Assessment of whole-body muscle MRI for the early diagnosis of Amyotrophic Lateral Sclerosis.

OBJECTIVES: To evaluate muscle signal abnormalities on whole-body muscle MRI with T2 and diffusion-weighted imaging in early ALS stages. METHODS: 101 muscles were analyzed in newly diagnosed ALS patients and healthy controls on a whole-body MRI protocol including four-point T2-Dixon imaging and diffusion-weighted imaging (b0 and b800). Sensitivity and inter-observer agreement were assessed. RESULTS: 15 patients (mean age, 64 +/- 12 [SD], 9 men) who met the Awaji-Shima criteria for definite, probable or possible ALS and 9 healthy controls were assessed (mean age, 53 +/- 13 [SD], 2 men). 61 % of the muscles assessed in ALS patients (62/101) showed signal hyperintensities on T2-weighted imaging, mainly in the upper and lower extremities (legs, hands and feet). ALS patients had a significantly higher number of involved muscles compared to healthy controls (p = 0,006). Diffusion-weighted imaging allowed for the detection of additional involvement in 22 muscles, thus improving the sensitivity of whole-body MRI from 60 % (using T2-weighted imaging only) up to 80 % (with the combination of T2-weighted and diffusion-weighted imaging). CONCLUSIONS: ALS patients exhibited significant muscle signal abnormalities on T2-weighted and diffusion-weighted imaging in early disease stages. Whole-body MRI could be used for pre-EMG mapping of muscle involvement in order to choose suitable targets, thus improving early diagnosis.

Percutaneous cryoablation of abdominal wall endometriosis: An analysis of 38 patients.

PURPOSE: The purpose of this study was to evaluate the efficacy of percutaneous cryoablation in the treatment of abdominal wall endometriosis (AWE) nodules. MATERIALS AND METHODS: Thirty-eight women treated for symptomatic AWE nodules with percutaneous cryoablation under ultrasound and computed tomography (CT) guidance between May 2020 and July 2023 were retrospectively included. Pain was estimated using visual analog scale (VAS) and assessed at baseline, three months, six months, and 12 months after percutaneous cryoablation. Baseline VAS score, volume of AWE nodule and magnetic resonance imaging (MRI) features of AWE nodules were compared to those obtained after percutaneous cryoablation. Major complications, if any, were noted. RESULTS: Thirty-eight women with a median age of 35.5 years (interquartile range [IQR]: 32, 39; range: 24-48 years) and a total of 60 AWE nodules were treated. Percutaneous cryoablation was performed under local or regional anesthesia in 30 women (30/38; 79%). Significant decreases between initial median VAS score (7; IQR: 6, 8; range: 3-10) and median VAS score after treatment at three months (0; IQR: 0, 5; range; 0-8) (P < 0.001), six months (0; IQR: 0, 1; range; 0-10) (P < 0.001) and 12 months (0; IQR: 0, 2; range: 0-7) (P < 0.001) were observed. Percutaneous cryoablation resulted in effective pain relief in 31 out of 38 women (82%) at six months and 15 out of 18 women (83%) at 12 months. Contrast-enhanced MRI at six-month follow-up showed a significant decrease in the volume of AWE nodules and the absence of AWE nodule enhancement after treatment by comparison with baseline MRI (P < 0.001). No major complications were reported. CONCLUSION: Percutaneous cryoablation is an effective, minimally invasive intervention for the treatment of AWE nodules that conveys minimal or no morbidity.

Paget's Disease or Densifying Metastasis: How to Sort It Out.

Although the prevalence of Paget's disease has decreased over the past 20 years, incidental discovery on imaging is not unusual. The challenge is to establish the diagnosis, especially in unusual forms that may be mistaken for metastases. This review describes the typical imaging features of Paget's disease and some rare presentations that may be more difficult to recognize.

Hindfoot alignment assessment by the foot-ankle offset: a diagnostic study.

INTRODUCTION: Foot-ankle offset (FAO) is a three-dimensional (3D) biometric measurement of hindfoot alignment (HA) measured on images from weight-bearing computed tomography (WBCT). Our aim was to investigate its distribution in a large cohort of patients, hypothesizing that threshold FAO values in valgus or varus could be identified as markers for increased risk of associated pathologies. MATERIALS AND METHODS: Prospective, monocentric, level II study including 125 subjects (250 feet) undergoing bilateral WBCT [58.4% female; mean age, 54 years (18-84)]. Patients were clinically assessed and pathologies were classified according to anatomic location (valgus- or varus associated). HA was measured using FAO on 3D datasets and tibio-calcaneal angles (TCA) on two-dimensional Saltzman-El-Khoury views. Threshold FAO values and area under the receiver operating characteristics curve (AUC) were calculated for predicting increased risk of medial or lateral pathologies. RESULTS: Mean FAO was 1.65% ± 4.72 and mean TCA was 4.15° ± 7.67. Clinically, 167 feet were normal, 33 varus and 50 valgus with FAO values of 1.71% ± 3.16, - 4.96% ± 5.30 and 5.79% ± 3.77, respectively. Mean FAO was 0.99% ± 3.26 for non-pathological feet, - 2.53% ± 5.05 for lateral and 6.81% ± 2.70 for medial pathologies. Threshold FAO values of - 1.64% (51.4% sensitivity, 85.1% specificity, AUC = 0.72) and 2.71% (95% sensitivity, 82.8% specificity, AUC = 0.93) best predicted the risk of lateral and medial pathology, respectively. CONCLUSION: Patients with FAO between - 1.64% and 2.71% had the least risk of degenerative foot and ankle pathology. This interval could be considered a target for patients undergoing realignment procedures. CLINICAL RELEVANCE: A "safe zone" for Foot Ankle Offset was described between - 1.64% and 2.71%, for which the risk of foot and ankle pathologies is lower. LEVEL OF EVIDENCE: II-Diagnostic study.

Ultrasonography: an interesting imaging method for ligament assessment during the acute phase of closed elbow injuries.

PURPOSE: To evaluate whether ultrasonography can be used to explore the medial and lateral ligament structures during the acute phase of a closed elbow injury. METHODS: A single-center, prospective study performed between December 2019 and June 2020, including patients who suffered a radial head fracture or elbow dislocation. Two radiologists did a blinded analysis using ultrasonography of visibility, injury grade, and presence of bone avulsion for the radial collateral ligament (RCL), lateral ulnar collateral ligament (LUCL), annular ligament (AL), and anterior (MCLant) and posterior bundles (MCLpost) of the medial collateral ligament. The inter-rater agreement was calculated. The ultrasonography findings were compared with the intraoperative findings in the patients who subsequently underwent surgery. RESULTS: Forty patients were included (28 radial head fractures and 12 elbow dislocations). The inter-rater agreement was strong for all the study parameters (kappa between 0.65 and 1), except for the visibility of the LUCL (kappa 0.52) and the visibility and appearance of the MCLpost (kappa 0.54 and 0.47, respectively). The injured ligaments were thicker than their contralateral counterparts (p < 0.05). In the 10 patients who underwent surgery, the radiological-surgical correlation was 100% for the RCL and medial ligaments and 70% for the LUCL. CONCLUSION: Ultrasonography is a reproducible examination that can be used to assess the damage to elbow ligaments during the acute phase following an injury. This examination could be incorporated into the exploration protocol for elbow injuries during the preoperative assessment and to adapt the treatment.

How to improve the performance of acetabulum fracture diagnoses: investigating the use of three-dimensional CT-scan reconstructions.

PURPOSE: The classification of acetabular fractures remains a challenge for the junior radiologist, although he is the first line of diagnosis in Emergency Department. The advantages of three-dimensional reconstructions have yet to be evaluated on a large scale. METHOD: A total of 212 fractures were classified according to Letournel and Judet by a senior orthopaedic surgeon, a senior radiologist, and a resident radiologist. The CT scans were first analysed in 2D and then a second time using 2D + 3D reconstructions of the acetabulum excluding the femoral head. RESULTS: 3D reconstructions improved correct classification not only for the radiologist resident (+ 5%) but also for senior radiologist and orthopaedist (+ 2 and + 3%). 3D reconstructions also more significantly improved the diagnoses of complex fractures (+ 8.3%) compared to simple fractures (+ 0.4%). CONCLUSIONS: 3D reconstructions have improved the routine diagnosis of acetabular fractures, especially for junior radiologist or in cases of complex fractures.

The concept of ring of injuries: evaluation in ankle trauma.

OBJECTIVE: Radiographs are first-line imaging in ankle trauma but lack sensitivity to detect ligamentous injuries and undisplaced fractures. Our hypothesis was that ankle injuries occur in predefined sequences along two osteoligamentous rings, so that occult injuries non-visible on initial radiographs can be predicted. We, therefore, aimed to validate a ring model of progressive damages in the interpretation of ankle trauma radiographs. METHODS: This study retrospectively enrolled 277 adult patients that presented an acute fibular fracture on ankle radiographs between May and November 2019. Four different types of fibula fracture were differentiated, each being considered to correspond to a different mechanism of injury. Patients were classified into four groups, upon the appearance of their fibular fracture. Then, injuries to the distal tibiofibular syndesmosis, medial malleolus, and deltoid ligament (medial clear space) were assessed in each patient radiographs. Traumatic injuries were independently evaluated by a resident and an experienced MSK radiologist. For each patient, observed features were compared to those predicted by the ring concept. Inter- and intraobserver agreements were calculated. RESULTS: Injuries were observed according to the predictable sequence in 266 of the 277 patients (96%). In the 11 remaining patients, discordances were presumably due to undisplaced injuries to the syndesmosis or deltoid ligament. Agreements were considered very good for each evaluated item. CONCLUSION: The Lauge-Hansen ring concept was found to be highly accurate and reproducible for radiographic assessment of ankle injuries. Discordances to the predicted sequence might reflect occult injuries, especially of the syndesmosis or deltoid ligament.

Double Reading of Outsourced CT/MR Radiology Reports: Retrospective Analysis.

OBJECTIVES: Our objective was to determine disagreement rates in radiological reports provided by using a double-reading protocol in a national teleradiology company. METHODS: From January 2015 to July 2016, 134169 radiological exams from 36 French centers, benefited outsourced interpretations by certified radiologists, in both regular and after-hours activities. Of these, 2040 CT and MR-scans (1.5%) were subjected to a second opinion by other radiologists in the field of their anatomical specialty (cerebral, thoracic, abdominal-pelvic, and osteoarticular). A five-point agreement scale graded from 0 to 4 was assigned for each exam. Disagreements were considered as minor if no clinical consequence for patient (scores 1 and 2) and major if potential clinical consequence (score 3 and 4). Independent radiologists performed a retrospective analysis and a stratified statistical analysis. RESULTS: Double reading was performed on CT-scans (n = 934/2040, 45.8%) and MR-scans (n = 1106/2040, 54.2%) performed in regular (80.1%) and after-hours activities (19.9%). Disagreement scores occurred in 437 exams (21.4%), including major disagreements in 59 (2.9%). Among these, 48/754 were assigned by the thoracic second reader (6.4%), 6/70 by the abdominal-pelvic second reader (8.6%), 3/901 by the osteoarticular second reader (0.3%), and 2/315 by the cerebral second reader (0.6%), with statistical significant difference. No additional disagreement rate was observed in regular and after-hours activities (P = 0.63). CONCLUSIONS: Double-reading of outsourced CT and MRI interpretations yielded 21.4% disagreement rate, with potential clinical consequence for patient in 2,9% of the cases. These results are in accordance with those previously reported and suggests that quality assurance of outsourced interpretations is needed.

Bifascicular nature of the flexor digitorum profundus and flexor pollicis longus tendons: forgotten anatomical characteristics rediscovered with US imaging.

OBJECTIVES: To demonstrate the bifid configuration of the flexor digitorum profundus (FDP) and flexor pollicis longus (FPL). METHODS: In the first part of this study, 20 digits from 4 cadaver hands were dissected and analyzed using anatomical and histological slices. The second part of the study was carried out over a 12-month period starting in August 2018. It was a prospective US imaging study of 300 digits from 30 healthy participants performed by two radiologists in a double-blinded manner. This study focused on two items: tendon shape and whether a central septum separated the two hemitendons. Descriptive statistics were calculated along with the inter-rater reliability. RESULTS: In 100% (300/300) of fingers and thumbs, the FDP and FPL tendons were made up of two parallel bundles arranged side by side, with a central vertical septum between these two hemitendons, starting at the head of the proximal phalanx (PP) and continuing distally. This central septum was always present starting at the proximal third of PP for the FDP of the index, middle, and ring fingers. The septum was more difficult to identify in the thumb and little finger. Cohen's kappa indicated near perfect agreement when all digits were considered together (≥ 0.9), and substantial agreement for the thumb (0.71) and for the little finger (0.82). CONCLUSIONS: With US imaging, the bifascicular nature of the FDP and FPL tendons is easy to see, as these tendons have a double-barreled configuration starting at the head of the proximal phalanx. KEY POINTS: •Analysis of anatomical slices of the hand tendons found a bifascicular appearance of the flexor digitorum profundus and flexor pollicis longus tendons starting at the head of the proximal phalanx. •This distinct feature of two hemitendons arranged side by side was seen in 100% of tendons we examined with US. It is associated with a vertical central septum that causes anisotropy. •Awareness of this "forgotten" anatomical detail has practical implications when interpreting images generated by latest-generation US systems and during surgery on hand flexor tendons.

COVID-19 impact assessment on the French radiological centers: a nationwide survey.

PURPOSE: To determine the impact of the COVID-19 on the CT activities in French radiological centers during the epidemic peak. MATERIALS AND METHODS: A cross-sectional prospective CT scan survey was conducted between March 16 and April 12, 2020, in accordance with the local IRB. Seven hundred nine radiology centers were invited to participate in a weekly online survey. Numbers of CT examinations related to COVID-19 including at least chest (CTcovid) and whole chest CT scan activities (CTchest) were recorded each week. A sub-analysis on French departments was performed during the 4 weeks of the study. The impact of the number of RT-PCRs (reverse transcriptase polymerase chain reactions) on the CT workflow was tested using two-sample t test and Pearson's test. RESULTS: Five hundred seventy-seven structures finally registered (78%) with mean response numbers of 336 ± 18.9 (323; 351). Mean CTchest activity per radiologic structure ranged from 75.8 ± 133 (0-1444) on week 12 to 99.3 ± 138.6 (0-1147) on week 13. Mean ratio of CTcovid on CTchest varied from 0.36 to 0.59 on week 12 and week 14 respectively. There was a significant relationship between the number of RT-PCR performed and the number of CTcovid (r = 0.73, p = 3.10-16) but no link with the number of positive RT-PCR results. CONCLUSION: In case of local high density COVID-19, CT workflow is strongly modified and redirected to the management of these specific patients. KEY POINTS: • Over the 4-week survey period, 117,686 chest CT (CTtotal) were performed among the responding centers, including 61,784 (52%) CT performed for COVID-19 (CTcovid). • Across the country, the ratio CTcovid/CTtotal varied from 0.36 to 0.59 and depended significantly on the local epidemic density (p = 0.003). • In clinical practice, in a context of growing epidemic, in France, chest CT was used as a surrogate to RT-PCR for patient triage.

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.

MRI of sacroiliac joints for the diagnosis of axial SpA: prevalence of inflammatory and structural lesions in nulliparous, early postpartum and late postpartum women.

OBJECTIVES: To determine the prevalence of bone marrow oedema (BME) at the sacroiliac joint (SIJ) in early postpartum (EPP), nulliparous (NP) and late postpartum (LPP) women, and to identify factors associated with BME presence at the SIJ. METHODS: Three groups were obtained: NP (never given birth), EPP (given birth within 12 months) and LPP (given birth more than 24 months). The primary outcome was the presence of BME and/or structural lesions (erosions, osteophytes, ankylosis and sclerosis) at the SIJ MRI. RESULTS: BME prevalence was greater among EPP (33%) than NP (14%, p=0.001), but was not different to LPP (21%, p=0.071). The Assessment of SpondyloArthritis international Society (ASAS) MRI criteria for sacroiliitis were positive in 75%, 71% and 80%, respectively, of EPP, NP and LPP women with BME. EPP (38%) had similar prevalence of sclerosis than LPP (28%, p=0.135), but greater than NP (18%, p=0.001). Lastly, EPP (28%) had similar prevalence of osteophytes than LPP (42%) and NP (27%), although there was a difference between LPP and NP (p=0.006). CONCLUSIONS: EPP have higher BME prevalence at the SIJ than NP, EPP tend to have higher BME prevalence compared with LPP and BME presence decreases with time from delivery. Three-quarters of women with BME at the SIJ had a positive ASAS MRI criteria for sacroiliitis, indicating that BME presence as the main criterion for a positive diagnosis can lead to false-positive results. SIJ MRIs should not be interpreted in isolation, since age, time from delivery and other factors may outweigh the pertinence of MRI findings. Trial registration number NCT02956824.

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.

Geometric morphometric study of the early shape of the hip bone (os coxae): variations with age and sex.

Data regarding sexual dimorphism in children are sparse with contradictory results. Recently, geometric morphometric analysis has shown that the pubis and ilium have both sexual shape dimorphism and shape differences that increase during ontogeny, but little is known about the entire pelvic (os coxae) bone shape in very young children. The goal of this study was to show pelvic bone age-related and sex-related shape changes using 3D geometric morphometric analysis in very young children. Geometric morphometric analysis was carried out on CT scans of the pelvic bone of 96 children aged from 3 to 24 months. Eleven landmarks were defined on the left pelvic bone. Geometric morphometric analyses were carried out to identify trends in bone shape in sex-based and age-based subgroups. Age-related differences in shape were statistically significant (Goodall's F = 3.68; p < 0.001) but there were no sex-related differences in shape (Goodall's F = 1.95; p = 0.065). Overall, the superior part of the pelvic bone becomes narrower with age. This study has shown that geometric morphometric analysis of the pelvic bone is feasible in very young children and revealed changes in shape with age but not differences with sex.

Prevalence of inflammatory posterior arch abnormalities on lumbar spine MRI in spondyloarthritis patients compared with low back pain patients.

OBJECTIVES: This study was conducted in order to compare the prevalence of inflammatory posterior arch abnormalities on lumbar spine MRI between axial spondyloarthritis (axSpA) patients and low back pain (LBP) patients. METHODS: Patients-axSpA patients meeting the 2009 ASAS criteria and chronic LBP patients who had a lumbar spine MRI were selected. MRI-STIR and T1 sagittal images up to T8-T9 were reviewed by two experienced rheumatologists blinded to the diagnosis and clinical data to identify inflammatory posterior arch abnormalities. Analyses-The prevalence of inflammatory posterior arch abnormalities between axSpA and LBP patients was compared. Clinical data were compared in the axSpA group depending on whether or not inflammatory posterior arch abnormalities were present. RESULTS: Ninety-five patients were enrolled in each group. The prevalence of all inflammatory posterior arch abnormalities was the same in the axSpA and LBP groups (58% in the SpA group versus 70% in the LBP group, p = 0.1). However, differences in terms of the prevalence of costotransverse joint arthritis, pedicle oedema above L3 and transverse and spinous process oedema were observed between the two groups (axSpA 27% versus LBP 6%, p = 0.0004). Patients with inflammatory posterior arch abnormalities in the axSpA group had a longer disease duration (11 versus 8 years, p = 0.02), higher CRP levels (median 11 versus 3 mg/l, p = 0.0002) and higher prevalence of radiographic sacroiliitis (84 versus 47%, p = 0.001) compared to patients without inflammatory posterior arch abnormalities. CONCLUSIONS: Costotransverse arthritis, pedicle oedema and transverse process oedema are more frequent in axSpA patients than LBP patients, on lumbar spine MRI depicting TH9-S1. KEY POINTS: • MRI pedicle oedema above L3, transverse process oedema, spinous process oedema or costotransverse arthritis is more frequently observed in axial spondyloarthritis (SpA). • SpA patients with at least one MRI inflammatory lesion on the posterior arch had higher clinical activity scores and biological inflammation. • Facet joint arthritis was more common in patients with chronic low back pain.

Case 264: A Case of Osseous Sarcoidosis.

History A 28-year-old woman presented to the emergency department with painful swelling of the third finger on her right hand, which developed quickly. She had no relevant medical or surgical history. Her pain was worse at night, with stiffness decreasing during the morning. Clinical examination revealed generalized swelling of the third finger, cyanotic skin, and fingernail splitting on the second finger of the left hand ( Fig 1 ). Laboratory test results were normal, with no evidence of inflammatory disease. Radiographs of both hands were obtained. CT scanning and MRI were also performed. Figure 1: Photograph of both of the patient's hands shows generalized swelling of the third digit of the right hand, corresponding to dactylitis (arrow). Also note the nail striations in the second digit of the left hand (∗).