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Conventional radiography is the first modality to investigate the radio-ulno-carpal joint in the event of trauma or instability. This study sought to determine the reliability of cone beam computer tomography (CBCT) and scout of view in evaluating carpal alignment compared with conventional radiographs in order to assess the influence of wrist kinematics on usual measurements.We prospectively recruited 305 patients who successively underwent plain radiography and CBCT. 51 patients with prior acute unilateral wrist trauma were eligible for entry into the study (mean age of 39 years). Three blinded readers performed the measurements separately. The axial method and bony axial lines defined previously in the literature were applied, with three categories of measurements performed, consisting of distal radio-ulnar, radiocarpal, and radio/carpometacarpal measurements. Intraclass correlation coefficients (ICCs) for paired t-test were calculated to assess inter- and intra-observer agreements.Inter-observer agreement was very high (0.94) for all modalities. Intra-observer reliability between scout view and CBCT was almost perfect for all measurements. Intra-observer reliability between radiograph and scout view/CBCT was perfect for distal radio-ulnar measurements, substantial for radio-carpal, and moderate for radio/carpometacarpal measurements.In the absence of a strict position control between two imaging acquisitions, only distal radio-ulnar measurements were shown perfectly reliable when using these two imaging methods, which is suggestive of a minor relevance of ulnar/radial deviation. Excepting for some angles, the radio-carpal and radio-carpometacarpal measurements were shown to differ according to wrist position, being thus more sensitive to flexion/extension of the wrist.

Objective: To assess the diagnostic performance of morphological MRI features separately and in combination for distinguishing low- from high-grade soft tissue sarcoma (STS). Methods and materials: We retrospectively analysed pre-treatment MRI examinations with T1, T2 with and without fat suppression (FS) and contrast-enhanced T1 obtained in 64 patients with STS categorized histologically as low (n = 21) versus high grade (n = 43). Two musculoskeletal radiologists blinded to histology evaluated MRI features. Diagnostic performance was calculated for each reader and for MRI features showing significant association with histology (p < 0.05). Logistic regression analysis was performed to develop a diagnostic model to identify high-grade STS. Results: Among all evaluated MRI features, only six features had adequate interobserver reproducibility (kappa>0.5). Multivariate logistic regression analysis revealed a significant association with tumour grade for lesion heterogeneity on FS images, intratumoural enhancement≥51% of tumour volume and peritumoural enhancement for both readers (p < 0.05). For both readers, the presence of each of the three features yielded odds ratios for high grade versus low grade from 4.4 to 9.1 (p < 0.05). The sum of the positive features for each reader independent of reader expertise yielded areas under the curve (AUCs) > 0.8. The presence of ≥2 positive features indicated a high risk for high-grade sarcoma, whereas ≤1 positive feature indicated a low-to-moderate risk Conclusion: A diagnostic MRI score based on tumour heterogeneity, intratumoural and peritumoural enhancement enables identification of lesions that are likely to be high-grade as opposed to low-grade STS. Advances in knowledge: Tumour heterogeneity in Fat Suppression sequence, intratumoural and peritumoural enhancement is identified as signs of high-grade sarcoma.

Distinguishing lipoma from liposarcoma is challenging on conventional MRI examination. In case of uncertain diagnosis following MRI, further invasive procedure (percutaneous biopsy or surgery) is often required to allow for diagnosis based on histopathological examination. Radiomics and machine learning allow for several types of pathologies encountered on radiological images to be automatically and reliably distinguished. The aim of the study was to assess the contribution of radiomics and machine learning in the differentiation between soft-tissue lipoma and liposarcoma on preoperative MRI and to assess the diagnostic accuracy of a machine-learning model compared to musculoskeletal radiologists. 86 radiomics features were retrospectively extracted from volume-of-interest on T1-weighted spin-echo 1.5 and 3.0 Tesla MRI of 38 soft-tissue tumors (24 lipomas and 14 liposarcomas, based on histopathological diagnosis). These radiomics features were then used to train a machine-learning classifier to distinguish lipoma and liposarcoma. The generalization performance of the machine-learning model was assessed using Monte-Carlo cross-validation and receiver operating characteristic curve analysis (ROC-AUC). Finally, the performance of the machine-learning model was compared to the accuracy of three specialized musculoskeletal radiologists using the McNemar test. Machine-learning classifier accurately distinguished lipoma and liposarcoma, with a ROC-AUC of 0.926. Notably, it performed better than the three specialized musculoskeletal radiologists reviewing the same patients, who achieved ROC-AUC of 0.685, 0.805, and 0.785. Despite being developed on few cases, the trained machine-learning classifier accurately distinguishes lipoma and liposarcoma on preoperative MRI, with better performance than specialized musculoskeletal radiologists.

Spinal infections are very commonly encountered by radiologists in their routine clinical practice. In case of typical MRI features, the diagnosis is relatively easy to interpret, all the more so if the clinical and laboratory findings are in agreement with the radiological findings. In many cases, the radiologist is able to make the right diagnosis, thereby avoiding a disco-vertebral biopsy, which is technically challenging and associated with a risk of negative results. However, several diseases mimic similar patterns, such as degenerative changes (Modic) and crystal-induced discopathy. Differentiation between these diagnoses relies on imaging changes in endplate contours as well as in disc signal. This review sought to illustrate the imaging pattern of spinal diseases mimicking an infection and to define characteristic MRI and CT patterns allowing to distinguish between these different disco-vertebral disorders. The contribution of advanced techniques, such as DWI and dual-energy CT (DECT) is also discussed.

Highlights • Scaphoid union is controversial regarding diagnosis of healing. • XR is the most used modality with poor reliability and reproducibility. • CBCT allows with higher confidence diagnosis of consolidation avoiding longer immobilisation. • Evaluation for translation is better with CBCT than XR at un early follow up. • Six weeks is a reasonable delay to perform the first imaging follows up in waist scaphoid fracture., Purpose To assess the accuracy and reliability of using cone beam computed tomography (CBCT) compared to X-ray six weeks after injury for predicting scaphoid union. Materials and methods Overall; 52 patients with scaphoid fractures between April 2018 and March 2019 were prospectively included in this study. The mean age was 34.52 (13–88) years, and the gender ratio male/female 43/9. Of the fractures, 26 had occurred on the right side, and 26 on the left side. In total, 28 % of patients were manual workers. All patients underwent X-ray and CBCT six weeks after injury. Four readers, two radiologists, and two hand surgeons analyzed the findings using double-blinded X-ray and CBCT and categorized fractures as consolidated based on a 50 % visibility threshold concerning trabecular bridges. Proximal pole sclerosis, communition, cyst formation, and humpback deformity were similarly analyzed for all cases. Agreement between readers was calculated using Kappa, and sensitivity, specificity, and accuracy using RStudio software. The gold standard was the radiologic and clinical follow-up for all patients at two months. Results Inter-reader agreement between the four readers was moderate concerning X-ray (0.543) but substantial concerning CBCT (0.641). It was almost perfect between seniors regarding CBCT (Kappa = 0.862). Sensitivity, specificity, and accuracy were 0.75–0.78, 0.4, and 0.61–0.64, respectively, for two readers regarding CBCT. The X-ray values were 0.65–0.71, 0.35–0.4, and 0.53–0.59, respectively. Conclusion CBCT proves more accurate and reliable than X-ray for diagnosing scaphoid union at an early follow-up and prevents longer immobilization and interruption of activity or work.

Syndesmosis injury can lead to ankle mortise instability and early osteoarthritis. Several multiple detector computed tomography (MDCT) methods for measurement have been developed. Weight-bearing cone beam CT (WB CBCT) is an emerging technique that offers the possibility of upright-position scanning and lower doses. This study sought to assess the diagnostic accuracy of WB CBCT in syndesmose injury compared to MDCT, with instability confirmed via manual testing upon arthroscopic examination.Three musculoskeletal radiologists with different levels of expertise prospectively analyzed 11 MDCT and eight WB CBCT scans of the same trauma-afflicted ankles with clinical suspicion of syndesmosis lesion over a period of 5 months. They evaluated 10 methods of measurement in both sides. Syndesmosis was considered pathological on arthroscopic examination in four patients. Correlation between readers was evaluated with intra-class correlation testing (p 0.05 was considered significant). Capacity of discrimination was assessed by area under the curve (AUC) for all methods.Inter-observer agreement was near excellent for both WB CBCT and MDCT for the anterior tibio-fibular (TF) distance (ICC = 0.781 and 0.831, respectively), posterior TF distance (ICC = 0.841 and 0.826), minimal TF distance (ICC = 0.899 and 0.875), and TF surface (ICC = 0.93 and 0.84). AUC were better for MDCT than WB CBCT in assessing syndesmosis instability for: anterior TF distance (ROC = 0.869 vs. 0.555, p = 0.01), minimal TF distance (ROC = 0.883 vs. 0.608, p = 0.02) and antero-posterior fibular translation (ROC = 0.894 vs. 0.467, p = 0.006).MDCT demonstrated better ability to distinguish pathological syndesmosis than WB CBCT, with the antero-posterior fibular translation the best discriminating measurement. The physiological widening of the contralateral syndesmosis occurring with the WB CBCT upright position may explain these results.

Syndrome of the trephined (ST) is a post-craniectomy complication. It is characterized by the appearance of new neurological symptoms following the craniectomy, which are relieved after cranioplasty. The purpose of our work was to identify radiological signs and imaging biomarkers of the ST.CT images of 32 patients were retrospectively analyzed (ST = 13, controls = 19). While the shapes of craniectomy flap were qualitatively assessed, deviation of the midline structures, relative intracranial cerebrospinal fluid (CSF) volume, and the 3rd ventricle's volume were quantitatively measured.We did not find between-group differences in the mean age or number of post-craniectomy days. ST was diagnosed during the second post-craniectomy month. The occurrence of a sunken skin flap sign was similar in both groups (69.23 % in ST group, 57.89 % in control group). Occurrence of paradoxical herniation and deviation of the midline structures were not significantly different between groups. Mean relative intracranial CSF volume was significantly smaller in ST patients (ST = 5.59 %, controls = 8.12 %, p = 0.01). ST patients, compared to controls, had also significantly smaller mean 3rd ventricle volumes (ST = 1748 mm(3), controls = 2772.97 mm(3), p = 0.03).ST is an infrequent and delayed post-craniectomy complication. The most common radiological findings (paradoxical herniation, deviation of the midline structures, and sunken skin flap sign) might not be specific for ST. Significantly lower 3rd ventricle, and relative intracranial CSF volumes, suggest that altered biophysical CSF properties underlie ST pathophysiology. Therefore, volume measurements of 3rd ventricle could be useful for identification of patients who have higher probability of developing the ST.

Retroodontoid pseudotumor (ROP) is a nonneoplasic lesion of unknown etiology, commonly associated with inflammatory conditions, and the term of pannus is usually used. Less frequently, ROP formation can develop with other noninflammatory entities, with atlantoaxial instability as most accepted pathophysiological mechanism for posttraumatic or degenerative ROP. As it can clinically and radiologically mimic a malignant tumor, it is paramount for the radiologist to know this entity. Magnetic resonance imaging is the modality of choice to reveal the possible severe complication of ROP in the form of a compressive myelopathy of the upper cervical cord. The purpose of the surgical treatment is the regression or complete disappearance of ROP, with posterior decompression by laminectomy and posterior C1-C2 or occipitocervical fixation. We present the case of an elderly patient with retroodontoid soft tissue mass secondary to a chronic atlantoaxial instability on os odontoideum, an extremely rare cause of ROP. The patient developed a posttraumatic cervical myelopathy related to the decompensation of this C1-C2 instability responsible for the formation of a compressive ROP. We will overview the retroodontoid pseudotumor and its differential diagnosis.

Background Synthetic magnetic resonance (MR) is a method allowing reduction of examination time and access to quantitative imaging. Purpose This study sought to assess the image quality and diagnostic accuracy of synthetic magnetic resonance imaging (MRI) compared to standard MRI in patients with knee pain. Material and Methods In total, 22 patients underwent standard 1.5 knee MRI with an added synthetic sequence. Quantitative T1, T2, and proton density (PD) images were generated synthetically; T1, PD, and short tau inversion recovery (STIR) weighted images were created with chosen echo time (TE), repetition time (TR), and inversion time (TI). Two blinded musculoskeletal radiologists evaluated the overall sequence quality, visualization of anatomic structures, and presence of artifacts using a 3-point score. Results The synthetic sequence was acquired in 39% less time than the conventional MRI. Synthetic PD, T1, and STIR images were rated fair (2%, 5%, and 2%, respectively) or good quality (98%, 95%, and 98%, respectively), despite the presence of popliteal artery artifacts. Cartilage and meniscus were well visualized in all cases. Anterior cruciate ligament visualization was rated poor in 7%, 14%, and 30% of PD, STIR, and T1 images, respectively. Conclusion Our pilot study confirmed the feasibility of synthetic MRI in knee examinations, proving faster and achieving appropriate quality and good diagnostic confidence.

Asymptomatic spontaneous nephrocutaneous fistula is a rare and severe complication of chronic urolithiasis. We report a case of 56-year-old woman with a nephrocutaneous fistula (NFC) which developed from a superinfected urinoma following calyceal rupture due to an obstructing calculus in the left ureter. The patient was clinically asymptomatic and came to the emergency department for a painless left flank fluctuating mass. This urinoma was superinfected, with a delayed development of renal abscesses and perirenal phlegmon found on contrast-enhanced uro-computed tomography (CT), responsible for left renal vein thrombophlebitis and left psoas abscess. Thereafter, a 99 mTc dimercaptosuccinic acid (DMSA) scintigraphy revealed a nonfunctional left kidney, leading to the decision of left nephrectomy. Chronic urolithiasis complications are rare and only few cases are reported in medical literature. A systematic medical approach helped selecting the best imaging modality to help diagnosis and treatment. Indeed, uro-CT scan and renal scintigraphy with 99 mTc-DMSA are the most sensitive imaging modalities to investigate morphological and functional urinary tract consequences of NFC, secondary to chronic urolithiasis.

To evaluate iterative metal artifact reduction (iMAR) technique in images data of hip prosthesis on computed tomography (CT) and the added value of advanced modeled iterative reconstruction (ADMIRE) compared with standard filtered back projection (FBP). Twenty-eight patients addressed to CT examinations for hip prosthesis were included prospectively. Images were reconstructed with iMAR algorithm in addition to FBP and ADMIRE techniques. Measuring image noise assessed objective image quality and attenuation values with standardized region of interest (ROI) in 4 predefined anatomical structures (gluteus medius and rectus femoris muscles, inferior and anterior abdominal fat, and femoral vessels when contrast media was present). Subjective image quality was graded on a 5-point Likert scale, taking into account the size of artifacts, the metal–bone interface and the conspicuity of pelvic organs, and the diagnostic confidence. Improvement in overall image quality was statistically significant using iMAR (P