RPS 110 - Cartilage, bone marrow oedema, tissue and body imaging

Purpose:

To assess morphological changes in the sub-regions of knee articular cartilage in the presence of pathologic/degenerative or traumatic disease through automated and quantitative computation method.

This prospective observational study was designed to assess 35 normal and 20 patients (chondromallacia patellae=8, osteoarthritis=7, and traumatic injuries with degraded cartilage=5). MR scanning was performed on 3T MAGNETOM Vida (Siemens Healthineers, Germany) using an 18-channel knee coil. Regional and sub-regional analysis of the cartilage in terms of morphological changes such as thickness and volume were performed using an MR chondral health (Version 2.1) work-in-progress (WIP) package provided by Siemens Healthineers.

Cartilage was segmented in various zones and regions, which were colour demarcated, and quantitative measurements in terms of thickness and volume were performed. Mean thicknesses of the femur, patella, and tibia of normal subjects were1.63±0.22 mm, 2.11±0.38mm, and 1.51±0.20 mm, respectively, while mean volumes were 10.17±2.39, 3.11±0.79, and 3.74±0.85, respectively. Thicknesses in OA (femur=1.59 mm, tibia=1.45 mm), traumatic (femur-=1.59 mm, tibia=1.50 mm) and chondromallacia patellae (femur=1.57 mm, tibia=1.48 mm) patients were found to be slightly decreased compared to normal, while it was increased for the patella region (OA=2.15 mm, traumatic=1.97 mm, and chondrmallacia patellae=2.15 mm). A similar pattern was observed for volume, in OA (femur=9.52 ml, tibia=3.37 ml), traumatic (femur=9.04 ml, tibia=3.13 ml), and chondromallacia patellae (femur=9.24 mm, tibia=3.32 ml) patients were found to be slightly decreased compared to normal, while it was increased for the patella region (OA=3.18 ml, traumatic=2.7 ml, and chondromallacia patellae=3.20 ml). This evidenced the degenerative changes in the morphology of cartilage.

Automated cartilage segmentation and quantitative measurements in terms of thickness and volume have significantly reduced time and improved diagnostic accuracies quantitatively.

A small sample size.

Ethics committee approval obtained.

WIP loaned by Siemens under Master Research Agreement.

Purpose:

To investigate the feasibility of using a quantitative ultrashort echo time magnetisation transfer (UTE-MT) technique to evaluate cartilage degeneration.

20 human anterolateral condyle specimens were obtained from total knee arthroplasty and then underwent MR scans on a clinical 3.0T scanner. 72 regions of interest (ROI) were manually drawn on specimens for UTE-MT measurement and the corresponding cartilage-bone regions were further divided into normal, mild, moderate, and severe degeneration groups based on histological measures of degeneration (Mankin scores) as a reference standard. 20 healthy volunteers and 15 osteoarthritis patients (the anterolateral condyle was involved) underwent MRI scans with UTE-MT and clinical sequences. The cartilage regions were grouped according to MRI Recht grades and UTE-MTR were obtained by drawing the ROI in the corresponding regions. The differences in quantitative results among different grades were compared.

Ex vivo results showed that the UTE magnetisation transfer ratio (UTE-MTR) in the normal group was significantly different from the mild group (P=0.021), moderate group (P<0.001), and severe group (P<0.001). UTE-MTR strongly correlated with histological grades of cartilage degeneration (Mankin scores) (P=-0.678, P<0.001). In vivo results showed that UTE-MTR in the normal group was significantly different from the moderate group (P=0.02).

UTE-MT may provide a promising imaging biomarker with potential application in the diagnosis and monitoring of cartilage degeneration.

MTR values are susceptible to many factors, including deviation fre­quencies, radio-frequency angles, and field intensities. We have not been confirmed using the corresponding histological measures of a degeneration in vivo study.

The study was approved by the ethics committee at our research hospital (shsy-iec-ky-3964).

National Natural Science Foundation of China (81871325,81801656).

Purpose:

To evaluate the diagnostic performance of dual-energy CT with water-hydroxyapatite (HAP) imaging for bone marrow oedema in patients with non-traumatic hip pain.

40 patients (mean age, 58 years; 16 male and 24 female) who underwent rapid kVp-switching dual-energy CT and MRI within 1 month from April 2018-February 2019 with hip pain but no trauma were enrolled. Two radiologists retrospectively evaluated 80 hip joints for the presence, extent (femoral head involved, head and neck, and head to intertrochanter), and severity (mild oedema, moderate, and severe) of bone marrow oedema on dual-energy water-HAP images. Water mass density (mg/cm3) on water-HAP images was determined with a region-of-interest-based quantitative analysis. MRI served as the standard of reference.

Sensitivity, specificity, and accuracy of readers 1 and 2 for the identification of bone marrow oedema in water-HAP images were 85% and 85%, 93% and 73%, and 89% and 79%, respectively. The area under the receiver operating characteristic curve was 0.96 for reader 1 and 0.91 for reader 2 for the differentiation of the presence of oedema from no oedema. The optimal water mass density to classify the presence of oedema for reader 1 was 951 mg/cm3 with 93% sensitivity and 93% specificity, and for reader 2 was 957 mg/cm3 with 80% sensitivity and 80% specificity.

Dual-energy water-HAP images showed good diagnostic performance for bone marrow oedema in patients with non-traumatic hip pain.

Only two readers were involved in this study. Subcortical zones could not be evaluated to reduce artefacts. We evaluated only water-HAP images without conventional CT images to minimise bias.

This retrospective study was approved by IRB.

No funding was received for this work.

Purpose:

To assess morphological and functional alterations of the skeletal muscle after induction of delayed onset muscle soreness (DOMS) using 7 Tesla (T) magnetic resonance imaging (MRI).

DOMS was induced in 16 participants who performed a standardised eccentric exercise protocol of the calf muscles. 7T MRI including 2D T1w- (0.18x0.18x1 mm3), 2D T2w-sequences (0.2x0.2x2 mm3), T2-mapping (0.5x0.5x5 mm3), and 3D quantitative susceptibility mapping (QSM, 0.7x0.7x0.7 mm3) was acquired at baseline (prior the exercise), directly (t1), and 60 hours (t2) after the exercise. T2 signal intensity (SI), T2 values [ms], T1 SI, and computed quantitative susceptibility maps [ppb] were assessed in the medial (MG) and lateral gastrocnemius muscle (LG), in the soleus muscle (SM), and in the tibialis anterior muscle (AM).

Directly after exercise (t1), T2 SI (p=0.03) and T2-values (p=0.03) had increased significantly in the LG, whereas no change was observed for MG, SM, or AM. At t2, T2 SI and T2-values of LG (p=0.001, p=0.02) and MG (p=0.04, p=0.03) had increased significantly compared to baseline. T1 SI and susceptibility did not change in any muscle at any time point. No structural muscle injuries could be visually detected, regardless of the degree of intramuscular oedema. Clinical parameters confirmed the induction of DOMS in every participant.

MRI at 7T allows the visualisation of DOMS immediately after the inducing exercise, whereas expected changes in susceptibility e.g. reflecting micro-haemorrhage could not be detected with quantitative susceptibility mapping.

The limited number of patients.

Institutional review board approval was obtained from Friedrich-Alexander-University Erlangen-Nuremberg, Germany.

Funded by the German Society of Musculoskeletal Radiology (DGMSR).

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Purpose:

To investigate intramuscular tissue perfusion (ITP) in athletes before, during, and after PRICE-therapy in sport-specific conditions and to prove the hypothesis of reactive hyperemia after PRICE-therapy.

20 healthy athletes (11 female, 9 males: age 25±3; 21-30 years (mean±SD; range), BMI 23±3 kg/m2) were randomised into a PRICE or control group. Quantifiable contrast-enhanced ultrasound (CEUS) was assessed to analyse microvascular blood flow of the anterior thigh (rectus femoris muscle, RF; vastus intermedius muscle, VI). Baseline perfusion measurements (T0) were compared to exercise (cycling, T1), intervention (PRICE or control (rest), (T2)), and to 60 min follow-up (T3). PRICE included rest, cryotherapy (3° celsius), compression (35 mmHg), and elevation.

After cycling, an upregulation of ITP was observed in the VI and RF for both groups. The PRICE measurements revealed a decrease of ITP, corresponding to a 47% and 53% decrease in the VI (WiAUC, PE; p=0.01, n.s.) and a 50% and 72% decrease in the RF (p=0.037; p=0.002). In contrast, an increase of ITP was observed for the control group at T1 and T2. At T3, the superficial RF (PRICE) revealed a significant persistent decrease of 15% and 50% (n.s.; p=0.003), whereas the RF (control) and VI (both groups) showed no significant changes to baseline conditions.

Our study highlights the fundamental impact of PRICE on ITP. PRICE applied after exercise leads to a downregulation of microvascular blood flow in superficial as well as deep muscle layers. The termination of PRICE is not associated with a reactive hyperemia.

The imited number of participants. No cross-over design.

IRB approval was obtained from Friedrich-Alexander-University Erlangen-Nuremberg, Germany. All participants signed an institutionally approved informed-consent document.

No funding was received for this work.

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Purpose:

To elucidate the emerging clinical applications of MAGIC (magnetic resonance image compilation) beyond the brain.

79 subjects aged from 28-64 years with a M:F ratio of 3:2 who were referred for MR examinations for neck mass (n=3), pelvis (n=16), knee pain (n=19), hip pain (n=9), shoulder injury (n=11), ankle and foot pain (n=16), and wrist and hand (n=5) were included in the study.

MR imaging protocols were supplemented with the MAGIC sequence with 6 image contrasts. T1, T2, PD, STIR, DIR, and PSIR with quantitative T1 and T2 R1.R2 maps in 4 minutes.

The images were randomised and independently assessed for diagnostic quality, morphologic legibility, and diagnostic radiologic findings. The MAGIC T2 quantitative maps of the knee and hip with ROIs on cartilage were compared with cartigram maps.

The overall diagnostic quality of synthetic MR images was non-inferior to conventional MR imaging on a 5-level Likert scale (P<0.001).

The legibility of synthetic and conventional morphology agreed in >95%.

Morphological findings like joint effusion, erosions, chondromalacia, ligament, tendon injuries, meniscal and labral tears, and sacroiliitis showed acceptable concordance.

STIR and DIR views of MAGIC contributed the maximum for detections of sacroiliitis, tenosynovitis, and chondromalacia, and so as quantitative T2 maps of MAGIC. Interobserver variability was in acceptable limits (Cohen’s kappa 0.9).

Synthetic MR imaging quality was similar to that of conventional joint and MSK imaging with the facility of additional contrast views: STIR, PSIR and DIR quantitative T1, T2, R1, and R2 maps thus increasing the sensitivity and specificity.

The small sample size.

Waiver from ERB as it is a supplementary sequence to conventional imaging.

No funding was received for this work.

Purpose:

Methotrexate (MTX) is a first-line treatment for morphea (cutaneous scleroderma). To date, no studies have evaluated the effectiveness of MTX in morphea considering colour Doppler ultrasonography. We aimed to assess the effectiveness of using MTX in patients with morphea according to ultrasound activity.

A retrospective cohort study with 22 morphea patients treated with MTX was evaluated clinically and ultrasonographically (July 2014-July 2019). Clinical data, dose, and duration of treatment were correlated with an ultrasound activity score (UAS). The UAS was based on the presence of increased hypodermal hyperechogenicity and dermal-hypodermal hypervascularity, type of vessels, number, and the type of involved corporal segments in consecutive ultrasound examinations per patient. Statistics included Wilcoxon and Fisher exact tests, the odds ratio (OR), and the risk ratio (RR) with their 95% confidence intervals. Significance was set at 0.05.

Between the first and second ultrasound, there was a significant decrease of one point of the UAS (p<0.05) and 7.9 times more chance of lowering the UAS in the group exposed to >15 mg/week of MTX versus the group exposed to ≤15 mg/week of MTX. However, between the first and last ultrasound, there was an increase in a point of the UAS (p<0.05), and only 3.6 times more chance of lowering the activity score in the group exposed to concentrations >15 mg/week of MTX. A non-significant decrease of the activity was detected in the group exposed to ≤15 mg/week of MTX.

A decrease of activity is seen in patients treated with MTX doses ≥15 mg/week, but there is a long-term loss of the effect of MTX.

The small size of the sample.

Approved by the ethics committee.

No funding was received for this work.