Automated Classification of Free-Text Radiology Reports: Using Different Feature Extraction Methods to Identify Fractures of the Distal Fibula.

PURPOSE: Radiology reports mostly contain free-text, which makes it challenging to obtain structured data. Natural language processing (NLP) techniques transform free-text reports into machine-readable document vectors that are important for creating reliable, scalable methods for data analysis. The aim of this study is to classify unstructured radiograph reports according to fractures of the distal fibula and to find the best text mining method. MATERIALS & METHODS: We established a novel German language report dataset: a designated search engine was used to identify radiographs of the ankle and the reports were manually labeled according to fractures of the distal fibula. This data was used to establish a machine learning pipeline, which implemented the text representation methods bag-of-words (BOW), term frequency-inverse document frequency (TF-IDF), principal component analysis (PCA), non-negative matrix factorization (NMF), latent Dirichlet allocation (LDA), and document embedding (doc2vec). The extracted document vectors were used to train neural networks (NN), support vector machines (SVM), and logistic regression (LR) to recognize distal fibula fractures. The results were compared via cross-tabulations of the accuracy (acc) and area under the curve (AUC). RESULTS: In total, 3268 radiograph reports were included, of which 1076 described a fracture of the distal fibula. Comparison of the text representation methods showed that BOW achieved the best results (AUC = 0.98; acc = 0.97), followed by TF-IDF (AUC = 0.97; acc = 0.96), NMF (AUC = 0.93; acc = 0.92), PCA (AUC = 0.92; acc = 0.9), LDA (AUC = 0.91; acc = 0.89) and doc2vec (AUC = 0.9; acc = 0.88). When comparing the different classifiers, NN (AUC = 0,91) proved to be superior to SVM (AUC = 0,87) and LR (AUC = 0,85). CONCLUSION: An automated classification of unstructured reports of radiographs of the ankle can reliably detect findings of fractures of the distal fibula. A particularly suitable feature extraction method is the BOW model. KEY POINTS: · The aim was to classify unstructured radiograph reports according to distal fibula fractures.. · Our automated classification system can reliably detect fractures of the distal fibula.. · A particularly suitable feature extraction method is the BOW model.. CITATION FORMAT: · Dewald CL, Balandis A, Becker LS et al. Automated Classification of Free-Text Radiology Reports: Using Different Feature Extraction Methods to Identify Fractures of the Distal Fibula. Fortschr Röntgenstr 2023; 195: 713 - 719.

Arthroscopic defect size measurement in osteochondral lesions of the talus underestimates the exact defect size and size measurement with arthro-MRI (MR-A) and high-resolution flat-panel CT-arthro imaging (FPCT-A).

PURPOSE: The size of osteochondral lesions of the talus (OLTs) is highly relevant for their treatment. In addition to intraoperative measurement of defect size, preoperative planning by means of magnetic resonance imaging (MRI) or computed tomography (CT) is crucial. METHODS: Four defects of different sizes and depths were created on the talar joint surface in 14 cadaver feet. All defects were evaluated, both arthroscopically and via arthrotomy with a probe. Arthro-MRI (MR-A) and high-resolution flat-panel CT arthro scans (FPCT-A) were acquired. Length, width, and depth were measured for every defect and the defect volume was calculated. To determine the exact defect size, each talar defect was filled with plastic pellets to form a cast and the casts were scanned using FPCT to create a 3D multiplanar reconstruction data set. Finally, the surgically measured values were compared with the radiological values and the exact defect size. RESULTS: Overall, the surgically measured values (both arthroscopic and open) underestimated the exact defect size (p < 0.05). Arthroscopically determined defect length and width showed the largest deviation (p < 0.05) and underestimated the size in comparison with MR-A and FPCT-A. The FPCT-A measurements demonstrated higher correlation with both the arthroscopic and open surgical measurements than did the MR-A measurements (p < 0.05). CONCLUSION: The exact defect size is underestimated on intraoperative measurement, in both arthroscopic and open approaches. Arthroscopic defect size measurement underestimates defect size in comparison with MR-A and FPCT-A. FPCT-A was shown to be a reliable imaging technique that allows free image reconstruction in every plane and could be considered as the new reference standard for preoperative evaluation of defect size in OLT.

Effectuality study of a 3D motion correction algorithm in C-arm CTs of severely impaired image quality during transarterial chemoembolization.

BACKGROUND: To evaluate effectivity of a 3D-motion correction algorithm in C-Arm CTs (CACT) with limited image quality (IQ) during transarterial chemoembolization (TACE). METHODS: From 1/2015-5/2021, 644 CACTs were performed in patients during TACE. Of these, 27 CACTs in 26 patients (18 m, 8f; 69.7 years ± 10.7 SD) of limited IQ were included. Post-processing of the original raw-data sets (CACTOrg) included application of a 3D-motion correction algorithm and bone segmentation (CACTMC_no_bone). Four radiologists (R1-4) compared the images by choosing their preferred dataset and recommending repeat acquisition in case of severe IQ-impairment. R1,2 performed additional grading of intrahepatic vessel visualization, presence/extent of movement artifacts, and overall IQ. RESULTS: R1,2 demonstrated excellent interobserver agreement for overall IQ (ICC 0.79,p < 0.01) and the five-point vessel visualization scale before and after post-processing of the datasets (ICC 0.78,p < 0.01). Post-processing caused significant improvement, with overall IQ improving from 2.63 (CACTOrg) to 1.39 (CACTMC_no_bone;p < 0.01) and a decrease in the mean distance of identifiable, subcapsular vessels to the liver capsule by 4 mm (p < 0.01). This proved especially true for datasets with low parenchymal and high hepatic artery contrast. A good interobserver agreement (ICC = 0.73) was recorded concerning the presence of motion artifacts, with significantly less discernible motion after post-processing (CACTOrg:1.31 ± 1.67, CACTMC_no_bone:1.00 ± 1.34, p < 0.01). Of the 27 datasets, ≥ 23 CACTMC_no_bone were preferred, with identical datasets chosen by the readers to show benefit from the algorithm. CONCLUSION: Application of a 3D-motion correction algorithm significantly improved IQ in diagnostically limited CACTs during TACE, with the potential to decrease repeat acquisitions.

New hybrid multiplanar cone beam computed tomography-laser-fluoroscopic-guided approach in cochlear implant surgery.

PURPOSE: Cochlea implant surgery with proper positioning of the cochlear electrode can be challenging. Intraoperative real-time hybrid laser-fluoroscopic-guided navigation based on a multiplanar cone beam computed tomography (CBCT) dataset opens up the opportunity to immediate radiological control of primary electrode misalignments and offering new insights into the cochlea electrode insertion routes and favorable cochlear implant-insertion angle. METHODS: In this retrospective study, 50 cases (29 males, 18 females) of conventional electrode implantation (without intraoperative image control; group A) and nine cases (7 males, 2 females) of CBCT-laser-fluoroscopic-guided surgery (group B) were included in the present study. CBCT-laser-guided surgery under real-time fluoroscopic control was conducted using an intraoperative C-arm CBCT. All patients received preoperative cross-sectional imaging (CT and MRI), in which cochlear malformation could be excluded. Postoperatively, we looked for electrode misplacements. RESULTS: In group A, electrode misalignment was detected postoperatively in 14 of 50 cases (28.0%). In group B, primary electrode misalignment was detected intraoperatively in two patients (22.2%). In both patients, the misalignments were corrected in the same session. The comparison of cochlear insertion angles showed significant differences. Group A: 47.5 ± 2.6° (actual conventional surgery) vs 17.6 ± 2.8° (theoretical CBCT-laser-fluoroscopic-guided surgery) P < 0.001. Group A vs group B: 47.5 ± 2.6° (actual conventional surgery; Group A) vs 17.9 ± 2.5° (actual CBCT-laser-fluoroscopic-guided surgery; Group B) P < 0.001. CONCLUSION: We consider that an intraoperative hybrid CBCT-laser-fluoroscopic-controlled approach in cochlear implant surgery using a C-arm CT can be beneficial, because electrode misalignments can be reduced and if it does occur, remedied in the same surgical session.

New ultra-fast algorithm for cochlear implant misalignment detection.

PURPOSE: Postoperative imaging following cochlear implant (CI) placement is currently the only means of diagnosing proper electrode position. Manual multiplanar reconstruction (MPR) analysis of CT and CBCT is time-consuming and requires extensive training. This study aims to evaluate the rate of CI misalignment and to determine the amount of time necessary to reach a diagnosis of correct versus incorrect CI placement for readers of different experience levels, using a novel algorithm for image analysis (ACIR) compared to MPR analysis. METHOD: The retrospective single centre study included 333 patients with cochlear implant surgery between May 2002 and May 2021. Postoperative CT and CBCT images were evaluated in three subgroups and the time to diagnosis was documented. Group 1: image evaluation using conventional MPR analysis; group 2: image evaluation by an experienced neuroradiologist via a novel ultra-fast algorithm; group 3: image evaluation by a young specialist via novel ultra-fast algorithm. T-test and Pearson's chi-squared test were used for inter-group comparisons. RESULTS: 333 patients (63.3 ± 15.9 years; 188 men) with 335 CIs were evaluated. The rate of CI misalignment diagnosed from 3D imaging was 14.3% (n = 48). MPR analysis required 255.7 ± 70.4 s per temporal bone, whereas Slicer plugin reduced analysis time to 83.3 ± 7.7 s (p < 0.001) for the experienced reader and 89.6 ± 8.7 s for the young specialist (p < 0.001). CONCLUSION: 3D postoperative imaging reveals high incidences of CI misalignment. Application of a novel ultra-fast algorithm significantly reduces the time for diagnosis compared to MPR analysis for readers of varying experience levels.

A Comparative Evaluation of Standard and Balloon-Assisted Coiling of Intracranial Aneurysms Based on Neurophysiological Monitoring.

BACKGROUND AND PURPOSE: Intracranial aneurysms are commonly treated with balloon-assisted endovascular coiling because the balloon allows for the control und modulation of wide-necked aneurysms and the coil basket. However, this approach might be associated with a higher complication rate. This retrospective study compared the multimodal results between balloon-assisted coiling of aneurysms (group 1) and coiling without balloon assistance (group 2). MATERIALS AND METHODS: We included 67 patients with unruptured intracranial aneurysms in this retrospective analysis; acutely ruptured aneurysms were excluded from the analysis. We divided these patients into two groups and evaluated them for symptomatic thromboembolic complications in the course of intracranial aneurysm treatment. All patients had an intrainterventional neurophysiological monitoring (IINM) and a pre- and postinterventional NIH Stoke Scale (NIHSS) survey and MR imaging. Multiple logistic regression was used to assess whether balloon-assisted coiling increased the rate of thromboembolic complications. Periprocedural aneurysm hemorrhage did not occur in any of the cases. RESULTS: We detected no statistically significant difference in rates of neurophysiological disturbances (19.5% (group 1) versus 34.6% (group 2); p = 0.249). There was no association with age, gender, or aneurysm location. The occurrence of new diffusion-weighted defects was not statistically significantly different (19.5% (group 1) versus 35.0% (group 2); p = 0.166). The difference in NIHSS before and after the intervention showed also no statistical significance in both groups (p = 0.426). CONCLUSION: The use of balloon-assisted coiling did not increase the rate of neurological disturbances during endovascular coiling. MR imaging and NIHSS survey also showed no increased risk of embolization from balloon-assisted aneurysm coiling. IINM is a central aspect of care during endovascular coiling as it can substantially decrease morbidity.

[Uncommon tumor-associated deep vein thrombosis]. / Eine nicht alltägliche tumorassoziierte Thrombose.

Here, we report on a patient with deep vein thrombosis of the right leg, in whom diagnostic work-up revealed a previously unknown chondrosarcoma of the tibia. Physical examination revealed a firm, nondisplaceable mass on the dorsal side of the right knee that appeared as a cystic formation on ultrasound. X­ray, computed tomography, and magnetic resonance imaging were consistent with chondrosarcoma, which had likely provoked the thrombosis by local compression or paraneoplastic mechanisms. After resection of the tumor, anticoagulation was continued. In a review of all findings, a final diagnosis of highly differentiated chondrosarcoma with thrombosis of the popliteal vein was made.

New classification of superior semicircular canal dehiscence in HRCT.

BACKGROUND AND PURPOSE: The complex anatomy of the temporal bone is difficult to understand and constitutes a challenge in the daily diagnostic routine even for experienced neuroradiologists. In the context of otoneurological (oVEMP) and preoperative diagnostics, the diagnosis of superior semicircular canal dehiscence (SSCD) is of great importance for Ear, Nose, and Throat (ENT) specialists. The gold standard for this diagnosis is a high-resolution CT (HRCT) of the temporal bone. In order to correctly diagnose SSCD, special oblique reconstructions are necessary in addition to standard (axial, coronal, sagittal) reconstructions. We evaluated the frequency of diagnosis and its location in HRCT in correlation with otoneurological examination. From this analysis, we present a new SSCD classification. This classification yields the potential of a differentiated analysis of the patient's clinical symptoms with correlation to the cross-sectional anatomy and may lead to a differentiated therapy approach. STUDY DESIGN AND SETTING: We evaluated 1370 temporal bone scans of patients with residual hearing and verified 343 superior semicircular canal dehiscence (SSCD). We conducted a subgroup analysis of these 343 HRCT scans displaying a SSCD and used them as a basis to create a classification. RESULTS: Three location types of SSCD were identified. These were anterior type 1, superior type 2 and posterior type 3. Type 2 were significantly more frequent in both sexes. SSCD at this location can be overlooked if diagnosis is performed only in the standard axial plane, since it can only be visualized by means of double oblique reconstruction. We present a standardized reconstruction algorithm. CONCLUSION: In total, three types of SSCD with differing incidences can be extrapolated from the locations. Superior type 2 is the most frequent one. Both sexes are affected with roughly equal incidence. The use of standardized double oblique reconstruction algorithm ensures that all three types are diagnosed in the HRCT.

The impact of the field of view (FOV) on image quality in MDCT angiography of the lower extremities.

OBJECTIVES: To evaluate the impact of the reconstructed field-of-view (FOV) on image quality in computed-tomography angiography (CTA) of the lower extremities. METHODS: A total of 100 CTA examinations of the lower extremities were acquired on a 2 × 192-slice multidetector CT (MDCT) scanner. Three different datasets were reconstructed covering both legs (standard FOV size) as well as each leg separately (reduced FOV size). The subjective image quality was evaluated for the different vessel segments (femoral, popliteal, crural, pedal) by three readers using a semi-quantitative Likert scale. Additionally, objective image quality was assessed using an automated image quality metric on a per-slice basis. RESULTS: The subjective assessment of the image quality showed an almost perfect interrater agreement. The image quality of the small FOV datasets was rated significantly higher as compared to the large datasets for all patients and vessel segments (p < 0.05) with a tendency towards a higher effect in smaller vessels. The difference of the mean scores between the group with the large FOV and small FOV was 0.68 for the femoral level, 0.83 for the popliteal level, 1.12 for the crural level, and 1.08 for the pedal level. The objective image quality metric also demonstrated a significant improvement of image quality in the small FOV datasets. CONCLUSIONS: Side-separated reconstruction of each leg in CTA of the lower extremities using a small reconstruction FOV significantly improves image quality as compared to a standard reconstruction with a large FOV covering both legs. KEY POINTS: • In CT angiography of the lower legs, the side-separated reconstruction of each leg using a small field-of-views improves image quality as compared to a standard reconstruction covering both legs. • The side-separated reconstruction can be readily implemented at every commercially available CT scanner. • There is no need for additional hardware or software and no additional burden to the patient.

First Experience in the Control of the Venous Side of the Brain AVM.

BACKGROUND AND PURPOSE: Brain arteriovenous malformations (AVM) are increasingly curable with endovascular embolization. This study examines the preliminary experience with a novel double-sided hybrid approach in the treatment of cerebral arteriovenous malformations (AVM) versus a purely single-sided intra-arterial approach. MATERIALS AND METHODS: The single-center study cohort included 18 patients with brain AVMs (Spetzler-Martin Grade 2 or 3) having stand-alone endovascular treatment with either the arterial-side-only pressure cooker technique (aPCT) (group 1; n = 9) or a double-sided hybrid intra-arterial and transvenous approach (HIPRENE) (group 2; n = 9). RESULTS: Patients belonging to group 2 had lower rates of intra-procedural hemorrhaging (66.7% vs. 33.3%, p = 0.169) and needed fewer treatment sessions to achieve nidus occlusion (1.7 vs. 1.2, p = 0.136). The HIPRENE treatment regime led to higher nidus occlusion rates after the initial treatment compared to aPCT (77.7% vs. 44.4%, p = 0.167). Group 2 patients had a lower rate of neuromonitoring events (22.2% vs. 44.4%, p = 0.310) and fewer accounts of blood flow obstruction in post-operative MRIs (33.3% vs. 55.6%, p = 0.319). CONCLUSION: A double-sided hybrid intra-arterial and transvenous approach might have benefits for curative endovascular brain AVM treatment in patients with Spetzler-Martin Grade 2 or 3. In our small study cohort, the HIPRENE treatment regime had higher nidus occlusion rates after the first treatment, which reduces the number of treatment sessions and lowers intra- and post-operative complication rates. Further randomized controlled studies are awaited to corroborate our preliminary outcomes.

Determination of Cochlear Duct Length With 3D Versus Two-dimensional Methods: A Retrospective Clinical Study of Imaging by Computed Tomography and Cone Beam Computed Tomography.

BACKGROUND: The aim of this study was to compare three different methods for measurement of cochlear duct length (CDL) in the clinical setting for two different imaging modalities, namely computed tomography (CT) and cone-beam computed tomography (CBCT). PATIENTS AND METHODS: One hundred temporal bone data sets (CT: n=50; CBCT: n=50) of non-malformed cochleae were retrospectively analyzed using three different CDL estimation techniques: 3D curved multiplanar reconstruction (cMPR), 2D cMPR and the A-value formula. RESULTS: The data sets belonged to 60 patients (34 males, 26 females; mean age=50.28±18.58 years). For both imaging modalities, application of the 3D cMPR estimation technique led to significantly greater mean CDL values than the two-dimensional methods (p<0.0083). The CDL measurements viewed in CT imaging software were significantly shorter than the corresponding CBCT measurements (p<0.05). Using a linear mixed model, differences in CDL by sex (p=0.796), age (p=0.377) and side of ear (p=0.690) were not significant. CONCLUSION: The 3D cMPR technique was found to provide the most accurate in vivo CDL measurement in non-malformed cochlea in both CT and CBCT imaging compared to 2D methods. The study results also suggest that the higher spatial resolution in CBCT imaging results in more precise CDL determination than in CT.

[Treatment strategies for tumor-related pathological fractures of the extremities]. / Versorgungsstrategien bei tumorbedingten pathologischen Frakturen der Extremitäten.

Pathological fractures of the extremities frequently lead to uncertainty with respect to the treatment strategy and timing. The origin of metastases is typically breast, bronchial, renal and prostate cancer and myelomas. Primary bone tumors play a subordinate role. The majority affect the femur, humerus and occasionally the tibia. Surgery is typically the first line treatment as healing under conservative treatment is unlikely. The most important goal is to relieve pain and the preservation or restoration of function. For correct assessment of indications, analysis of the fracture pattern and oncological aspects including dignity, entity, prognosis, metastatic status and the general condition of the patient need to be taken into consideration. Based on all these aspects the surgical approach can be chosen. Treatment options range from osteosynthetic stabilization and augmentation osteosynthesis up to endoprosthesis replacement. The treatment is carried out in an interdisciplinary procedure as additional measures need to be addressed in addition to the surgical treatment.

High resolution flat-panel CT arthrography vs. MR arthrography of artificially created osteochondral defects in ex vivo upper ankle joints.

PURPOSE: High resolution flat-panel computed tomography arthrography (FPCT-A) and magnetic resonance arthrography (MR-A) are well suited to evaluate osteochondral lesions. The current study compares the performance of FPCT-A versus MR-A in an experimental setting. METHODS: Fourteen cadaveric ankles were prepared with artificial osteochondral defects of various sizes in four separate talar locations. After intra-articular contrast injection, FPCT-A and 3-T MR-A were acquired. Each defect was then filled with synthetic pallets. The resulting cast was used as reference. Two independent radiologists measured the dimensions of all defects with FPCT-A and MR-A. Intra-class correlation coefficients (ICC) were calculated. Data were compared using t-tests and Bland-Altman plots. RESULTS: The correlation for FPCT-A and cast was higher compared to MR-A and cast (ICC 0.876 vs. 0.799 for surface [length x width]; ICC 0.887 vs. 0.866 for depth, p<0.001). Mean differences between FPCT-A and cast measurements were -1.1 mm for length (p<0.001), -0.7 mm for width (p<0.001) and -0.4 mm for depth (p = 0.023). By MR-A, there were no significant differences for length and width compared to cast (p>0.05). Depth measurements were significantly smaller by MR-A (mean difference -1.1 mm, p<0.001). There was no bias between the different modalities. CONCLUSIONS: Ex vivo FPCT-A and MR-A both deliver high diagnostic accuracy for the evaluation of osteochondral defects. FPCT-A was slightly more accurate than MR-A, which was most significant when measuring lesion depth.

[Radiological aspects in the diagnostics of pathological fractures]. / Radiologische Aspekte in der Diagnostik von pathologischen Frakturen.

Radiological diagnostics play a key role in the identification and assessment of pathological fractures. Conventional projection radiography is still the mainstay of imaging investigations. With knowledge of the patient history, the morphology and location of a fracture as well as concomitant findings, such as osteolysis or periosteal reactions can add valuable information on the origin of the fracture. Magnetic resonance imaging (MRI) is the imaging modality of choice for the local diagnostic work-up as it provides insights into the medullary cavity and visualizes potential extraosseous tumor tissue in the fracture zone. Computed tomography (CT) imaging provides valuable information on the morphological features of fractures and is useful for the planning of the surgical approach. Furthermore, it is the modality of choice for whole-body staging. In most cases of pathological fractures without a history of malignancy, a biopsy and histological work-up is recommended.

CT based PSI blocks for osteotomies around the knee provide accurate results when intraoperative imaging is used.

PURPOSE: Correction osteotomies around the knee are common methods for the treatment of varus or valgus malalignment of the lower extremity. In recent years, patient specific instrumentation (PSI) guides were introduced in order to enhance the accuracy of these procedures. The purpose of this study was to determine the accuracy of CT based PSI guides for correction osteotomies around the knee of low volume osteotomy surgeons and to evaluate if CT based PSI blocks deliver a high degree of accuracy without using intraoperative fluoroscopy. METHODS: Two study arms with CT based PSI cutting blocks for osteotomies around the knee were conducted. Part one: A retrospective analysis of 19 osteotomies was made in order to evaluate the accuracy in the hands of a low volume surgeon on long-leg radiographs. Part two: A cadaveric study with 8 knees was performed for the purpose of analyzing the accuracy without using intraoperative fluoroscopy on pre- and postoperative CT scans. Hip-Knee-Ankle angle (HKA), lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) were analyzed. The mean absolute delta (∂) between the planned and postoperative parameters were calculated. The accuracy of both study arms were compared. RESULTS: Part one: The mean MPTA ∂, LDFA ∂ and HKA ∂ was 0.9°, 1.9° and 1.5°, respectively. Part two: The mean MPTA ∂ and LDFA ∂ was 3.5° and 2.2°, respectively. The mean ∂ of MPTA is significantly different between clinical patients with fluoroscopic control and cadaveric specimens without fluoroscopic control (P < 0.001). All surgeries were performed without complications such as a hinge fracture. CONCLUSION: The clinical use of PSI guides for osteotomies around the knee in the hands of low volume surgeons is a safe procedure. The PSI guides deliver a reliable accuracy under fluoroscopic control whereas their non-use of intraoperative fluoroscopy leads to a lack of accuracy. The use of fluoroscopic control during PSI guided correction osteotomies is highly recommended. LEVEL OF EVIDENCE: IV - Retrospective and experimental Study.

The novel arthroscopic subscapular quadriceps tendon-bone sling procedure provides increased stability in shoulder cadavers with severe glenoid bone loss.

PURPOSE: Treatment of anterior glenoid bone loss in patients with recurrent anterior shoulder instability is a challenge. The subscapular sling method with quadriceps tendon bone (QTB) graft is a modification of the subscapular sling with a semitendinosus (ST) graft. The aim of the study was to test the biomechanical stability of the QTB sling procedure in human shoulder cadavers with severe anterior glenoid bone loss. METHODS: Fourteen cadaveric shoulders were tested with a force-moment-guided robot in three conditions: physiologically intact, anterior glenoid bone resection, and the subscapular sling procedure with a QTB graft. Joint stability was measured in anterior, anterior inferior and inferior directions in four glenohumeral joint positions: 0° and 60° of glenohumeral abduction, with each at 0° and 60° of external rotation. Maximum external rotation was measured at 0° and 60° glenohumeral abduction. Computer tomography scans were obtained preoperatively to plan the glenoid bone resection, as well as postoperatively to calculate the proportion of the glenoid bone actually resected. RESULTS: Significantly decreased translations were observed in the shoulders with the QTB sling compared to the intact joint and the glenoid bone loss model. No significant differences in maximum external rotation were observed between the three different conditions. CONCLUSION: This biomechanical study revealed a significant stabilizing effect of the arthroscopic subscapular QTB graft sling procedure in human shoulder cadavers without compromising external rotation. Clinical trials may reveal the usefulness of this experimental method.

Evaluation of a Motion Correction Algorithm for C-Arm Computed Tomography Acquired During Transarterial Chemoembolization.

PURPOSE: The aim of this retrospective study was to evaluate the feasibility of a motion correction 3D reconstruction prototype technique for C-arm computed tomography (CACT). MATERIAL AND METHODS: We included 65 consecutive CACTs acquired during transarterial chemoembolization of 54 patients (47 m,7f; 67 ± 11.3 years). All original raw datasets (CACTOrg) underwent reconstruction with and without volume punching of high-contrast objects using a 3D image reconstruction software to compensate for motion (CACTMC_bone;CACTMC_no bone). Subsequently, the effect on image quality (IQ) was evaluated using objective (image sharpness metric) and subjective criteria. Subjective criteria were defined by vessel geometry, overall IQ, delineation of tumor feeders, the presence of foreign material-induced artifacts and need for additional imaging, assessed by two independent readers on a 3-(vessel geometry and overall IQ) or 2-point scale, respectively. Friedman rank-sum test and post hoc analysis in form of pairwise Wilcoxon signed-rank test were computed and inter-observer agreement analyzed using kappa test. RESULTS: Objective IQ as defined by an image sharpness metric, increased from 273.5 ± 28 (CACTOrg) to 328.5 ± 55.1 (CACTMC_bone) and 331 ± 57.8 (CACTMC_no bone; all p < 0.0001). These results could largely be confirmed by the subjective analysis, which demonstrated predominantly good and moderate inter-observer agreement, with best agreement for CACTMC_no bone in all categories (e.g., vessel geometry: CACTOrg: κ = 0.51, CACTMC_bone: κ = 0.42, CACTMC_no bone: κ = 0.69). CONCLUSION: The application of a motion correction algorithm was feasible for all data sets and led to an increase in both objective and subjective IQ parameters. LEVEL OF EVIDENCE: 3.

[Fracture diagnosis: upper extremities : Shoulder and shoulder girdle]. / Frakturdiagnostik: obere Extremität : Schulter und Schultergürtel.

BACKGROUND: The shoulder girdle is a chain of bones and joints which connect the upper extremity to the axial skeleton. The shoulder as a biomechanical unit has a remarkable range of motion and is therefore frequently prone to injuries of the three major joints (sternoclavicular joint, acromioclavicular joint, glenohumeral joint) and the bony elements (clavicle, scapula, humerus). Projection radiography is still the first imaging modality for injuries of the shoulder and usually sufficient for initial diagnosis and injury classification. Computed tomography (including 3D reconstructions) and magnetic resonance imaging provide additional useful information for the detection of accompanying soft-tissue injury, for surgical planning and in cases of complex anatomy (e.g., scapular fractures). PURPOSE: We aim to describe the fundamentals of injuries of the shoulder girdle and the proximal humerus with special emphasis on radiological diagnostics. MATERIALS AND METHODS: A selective PubMed literature search was performed using the following terms: "sternoclavicular joint dislocation", "clavicle fracture", "acromioclavicular joint injury", "scapular fracture", "shoulder dislocation", "proximal humerus fracture", and "shoulder girdle injuries". RESULTS: The article describes the basics of the anatomy, the trauma mechanism and the epidemiology of the most common injuries of the shoulder girdle and the proximal humerus. Special emphasis is given to radiological diagnostics, including basic projection radiography and advanced cross-sectional imaging.

Non-occlusive mesenteric ischemia (NOMI): evaluation of 2D-perfusion angiography (2D-PA) for early treatment response assessment.

PURPOSE: To evaluate the feasibility of 2D-perfusion angiography (2D-PA) for the analysis of intra-procedural treatment response after intra-arterial prostaglandin E1 therapy in patients with non-occlusive mesenteric ischemia (NOMI). METHODS: Overall, 20 procedures in 18 NOMI patients were included in this retrospective case-control study. To evaluate intra-procedural splanchnic circulation changes, post-processing of digital subtraction angiography (DSA) series was performed. Regions of interest (ROIs) were placed in the superior mesenteric artery (SMA; reference), the portal vein (PV; ROIPV), as well as the aorta next to the origin of the SMA (ROIAorta). Peak density (PD), time to peak (TTP), and area under the curve (AUC) were assessed, and parametric ratios 'target ROIPD, TTP, AUC/reference ROI' were computed and compared within treatment and control group. Additionally, a NOMI score was assessed pre- and post-treatment compared to 2D-PA. RESULTS: Vasodilator therapy leads to a significant decrease of the 2D-PA-derived values PDAorta (p = 0.04) and AUCAorta (p = 0.03). These findings correlated with changes of the simplified NOMI score, both for overall (4 to 1, p < 0.0001) and for each category. Prostaglandin application caused a significant increase of the AUCPV (p = 0.04) and TTPPV was accelerated without reaching statistical significance (p = 0.13). When compared to a control group, all 2D-PA values in the NOMI group (pre- and post-intervention) differed significantly (p < 0.05) with longer TTPAorta/PV and lower AUCAorta/PV and PD Aorta/PV. CONCLUSION: 2D-PA offers an objective approach to analyze immediate flow and perfusion changes following vasodilatory therapies of NOMI patients and may be a valuable tool for assessing treatment response.

Comparison of SCAphoid fracture osteosynthesis by MAGnesium-based headless Herbert screws with titanium Herbert screws: protocol for the randomized controlled SCAMAG clinical trial.

BACKGROUND: Scaphoid fractures are the most common carpal fractures. They often need to be treated by surgery, where the use of a compression screw is the globally accepted gold standard. Surgeons may choose between different implant materials including titanium alloys, which remain in the body or are removed after healing. An alternative are biodegradable magnesium-based implants. Properties of magnesium alloys include high stability, osteoconductivity, potential reduction of infections and few artifacts in magnetic resonance imaging (MRI). The aim of this trial is to demonstrate non-inferiority of magnesium-based compression screws compared with titanium Herbert screws for scaphoid fractures. METHODS: The trial is designed as a multicenter, blinded observer, randomized controlled parallel two-group post market trial. Approximately 190 patients will be randomized (1:1) with stratification by center either to titanium or magnesium-based compression screws. Follow-up is 1 year per patient. Surgical procedures and aftercare will be performed according to the German treatment guideline for scaphoid fractures. The first primary endpoint is the patient-rated wrist evaluation (PRWE) score after 6 months. The second primary endpoint is a composite safety endpoint including bone union until 6 months, no adverse device effect (ADE) during surgery or wound healing and no serious ADE or reoperation within 1 year. The third primary endpoint is the difference in change MRI artifacts over time. Non-inferiority will be investigated for primary endpoints 1 (t-test confidence interval) and 2 (Wilson's score interval) using both the full analysis set (FAS) and the per protocol population at the one-sided 2.5% test-level. Superiority of magnesium over titanium screws will be established using the FAS at the two-sided 5% test-level (Welch test) only if non-inferiority has been established for both primary endpoints. Secondary endpoints include quality of life. DISCUSSION: This study will inform care providers whether biodegradable magnesium-based implants are non-inferior to standard titanium Herbert screws for the treatment of scaphoid fractures in terms of wrist function and safety. Furthermore, superiority of magnesium-based implants may be demonstrated using MRI, which is used as surrogate endpoint for screw degradation. TRIAL REGISTRATION: DRKS, DRKS00013368 . Registered Dec 04, 2017.