Search

Background Sufficient and timely spinal cord decompression is a critical surgical objective for neurological recovery in spinal cord injury (SCI). Residual cord compression may be associated with disturbed cerebrospinal fluid pressure (CSFP) dynamics. Objectives This study aims to assess whether intrathecal CSFP dynamics in SCI following surgical decompression are feasible and safe, and to explore the diagnostic utility. Methods Prospective cohort study. Bedside lumbar CSFP dynamics and cervical MRI were obtained following surgical decompression in N = 9 with mostly cervical acute-subacute SCI and N = 2 patients with non-traumatic SCI. CSFP measurements included mean CSFP, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp), Valsalva maneuver, and Queckenstedt’s test (firm pressure on jugular veins, QT). From QT, proxies for cerebrospinal fluid pulsatility curve were calculated (ie, relative pulse pressure coefficient; RPPC-Q). CSFP metrics were compared to spine-healthy patients. computer tomography (CT)-myelography was done in 3/8 simultaneous to CSFP measurements. Results Mean age was 45 ± 9 years (range 17-67; 3F), SCI was complete (AIS A, N = 5) or incomplete (AIS B-D, N = 6). No adverse events related to CSFP assessments. CSFP rise during QT was induced in all patients [range 9.6-26.6 mmHg]. However, CSFPp was reduced in 3/11 (0.1-0.3 mmHg), and in 3/11 RPPC-Q was abnormal (0.01-0.05). Valsalva response was reduced in 8/11 (2.6-23.4 mmHg). CSFP dynamics corresponded to CT-myelography. Conclusions Comprehensive bedside lumbar CSFP dynamics in SCI following decompression are safe, feasible, and can reveal distinct patterns of residual spinal cord compression. Longitudinal studies are required to define critical thresholds of impaired CSFP dynamics that may impact neurological recovery and requiring surgical revisions.

To compare computer-based 3D-analysis for quantification of the femorotibial joint space width (JSW) using weight-bearing cone beam CT (WB-CT), non-weight-bearing multi-detector CT (NWB-CT), and weight-bearing conventional radiographs (WB-XR).Twenty-six participants prospectively underwent NWB-CT, WB-CT, and WB-XR of the knee. For WB-CT and NWB-CT, the average and minimal JSW was quantified by 3D-analysis of the minimal distance of any point of the subchondral tibial bone surface and the femur. Associations with mechanical leg axes and osteoarthritis were evaluated. Minimal JSW of WB-CT was further compared to WB-XR. Two-tailed p-values of0.05 were considered significant.Significant differences existed of the average medial and lateral JSW between WB-CT and NWB-CT (medial: 4.7 vs 5.1 mm [P = 0.028], lateral: 6.3 vs 6.8 mm [P = 0.008]). The minimal JSW on WB-XR (medial:3.1 mm, lateral:5.8 mm) were significantly wider compared to WB-CT and NWB-CT (both medial:1.8 mm, lateral:2.9 mm, all p 0.001), but not significantly different between WB-CT and NWB-CT (all p ≥ 0.869). Significant differences between WB-CT and NWB-CT existed in participants with varus knee alignment for the average and the minimal medial JSW (p = 0.004 and p = 0.011) and for participants with valgus alignment for the average lateral JSW (p = 0.013). On WB-CT, 25% of the femorotibial compartments showed bone-on-bone apposition, which was significantly higher when compared to NWB-CT (10%,P = 0.008) and WB-XR (8%,P = 0.012).Combining WB-CT with 3D-based assessment allows detailed quantification of the femorotibial joint space and the effect of knee alignment on JSW. WB-CT demonstrates significantly more bone-on-bone appositions, which are underestimated or even undetectable on NWB-CT and WB-XR.

Additional file 1.

Magnetic resonance imaging (MRI) is a powerful imaging modality for visualizing a wide range of ankle disorders that affect ligaments, tendons, and articular cartilage. Standard two-dimensional (2D) fast spin-echo (FSE) and turbo spin-echo (TSE) pulse sequences offer high signal-to-noise and contrast-to-noise ratios, but slice thickness limitations create partial volume effects. Modern three-dimensional (3D) FSE/TSE pulse sequences with isotropic voxel dimensions can achieve higher spatial resolution and similar contrast resolutions in ≤ 5 minutes of acquisition time. Advanced acceleration schemes have reduced the blurring effects of 3D FSE/TSE pulse sequences by affording shorter echo train lengths. The ability for thin-slice partitions and multiplanar reformation capabilities eliminate relevant partial volume effects and render modern 3D FSE/TSE pulse sequences excellently suited for MRI visualization of several oblique and curved structures around the ankle. Clinical efficiency gains can be achieved by replacing two or three 2D FSE/TSE sequences within an ankle protocol with a single isotropic 3D FSE/TSE pulse sequence. In this article, we review technical pulse sequence properties for 3D MRI of the ankle, discuss practical considerations for clinical implementation and achieving the highest image quality, compare diagnostic performance metrics of 2D and 3D MRI for major ankle structures, and illustrate a broad spectrum of ankle abnormalities.

This study was conducted in order to determine the predictive value of MR arthrography findings for pain relief after glenohumeral corticosteroid injection. This study prospectively enrolled 212 patients (mean age 51.4 years; range 15–90) who underwent fluoroscopy-guided glenohumeral corticosteroid injection. All patients received MR arthrography of the shoulder less than 3 months prior to the infiltration and returned questionnaires which assessed patients’ shoulder pain using the 11-point numeric rating scale (NRS), covering a 1-month follow-up period. MR arthrograms were retrospectively assessed for abnormalities of the rotator cuff, long biceps tendon, glenohumeral bone, cartilage, and labrum as well as for synovitis, bursitis, and signs of adhesive capsulitis. MR arthrography findings were compared to patients’ NRS change using the Mann–Whitney U and Kruskal–Wallis tests for univariate analysis and multiple linear regression for multivariate analysis. Pain reduction of ≥ 2 points was considered to represent clinically relevant improvement, which was seen in 71% of patients 1 week and in 74% of patients 1 month after glenohumeral injection. Univariate analysis of MR findings showed that signs of adhesive capsulitis and an intact labrum were associated with significantly higher NRS reductions after 1 month in comparison to patients without these findings (median 4 vs. 3, p = 0.007 and 4 vs. 2, p = 0.003, respectively). Multivariate analysis proved both factors to be independent predictors of improved outcome after 1 month (beta = 0.176, p = 0.039 and beta = 0.212, p = 0.001, respectively). Glenohumeral corticosteroid injections for pain relief have a high success rate with 74% of patients reporting clinically relevant improvement after 1 month. Signs of adhesive capsulitis and an intact labrum on MR arthrography are independent predictors of a better outcome. • Seventy-four percent of patients report clinically relevant improvement 1 month after glenohumeral corticosteroid injection. • Signs of adhesive capsulitis and an intact labrum on MR arthrography are independent predictors of a high pain level decrease.

To evaluate the feasibility of 2D and 3D acetabular coverage assessments based on low-dose biplanar radiographs (BPR) in comparison with CT, and to demonstrate the influence of weight-bearing position (WBP) on anterior and posterior acetabular coverages. Fifty patients (21 females, 29 males) underwent standing BPR and supine CT of the pelvis. Using dedicated software, BPR-based calculations of anterior and posterior 2D coverages and anterior, posterior, and global 3D coverages were performed in standardized anterior pelvic plane (APP) and WBP. CT-based anterior and posterior 2D coverages and global 3D coverage was calculated in APP and compared with BPR-based data. Statistics included intraclass correlation coefficients (ICC) and Bland-Altman plots. Mean anterior 2D coverage was 21.2% (standard deviation, ± 7.4%) for BPR and 23.8% (± 8.4%) for CT (p = 0.226). Mean posterior 2D coverage was 54.2% (± 9.8%) for BPR and 61.7% (± 9.7%) for CT (p = 0.001). Mean global 3D coverage was 46.5% (± 3.0%) for BPR and 45.6% (± 3.6%) for CT (p = 0.215). The inter-method reliability between CT and BPR and inter-reader reliability for BPR-based measurements were very good for all measurement (all ICC > 0.8). Based on BPR, mean anterior and posterior 3D coverages were 20.5% and 26.0% in WBP and APP, while 25 patients increased anterior and 24 patients increased posterior 3D coverage from APP to WBP with a relative change of coverage of up to 11.9% and 10.0%, respectively. 2D and 3D acetabular coverages can be calculated with very good reliability based on BPR. The impact of standing position on acetabular coverage can be quantified with BPR on an individual basis. • 2D and 3D acetabular coverages can be calculated with very good reliability based on biplanar radiographs in comparison with CT. • The impact of standing position on anterior and posterior acetabular coverages can be quantified with BPR on an individual basis.

OBJECTIVES The aim of this study was to clinically validate a Deep Convolutional Neural Network (DCNN) for the detection of surgically proven anterior cruciate ligament (ACL) tears in a large patient cohort and to analyze the effect of magnetic resonance examinations from different institutions, varying protocols, and field strengths. MATERIALS AND METHODS After ethics committee approval, this retrospective analysis of prospectively collected data was performed on 512 consecutive subjects, who underwent knee magnetic resonance imaging (MRI) in a total of 59 different institutions followed by arthroscopic knee surgery at our institution. The DCNN and 3 fellowship-trained full-time academic musculoskeletal radiologists evaluated the MRI examinations for full-thickness ACL tears independently. Surgical reports served as the reference standard. Statistics included diagnostic performance metrics, including sensitivity, specificity, area under the receiver operating curve ("AUC ROC"), and kappa statistics. P values less than 0.05 were considered to represent statistical significance. RESULTS Anterior cruciate ligament tears were present in 45.7% (234/512) and absent in 54.3% (278/512) of the subjects. The DCNN had a sensitivity of 96.1%, which was not significantly different from the readers (97.5%-97.9%; all P ≥ 0.118), but significantly lower specificity of 93.1% (readers, 99.6%-100%; all P < 0.001) and "AUC ROC" of 0.935 (readers, 0.989-0.991; all P < 0.001) for the entire cohort. Subgroup analysis showed a significantly lower sensitivity, specificity, and "AUC ROC" of the DCNN for outside MRI (92.5%, 87.1%, and 0.898, respectively) than in-house MRI (99.0%, 94.4%, and 0.967, respectively) examinations (P = 0.026, P = 0.043, and P < 0.05, respectively). There were no significant differences in DCNN performance for 1.5-T and 3-T MRI examinations (all P ≥ 0.753, respectively). CONCLUSIONS Deep Convolutional Neural Network performance of ACL tear diagnosis can approach performance levels similar to fellowship-trained full-time academic musculoskeletal radiologists at 1.5 T and 3 T; however, the performance may decrease with increasing MRI examination heterogeneity.

The objective of our study was to evaluate a novel measurement technique for assessing the supra- and infratrochanteric components of femoral torsion, establish reference values in healthy volunteers, and compare supra- and infratrochanteric torsion angles in patients with hip dysplasia and patients with femoroacetabular impingement (FAI) with those in healthy volunteers.Femoral torsion was assessed in 380 patients and 61 healthy volunteers on MRI. For assessing supra- and infratrochanteric torsion, three measurement techniques (i.e., Kim, simplified Kim, and centroid methods) were evaluated by two readers on 100 patients. The technique with the highest interreader reliability was selected to perform measurements on all patients and volunteers. Supra- and infratrochanteric torsion angles of patients were stratified by hip disorders, which were diagnosed by specialized hip surgeons, and were compared with reference values of healthy volunteers. Statistical analysis included the independent t test, Mann-Whitney U test, and intraclass correlation coefficient (ICC).The centroid method showed the highest interreader reliability for measuring supra-and infratrochanteric torsion with an ICC of 0.979. The supra- and infratrochanteric torsion values of the volunteers were 31.5° ± 7.4° (mean ± SD) and -18.3° ± 9.9°, respectively. In comparison with the volunteers, patients with hip dysplasia had significantly higher supraand infratrochanteric torsion values of 37.5° ± 10.3° (p = 0.001) and -9.6° ± 11.7° (p0.001) and patients with pincer-type FAI had significantly higher supratrochanteric torsion values of 37.8° ± 8.0° (p = 0.002).The supra- and infratrochanteric components of femoral torsion differ substantially between hip disorders: Patients with hip dysplasia have predominantly increased infratrochanteric torsion, whereas patients with pincer-type FAI have increased supratrochanteric torsion. Quantification of separate supra- and infratrochanteric torsion angles allows a more detailed analysis of hip disorders and may influence treatment planning.

Objective To clinically validate a fully automated deep convolutional neural network (DCNN) for detection of surgically proven meniscus tears. Materials and methods One hundred consecutive patients were retrospectively included, who underwent knee MRI and knee arthroscopy in our institution. All MRI were evaluated for medial and lateral meniscus tears by two musculoskeletal radiologists independently and by DCNN. Included patients were not part of the training set of the DCNN. Surgical reports served as the standard of reference. Statistics included sensitivity, specificity, accuracy, ROC curve analysis, and kappa statistics. Results Fifty-seven percent (57/100) of patients had a tear of the medial and 24% (24/100) of the lateral meniscus, including 12% (12/100) with a tear of both menisci. For medial meniscus tear detection, sensitivity, specificity, and accuracy were for reader 1: 93%, 91%, and 92%, for reader 2: 96%, 86%, and 92%, and for the DCNN: 84%, 88%, and 86%. For lateral meniscus tear detection, sensitivity, specificity, and accuracy were for reader 1: 71%, 95%, and 89%, for reader 2: 67%, 99%, and 91%, and for the DCNN: 58%, 92%, and 84%. Sensitivity for medial meniscus tears was significantly different between reader 2 and the DCNN (p = 0.039), and no significant differences existed for all other comparisons (all p ≥ 0.092). The AUC-ROC of the DCNN was 0.882, 0.781, and 0.961 for detection of medial, lateral, and overall meniscus tear. Inter-reader agreement was very good for the medial (kappa = 0.876) and good for the lateral meniscus (kappa = 0.741). Conclusion DCNN-based meniscus tear detection can be performed in a fully automated manner with a similar specificity but a lower sensitivity in comparison with musculoskeletal radiologists.

Purpose To evaluate 3D-printed anatomic models of the distal femur and patella for diagnosis and classification of patellofemoral dysplasia in comparison to conventional radiographs (CR) and CT. Method Following local ethics committee approval, CT-datasets of 50 patients were segmented and 3D-anatomic models of the distal femur and patella were printed. An expert panel reviewed CR, CT, 3D-models and patient history and classified the femoral trochleas into normal or Dejour type A–D and the patellas into Wiberg type A–C, which served as the standard of reference. The same classifications were performed by two readers independently, first based on 3D-models and after 3 weeks based on CR and CT. Descriptive statistics, ROC-analysis and inter-reader reliability were performed. Results Trochlear dysplasia was present in 28/50 patients. Evaluations of 3D-models vs. CR/CT for trochlear dysplasia showed a sensitivity/specificity of 89.3 %/100 % vs. 96.4 %/68.2 % for reader 1 and 96.4 %/100 % vs. 96.4 %/90.9 % for reader 2, and an area under the curve of 0.946 vs. 0.823 for reader 1 (p = 0.029) and 0.982 vs. 0.937 for reader 2 (p = 0.147). Evaluations of 3D-models vs. CR/CT for the Dejour classification showed a sensitivity/specificity of 32.1 %/100 % vs. 57.1 %/68.2 % for reader 1 and 46.4 %/100 % vs. 50 %/90.9 % for reader 2 without significant differences. No significant differences existed for Wiberg-classification (50–66 % exact matches) or inter-reader reliabilities between 3D-models and CR/CT for all assessments (Kappa 0.428–0.92). Conclusion In comparison to radiographs and CT, 3D-models achieve similar diagnostic accuracy for detection of patellofemoral dysplasia and have the potential to improve diagnosis for less experienced physicians.