOSE: To investigate the potential of delayed gadolinium-enhanced magnetic resonance imaging in cartilage (dGEMRIC) after intra-articular (ia) contrast agent administration at 3 Tesla (T), a paired study comparing intravenous (iv) dGEMRIC (standard) with ia-dGEMRIC was performed. MATERIALS AND METHODS: Thirty-five symptomatic patients with suspected cartilage damage underwent ia- and iv-dGEMRIC. MRI was performed with a 3T system wherein the interval between both measurements was 2 weeks. For iv-dGEMRIC, FDA approved Gd-DOTA(-) was injected intravenously 45 min before the MRI scan. For ia-dGEMRIC, 10-20 mL of a 2 mM solution of Gd- DOTA(-) was injected under fluoroscopic guidance 30 min before the MRI scan. RESULTS: Both ia- and iv-dGEMRIC demonstrated the typical T1Gd pattern in hip joint cartilage with increasing values toward the superior regions in acetabular cartilage reflecting the higher glycosaminoglycan (GAG) content in the main weight-bearing area. Correlation analysis revealed a moderate correlation between both techniques (r = 0.439, P-value < 0.001), whereas the T1Gd values for iv-dGEMRIC were significantly higher than those for ia-dGEMRIC. This corresponds with the Bland-Altman plot analysis, which revealed a systemic bias (higher T1Gd values after iv gadolinium application) of ∼70 ms. CONCLUSION: Ia-dGEMRIC was able to reveal the characteristic T1Gd pattern in hip joint cartilage confirming the sensitivity of ia-dGEMRIC for GAG. In addition, there was a significant correlation between iv-dGEMRIC and ia-dGEMRIC. However, the T1Gd values after ia contrast media application were significantly lower than those after iv application that has to be considered for future studies.

Inflammation and vascularisation markers of arthroscopically-guided finger joint synovial biospies reflect global disease activity in rheumatoid arthritis.

OBJECTIVES: To analyse whether synovial markers of the clinically dominant metacarpophalangeal (MCP) joint reflect global disease activity measures in rheumatoid arthritis (RA). METHODS: Arthroscopically-guided synovial biopsies from the dominant metacarpophalangeal (MCP) joint of 10 patients with RA (DAS28 >3.2) were stained for determination of the synovitis score, CD68, vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1α (HIF-1α). MRI and ultrasound were used to calculate the RAMRIS and US7 score respectively. Arthroscopy of the same joint was repeated in 6 patients after 6 months. RESULTS: The synovitis score significantly correlated to DAS28 (Spearman r=0.74), CRP (r=0.69), and US7 (r=0.66); sublining CD68 macrophages to CRP (r=0.6); HIF-1α to DAS28 (r=0.77), CRP (r=0.73); and VEGF to DAS28 (r=0.753) and RAMRIS (r=0.663). All patients showed a reduction of the DAS28 after 6 months (mean±SD: 5.2±1.5 vs. 2.75±1.1; p<0.05). There were three patients with a good EULAR response, and only these showed declining sublining CD68 macrophages in the control biopsy (χ2 test: LR 8.3, p=0.05). Two of the remaining patients with increasing CD68 sublining macrophages showed a deterioration of the RAMRIS. CONCLUSIONS: Some histological findings in arthroscopically-guided biopsies of the dominantly affected MCP joint reflect global disease activity measures and their changes in RA patients. Moreover, repeated MCP synovial biopsy may distinguish true responders from individuals with residual disease activity, who are not readily recognized by clinical means.

Advantages of a combined rheumatoid arthritis magnetic resonance imaging score (RAMRIS) for hand and feet: does the RAMRIS of the hand alone underestimate disease activity and progression?

BACKGROUND: To evaluate a combined rheumatoid arthritis magnetic resonance imaging score (RAMRIS) for hand and foot (HaF-score) in rheumatoid arthritis (RA). METHODS: Magnetic resonance imaging (MRI, 0.2 Tesla) of the dominant hand and foot of 26 ACPA positive RA patients before and 6 months after initiation of methotrexate was obtained. RAMRIS of the hand was complemented by corresponding scoring of the foot (MTP I-V; HaF-score). Disease Activity Score 28 (DAS28) and a tender and swollen joint count (JC) of the joints scored in MRI were recorded. Changes in these scores (Δ) were assessed. RESULTS: ΔHaF-score correlated significantly with ΔDAS28 (r = 0.820, 95%-CI 0.633-0.916). Correlations to ΔDAS28 were best for changes in the synovitis subscore (0.648) and bone marrow edema (0.703). Correlations to ΔDAS28 were significantly better for of the ΔHaF-score than ΔRAMRIS (0.499, 0.139-0.743, p = 0.0368).All patients with at least moderate response (EULAR criteria, n = 11) had continuing disease activity on MRI, including five cases with new erosions, three of them at the feet. Improvements of the hand JC or foot JC were seen in 16 and 15 cases, respectively. However, MRI of the hand or feet improved in only 10 and 9 cases, respectively. No patient fulfilled SDAI remission criteria. CONCLUSIONS: The HaF-score identifies patients with continuing disease activity despite clinical response that would have been missed by consideration of the traditional RAMRIS or the DAS28 alone. Response as opposed to remission may be an insufficient goal in RA as all patients showed continuing disease activity, especially at the feet.

Spectrum of T2* values in knee joint cartilage at 3 T: a cross-sectional analysis in asymptomatic young adult volunteers.

OBJECTIVE: To establish baseline T2* values in healthy knee joint cartilage at 3 T. MATERIALS AND METHODS: Thirty-four volunteers (mean age: 24.6 ± 2.7 years) with no history or clinical findings indicative of any knee joint disease were enrolled. The protocol included a double-echo steady-state (DESS) sequence for morphological cartilage evaluation and a gradient-echo multi-echo sequence for T2* assessment. Bulk and zonal T2* values were assessed in eight regions: posterior lateral femoral condyle; central lateral femoral condyle; trochlea; patella; lateral tibial plateau; posterior medial femoral condyle; central medial femoral condyle; and medial tibial plateau. Statistical evaluation comprised a two-tailed t test and a one-way analysis of variance to identify zonal and regional differences. RESULTS: T2* mapping revealed higher T2* values in the superficial zone in all regions (P values ≤ 0.001) except for the posterior medial femur condyle (P = 0.087), and substantial regional differences demonstrating superior values in trochlear cartilage, intermediate values in patellar and central femoral condylar cartilage, and low T2* values in posterior femoral condylar cartilage and tibial plateau cartilage. CONCLUSION: Substantial regional differences in T2* measures should be taken into consideration when conducting T2* mapping of knee joint cartilage.

Kidney transplant: functional assessment with diffusion-tensor MR imaging at 3T.

PURPOSE: To evaluate the feasibility of diffusion-tensor (DT) imaging at 3 T for functional assessment of transplanted kidneys. MATERIALS AND METHODS: This study was approved by the local ethics committee; written informed consent was obtained. Between August 2009 and October 2010, 40 renal transplant recipients were prospectively included in this study and examined with a clinical 3-T magnetic resonance (MR) imager. An echo-planar DT imaging sequence was performed in coronal orientation by using five b values (0, 200, 400, 600, 800 sec/mm(2)) and 20 diffusion directions. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were determined for the cortex and medulla of the transplanted kidney. Relationships between FA, ADC, and allograft function, determined by the estimated glomerular filtration rate (eGFR), were assessed by using Pearson correlation coefficient. ADC and FA were compared between patients with good or moderate allograft function (group A; eGFR > 30 mL/min/1.73 m(2)) and patients with impaired function (group B; eGFR ≤ 30 mL/min/1.73 m(2)) by using a student t test. P < .05 indicated a statistically significant difference. RESULTS: Mean FA of the renal medulla and cortex was significantly higher in group A (0.39 ± 0.06 and 0.17 ± 0.4) compared with group B (0.27 ± 0.05 and 0.14 ± 0.03) (P < .001 and P = .009, respectively). Mean ADCs of renal cortex and medulla were significantly higher in group A than in group B (P = .007 and P = .01, respectively). In group B, mean medullary FA was significantly lower in patients whose renal function did not recover (0.22 ± 0.02) compared with those with stable allograft function at 6 months (0.29 ± 0.05, P < .001). There was significant correlation between eGFR and medullary FA (r = 0.65, P < .001), cortical ADC (r = 0.43, P = .003), and medullary ADC (r = 0.35, P = .01). CONCLUSION: DT imaging is a promising noninvasive technique for functional assessment of renal allografts. FA values in the renal medulla exhibit a good correlation with renal function.