Postoperative spino-pelvic stereoradiography to predict adjacent segment disease.

PURPOSE: The purpose of this study was to identify sagittal spinopelvic parameters predictive of adjacent segment disease (ASD) on postoperative whole spine weight-bearing stereoradiography. MATERIALS AND METHODS: A total of 84 patients with previous spinal fusion surgery and documented radiological follow-up with early weight-bearing postoperative whole spine stereoradiography (EOS® Imaging System) were retrospectively included. A pathological group of 42 patients (9 men, 33 women; mean age, 63.1±11.5 [SD] years) who developed documented ASD (mean follow-up, 76.75 months; range: 31.5-158.5 months) was compared with a control group of 42 asymptomatic patients (7 men, 35 women; mean age, 60.9±11.8 [SD] years) (mean follow-up, 115 months; range: 60-197 months) based on sagittal balance evaluation and routinely used spino-pelvic parameters. Comparisons were made using uni- and multivariate analyses. RESULTS: At univariate analysis, patients with ASD had an anteriorly displaced sagittal vertical axis (CAM plumb line) and an inadequate lumbar lordosis (LL) in reference to pelvic incidence (PI) compared to controls. They also had higher C7 slope and C2-C7 offset. At multivariate analysis, C2-C7 offset (OR=1.152; 95% CI: 1.056-1.256; P=0.001) and a lack of LL (OR=5.063; 95% CI: 1.139-22.498; P=0.033) were significantly associated with ASD. CONCLUSION: Anterior cervical imbalance, reflected by an increase in C2-C7 offset and insufficient restoration of LL are postoperative predictive factors of ASD on stereoradiography.

Five simultaneous artificial intelligence data challenges on ultrasound, CT, and MRI.

PURPOSE: The goal of this data challenge was to create a structured dynamic with the following objectives: (1) teach radiologists the new rules of General Data Protection Regulation (GDPR), while building a large multicentric prospective database of ultrasound, computed tomography (CT) and MRI patient images; (2) build a network including radiologists, researchers, start-ups, large companies, and students from engineering schools, and; (3) provide all French stakeholders working together during 5 data challenges with a secured framework, offering a realistic picture of the benefits and concerns in October 2018. MATERIALS AND METHODS: Relevant clinical questions were chosen by the Société Francaise de Radiologie. The challenge was designed to respect all French ethical and data protection constraints. Multidisciplinary teams with at least one radiologist, one engineering student, and a company and/or research lab were gathered using different networks, and clinical databases were created accordingly. RESULTS: Five challenges were launched: detection of meniscal tears on MRI, segmentation of renal cortex on CT, detection and characterization of liver lesions on ultrasound, detection of breast lesions on MRI, and characterization of thyroid cartilage lesions on CT. A total of 5,170 images within 4 months were provided for the challenge by 46 radiology services. Twenty-six multidisciplinary teams with 181 contestants worked for one month on the challenges. Three challenges, meniscal tears, renal cortex, and liver lesions, resulted in an accuracy>90%. The fourth challenge (breast) reached 82% and the lastone (thyroid) 70%. CONCLUSION: Theses five challenges were able to gather a large community of radiologists, engineers, researchers, and companies in a very short period of time. The accurate results of three of the five modalities suggest that artificial intelligence is a promising tool in these radiology modalities.

Three-dimensional ultrashort echo time (3D UTE) MRI of Achilles tendon at 4.7T MRI with comparison to conventional sequences in an experimental murine model of spondyloarthropathy.

BACKGROUND: Due to the very short T2 of its components, the normal anatomy of Achilles enthesis is impossible to define with "conventional" long echo time (TE) T2 sequences. However, this is a common site affected by rheumatologic disease. Early abnormalities related to inflammatory processes are impossible to detect in this location. PURPOSE: To assess the feasibility of a 3D-UTE (ultrashort echo time) sequence to evaluate normal and pathological Achilles entheses, determining both anterior fibrocartilaginous and posterior collagenic portions at 4.7T, in a rat model of spondyloarthropathy (SpA) with histological correlation. To assess whether this sequence detects SpA enthesopathy prior to long TE T2 sequences, enabling disease monitoring. STUDY TYPE: Prospective case-control study. ANIMAL MODEL: Twelve immunocompetent Wistar male rats imaged before (controls); the model was induced in eight rats (16 tendons) imaged at day 6, day 13, and day 21 with regular sacrifice for ex vivo imaging and histological correlation. FIELD STRENGTH: 4.7T Bruker Biospec Systems. 3D balanced steady-state free precession (bSSFP) and 3D-UTE sequences, performed at baseline (day 0, n = 12 animals / 24 tendons), day 6 (n = 8/16), 13 (n = 4/8), and day 21 (n = 2/4). ASSESSMENT: Visual analysis and signal intensity measurements (signal to noise ratio, SNR) of both bSSFP and UTE images were performed by two independent musculoskeletal radiologists at different locations of the Achilles enthesis and preinsertional area. STATISTICAL TESTS: Normal and pathological rat values were compared by Wilcoxon signed-rank tests, as well as interobserver differences. MRI findings were compared against histological data. RESULTS: The 3D-UTE sequence identified the anterior fibrocartilage and posterior collagenic areas of Achilles entheses in all cases. Visual analysis and signal intensity measurements distinguished SpA-affected entheses from healthy ones at days 6 and 13 (P = 0.002 and P = 0.006, respectively). Neither the normal anatomy of the enthesis nor its pathological pattern could be identified on T2 bSSFP sequences. DATA CONCLUSION: Unlike bSSFP T2 sequences, 3D-UTE sequences enable visualization of normal enthesis anatomy and early detection of abnormalities in pathological conditions. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:127-135.

Standardization of selection criteria for percutaneous image-guided cryoablation of recurrent soft-tissue sarcomas.

PURPOSE: Percutaneous image-guided cryoablation has not been validated for local management of recurrence of soft tissue sarcoma (STS) of the trunk or limbs. This study aims to identify selection criteria for cryoablation in order to standardize indications of this treatment. PATIENTS AND METHODS: Between 2000 and 2010, 46 patients (57 tumors) presenting local recurrences of STS of the trunk or limbs and treated following standards of care were selected from our institutional database. Eligibility for cryoablation was assessed by two radiologists according to predefined criteria: maximal diameter size of the tumor ≤10cm, distance to skin >5mm, distance to neurovascular structures 3mm at least, absence of articular involvement and planned cryoablation covering the entire lesion volume. Characteristics and outcomes were compared. RESULTS: There was nearly perfect agreement for all criteria (k coefficient ranging from 0.83 to 0.98) between both readers. A subgroup of 13patients was identified as eligible for cryoablation. Locations to the trunk, pelvic girdle or shoulder were significantly more present in the cryoablation group (P=0.002). In this group, tumors were mainly located deeply (P=0.002) with great axes ≤5cm (P=0.044). High local tumor aggressiveness (P=0.016) and differentiated myxoid liposarcoma or myxofibrosarcoma (P=0.007) were more frequent in the eligible group. CONCLUSION: Based on these criteria, two groups of patients with local relapse of STS can be identified. These results may improve the standardization of selection of patients who could be candidates for cryoablation.

Percutaneous image-guided cryoablation in inoperable extra-abdominal desmoid tumors: a study of tolerability and efficacy.

OBJECTIVE: To determine the tolerability, effectiveness and outcomes of percutaneous image-guided cryoablation on inoperable extra-abdominal desmoid tumors. METHODS: Between 2011 and 2012, 13 patients (mean age 39.3 years, range 15-74) with inoperable extra-abdominal desmoid tumors were consecutively treated with cryoablation (17 tumors treated in 17 procedures), including two patients with Gardner syndrome and nine recurrences after surgery. Disease-free survival (DFS) and local control based on RECIST criteria were calculated on prospective clinical and imaging follow-up until 2013. RESULTS: Cryoablation was performed under ultrasound (n = 8), computed tomography (n = 1), or combined (n = 8) guidance, and under general (n = 15) or local (n = 2) anesthesia. A major complication was observed in one session (5.8%). Mean follow-up was 11.3 months (6-27 months). Among all the patients treated, eight patients (47%) presented residual tumors on the first magnetic resonance follow-up, which were asymptomatic. The DFS rate was stable at 82.3% (95% confidence interval 0.55-0.94) at 6, 12, and 24 months. The local tumor progression rate was 0% at 6, 12, and 24 months. Two patients (12%) presented an in situ recurrence. CONCLUSIONS: Despite high rates of partial ablation, percutaneous image-guided cryoablation appears to be safe and effective for local control for patients with inoperable extra-abdominal desmoid tumors.

Bisphosphonate therapy for unresectable symptomatic benign bone tumors: a long-term prospective study of tolerance and efficacy.

OBJECTIVES: To evaluate the long-term tolerance of bisphosphonates proposed as an alternative therapeutic option for symptomatic unresectable benign bone tumors and to evaluate the long-term efficacy of this treatment. METHODS: From March 2007 to March 2011, patients with unresectable symptomatic benign bone tumors were consecutively included in this institutional review board-approved study and treated with bisphosphonates. Prospectively long-term follow-up is reported. The study endpoints were to describe the long-term tolerance, the clinical evolution of pain for each patient and the radiological success defined as a complete disappearance of inflammation and ossification of the bone lesion. All complications and side effects were recorded. RESULTS: Eight patients (mean age 16 years; range 7-42) with various tumor subtypes were included: aneurysmal bone cysts (N=5), Langerhans cell histiocytosis (N=1), osteoblastoma (N=1), and a giant cell tumor (N=1). Tumors were located in cervical (N=4) or thoracic (N=1) vertebrae, femoral shaft (N=1), acetabulum (N=1) and sacrum (N=1). Mean number of bisphosphonate cycles was 3 (range: 1-6) over a median period of 10 months. The median clinical and imaging follow-up period was 21 months (6 to 63 months). No severe complications due to treatment or lesion recurrence were reported. Pain disappeared within 6 weeks of the first cycle for all but one patient. Ossification of the bone lesion was observed for all patients but one, complete for two and partial for the five others. CONCLUSIONS: Bisphosphonates appear to be an effective option without adverse effects for the non-operative management of symptomatic benign bone tumors.

Radiologically guided percutaneous cryotherapy for soft tissue tumours: A promising treatment.

Studies of percutaneous cryotherapy in the treatment of benign or malignant soft tissue tumours are rare and mainly involve small populations. Nevertheless, results show cryotherapy's potential in terms of local control of tumours, analgesic efficacy, reduced intra- and postoperative complications, and reduction in the length of convalescence after the procedure. The objective of this update is to set out the short-term prospects for this technique in the treatment of soft tissue tumours, so that it may be more widely offered in these indications.

Imaging of intervertebral disc prostheses.

Disc arthroplasty is the replacement of a painful pathological intervertebral disc by a prosthesis, which, unlike spinal fixation, has the advantage of retaining vertebral mobility in the segment concerned. The success of the procedure is dictated by the indication. The radiologist must look for radiographic arguments indicating or contraindicating fitting an implant, and particularly for the presence of facet arthritis which will prompt the surgeon to choose an arthrodesis. Moreover, radiological information plays a major part in preparing for a surgical procedure, as far as access to the disc via the anterior approach is concerned and assessment by CT angiography of the risk of vascular complications. After insertion, radiological monitoring using dynamic X-ray images checks that the implant is correctly positioned and that mobility is restored. In the long term, it can detect complications related to the prosthesis and premature wear to other points of support such as adjacent discs and the facet joints.

Fast 3D reconstruction of the lower limb using a parametric model and statistical inferences and clinical measurements calculation from biplanar X-rays.

In clinical routine, lower limb analysis relies on conventional X-ray (2D view) or computerised tomography (CT) Scan (lying position). However, these methods do not allow 3D analysis in standing position. The aim of this study is to propose a fast and accurate 3D-reconstruction-method based on parametric models and statistical inferences from biplanar X-rays with clinical measurements' (CM) assessment in standing position for a clinical routine use. For the reproducibility study, the 95% CI was under 2.7° for all lower limbs' angular measurements except for tibial torsion, femoral torsion and tibiofemoral rotation ( < 5°). The 95% CI were under 2.5 mm for lower limbs' lengths and 1.5 to 3° for the pelvis' CM. Comparisons between X-rays and CT-scan based 3D shapes in vitro showed mean differences of 1.0 mm (95% CI = 2.4 mm). Comparisons of 2D lower limbs' and 3D pelvis' CM between standing 'Shifted-Feet' and 'Non-Shifted-Feet' position showed means differences of 0.0 to 1.4°. Significant differences were found only for pelvic obliquity and rotation. The reconstruction time was about 5 min.

[Discoscanner: indications, technique, tips and tricks, interpretation]. / Discoscanner: indications, technique, trucs et astuces, interprétation.

Discography test associated with the scanner (discoscanner) is an exam that has been a renewed interest in recent few years. Thanks to the emergence of new interventions such as disc prosthesis, the procedures require confirmation of the disc level to deal with and the origin of discogenic symptoms. The aim of this paper is to describe the techniques, challenges and tips as well as the interpretation of functional and morphological examination.

[Labral pathology and impingement]. / Pathologie labrale et conflits de hanche.

The acetabular labrum, a fibrocartilaginous structure essential to the proper functioning of the hip joint, may be damaged from a variety of conditions including femoroacetabular impingement. FAI is defined by abnormal contact between the femur and acetabulum and is characterized by an underlying morphological abnormality of the femur (dysplastic bump at the head/neck junction, Cam effect), acetabulum (excessive coverage, Pincer effect), or both. The abnormal morphology is suspected on plain films and additional evaluation with either CT or MR arthrography is then performed. The role of the radiologist is to describe the imaging findings while allowing the clinician to make the diagnosis based on clinical symptoms (groin pain, reduced internal rotation). Comprehensive evaluation of the underlying structural abnormalities and associated lesions is important to optimize surgical management with the goal of reducing painful symptoms, improve range of motion and prevent early hip joint degeneration.

[Posterior percutaneous arthrodesis under CT guidance after surgical anterior arthrodesis: a new technique]. / Arthrodèse percutanée postérieure sous guidage scanner en complément de l'arthrodèse antérieure chirurgicale: une nouvelle technique.

Transfacet screws may be useful for stabilizing segments reconstructed with bone graft or cages, the role of supplementary posterior fixation, particularly minimally invasive techniques such as transfacetar percutaneous screws is relevant. To benefit from a mechanical fixation after anterior arthrodesis without the inconveniences of the open classical posterior surgical intervention, we have developed a new procedure performed under local anesthesia and CT guidance and based on the intra-articular application of screws. This study was designed to demonstrate the feasibility of using a CT-scan to perform posterior arthrodesis of the spine under local anesthesia.

[Vertebroplasty and kyphoplasty under dual guidance (CT and fluoroscopy): radiation dose to radiologist. A comparative study]. / Étude dosimétrique comparative de la vertébroplastie et de la kyphoplastie sous double guidage: scanner et fluoroscopique.

OBJECTIVES: The goals of this study is to evaluate and compare the irradiation received by the practitioner when performing percutaneous vertebroplasty or kyphoplasty guided by CT and fluoroscopy, for precise anatomical sites. METHODS: For each intervention, radiothermoluminescent dosimeters were carefully positioned on both orbitals, both hands, and both ankles of the practitioner. RESULTS: Twenty-four vertebroplasties were performed in 18 patients and nine kyphoplasties on seven patients. The anatomical site that is most exposed to radiation is the right hand. The two other sites subjected to irradiation are the left hand and the left orbital. This study demonstrates a significant correlation between the irradiation dose and fluoroscopy duration, reflecting both the quantity of primary-beam radiation and backscattered radiation. CONCLUSION: The radiation dose to radiologist is more important for kyphoplasty procedures than vertebroplasty.

[Imaging of the fused spine]. / Imagerie du rachis arthrodésé

Imaging interpretation of the fused spine requires adequate knowledge of instrumentation and fusion techniques. Familiarity with the normal imaging features is needed in order to detect complications. While such complications are relatively rare, their presence is clinically significant and may lead to repeat surgery. Mechanical complications related to instrumentation and fusion (improper device placement, pseudarthrosis, progression of disease at the adjacent non-fused segments) are distinguished from non-mechanical complications (infection, postoperative hematoma, pseudo-meningocele) that usually occur sooner. The different complications will be illustrated with focus on the optimal imaging work-up (radiographs, CT, MRI).

Pseudo-cysts, lipomas, infarcts and simple cysts of the calcaneus: are there different or related lesions?

Pseudocysts, lipomas, infarcts and simple cysts of the calcaneus are described as different entities in the medical literature. However, some evolutions or associations may suggest a relationship which is not yet demonstrated in all cases. The aim of this article is to describe each lesion and emphasize their different characteristics that may suggest a relationship between them.

MR imaging of nephropathies.

Acute and chronic nephropathies are responsible for morphologic and functional renal changes. However, radiologic techniques currently play a minor role in imaging of parenchymal nephropathies in native or transplanted kidneys. From a morphologic point of view, three-dimensional magnetic resonance (MR) volumetric biomarkers of kidney function, such as renal and cortical volumes or cystic volume, in polycystic kidney diseases play a growing role in nephrologic practice. From a functional point of view, if scintigraphic techniques remain the major sources of renal performance assessment, new MR imaging systems and specific MR contrast agents may soon provide significant developments in the evaluation of renal performance (glomerular filtration rate measurement), in the search for prognostic factors (hypoxia, inflammation, cell viability, degree of tubular function, and interstitial fibrosis), and for monitoring new cell therapies. New developments that have provided higher signal-to-noise ratio and higher spatial and/or temporal resolutions have the potential to direct new opportunities for obtaining morphologic and functional information on tissue characteristics that are relevant for various renal diseases with respect to diagnosis, prognosis, and treatment follow-up.

[Imaging of tumors and tumor-like diseases of the hand]. / Imagerie des tumeurs et des lésions d'apparence tumorale de la main.

Tumors and tumor-like lesions of the hand are more frequently benign lesions. Plain film X-rays must be obtained in all patients since they are extensive and panoramic. Ultrasound can accurately assess the internal structure of the mass and its relation with adjacent nerves and vessels. MRI is particularly sensitive to bone marrow and is highly effective in characterizing a wide variety of soft tissue conditions. However, CT remains the method of choice for evaluating bone involvement of soft tissue tumors and small bone tumors such as osteoid oteoma. Where a malignant tumor is considered, thoraco-abdominal and/or bone scintigraphy are essential to evaluate the presence of metastatic lesions.

[Is the rings and arcs pattern of mineralization specific for chondroid matrix tumors?]. / Les calcifications annulaires sont-elles spécifiques des matrices tumorales cartilagineuses?

The rings and arcs pattern of mineralization is considered pathognomonic for cartilaginous tumors. The authors report four cases of osteoblastomas in which the presence of such a pattern of mineralization mistakenly lead to a diagnosis of cartilaginous tumor. These densities are not explained by the histologic findings.

[Monostotic fibrous dysplasia of the calcaneus: two case reports]. / Dysplasie fibreuse monostotique du calcaneus: à propos de 2 cas.

The authors report two unusual cases of aggressive monostotic fibrous dysplasia involving the calcaneus. This lesion occurs on the 2th decade of life. The main symptom is talalgia. On plain films, differential diagnosis includes aggressive cystic or pseudocystic lesions of the calcaneus. On MR imaging, the tumor matrix is more suggestive of the diagnosis. Treatment of this aggressive form of fibrous dysplasia consists of a surgical curettage completed by cryotherapy and graft because of a high level of recurrence.

[Imaging of chilhood and adolescent scoliosis]. / Imagerie des scolioses de l'enfant et de l'adolescent.

Scoliosis is frequent, especially during the peripubertal period, which corresponds to the period of greatest activity. About 75% of scoliosis are idiopathic, while the remaining 25% can be divided into neuromuscular, congenital and miscellaneous etiologies. When it is associated with pain, a comprehensive work up should be undertaken to identify the underlying etiology of the scoliosis. Idiopathic scoliosis is typically evaluated using standard radiographs. The number of follow-up radiographs and radiation exposure must be maintained to a minimum. Radiation safety guidelines and protocols must be implemented. Large cassettes can be replaced by digital acquisitions using units with reconstruction software. The technique of evaluation of these scoliosis series radiographs as well as their results will be reviewed. Recent data regarding the evaluation of spinal and pelvic balance parameters in the standing position will be introduced. Atypical idiopathic and other scoliosis require additional evaluation. Computed tomography, with 2D and 3D reformations, is ideal for evaluation of bony anomalies. MRI is ideal for evaluation of the spinal canal and cord, from the skull base down to the sacrum, for all patients with surgical scoliosis or patients with neurological symptoms. The increased availability of MR imaging has resulted in an increased number of so-called idiopathic asymptomatic scoliosis where an underlying anomaly can be identified.