Search

Objective: We hypothesised that the orientation of the fracture line in the cervical vertebral arch depends on the traumatic mechanism, specifically focusing on frontal oblique spino-laminar fractures to determine if this pattern can serve as an indicator of a hyperextension mechanism of injury of the cervical spine., Materials and Methods: We reviewed the imaging records of 114 adult patients admitted to the emergency department of the Strasbourg University Hospital for severe polytrauma between January 2016 and December 2021 and who presented with a fracture of the posterior vertebral arch of the lower cervical spine on the whole-body CT scan. A radiology resident (R1) and a musculoskeletal radiologist (R2) independently read the CT scans to determine the type of vertebral arch fracture; inter- and intra-observer agreements were calculated using Cohen's Kappa test. Two musculoskeletal radiologists (R2 and R3) then reviewed the CT scans and possible MRIs to identify specific hyperextension injuries of the cervical spine. The association between frontal oblique spino-laminar fracture and hyperextension injuries was assessed using chi 2 test., Results: Thirty-five patients had frontal oblique spino-laminar fractures of the cervical spine. These fractures were significantly associated (p = 0.001) with hyperextension injuries of the cervical spine. The inter- and intra-observer agreements for the identification of these spino-laminar fractures were very good (0.86 (0.75-0.96) and 0.90 (0.81-0.99))., Conclusion: Frontal oblique spino-laminar fractures are easily recognisable on CT scans and significantly associated with other traumatic injuries known as resulting from hyperextension. Their identification should lead to a search for potential associated unstable vertebral disco-ligamentous injuries with MRI., (© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Objective: The goal of this study is to determine whether smooth kernel reconstructions are more sensitive than sharp kernel ones for the detection of sacral stress fractures (SF) using MRI as the reference standard., Materials and Methods: This retrospective study included 100 subjects in whom CT and MR of the pelvis were performed for a clinical suspicion of SF from January 2014 to May 2020 in our institution. MR was used as the reference standard for the presence of SF. Smooth and sharp kernel CT datasets of the 100 patients were pooled and analyzed randomly. Three readers of various experiences in MSK imaging independently evaluated the axial CT images for the presence of a SF., Results: SF was present on MR in 31 patients (22 women, 9 men; mean age 73.6 ± 19.6) and absent in 69 (48 women, 21 men; mean age 68.8 ± 19.0). Depending on readers, sensitivities ranged from 58 to 77% for the smooth kernel and from 52 to 74% for the sharp kernel reconstructions. For each reader, sensitivities (as well as negative predictive values) of CT were slightly greater on the smooth kernel reconstructions., Conclusion: The use of smooth kernel reconstructions improved the sensitivity of CT for the detection of SF compared to the sharp kernel reconstructions usually used and regardless of the experience of the radiologist. Smooth kernel reconstructions should, therefore, be scrutinized in patients with suspicion of SF., (© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

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., (© 2022. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Objective: To analyze full-thickness rotator cuff tears, compare retraction patterns in delaminated and nondelaminated tendons, and correlate retraction distances with anteroposterior tear lengths., Materials and Methods: In 483 MR examinations reported as showing full-thickness cuff tear, two musculoskeletal radiologists independently characterized tendons as delaminated or nondelaminated. Tendon delamination was defined as either horizontal intra-substance splitting of bursal and articular layers by an intervening plane of fluid, or differential retraction of bursal and articular layers. In a subset of 144 shoulders with surgically proven full-thickness cuff tears (45 delaminated, 99 nondelaminated tendons), matched cohorts (n = 45) were further analyzed to compare tendon retraction distance, anteroposterior tear length and retraction ratios (retraction distance/anteroposterior length)., Results: Delamination was present in 13% of 483 total tears, and 31% of 144 operated tears (p = 0.001). In nondelamination and delamination cohorts, mean anteroposterior tear length measured 30.0 and 31.5 mm respectively (p = 0.6). Although nondelaminated tendons showed mean retraction 31.5 mm, articular and bursal layers of delaminated tendons showed mean retractions 36.3 mm and 21 mm respectively (p < 0.0001). Anteroposterior tear length and retraction distance were significantly associated in all cuff tears (p < 0.0001). Retraction ratio for nondelaminated tendons (1.05) was significantly different from retraction ratios for articular (1.21) and bursal (0.70) layers of delaminated tendons (p < 0.0001)., Conclusion: In full-thickness rotator cuff tear, delaminated and nondelaminated tendons show significant differences in retraction distances, despite similarities in anteroposterior dimensions. Delaminated tendons are important to identify and report because they are more likely to fail conservative treatments and undergo operative repairs.

Objectives: The goal of this study was to evaluate different fat-suppressed fluid-sensitive sequences in association with different metal artifacts reduction techniques (MARS) to determine which combination allows better fat suppression around metallic hip implants., Methods: An experimental study using an MRI fat-water phantom quantitatively evaluated contrast shift induced by metallic hip implant for different fat-suppression techniques and MARS. Then a clinical study with patients addressed to MRI unit for painful hip prosthesis compared these techniques in terms of fat suppression quality and diagnosis confidence., Results: Among sequences without MARS, both T2 Dixon and short tau inversion recuperation (STIR) had significantly lower contrast shift (p < 0.05), Dixon offering the best fat suppression. Adding MARS (view-angle tilting or slice-encoding for metal artifact correction (SEMAC)) to STIR gave better results than Dixon alone, and also better than SPAIR and fat saturation with MARS (p < 0.05). There were no statistically significant differences between STIR with view-angle tilting and STIR with SEMAC in terms of fat suppression quality., Conclusions: STIR sequence is the preferred fluid-sensitive MR sequence in patients with metal implant. In combination with MARS (view-angle tilting or SEMAC), STIR appears to be the best option for high-quality fat suppression.

Objective: To prospectively evaluate the performance of virtual non-calcium (VNC) dual-energy CT (DECT) images for the demonstration of trauma-related abnormal marrow attenuation in collapsed and non-collapsed vertebral compression fractures (VCF) with MRI as a reference standard., Materials and Methods: Twenty patients presenting with non-tumoral VCF were consecutively and prospectively included in this IRB-approved study, and underwent MRI and DECT of the spine. MR examination served as a reference standard. Two independent readers visually evaluated all vertebrae for abnormal marrow attenuation ("CT edema") on VNC DECT images; specificity, sensitivity, predictive values, intra and inter-observer agreements were calculated. A last reader performed a quantitative evaluation of CT numbers; cut-off values were calculated using ROC analysis., Results: In the visual analysis, VNC DECT images had an overall sensitivity of 84%, specificity of 97%, and accuracy of 95%, intra- and inter-observer agreements ranged from k = 0.74 to k = 0.90. CT numbers were significantly different between vertebrae with edema on MR and those without (p < 0.0001). Cut-off values provided sensitivity of 85% (77%) and specificity of 82% (74%) for "CT edema" on thoracic (lumbar) vertebrae., Conclusions: VNC DECT images allowed an accurate demonstration of trauma-related abnormal attenuation in VCF, revealing the acute nature of the fracture, on both visual and quantitative evaluation.

Inflammation is the non-specific stereotyped reaction of the musculoskeletal system to various types of aggression, such as infection, tumor, autoimmune diseases, or trauma. Precise evaluation and, increasingly, reliable quantification of inflammation are now key factors for optimal patient management, as targeted therapies (e.g., anti-angiogenesis, anti-macrophages, anti-cytokines) are emerging as everyday drugs. In current practice, inflammation is evaluated mostly using MRI and US on the basis of its non-specific extracellular component due to the increased volume of free water. Inflamed tissue is described as areas of low T1 signal and high T2 signal on magnetic resonance imaging or as hypoechogenic areas on ultrasound imaging, and the evaluation of the increased tissue vascularity can be performed using gadolinium-enhanced MRI or power Doppler US. Emerging new imaging tools, regrouped under the label "cellular and molecular imaging" and defined as the in vivo characterization and measurement of biologic processes at the cellular and molecular level, demonstrate the possible shift of medical imaging from a macroscopic and non-specific level to a microscopic and targeted scale. Cellular and molecular imaging now allows the investigation of specific pathways involved in inflammation (e.g., angiogenesis, cell proliferation, and recruitment, proteases generation, metabolism, gene expression). PET and SPECT imaging are the most commonly used "molecular" imaging modalities, but recent progress in MR, US, and optical imaging has been made. In the future, those techniques might enable a detection of inflammation at its very early stage, its quantification through the definition of biomarkers, and possibly demonstrate the response to therapy at molecular and cellular levels.

Objective: To determine the prevalence of infection diagnosed by percutaneous computed tomography (CT)-guided sternoclavicular (SC) sampling in cases of suspected joint infection., Materials and Methods: A retrospective search was performed in reports of SC joint CT-guided biopsies in adults from July 1992 to July 2012. We reviewed medical records, radiology, microbiology, laboratory, and surgical reports. A positive result was defined as demonstration of a pathogenic organism, either by microscopy or growth in culture, confirming the diagnosis of SC joint infection. A negative result was defined as the absence of such findings. Patients in whom sampling was unsuccessful or not subjected to microbiology were excluded. In addition, CT images were reviewed by the consensus of two musculoskeletal radiologists., Results: A total of 41 patients (mean age 57.1 years) underwent CT-guided SC joint sampling, 27 of whom underwent microbiology studies. Sampling was performed using core biopsy alone in 19%, fine needle aspiration alone in 44%, and aspiration combined with core biopsy in 37%. Positive results were found in 52% (14/27) of patients. Related diseases and predisposing conditions for infection were found in 79% of positive patients. Negative results were found in 48% (13/27) of patients. There were no procedure-related complications. The dominant CT findings were soft tissue swelling (negative group), and effusion and/or capsular hypertrophy/distension (positive group)., Conclusions: CT-guided sampling is a safe procedure with positive microbiological cultures in slightly more than half of cases.

Purpose: To describe the technique and clinical outcome of percutaneous injection of bone cement in the treatment of symptomatic para-articular intraosseous cysts., Materials and Methods: Five patients (three men, two women; mean age 35 years) with painful para-articular intraosseous cysts were treated by percutaneous injection of bone cement under combined fluoroscopic and computed tomography (CT) guidance. The lesions were all located in weight-bearing bones, involving the acetabulum, proximal tibia, distal tibia, talus, and calcaneus, respectively., Results: The average amount of bone cement injected was 2.1 ml (range, 0.6-3.5 ml). Calcium phosphate cement was used in four cases and acrylic cement in one case. There were no immediate or delayed complications. Full pain relief was obtained between 1 and 4 weeks after treatment. All patients made a complete recovery and were pain-free at their last visit., Conclusions: Percutaneous injection of bone cement was a safe and efficient technique in the management of symptomatic para-articular intraosseous cysts in our population.

Introduction: The purpose of this study was to report the MRI findings that can be encountered in successfully treated bacterial septic arthritis., Materials and Methods: The study included 12 patients (8 male and 4 female; mean age 38 years, range 9-85) with 13 proven cases of bacterial septic arthritis. The joints involved were hip (n = 3), knee (n = 3), shoulder (n = 2), sacroiliac (n = 2), ankle (n = 1), wrist (n = 1), and elbow (n = 1). MRI examinations following surgical debridement and at initiation of antibiotic therapy and after successful treatment were compared for changes in effusion, synovium, bone, and periarticular soft tissues. Imaging findings were correlated with microbiological and clinical findings., Results: Joint effusions were present in all joints at baseline and regressed significantly at follow-up MRI (p = 0.001). Abscesses were present in 5 cases (38 %), and their sizes decreased significantly at follow-up (p = 0.001). Synovial enhancement and thickening were observed in all joints at both baseline and follow-up MRI. Myositis/cellulitis was present in 10 cases (77 %) at baseline and in 8 cases (62 %) at follow-up MRI. Bone marrow edema was present in 10 joints (77 %) at baseline and persisted in 8 joints (62 %). Bone erosions were found in 8 joints (62 %) and persisted at follow-up MRI in all cases., Conclusion: The sizes of joint effusions and abscesses appear to be the factors with the most potential for monitoring therapy for septic arthritis, since both decreased significantly following successful treatment. Synovial thickening and enhancement, periarticular myositis/cellulitis, and bone marrow edema can persist even after resolution of the infection.

Objective: Enchondromas are benign lesions that may present with nonspecific features on imaging in children. Correlation of histology with imaging findings is often required to make the final diagnosis of a benign lesion. The aim of this study was to review imaging and pathological findings of enchondromas in children., Materials and Methods: Imaging examinations of 12 enchondromas in 11 patients (median age 14 years) were retrospectively reviewed. Imaging evaluation included an assessment of lesion size, relationship to the growth plate, mineralization, matrix and periosteal reaction, intrinsic MR signal characteristics, and intraosseous and soft-tissue edema. Pathological findings were reviewed., Results: Lesions were located in the phalanx in 33% (4 out of 12), metacarpal in 25% (3 out of 12), femur in 33% (4 out of 12) and tibia in 8% cases (1 out of 12). The mean size was 28 mm (range, 11-70 mm). Matrix mineralization in a typical "rings-and-arcs" pattern was observed in 20% of the lesions with available radiographs/CT (2 out of 10). Lesions were expansive with endosteal scalloping in 75% of cases (9 out 12) and contacted the growth plate in 50% of cases (6 out of 12). All enchondromas in which MR imaging was available (5 out of 5) demonstrated typical cartilaginous matrix of lobules of high T2 signal, low T1 signal, and peripheral enhancement., Conclusion: Enchondromas in children are relatively large lesions, with frequent endosteal scalloping and rare matrix mineralization.

Purpose: Cone-beam computed tomography (CBCT) has become an important modality in dento-facial imaging but remains poorly used in the exploration of the musculoskeletal system. The purpose of this study was to prospectively evaluate the performance and radiation exposure of CBCT arthrography in the evaluation of ligament and cartilage injuries in cadaveric wrists, with gross pathology findings as the standard of reference., Materials and Methods: Conventional arthrography was performed under fluoroscopic guidance on 10 cadaveric wrists, followed by MDCT acquisition and CBCT acquisition. CBCT arthrography and MDCT arthrography images were independently analyzed by two musculoskeletal radiologists working independently and then in consensus. The following items were observed: scapholunate and lunotriquetral ligaments, triangular fibrocartilage complex (TFCC) (tear, integrity), and proximal carpal row cartilage (chondral tears). Wrists were dissected and served as the standard of reference for comparisons. Interobserver agreement, sensitivity, specificity, and accuracy were determined. Radiation dose (CTDI) of both modalities was recorded., Results: CBCT arthrography provides equivalent results to MDCT arthrography in the evaluation of ligaments and cartilage with sensitivity and specificity between 82 and 100%, and interobserver agreement between 0.83 and 0.97. However, radiation dose was significantly lower (p < 0.05) for CBCT arthrography than for MDCT arthrography with a mean CTDI of 2.1 mGy (range 1.7-2.2) versus a mean of 15.1 mGy (range 14.7-16.1)., Conclusion: CBCT arthrography appears to be an innovative alternative to MDCT arthrography of the wrist as it allows an accurate and low radiation dose evaluation of ligaments and cartilage.

Percutaneous image-guided thermal ablation of tumor is widely used, and thermal injury to collateral structures is a known complication of this technique. To avoid thermal damage to surrounding structures, several protection techniques have been reported. We report the use of a simple and effective protective technique combining carbon dioxide dissection and thermocouple: CO(2) displaces the nontarget structures, and its low thermal conductivity provides excellent insulation; insertion of a thermocouple in contact with vulnerable structures achieves continuous thermal monitoring. We performed percutaneous thermal ablation of 37 tumors in 35 patients (4 laser, 10 radiofrequency, and 23 cryoablations) with protection of adjacent vulnerable structures by using CO(2) dissection combined with continuous thermal monitoring with thermocouple. Tumor locations were various (19 intra-abdominal tumors including 4 livers and 9 kidneys, 18 musculoskeletal tumors including 11 spinal tumors). CO(2) volume ranged from 10 ml (epidural space) to 1500 ml (abdominal). Repeated insufflations were performed if necessary, depending on the information given by the thermocouple and imaging control. Dissection with optimal thermal protection was achieved in all cases except two patients where adherences (one postoperative, one arachnoiditis) blocked proper gaseous distribution. No complication referred to this technique was noted. This safe, cost-effective, and simple method increases the safety and the success rate of percutaneous thermal ablation procedures. It also offers the potential to increase the number of tumors that can be treated via a percutaneous approach.

Objective: The aim of this study was to investigate skeletal muscle denervation using diffusion-weighted magnetic resonance imaging (DWMRI)., Materials and Methods: Sciatic nerve axotomy was performed in a group of nine New Zealand White rabbits, and electromyographic (EMG), pathological, and DWMRI studies were conducted on ipsilateral hamstring muscles 1 and 8 days after axotomy. In addition, DWMRI studies were carried out on leg muscles of ten patients with acute and subacute lumbosacral radiculopathy., Results: High intensity signals on short tau inversion recovery (STIR) magnetic resonance imaging and an increased apparent diffusion coefficient (ADC) were observed in denervated muscles of the animals 1 and 8 days after axotomy as well as in denervated muscles of the patients with radiculopathy. In the clinical study, ADC was 1.26 +/- 0.18 x 10(-9) m(2)/s in normal muscle and increased to 1.56 +/- 0.23 x 10(-9) m(2)/s in denervated muscles (p = 0.0016). In animals, EMG and muscle pathological studies were normal 1 day after axotomy, and the muscles demonstrated spontaneous activity on EMG and neurogenic atrophy on histological studies 7 days later., Conclusion: This DWMRI study demonstrates that enlargement of extracellular fluid space in muscle denervation is an early phenomenon occurring several days before the appearance of EMG and histological abnormalities.

Paravertebral lumbar muscles are important for spine stabilization and mobility. They may be abnormal in several disorders that may be associated with pain or functional impairment. Special attention should be paid to the paravertebral muscles during imaging, so that a possible muscular disease is not overlooked, especially in patients with low back pain. This article reviews such imaging abnormalities.