Commercially-available AI algorithm improves radiologists' sensitivity for wrist and hand fracture detection on X-ray, compared to a CT-based ground truth.

OBJECTIVES: Algorithms for fracture detection are spreading in clinical practice, but the use of X-ray-only ground truth can induce bias in their evaluation. This study assessed radiologists' performances to detect wrist and hand fractures on radiographs, using a commercially-available algorithm, compared to a computerized tomography (CT) ground truth. METHODS: Post-traumatic hand and wrist CT and concomitant X-ray examinations were retrospectively gathered. Radiographs were labeled based on CT findings. The dataset was composed of 296 consecutive cases: 118 normal (39.9%), 178 pathological (60.1%) with a total of 267 fractures visible in CT. Twenty-three radiologists with various levels of experience reviewed all radiographs without AI, then using it, blinded towards CT results. RESULTS: Using AI improved radiologists' sensitivity (Se, 0.658 to 0.703, p < 0.0001) and negative predictive value (NPV, 0.585 to 0.618, p < 0.0001), without affecting their specificity (Sp, 0.885 vs 0.891, p = 0.91) or positive predictive value (PPV, 0.887 vs 0.899, p = 0.08). On the radiographic dataset, based on the CT ground truth, stand-alone AI performances were 0.771 (Se), 0.898 (Sp), 0.684 (NPV), 0.915 (PPV), and 0.764 (AUROC) which were lower than previously reported, suggesting a potential underestimation of the number of missed fractures in the AI literature. CONCLUSIONS: AI enabled radiologists to improve their sensitivity and negative predictive value for wrist and hand fracture detection on radiographs, without affecting their specificity or positive predictive value, compared to a CT-based ground truth. Using CT as gold standard for X-ray labels is innovative, leading to algorithm performance poorer than reported elsewhere, but probably closer to clinical reality. CLINICAL RELEVANCE STATEMENT: Using an AI algorithm significantly improved radiologists' sensitivity and negative predictive value in detecting wrist and hand fractures on radiographs, with ground truth labels based on CT findings. KEY POINTS: • Using CT as a ground truth for labeling X-rays is new in AI literature, and led to algorithm performance significantly poorer than reported elsewhere (AUROC: 0.764), but probably closer to clinical reality. • AI enabled radiologists to significantly improve their sensitivity (+ 4.5%) and negative predictive value (+ 3.3%) for the detection of wrist and hand fractures on X-rays. • There was no significant change in terms of specificity or positive predictive value.

Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance is effective, quick, and safe.

OBJECTIVES: The aim of this study was to assess the feasibility, performance, and complications of a non-surgical, minimally-invasive procedure of deep contraceptive implant removal under continuous ultrasound guidance. METHODS: The ultrasound-guided procedure consisted of local anesthesia using lidocaine chlorhydrate 1% (10 mg/mL) with a 21-G needle, followed by hydrodissection using NaCl 0.9% (9 mg/mL) and implant extraction using a Hartmann grasping microforceps. The parameters studied were the implant localization, success and complication rates, pain throughout the intervention, volumes of lidocaïne and NaCl used, duration of the procedure, and size of the incision. Between November 2019 and January 2021, 45 patients were referred to the musculoskeletal radiology department for ultrasound-guided removal of a deep contraceptive implant and were all retrospectively included. RESULTS: All implants were successfully removed en bloc (100%). The mean incision size was 2.7 ± 0.5 mm. The mean duration of the extraction procedure was 7.7 ± 6.3 min. There were no major complications (infection, nerve, or vessel damage). As a minor complication, 21 patients (46.7%) reported a benign superficial skin ecchymosis at the puncture site, spontaneously regressing in less than 1 week. The procedure was very well-tolerated, with low pain rating throughout (1.0 ± 1.5/10 during implant extraction). CONCLUSIONS: Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance alone is feasible, effective, and safe. In the present cohort, all implants were successfully removed, whatever the location, with short procedural time, small incision size, low pain levels, and no significant complications. This procedure could become a gold standard in this indication. KEY POINTS: • Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance alone is feasible, which led to a success rate of 100% whatever the location (even close to neurovascular structures), with only a small skin incision (2.7 ± 0.5 mm). • The procedure was safe, quick, without any major complications, and very well tolerated in terms of pain. • This minimally invasive ultrasound-guided procedure could become the future gold standard for the removal of deep contraceptive implants, as an alternative to surgical extraction, even for implants in difficult locations such as subfascial ones or those close to neurovascular structures.

Carpal tunnel ultrasound: is the "safe zone" on the ulnar side of the median nerve really avascular?

INTRODUCTION: Numerous publications have studied the regional anatomy of the carpal tunnel to define a "safe zone" to reduce the risk of perioperative neurovascular complications. This zone, located between the ulnar neurovascular bundle and the median nerve, is considered to be safe mainly because of the absence of vascular structures. This study aims to assess the presence of arterioles within this area using superb microvascular imaging (SMI). MATERIALS AND METHODS: The images from patients who underwent a bilateral routine wrist ultrasound with SMI, between January 28 and February 28, 2019, were retrospectively reviewed by two radiologists to evaluate the presence and location of arterioles in the safe zone. In addition, cadaveric wrists injected with intra-arterial red latex underwent dissection of the carpal tunnel. RESULTS: The images from 27 patients (54 wrists) were reviewed. In the safe zone, arterioles were seen superficial to the retinaculum in 36 wrists (36/54; 66.7%) and deep to the retinaculum in 21 wrists (21/54; 38.9%). The arterioles located deep to the retinaculum were more frequently found close to the median nerve (21/54; 38.9%) than to the ulnar artery (9/54; 16.7%). In five cadaveric wrists, arterioles were detected superficial to the retinaculum in 3 wrists (3/5; 60%) and deep to the retinaculum in 2 wrists (2/5; 40%). CONCLUSION: Arterioles can be seen in the safe zone both superficial and deep to the flexor retinaculum. Deep to the retinaculum, they are mainly observed in the proximal aspect of the carpal tunnel and more frequently close to the median nerve. KEY POINTS: • Superb microvascular imaging (SMI) enables the visualization of arterioles within the "safe zone" of the carpal tunnel (visible both superficial and deep to the flexor retinaculum). • Arterioles were more frequently observed in the proximal aspect of the carpal tunnel. • Deep to the retinaculum, arterioles were more frequently seen in proximity to the median nerve.

National dose reference levels in computed tomography-guided interventional procedures-a proposal.

OBJECTIVES: To establish national reference levels (RLs) in interventional procedures under CT guidance as required by the 2013/59/Euratom European Directive. METHODS: Seventeen categories of interventional procedures in thoracic, abdominopelvic, and osteoarticular specialties (percutaneous infiltration, vertebroplasty, biopsy, drainage, tumor destruction) were analyzed. Total dose length product (DLP), number of helical acquisitions (NH), and total DLP for helical, sequential, or fluoroscopic acquisitions were recorded for 10 to 20 patients per procedure at each center. RLs were calculated as the 3rd quartiles of the distributions and target values for optimization process (TVOs) as the median. RLs and TVOs were compared with previously published studies. RESULTS: Results on 5001 procedures from 49 centers confirmed the great variability in patient dose for the same category of procedures. RLs were proposed for the DLPs and NHs in the seventeen categories. RLs in terms of DLP and NH were 375 mGy.cm and 2 NH for spinal or peri-spinal infiltration, 1630 mGy.cm and 3 NH for vertebroplasty, 845 mGy.cm and 4 NH for biopsy, 1950 mGy.cm and 8 NH for destruction of tumors, and 1090 mGy.cm and 5 NH for drainage. DLP and NH increased with the complexity of procedures. CONCLUSIONS: This study was the first nationwide multicentric survey to propose RLs for interventional procedures under CT guidance. Heterogeneity of practice in centers were found with different levels of patient doses for the same procedure. The proposed RLs will allow imaging departments to benchmark their practice with others and optimize their protocols. KEY POINTS: • National reference levels are proposed for 17 categories of interventional procedures under CT guidance. • Reference levels are useful for benchmarking practices and optimizing protocols. • Reference levels are proposed for dose length product and the number of helical acquisitions.

Correction to: National dose reference levels in computed tomography-guided interventional procedures-a proposal.

The original version of this article, published on 02 May 2020, unfortunately contained a mistake.

Musculoskeletal Manifestations of Non-RA Connective Tissue Diseases: Scleroderma, Systemic Lupus Erythematosus, Still's Disease, Dermatomyositis/Polymyositis, Sjögren's Syndrome, and Mixed Connective Tissue Disease.

The most common systemic rheumatologic conditions are connective tissue diseases (including rheumatoid arthritis [RA]) followed by spondyloarthropathy. With the advent of biotherapies and imaging biomarkers, development in the imaging of RA and spondyloarthropathies has received substantial attention in the literature. This article details the various musculoskeletal imaging features of the other connective tissue diseases such as scleroderma and progressive systemic sclerosis, systemic lupus erythematosus, Still's disease, dermatomyositis and polymyositis, Sjögren's syndrome, and mixed connective tissue disease.

Renal phenotype in mice lacking the Kir5.1 (Kcnj16) K+ channel subunit contrasts with that observed in SeSAME/EAST syndrome.

The heteromeric inwardly rectifying Kir4.1/Kir5.1 K(+) channel underlies the basolateral K(+) conductance in the distal nephron and is extremely sensitive to inhibition by intracellular pH. The functional importance of Kir4.1/Kir5.1 in renal ion transport has recently been highlighted by mutations in the human Kir4.1 gene (KCNJ10) that result in seizures, sensorineural deafness, ataxia, mental retardation, and electrolyte imbalance (SeSAME)/epilepsy, ataxia, sensorineural deafness, and renal tubulopathy (EAST) syndrome, a complex disorder that includes salt wasting and hypokalemic alkalosis. Here, we investigated the role of the Kir5.1 subunit in mice with a targeted disruption of the Kir5.1 gene (Kcnj16). The Kir5.1(-/-) mice displayed hypokalemic, hyperchloremic metabolic acidosis with hypercalciuria. The short-term responses to hydrochlorothiazide, an inhibitor of ion transport in the distal convoluted tubule (DCT), were also exaggerated, indicating excessive renal Na(+) absorption in this segment. Furthermore, chronic treatment with hydrochlorothiazide normalized urinary excretion of Na(+) and Ca(2+), and abolished acidosis in Kir5.1(-/-) mice. Finally, in contrast to WT mice, electrophysiological recording of K(+) channels in the DCT basolateral membrane of Kir5.1(-/-) mice revealed that, even though Kir5.1 is absent, there is an increased K(+) conductance caused by the decreased pH sensitivity of the remaining homomeric Kir4.1 channels. In conclusion, disruption of Kcnj16 induces a severe renal phenotype that, apart from hypokalemia, is the opposite of the phenotype seen in SeSAME/EAST syndrome. These results highlight the important role that Kir5.1 plays as a pH-sensitive regulator of salt transport in the DCT, and the implication of these results for the correct genetic diagnosis of renal tubulopathies is discussed.

Overexpression of pendrin in intercalated cells produces chloride-sensitive hypertension.

Inherited and acquired disorders that enhance the activity of transporters mediating renal tubular Na(+) reabsorption are well established causes of hypertension. It is unclear, however, whether primary activation of an Na(+)-independent chloride transporter in the kidney can also play a pathogenic role in this disease. Here, mice overexpressing the chloride transporter pendrin in intercalated cells of the distal nephron (Tg(B1-hPDS) mice) displayed increased renal absorption of chloride. Compared with normal mice, these transgenic mice exhibited a delayed increase in urinary NaCl and ultimately, developed hypertension when exposed to a high-salt diet. Administering the same sodium intake as NaHCO3 instead of NaCl did not significantly alter BP, indicating that the hypertension in the transgenic mice was chloride-sensitive. Moreover, excessive chloride absorption by pendrin drove parallel absorption of sodium through the epithelial sodium channel ENaC and the sodium-driven chloride/bicarbonate exchanger (Ndcbe), despite an appropriate downregulation of these sodium transporters in response to the expanded vascular volume and hypertension. In summary, chloride transport in the distal nephron can play a primary role in driving NaCl transport in this part of the kidney, and a primary abnormality in renal chloride transport can provoke arterial hypertension. Thus, we conclude that the chloride/bicarbonate exchanger pendrin plays a major role in controlling net NaCl absorption, thereby influencing BP under conditions of high salt intake.

Anatomical study of the dorsal capsulo-scapholunate septum using high frequency ultrasonography.

INTRODUCTION: The dorsal capsulo-scapholunate septum (DCSS) is a recently described capsuloligamentous structure between the dorsal bundle of the scapholunate ligament (SLL) and the joint capsule of the wrist. It acts a secondary stabilizer of the scapholunate joint. The aim of this study was to evaluate the visibility and normal appearance of DCSS on high frequency ultrasound. HYPOTHESIS: The DCSS can be analyzed using high frequency ultrasound. MATERIALS AND METHODS: Three cadaveric wrists were dissected in order to study the DCSS; one without labeling and the other two after labeling under ultrasound guidance. On two other wrists, a correlation between the structure considered to be the DCSS on ultrasound and the corresponding CT arthrography and anatomical sections was carried out. Finally, sagittal ultrasound sections of the DCSS region on 42 healthy wrists were analyzed retrospectively. RESULTS: During dissection, the DCSS corresponded to a fibrous structure extending to the dorsal surface of the scaphoid and lunate, with certain fibers converging towards the SLL. On high-frequency ultrasound, a hyperechoic fibrillar structure was visualized at the theoretical position of the DCSS. The dissections performed after ultrasound-guided transfixion showed that its limits corresponded to the limits of the DCSS. The anatomical, CT arthrography and ultrasound sections in the DCSS region were concordant. The DCSS was retrospectively visible on at least one reference ultrasound slice in 90.5% of healthy wrists, and was always hyperechoic. Its average thickness was 1.38±0.24mm. DISCUSSION: Our study describes the normal sonographic characteristics of the DCSS, visible in a majority of healthy patients on high-frequency ultrasound. The analysis of the sonographic characteristics of the DCSS in the context of acute wrist trauma should be evaluated, and a diagnostic decision tree has been proposed. LEVEL OF EVIDENCE: IV.

How do medical students, residents and graduated physicians really perceive radiologists? A cross-national study.

BACKGROUND: Radiology has always been an attractive specialty for residents, but its attractiveness has recently decreased in France regarding the median choice rank after at the National Residency Board. AIM: To study Radiologists' perceptions and social representations (SRs) among a group of medical students, residents and graduated physicians in France, to better understand the view of Radiologists to debunk stereotypes. METHODS: The nationwide web-based survey was based on valid hierarchical evocation methods. We determined the corpus's central core and SRs' principal themes with prototypical and correspondence factor analysis (CFA), respectively. RESULTS: Overall, 419 answers were analyzed. Radiologists' SRs were divided into 3 classes: negative stereotypes of Radiologists, negative stereotypes of the Radiologists' daily practice and Radiologists' skills. After multivariate analysis, variables that seemed to have a positive influence on Radiologists' SRs were considering radiology as a potential choice of specialty (p < 0.001) and the existence of practical experience in Radiology (p = 0.008). Women seemed to have a more negative SR of Radiologists than men (p = 0.035). DISCUSSION: This was the largest qualitative study on the subject and the only one among medical students, residents and graduated physicians, allowing a global picture. SRs of Radiologists seemed to be negative, potentially caused by poor knowledge of the Radiologists' profession. CONCLUSION: SRs of Radiologists among medical students and graduated physicians appears to be negative. Promoting the specialty among medical students and encouraging their immersion in a Radiology department could help to debunk many stereotypes about the daily life and missions of Radiologists.

Anatomical study of the sternoclavicular joint using high-frequency ultrasound.

OBJECTIVES: The purpose of the present study was to determine whether ultrasound enables assessment of sternoclavicular structures. METHODS: A preliminary study in 3 cadavers was followed by an ultrasound study, performed by 2 musculoskeletal radiologists working in consensus, in 59 patients without history of trauma, surgery or pain in the sternoclavicular joint. The visibility, echogenicity and thickness of the sternoclavicular structures were assessed. RESULTS: The anterior sternoclavicular ligament and the interclavicular ligament could be seen in all patients (mean thickness: 1.4 mm and 1.3 mm, respectively). The articular disc was clearly seen in 66.1% of cases, and shoulder antepulsion enabled analysis in an additional 20.3%. Intra-articular joint gas was frequent (33.89% of cases), preventing analysis of the disc in 2 patients. Only the superficial anterior aspect of the clavicular and sternal articular cartilages could be assessed. Joint effusion was seen in 6.8% of cases. Clavicular osteophytes, sternal osteophytes and bone irregularities at the anterior sternoclavicular ligament insertion were detected in 33.9%, 16.9% and 16.9% of cases, respectively. CONCLUSION: The anterior sternoclavicular ligament, interclavicular ligament and anterior intra-articular structures can be visualized by ultrasound. This means of assessment may have clinical applications, particularly in patients with trauma or microtrauma.

Main Diagnostic Pitfalls in Reading the Sacroiliac Joints on MRI.

Magnetic resonance imaging of the sacroiliac joints is now frequently performed to help identify patients with early axial spondyloarthritis. However, differential diagnoses exist and should be recognized. The aim of this article is to review the most frequent differential diagnoses that may mimic inflammatory sacroiliitis in clinical practice.

Anatomical study of the proximal tibiofibular ligaments using ultrasound.

OBJECTIVES: No description of the proximal tibiofibular (PTF) ligaments by means of high ultrasound has yet been reported in the literature. The purpose of this study was to assess whether ultrasound may allow the assessment of these ligaments. METHODS: This study was initially undertaken in three cadaveric knees, followed by an ultrasound study performed by two musculoskeletal radiologists working in consensus of 52 patients without history of trauma or surgery of the knee, and without lateral knee pain. The visibility, echogenicity, length and thickness of the PTF ligaments were assessed. RESULTS: Regarding the anterior PTF ligament, the superior bundle and the upper and lower middle bundles were clearly seen in 42.3%, 100% and 75% of the knees, respectively. Regarding the posterior PTF ligament, the superior and middle bundles were clearly seen in 88.4% and 51.9% of the knees, respectively. The echo-anatomy of these ligaments and the probe positioning allowing their best depiction were described in this study. CONCLUSION: Most of the PTF ligaments can be visualized by means of ultrasound. This possible assessment may have clinical applications, particularly in patients with lateral knee pain.

Impact of introducing extremity cone-beam CT in an emergency radiology department: A population-based study.

BACKGROUND: Musculoskeletal cone-beam CT (CBCT) recently appeared on the market, with image quality comparable to that of high-resolution CT. It was previously implemented mainly in craniofacial surgery and in orthopedic limb surgery for weight-bearing imaging, but without large-scale assessment in emergency settings. We therefore conducted a retrospective comparative study in an emergency radiology department: 1) to assess whether introduction of CBCT dedicated to extremity traumatology reduced radiation dose delivered to the patient undergoing cross-sectional imaging, 2) to assess whether it increased turnover, and 3) to study the feasibility and practical consequences. Study hypothesis Introducing CBCT dedicated to traumatology in an emergency radiology department reduces radiation dose related to cross-sectional imaging in extremity trauma. PATIENTS AND METHODS: Two periods were distinguished: in May-November 2016, the only cross-sectional imaging available in our emergency radiology department was multi-detector CT (MDCT); in May-November 2017, both MDCT and CBCT were available. Thus, the population in period 1 (n=165) had undergone only MDCT extremity imaging, while patients in period 2 underwent either CBCT (n=139) or MDCT (n=85). Study parameters notably included dose-length product (DLP) and length of patient stay in the radiology department (turnover). RESULTS: Mean DLP was significantly reduced with the introduction of CBCT: 210.3±133.6 mGy.cm (range, 20-595) in period 1, versus 138.4±92.7 mGy.cm (range, 32-623) in period 2 (p<0.0001). Taking both periods together, mean DLP was 50.7% lower with CBCT (n=139) than MDCT (n=249): respectively, 101.6±14.9 mGy.cm (range, 50.6-126.9) versus 206.5±131.8 mGy.cm (range, 20-623) (p<0.0001). Turnover accelerated with the introduction of CBCT, with mean stay of 84.9minutes in period 1 versus 72.1minutes in period 2 (p=0.011). In period 2, turnover was 23.6% faster with CBCT than MDCT: respectively, 64.9minutes versus 85.0minutes (p=0.0004). DISCUSSION: Introducing CBCT dedicated to the extremities in an emergency radiology department was feasible. It reduced overall radiation dose and accelerated turnover. LEVEL OF EVIDENCE: III; comparative case-control study.

Overview of tools for the measurement of the orbital volume and their applications to orbital surgery.

There are numerous applications in craniofacial surgery with orbital volume (OV) modification. The careful management of the OV is fundamental to obtain good esthetic and functional results in orbital surgery. With the growth of computer-aided design - computer-aided manufacturing (CAD-CAM) technologies, patient-specific implants and custom-made reconstruction are being used increasingly. The precise measurement of the OV before surgery is becoming a necessity for craniofacial surgeons. There is no consensus on orbital volume measurements (OVMs). Manual segmentation of computed tomography (CT) images is the most used method to determine the OV, but it is time-consuming and very sensitive to operator errors. Here, we describe the various methods of orbital volumetry validated in the literature that can be used by surgeons in preoperative planning of orbital surgery. We also describe the leading software employed for these methods and discuss clinical use (posttraumatic enophthalmos prediction and orbital reconstruction) in which OVMs are important.

The advantages of cone-beam computerised tomography (CT) in pain management following total knee arthroplasty, in comparison with conventional multi-detector CT.

BACKGROUND: Revision of total knee arthroplasty (TKA) requires preoperative assessment to identify the causes of failure. Multidetector computerised tomography (MDCT) is a commonly used imaging technique, but is sensitive to certain artifacts, such as metal implants, limiting its use. Cone-beam CT (CBCT) is a new technique dedicated to musculoskeletal imaging that is less sensitive to artifacts and could be utilised in knee implantation surgery. CBCT has not yet been validated for this indication, and we therefore undertook a retrospective assessment of MDCT versus CBCT, comparing: 1) image quality; 2) reproducibility of angle measurements; 3) effectiveness in screening for periprosthetic radiolucency and implant loosening; and 4) radiation dose. HYPOTHESIS: This study hypothesised that CBCT provides better image quality, angle measurement reproducibility, and screening for radiolucency and implant loosening at lower doses of radiation than MDCT. PATIENTS AND METHOD: Between October 2017 and March 2018, 28 patients, with a mean age of 61±11.6 years [range, 45-85 years] underwent both MDCT and CBCT for pain following TKA. Two radiologists performed angle measurements on both devices: patellofemoral tilt (PFT), rotation angle of the femoral component (RAFC) and rotation angle of the tibial component (RATC). They also screened for pathological radiolucency and/or implant loosening, and assessed image quality at the various bone/implant interfaces. The mean CT dose index per examination was recorded. RESULTS: Intraclass correlation coefficients for angles and radiolucency screening on MDCT and on CBCT were respectively good (0.73) and excellent (0.82) for PFT, borderline (0.28) and moderate (0.44) for RAFC, excellent (0.82) and excellent (0.96) for RATC, and moderate (0.45) and excellent (0.84) for radiolucency screening. The inter-observer kappa correlation coefficients for diagnosis of implant loosening and image quality assessment for MDCT and CBCT were respectively moderate (0.45) and excellent (0.93) for tibial loosening and low (0.19) and borderline (0.38) for femoral loosening. The mean image quality at the various interfaces for MDCT and CBCT was respectively 2.2/3 and 2.75/3 at the tibia/tibial implant interface, 1/3 and 2.3/3 at the trochlear region/femoral implant interface, 0.9/3 and 2/3 at the femoral condyle/femoral implant interface, and 1.25/3 and 2.1/3 at the patella/patellar medallion interface. The mean CT dose index was significantly lower, by a factor of 1.24, on CBCT (4.138 mGy) than MDCT (5.125 mGy) (p<00396). CONCLUSION: The results of the present study revealed added value for CBCT in the etiological work-up for pain following a TKA. It was reliable and reproducible for the rotation measurement and diagnosis of implant loosening, due to enhanced image quality despite a lower radiation dose than conventional MDCT. LEVEL OF EVIDENCE: III; retrospective comparative study.

Imaging in dermatomyositis in adults and children.

Dermatomyositis is a rare autoimmune disorder in which an abnormal immune reaction against vascular endothelial antigens and endomysium leads to obstructive inflammatory changes of blood vessels within muscles, skin and other tissues. The disease is characterized by involvement of muscles, and less frequently of other systems, including the gastrointestinal tract, heart and lungs. Dermatomyositis may be diagnosed based on a detailed patient history, through clinical examination, detection of characteristic physical findings and certain specialized tests. Additional imaging studies may be performed to aid in the diagnosis. These include magnetic resonance imaging and ultrasound of the affected muscles. Magnetic resonance imaging is the modality of choice in the diagnostic work-up and monitoring of dermatomyositis affecting muscles, fasciae, and the subcutis. It may recognize acute inflammatory edematous changes in the affected muscles as well fatty replacement and atrophy. The role of ultrasound to diagnose and follow up muscle echogenicity, vascularity, elasticity and volume during treatment has increased over the last years in both adults and children. Ultrasound is used to discriminate between high and low disease activity, may show features of subclinical disease and may be used to confirm remission.Dermatomyositis is a rare autoimmune disorder in which an abnormal immune reaction against vascular endothelial antigens and endomysium leads to obstructive inflammatory changes of blood vessels within muscles, skin and other tissues. The disease is characterized by involvement of muscles, and less frequently of other systems, including the gastrointestinal tract, heart and lungs. Dermatomyositis may be diagnosed based on a detailed patient history, through clinical examination, detection of characteristic physical findings and certain specialized tests. Additional imaging studies may be performed to aid in the diagnosis. These include magnetic resonance imaging and ultrasound of the affected muscles. Magnetic resonance imaging is the modality of choice in the diagnostic work-up and monitoring of dermatomyositis affecting muscles, fasciae, and the subcutis. It may recognize acute inflammatory edematous changes in the affected muscles as well fatty replacement and atrophy. The role of ultrasound to diagnose and follow up muscle echogenicity, vascularity, elasticity and volume during treatment has increased over the last years in both adults and children. Ultrasound is used to discriminate between high and low disease activity, may show features of subclinical disease and may be used to confirm remission.

Minimally-invasive fully ultrasound-guided removal of nonpalpable single-rod contraceptive implant: Case report and technical description.

A 38 year-old patient had a nonpalpable subfascial single-rod contraceptive implant close to major neurovascular structures. We removed the implant through a 3 mm incision using local anesthesia, hydrodissection and a grasping micro-forceps under continuous real-time ultrasound guidance.

Enlarged External Occipital Protuberance in young French individuals' head CT: stability in prevalence, size and type between 2011 and 2019.

External Occipital Protuberance (EOP) enlargement has been recently reported to increase in young adults, with a putative link with postural factors such as the use of smartphones. This study aims to analyze finely the changes in prevalence and size of EOP enlargement in millennials, throughout the smartphone era (2011 - 2019). Anonymized head Computerized Tomography (CT) examinations from patients aged 18-30 in 2011 (n = 205) or 2019 (n = 240), were reviewed to assess the type of EOP and to measure its volume in case of enlargement. Additional CT analyses were performed on two ancient skulls, from a XVIth century young male and a young female Egyptian mummy. There was no significant evolution in the prevalence of EOP enlargement between 2011 (92/205, 44.9%) and 2019 (106/240; 44.2%) (P = 0.92). There was no significant evolution either in the distribution of enlarged EOP volumes (P = 0.14) or of EOP types (P = 0.92) between 2011 and 2019. In the meantime, rates of smartphone ownership in millennials rose from 35% to 98%. Compared to 2019 volumes, the Egyptian mummy displayed an EOP enlargement corresponding to the 85th percentile for young women, and the XVIth century skull to the 73rd percentile for young men. In conclusion, on a population scale, prevalence and volume of enlarged EOP in millennials remain stable between 2011 and 2019, which makes the impact of rapidly growing modern environmental factors on EOP changes unlikely. EOP enlargement was also already present in ancient skulls from young individuals, with measurements within today's upper ranges.

Joint Effusion and Bone Outlines of the Knee: Radiographic/MR Imaging Correlation.

Knee radiographs are widely used in clinical practice. Many features can be depicted when a systematic analysis of the different views is performed. This article focuses on different types of joint effusion and on the analysis of the bone outlines of the knee, particularly on the lateral view. Systematic analysis of these bone outlines and knowledge of several key points are particularly useful for the depiction of abnormal bone morphology or positioning, and of several conditions, such as trochlear dysplasia, patellar dislocation, impaction fractures, or ligament injuries and avulsion fractures.