Diagnostic performance of sacroiliac joint MRI and added value of spine MRI to detect active spondyloarthritis

PURPOSE

To investigate the diagnostic performance of sacroiliac joint (SIJ) magnetic resonance imaging (MRI) and the incremental value of spine MRI to "predict" clinical disease activity in patients with axial spondyloarthritis (axSpA).

MATERIALS AND METHODS

This cross-sectional study included adult patients with known axSpA according to the SpondyloArthritis International Society (ASAS) classification criteria, radiological arm. MRI disease activity was scored semi-quantitatively for SIJ and total spine MRI in each patient. Two cut-off levels (≥ 1.3 and ≥ 2.1) for ankylosing spondylitis disease activity score with C-reactive protein (ASDAS-CRP) were considered for clinical disease activity categorization. MRI scores were first evaluated individually. Then, SIJ score was combined with the score from a spine segment (lumbar, cervical, thoracic or total spine) to build a bi-parametric model using a classification tree. Receiver operating characteristic (ROC) curves were constructed to evaluate the classification performance according to disease activity category of these models.

RESULTS

Forty-four patients (30 men, 14 women; mean age, 37 years±10 [SD] [range: 17-64 years]) with a mean disease duration of 5 years±8 (SD) (range: 0-35 years) were included. Thirty-six patients (36/44; 82%) had ASDAS-CRP≥1.3 and 27 patients (27/44; 61%) had ASDAS-CRP≥2.1. The most frequently involved spinal segment was mid-thoracic (T7-T8). The SIJ MRI score was an informative model to identify active axSpA (AUC≥0.7, regardless of the cut-off level on ASDAS-CRP). Performance of bi-parametric models based on "SIJ+thoracic spine" (for detecting patients with ASDAS-CRP≥1.3) or "SIJ+total spine" (for detecting patients with ASDAS-CRP≥2.1) outperformed that of the individual SIJ score (P<0.05).

CONCLUSION

The combination of MRI of the SIJ and spine allows to accurately discriminate between active and inactive axSpA, outperforming SIJ MRI alone.

FRI0175 SEMI-DYNAMIC MRI OF THE EXTENSOR DIGITORUM TENDONS IN JACCOUD ARTHROPATHY

Background:

Jaccoud arthropathy (JA) is a rare joint deformity mostly associated with systemic lupus erythematosus (SLE) (1). JA may be defined as a reversible deformity of the hands during flexion with ulnar deviation and swan neck deformities of the fingers. The physiopathology and the mechanisms leading to JA still remain to be elucidated.

Objectives:

To test the hypothesis that Jaccoud arthropathy (JA) in systemic lupus erythematosus (SLE) patients is associated with abnormal extensor digitorum (ED) tendons displacement during flexion of the metacarpophalangeal (MCP) joints.

Methods:

16 SLE patients with JA (JA+), 12 SLE patients without JA (JA-) and 24 control subjects were included in the study. Transverse spin echo T1-weighted MR sequences of the MCP joints in flexion and in extension were obtained in each hand of SLE patients and in one randomly-selected hand of control subjects. Two radiologists separately measured the amplitude and the direction of the displacement of the ED tendons with respect to the midline at the level of the MCP joints. Statistical analysis included two-way ANOVA with random effects to assess differences in amplitude (p<0.0083), Fisher-Freeman-Halton exact test to assess differences in direction (p<0.0063) and Gwet’s AC1 score to determine interobserver agreement.

Results:

Amplitude of the displacement of the ED tendons was statistically significantly higher in JA+ patients than in JA- patients and controls in flexion for both readers (p<0.0001) and in extension for one reader (p<0.0048). Ulnar deviation of the ED tendons was statistically significantly more frequent in JA+ patients than in JA- patients and controls in flexion and in extension for both readers (p<0.0001). Interobserver agreement for the assessment of displacement was moderate to very good (0.51≤kappa≤0.93).

Conclusion:

JA is associated with abnormal displacement of the ED tendons in flexion and extension. Abnormal displacement of the ED tendons is absent in patients without JA.

References:

[1]Santiago MB. Miscellaneous non-inflammatory musculoskeletal conditions. Jaccoud’s arthropathy. Best Pract Res Clin Rheumatol. 2011;25(5):715-25.

Figure 1.

Axial spin echo T1-weighted images of a 49-year-old woman with SLE and JA (a) in flexion and (b) extension. In flexion, the extensor digitorum (ED) tendons of the 3rdand 4thfingers are completely displaced on the ulnar aspect of the metacarpal heads (white arrows) with no tendon visible on the dorsal aspect (arrowheads). In extension, the ED tendons of the 3rdand 4thfingers are slightly displaced on the ulnar side of the dorsal aspect of the metacarpal heads (black arrows).

Figure 2.

Axial spin echo T1-weighted images of the sex- and age-matched control subject of the patient from Figure 1 (a) in flexion and (b) extension. The extensor digitorum tendons of the 3rdand 4thfingers are normally positioned on the dorsal aspect of the metacarpal heads in flexion (white arrows) and extension (black arrows).

Disclosure of Interests:

Thomas Kirchgesner: None declared, Maria Stoenoiu: None declared, Nicolas Michoux: None declared, Xavier Libouton: None declared, Frederic Houssiau Grant/research support from: UCB, Consultant of: GSK, Bruno Vande Berg: None declared

THU0533 A SINGLE MRI DIXON SEQUENCE TO ASSESS DISEASE ACTIVITY AND CARTILAGE IN EARLY RHEUMATOID HANDS: ONE SEQUENCE TO ASSESS THEM ALL?

Background:

OMERACT recommends three “core set” MRI sequences with an optional cartilage-dedicated sequence to perform Rheumatoid Arthritis (RA) MRI scoring (RAMRIS) (1). Dixon method allows the production of four different images from a single MRI sequence.

Objectives:

To test a short MRI protocol based on a single Dixon sequence to assess disease activity and cartilage in hands of patients with early RA.

Methods:

Twenty-four patients (16 women, mean age 45.7 years old) with early DMARD-naive RA meeting the ACR/EULAR 2010 criteria were prospectively included. Both hands of each patient were imaged with MRI including contrast-enhanced T1-weighted Dixon and OMERACT “core set” MRI sequences and with conventional radiography.

Two musculoskeletal radiologists (R1 and R2) separately assessed disease activity according to RAMRIS scoring system based on the Dixon images (contrast-enhanced T1-weighted Dixon water-only images to score synovitis, tenosynovitis and osteitis and contrast-enhanced T1-weighted Dixon fat-only images to score erosions) and the three OMERACT “core set” MRI sequences (contrast-enhanced fat-saturated T1-weighted images to score synovitis and tenosynovitis, fat-saturated T2-weighted images to score osteitis and T1-weighted images without contrast-material injection to score erosions).

One radiologist (R1) separately measured the thickness of the cartilage in the joints corresponding to those assessed by the Sharp/van der Heijde modified scoring method on contrast-enhanced T1-weighted Dixon out-of-phase images and radiographs (2).

RAMRIS scoring and measurement of the cartilage thickness were repeated by R1 to assess intra-observer agreement. Statistical analysis was based on intra-class correlation coefficients (ICC) with 95% confidence interval to assess inter-technique, intra-observer and inter-observer agreement. The strength of agreement was interpreted as follows: ≤0, poor; 0.01-0.20, slight; 0.21-0.40, fair; 0.41-0.60, moderate; 0.61-0.80, substantial and ≥0.81, excellent.

Results:

Agreement between total RAMRIS scores obtained with the Dixon water- and fat-only images and total RAMRIS scores obtained with the OMERACT sequences was excellent for R1 (0.94; 0.86-0.97) and R2 (0.91; 0.81-0.96). Intra-observer agreement was excellent with Dixon images (0.97; 0.92-0.98) and OMERACT sequences (0.96; 0.90-0.98). Inter-observer agreement was excellent with Dixon images (0.92; 0.82-0.96) and OMERACT sequences (0.93; 0.85-0.97).

Agreement between the measures of cartilage thickness on the Dixon out-of-phase images and the measures of cartilage thickness on radiographs was substantial (0.71; 0.66-0.75). Intra-observer agreement was excellent with Dixon out-of-phase images (0.94; 0.93-0.95) and radiographs (0.93; 0.92-0.94).

Conclusion:

An MRI protocol based on a single contrast-enhanced T1-weighted Dixon sequence allows reproducible RAMRIS scoring and measurement of the cartilage thickness. Further studies should be performed to evaluate the value of a short MRI protocol based on the Dixon method to monitor disease activity including cartilage loss in treated RA patients.

References:

[1]Ostergaard M, Peterfy CG, Bird P, Gandjbakhch F, Glinatsi D, Eshed I, et al. The OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging (MRI) Scoring System: Updated Recommendations by the OMERACT MRI in Arthritis Working Group. J Rheumatol. 2017;44(11):1706-12.

[2]van der Heijde D. How to read radiographs according to the Sharp/van der Heijde method. J Rheumatol. 1999;26(3):743-5.

Disclosure of Interests:

Thomas Kirchgesner: None declared, Maria Stoenoiu: None declared, Nicolas Michoux: None declared, Patrick Durez Speakers bureau: AbbVie, Bristol-Myers Squibb, Celltrion, Eli Lilly, Pfizer, Sanofi, Bruno Vande Berg: None declared

Fat suppression at three-dimensional T1-weighted MR imaging of the hands: Dixon method versus CHESS technique

PURPOSE

To compare the effectiveness of fat suppression and the image quality of the Dixon method with those of the chemical shift-selective (CHESS) technique in hands of normal subjects at non-enhanced three-dimensional (3D) T1-weighted MR imaging.

MATERIALS AND METHODS

Both hands of 14 healthy volunteers were imaged with 3D fast spoiled gradient echo (FSPGR) T1-weighted Dixon, 3D FSPGR T1-weighted CHESS and 3D T1-weighted fast spin echo (FSE) CHESS sequences in a 1.5T MR scanner. Three radiologists scored the effectiveness of fat suppression in bone marrow (EFS^BM) and soft tissues (EFS^ST) in 20 joints per subject. One radiologist measured the signal-to-noise ratio (SNR) in 10 bones per subject. Statistical analysis used two-way ANOVA with random effects (P<0.0083), paired t-test (P<0.05) and observed agreement to assess differences in effectiveness of fat suppression, differences in SNR and interobserver agreement.

RESULTS

EFS^BM was statistically significantly higher for the 3D FSPGR T1-weighted Dixon than for the 3D FSPGR T1-weighted CHESS sequence and the 3D FSE T1-weighted CHESS sequence (P<0.0001). EFS^ST was statistically significantly higher for the 3D FSPGR T1-weighted Dixon than for the 3D FSPGR T1-weighted CHESS sequence (P<0.0011) and for the 3D FSE T1-weighted CHESS sequence in the axial plane (P=0.0028). Mean SNR was statistically significantly higher for 3D FSPGR T1-weighted Dixon sequence than for 3D FSPGR T1-weighted CHESS and 3D FSE T1-weighted CHESS sequences (P<0.0001).

CONCLUSION

The Dixon method yields more effective fat suppression and higher SNR than the CHESS technique at 3D T1-weighted MR imaging of the hands.

Cartilage thickness at the posterior medial femoral condyle is increased in femorotibial knee osteoarthritis: a cross-sectional CT arthrography study (Part 2)

OBJECTIVE

To evaluate the thickness of cartilage at the posterior aspect of the medial and lateral condyle in Osteoarthritis (OA) knees compared to non-OA knees using computed tomography arthrography (CTA).

DESIGN

535 consecutive knee CTAs (mean patient age = 48.7 ± 16.0; 286 males), were retrospectively analyzed. Knees were radiographically classified into OA or non-OA knees according to a modified Kellgren/Lawrence (K/L) grading scheme. Cartilage thickness at the posterior aspect of the medial and lateral femoral condyles was measured on sagittal reformations, and compared between matched OA and non-OA knees in the whole sample population and in subgroups defined by gender and age.

RESULTS

The cartilage of the posterior aspect of medial condyle was statistically significantly thicker in OA knees (2.43 mm (95% confidence interval (CI) = 2.36, 2.51)) compared to non-OA knees (2.13 mm (95%CI = 2.02, 2.17)) in the entire sample population (P < 0.001), as well as for all subgroups of patients over 40 years old (all P ≤ 0.01), except for females above 60 years old (P = 0.07). Increase in cartilage thickness at the posterior aspect of the medial condyle was associated with increasing K/L grade in the entire sample population, as well as for males and females separately (regression coefficient = 0.10-0.12, all P < 0.001). For the lateral condyle, there was no statistically significant association between cartilage thickness and OA (either presence of OA or K/L grade).

CONCLUSIONS

Cartilage thickness at the non-weight-bearing posterior aspect of the medial condyle, but not of the lateral condyle, was increased in OA knees compared to non-OA knees. Furthermore, cartilage thickness at the posterior aspect of the medial condyle increased with increasing K/L grade.

Anatomical distribution of areas of preserved cartilage in advanced femorotibial osteoarthritis using CT arthrography (Part 1)

OBJECTIVE

To determine subregions of normal and abnormal cartilage in advanced stages of femorotibial osteoarthritis (OA) by mapping the entire femorotibial joint in a cohort of pre-total knee replacement (TKR) OA knees.

DESIGN

We defined an areal subdivision of the femorotibial articular cartilage surface on CT arthrography (CTA), allowing the division of the femorotibial articular surface into multiple (up to n = 204 per knee) subregions and the comparison of the same areas between different knees. Two readers independently classified each cartilage area as normal, abnormal or non-assessable in 41 consecutive pre-TKR OA knees.

RESULTS

A total of 6447 cartilage areas (from 41 knees) were considered assessable by both readers. The average proportion of preserved cartilage was lower in the medial femorotibial joint than in the lateral femorotibial joint for both readers (32.0/69.8% and 33.9/68.5% (medial/lateral) for reader 1 and 2 respectively, all P < 0.001). High frequencies of normal cartilage were observed at the posterior aspect of the medial condyle (up to 89%), and the anterior aspect of the lateral femorotibial compartment (up to 100%). The posterior aspect of the medial condyle was the area that most frequently exhibited preserved cartilage in the medial femorotibial joint, contrasting with the high frequency of cartilage lesions in the rest of that compartment.

CONCLUSIONS

Cartilage at the posterior aspect of the medial condyle, and at the anterior aspect of the lateral femorotibial compartment, may be frequently preserved in advanced grades of OA.

Tumour response and safety of cetuximab in a window pre-operative study in patients with squamous cell carcinoma of the head and neck

BACKGROUND

To investigate the safety and activity of cetuximab in the pre-operative treatment of squamous cell carcinoma of the head and neck (SCCHN).

PATIENTS AND METHODS

Cetuximab was administered for 2 weeks before surgery to 33 treatment-naïve patients selected for primary surgical treatment. Tumour biopsies, 2-[fluorine-18]-fluoro-2-deoxy-d-glucose positron emission tomography ((18)FDG-PET) and imaging were carried out at baseline and before surgery. The primary aim of the study was safety and the secondary aims included metabolical, radiological and pathological tumour response. Five untreated patients were included as controls.

RESULTS

Cetuximab given 24 h before surgery was safe. Ninety percent of patients had (18)FDG-PET partial response (EORTC guideline) in the cetuximab group versus 0% in the control group. Delta maximal standardized uptake values (ΔSUVmax) were correlated with tumour cellularity on the surgical specimens (P < 0.0001). For patients with ΔSUVmax less than -25% or less than -50%, Ki67 was significantly decreased by cetuximab (P = 0.01 and 0.003). Cetuximab induced down-regulation of pEGFR (P = 0.0004) and pERK (P = 0.003).

CONCLUSIONS

Short-course pre-operative administration of cetuximab is safe and shows a high rate of (18)FDG-PET response. (18)FDG-PET response was correlated with residual tumour cellularity suggesting that (18)FDG-PET deserves further investigation as a potential early marker of cetuximab activity in SCCHN.

MRI for response assessment in metastatic bone disease

BACKGROUND

Beyond lesion detection and characterisation, and disease staging, the quantification of the tumour load and assessment of response to treatment are daily expectations in oncology.

METHODS

Bone lesions have been considered "non-measurable" for years as opposed to lesions involving soft tissues and "solid" organs like the lungs or liver, for which response evaluation criteria are used in every day practice. This is due to the lack of sensitivity, specificity and measurement capabilities of imaging techniques available for bone assessment, i.e. skeletal scintigraphy (SS), radiographs and computed tomography (CT).

RESULTS

This paper reviews the possibilities and limitations of these techniques and highlights the possibilities of positron emission tomography (PET), but mainly concentrates on magnetic resonance imaging (MRI).

CONCLUSION

Practical morphological and quantitative approaches are proposed to evaluate the treatment response of bone marrow lesions using "anatomical" MRI. Recent developments of MRI, i.e. dynamic contrast-enhanced (DCE) imaging and diffusion-weighted imaging (DWI), are also covered.

KEY POINTS

• MRI offers improved evaluation of skeletal metastases and their response to treatment. • This new indication for MRI has wide potential impact on radiological practice. • MRI helps meet the expectations of the oncological community. • We emphasise the practical aspects, with didactic cases and illustrations.

Phase II study of sunitinib in patients with recurrent and/or metastatic squamous head and neck carcinoma: The GORTEC 2006–01 study

6024

Background: Up to 90% of head and neck squamous cell carcinoma (HNSCC) express the vascular endothelial growth factor (VEGF) or the VEGF receptors (VEGFR) 1–3. Angiogenic factors could have prognostic implication making anti-angiogenic therapies an attractive treatment modality. Sunitinib inhibits multiple tyrosine kinase receptors including VEGFR1–3 and PDGFR. Methods: Palliative HNSCC in PD after platinum therapy received sunitinib 37.5 mg/day continuously. The primary endpoint was the disease control rate (SD, PR, CR) at 6–8 wks. A two-stage design was used (Simon; a = 0.15,b = 0.10, H0 = 10%, H1 = 25%) meaning that at least 6 patients out of 37 should achieve a SD. Dynamic contrast enhanced (DCE) magnetic resonance (MR) perfusion-weighted imaging before and 6 wks after treatment initiation was performed on a 3T system. Results: 37 pts (M/F:28/9;PS 0/1:5/32) were included.11 pts were not evaluable by imaging due to rapid clinical PD (7 pts) or toxicity (4 pts) and were considered in PD.PR was found in 1 pts, SD in 18, and PD in 18 (RECIST). Among the SD, 6 had a minor response and 5 had an unconfirmed PR (maximum % reduction in sum of the largest diameters: 2%, 4%, 7%, 10%, 16%, 17%, 30%, 45%, 48%, 65%, 73%). PR could not be confirmed due to PD within 4 wks (3 pts) or treatment termination due to toxicity (2 pts). 4 pts had MR DCE monitoring. In 3, a significant decrease in the volume transfer constant Ktrans measuring the tumor perfusion and endothelial permeability was found during sunitinib treatment. The main Gr3–4 toxicities (N pts) were fatigue (12), tumor bleedings (2), LVEF decrease (2), hypertension (2). Gr5 tumor bleedings occurred in 4 pts. Other local complications included apparition/worsening of tumor skin ulceration or tumor fistula in 15 pts. Conclusions: This trial met its primary endpoint with modest activity of sunitinib in HNSSC. The rate of complications (i.e., fatal bleedings) outlines the importance of a better patient selection. DCE-MRI may be useful to predict response.

No significant financial relationships to disclose.

[Magnetic resonance imaging of angiogenesis in tumors]

Tumor angiogenesis induces the proliferation of immature blood vessels that are both heterogeneous and leaky. These characteristics can be demonstrated by measuring the perfusion parameters with MRI. Perfusion MRI is usually performed with in T1-weighted dynamic imaging after bolus injection of an exogenous contrast agent such as gadolinium chelate. The perfusion parameters are obtained by semi-quantitative or quantitative analysis of the enhancement curves in the tumor and the arterial input. Perfusion can also be assessed without injecting a contrast agent using arterial spin labeling techniques, diffusion MRI, or BOLD (blood oxygen level dependent) MRI. However, these latter methods are limited by a low signal-to-noise ratio and problems with quantification. The main indication for perfusion MRI is the assessment of antiangiogenic and antivascular treatments. New possibilities for demonstrating angiogenic blood vessels are being opened by molecular imaging.

Analysis of contrast-enhanced MR images to assess renal function

The image analysis and kinetic modeling methods used in dynamic contrast-enhanced magnetic resonance imaging of the kidney are reviewed. Image analysis includes various techniques of coregistration and segmentation. Few methods have been completely implemented. Nevertheless, the use of coregistration may become a standard to decrease the effect of motion on abdominal images and improve the quality of the renal signals. Kinetic models are classified into three categories: enhancement-based, external and internal representations. Enhancement-based representations are limited to a basic analysis of the tracer concentration curves in the kidneys. Their relationship to the underlying physiology is complex and undefined. However, they can be used to evaluate the split renal function. External representations assess the kidney input and output. An external representation based on the up-slope of the renal enhancement to calculate the renal perfusion is commonly used because of its simplicity. In contrast, external representation based on deconvolution or identification methods remain underexploited. For glomerular filtration, an internal representation based on a two-compartmental model is mostly used. Internal representations based on multi-compartmental models describe the renal function in a more realistic way. Because of their numerical complexity, these models remain rarely used.

Parametric and quantitative analysis of MR renographic curves for assessing the functional behaviour of the kidney

The aim of this study was to refine the description of the renal function based on MR images and through transit-time curve analysis on a normal population and on a population with renal failure, using the quantitative model of the up-slope. Thirty patients referred for a kidney MR exam were divided in a first population with well-functioning kidneys and in a second population with renal failure from ischaemic kidney disease. The perfusion sequence consisted of an intravenous injection of Gd-DTPA and of a fast GRE sequence T1-TFE with 90 degrees magnetisation preparation (Intera 1.5 T MR System, Philips Medical System). To convert the signal intensity into 1/T1, which is proportional to the contrast media concentration, a flow-corrected calibration procedure was used. Following segmentation of regions of interest in the cortex and medulla of the kidney and in the abdominal aorta, outflow curves were obtained and filtered to remove the high frequency fluctuations. The model of the up-slope method was then applied. Significant reduction of the cortical perfusion (Qc = 0.057+/-0.030 ml/(s 100 g) to Qc = 0.030 +/- 0.017 ml/(s 100 g), P < 0.013) of the medullary perfusion (Qm = 0.023 +/- 0.018 ml/(s 100 g) to Qm = 0.011 +/- 0.006 ml/(s 100 g), P < 0.046) and of the accumulation of contrast media in the medulla (Qa = 0.005 +/- 0.003 ml/(s 100 g) to Qa = 0.0009 +/- 0.0008 ml/(s 100 g), P < 0.001) were found in presence of renal failure. High correlations were found between the creatinine level and the accumulation Qa in the medulla (r2 = 0.72, P < 0.05), and between the perfusion ratio Qc/Qm and the accumulation Qa in the medulla (r2 = 0.81, P < 0.05). No significant difference was found in times to peak between both populations despite a trend showing Ta the time to the end of the increasing contrast accumulation period in the medulla, arriving later for renal failure. Advances in MR signal calibration with the building of quantitative model such as the up-slope allow to assess kinetic and haemodynamic and functional parameters of the diseased kidney.

Postprandial duodenojejunal motility in health and idiopathic severe gastroparesis: from conventional analysis to nonlinear dynamics analysis

Our aim was to compare the results of the analysis of postprandial duodenojejunal motor patterns provided by a conventional computer-aided analysis with those provided by the new nonlinear mathematical method borrowed from 'chaos theory for determining how nonlinear analysis can improve fed motor pattern analysis and detect organization of postprandial contractions. Ten patients who had been explored for an idiopathic gastroparesis, and 20 healthy volunteers underwent duodenojejunal manometric recording for 3 h after a 750 kcal meal. Computer-aided analysis on each half-hour of the postprandial recording period calculated the number of waves (NW) and the area under the curve (AUC). Pressure signals were concurrently described by phase portraits obtained by plotting each pressure value at time t with the pressure value at time t + 1 s. The shape and amplitude of phase portraits were visually analysed and the relative area covered (RAC) by the phase portraits was calculated. With conventional analysis, NW and AUC were maximal during the first post-meal hour then decreased with time both in healthy volunteers and gastroparetic patients. With this analysis, the only difference between patients and controls was a lower NW (P < 0.02) in patients, observed only in the duodenum. Phase portraits analysis demonstrated lower RAC, a different distribution of RAC and more regular phase portraits in patients than in controls. Phase portraits outlined the heterogeneity of the patient group contrasting with the homogeneity of the control group when no subgroup was demonstrated by conventional analysis. We therefore conclude that the study of post prandial duodenojejunal motor behaviour could be improved by nonlinear dynamic analysis.