ESR essentials: MRI of the knee-practice recommendations by ESSR.

Many studies and systematic reviews have been published about MRI of the knee and its structures, discussing detailed anatomy, imaging findings, and correlations between imaging and clinical findings. This paper includes evidence-based recommendations for a general radiologist regarding choice of imaging sequences and reporting basic MRI examinations of the knee. We recommend using clinicians' terminology when it is applicable to the imaging findings, for example, when reporting meniscal, ligament and tendon, or cartilage pathology. The intent is to standardise reporting language and to make reports less equivocal. The aim of the paper is to improve the usefulness of the MRI report by understanding the strengths and limitations of the MRI exam with regard to clinical correlation. We hope the implementation of these recommendations into radiological practice will increase diagnostic accuracy and consistency by avoiding pitfalls and reducing overcalling of pathology on MRI of the knee. CLINICAL RELEVANCE STATEMENT: The recommendations presented here are meant to aid general radiologists in planning and assessing studies to evaluate acute and chronic knee findings by advocating the use of unequivocal terminology and discussing the strengths and limitations of MRI examination of the knee. KEY POINTS: • On MRI, the knee should be examined and assessed in three orthogonal imaging planes. • The basic general protocol must yield T2-weighted fluid-sensitive and T1-weighted images. • The radiological assessment should include evaluation of ligamentous structures, cartilage, bony structures and bone marrow, soft tissues, bursae, alignment, and incidental findings.

Implementation of artificial intelligence in thoracic imaging-a what, how, and why guide from the European Society of Thoracic Imaging (ESTI).

This statement from the European Society of Thoracic imaging (ESTI) explains and summarises the essentials for understanding and implementing Artificial intelligence (AI) in clinical practice in thoracic radiology departments. This document discusses the current AI scientific evidence in thoracic imaging, its potential clinical utility, implementation and costs, training requirements and validation, its' effect on the training of new radiologists, post-implementation issues, and medico-legal and ethical issues. All these issues have to be addressed and overcome, for AI to become implemented clinically in thoracic radiology. KEY POINTS: • Assessing the datasets used for training and validation of the AI system is essential. • A departmental strategy and business plan which includes continuing quality assurance of AI system and a sustainable financial plan is important for successful implementation. • Awareness of the negative effect on training of new radiologists is vital.

A young woman with persistent nausea, vomiting and hiccups. / En ung kvinne med langvarig kvalme, oppkast og hikke.

BACKGROUND: Neuromyelitis optica is an inflammatory syndrome of the central nervous system, associated with anti-aquaporin-4 IgG antibodies. It is associated with severe neurological symptoms and risk of permanent neurological disability. The diagnosis can be established on the basis of clinical core characteristics of neuromyelitis optica, together with serological testing for anti-aquaporin-4 IgG antibodies and magnetic resonance imaging of the central nervous system. CASE PRESENTATION: We describe the case of a young woman presenting with obstipation, persistent nausea, vomiting and hiccups. The initial diagnostic workup confirmed obstipation, but did not find any underlying gastrointestinal pathology that could explain her persistent symptoms. Her condition deteriorated, she was unable to eat or drink without inducing vomiting, and eventually she received parenteral nutrition. Further diagnostic workup included magnetic resonance imaging of the brain, which revealed a T2-hyperintense lesion in the medulla oblongata, more specifically in the area postrema. Neurological and neuroradiological assessment led to a tentative clinical diagnosis of neuromyelitis optica spectrum disorder with a well-described, but rare, presentation: the area postrema syndrome. The diagnosis was confirmed by serological testing for anti-aquaporin-4 IgG antibodies. She was successfully treated with methylprednisolone with complete remission of symptoms. Patients with neuromyelitis optica spectrum disorders frequently experience relapses of the disease if untreated, and she was therefore treated with rituximab to prevent future relapses. INTERPRETATION: This case is a reminder that common gastrointestinal symptoms may be caused by diseases of the central nervous system.

Pulmonary embolism in a patient with Klinefelter's syndrome. / Lungeembolisme hos en pasient med Klinefelters syndrom.

BACKGROUND: Dyspnoea and syncope are common causes of admission to hospitals. Pulmonary embolism is often a differential diagnosis, and by examining the clinical history the clinician searches for known predisposing factors. This case report highlights the importance of Klinefelter's syndrome as a predisposing factor for venous thromboembolism. The syndrome is caused by an extra X chromosome in men, among whom the prevalence is estimated to be 1:500-1:1000. Probably only 25 % of men with the syndrome are diagnosed. CASE PRESENTATION: A man in his forties was admitted to hospital due to dyspnoea and syncope. CT showed submassive pulmonary embolism. The course illustrates the challenges of pulmonary embolism and its association with Klinefelter's syndrome. INTERPRETATION: Several studies have shown an increased incidence of venous thromboembolism in patients with Klinefelter's syndrome. Klinefelter's patients have a higher pre-test likelihood of venous thromboembolism than other patients, similar to patients with hereditary thrombophilia. Klinefelter's syndrome is a persistent risk factor for recurrent thromboembolism. Thus, Klinefelter's syndrome impacts both the diagnosis and treatment of thromboembolic disease.

COVID-19 patients and the radiology department - advice from the European Society of Radiology (ESR) and the European Society of Thoracic Imaging (ESTI).

This document from the European Society of Radiology (ESR) and the European Society of Thoracic Imaging (ESTI) aims to present the main imaging features, and the role of CT scan in the early diagnosis of COVID-19, describing, in particular, the typical findings which make it possible to identify the disease and distinguish it from bacterial causes of infection, and to define which category of patients may benefit from CT imaging. The precautions that must be taken when performing scans to protect radiologists and technologists from infection will be described. The organisational measures that can be taken within radiology departments in order to cope with the influx of patients, while continuing to manage other emergency and time-sensitive activity (e.g. oncology, other infectious diseases etc.), will be discussed. KEY POINTS: • Bilateral ground glass opacities are typical CT manifestations of COVID-19. • Crazy paving and organising pneumonia pattern are seen at a later stage. • Extensive consolidation is associated with a poor prognosis.

Sports Imaging of Team Handball Injuries.

Team handball is a fast high-scoring indoor contact sport with > 20 million registered players who are organized in > 150 federations worldwide. The combination of complex and unique biomechanics of handball throwing, permitted body tackles and blocks, and illegal fouls contribute to team handball ranging among the four athletic sports that carry the highest risks of injury. The categories include a broad range of acute and overuse injuries that most commonly occur in the shoulder, knee, and ankle. In concert with sports medicine, physicians, surgeons, physical therapists, and radiologists consult in the care of handball players through the appropriate use and expert interpretations of radiography, ultrasonography, CT, and MRI studies to facilitate diagnosis, characterization, and healing of a broad spectrum of acute, complex, concomitant, chronic, and overuse injuries. This article is based on published data and the author team's cumulative experience in playing and caring for handball players in Denmark, Sweden, Norway, Germany, Switzerland, and Spain. The article reviews and illustrates the spectrum of common handball injuries and highlights the contributions of sports imaging for diagnosis and management.

Rupture of the Posterior Cruciate Ligament: Preoperative and Postoperative Assessment.

Posterior cruciate ligament (PCL) ruptures are not common, but reconstruction is increasing because PCL-deficient knees are prone to develop osteoarthritis. Preoperative MRI may confirm a total or partial disruption of PCL fibers. An overstretched PCL is often mistaken for an intact PCL while the knee is functionally PCL deficient, resulting in false-negative MRI reports. Posterior translation of the medial condyle is a useful indirect sign on imaging. Preoperative stress radiographs are used to quantify the degree of PCL deficiency, and posterior translation determines whether to treat conservatively or with surgery. Early postoperative imaging is performed to evaluate tunnel placement and fixation devices. Late postoperative imaging is performed to assess graft rupture, arthrofibrosis, or tunnel widening. Pre- and postoperative imaging plays an important part in planning and treating functionally PCL-deficient knees and PCL ruptures.

Imaging of the Postoperative Anterior Cruciate Ligament: Emphasis on New Surgical and Imaging Methods.

The aim of anterior cruciate ligament (ACL) reconstruction is to restore normal function of the knee, but unfortunately abnormal kinematics and a predisposition to knee osteoarthritis occur in a significant percentage of patients. So there is an ongoing need to improve treatment options and long-term outcome of patients with a ruptured ACL. With the recent advancements in the field of ACL tissue engineering, the focus of treatment for ACL injuries is changing from resection and reconstruction toward repair and regeneration. Several new ACL repair methods were recently introduced as an alternative to traditional ACL reconstructive procedures. Radiologists must become familiar with these new surgical methods to interpret their appearance correctly on postoperative imaging studies. This article provides an overview of the latest advancements in ACL surgical methods and discusses the role of imaging to assess the postoperative ACL including both standard and advanced imaging methods.

How to read post-operative radiographs and CT scans after single-bundle anterior cruciate ligament reconstruction.

Reconstruction of the anterior cruciate ligament (ACL) is a well-established surgical procedure. However, post-operative imaging in the early phase is not routinely performed. The rationale for performing such imaging is to provide a baseline examination for future controls, to provide immediate feedback to surgeons regarding tunnel placement, and to assess placement of fixation devices. The purpose of this paper is to enable the reader to accurately read post-operative radiographs and CT scans after single-bundle ACL reconstruction.

Self-assessment of range of motion in patients undergoing surgery for a unilateral shoulder condition.

OBJECTIVE: This study aimed to investigate the agreement of patient-assessed and researcher/physician-assessed measurements of the difference in range of motion between the unaffected and affected shoulders in 55 patients undergoing arthroscopic surgery for a unilateral shoulder condition. METHODS: The investigation included 55 patients (17 women and 38 men; median age=53 years; range=26-74) with a symptomatic unilateral shoulder condition and a surgically treatable diagnosis. Images of a model/researcher performing active shoulder abduction, flexion, external rotation, and internal rotation were created. Each image was paired with a degree diagram or a level system (for internal rotation) on the back for the patient to accurately self-evaluate and record. Each patient was instructed to attentively examine the figures and perform the movements with the same posture as depicted. On the day of surgery, prior to the procedure, 2 independent researchers who were not involved in the patient's care used a standard goniometer to assess the same active movements that the patient had previously self-assessed. For agreement analyses, the intraclass correlation coefficient and Bland-Altman plots were calculated for continuous data (abduction, flexion, and external rotation), and Cohen's weighted kappa was calculated for ordinal categorical data (internal rotation). RESULTS: The intraclass correlation coefficient for abduction, flexion, and external rotation was 0.93 (excellent) 95% CI (0.87, 0.96), 0.89 (good) 95% CI (0.81, 0.94), and 0.72 (moderate) 95% CI (0.52, 0.84), respectively. Cohen's kappa for internal rotation (measured as reaching levels on the back) was 0.63 (moderate). CONCLUSION: We believe that patient-assessed measurements of abduction (intraclass correlation coefficient 0.93) and flexion (intraclass correlation coefficient 0.89) can be used as a valid substitute (for measurements by a clinician or researcher). Patient-assessed measurements for external rotation (intraclass correlation coefficient 0.72) and internal rotation (kappa 0.63) are in moderate agreement and should be used more cautiously as substitutes. LEVEL OF EVIDENCE: Level II, Diagnostic Study.

The Effect of Posterior Tibial Slope on the Risk of Revision Surgery After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: A significant proportion of patients undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) later experience graft failure. Some studies suggest an association between a steep posterior tibial slope (PTS) and graft failure. PURPOSE: To examine the PTS in a large cohort of patients about to undergo ACLR and to determine whether a steep PTS is associated with later revision surgery. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A retrospective review of a cohort undergoing isolated ACLR between 2002 and 2012 (with 8-19 years of follow-up) was conducted. Preoperative sagittal radiographs of knees in full extension were used for measurements of the PTS. There were 2 independent examiners who performed repeated measurements to assess the reliability of the method. Statistical analyses were performed to compare the PTS in the groups with and without later revision surgery. RESULTS: A total of 728 patients, with a mean age of 28 years at the time of surgery, were included. Overall, 10% (n = 76) underwent revision surgery during the observation period. The group of injured knees had a significantly steeper PTS compared with the group of uninjured knees (9.5° vs 8.7°, respectively; P < .05). The mean PTS in the no revision group was 9.5° compared with 9.3° in the revision group (not significant). Dichotomized testing of revision rates related to PTS cutoff values of ≥10°, ≥12°, ≥14°, ≥16°, and ≥18° showed no association of PTS steepness (not significant) to graft failure. Patients with revision were younger than the ones without (mean age, 24 ± 8 vs 29 ± 10 years, respectively) and had a shorter time from injury to ACLR (mean, 14 ± 27 vs 24 ± 44 months, respectively) as well as a smaller graft size (8.2 vs 8.4 mm, respectively; P = .040). CONCLUSION: The current study did not find any association between a steep PTS measured on lateral knee radiographs and revision ACL surgery. However, a steeper PTS was seen in the group of injured knees compared with the group of uninjured (contralateral) knees. Independent of the PTS, younger patients, those with a shorter time from injury to surgery, and those with a smaller graft size were found to undergo revision surgery more often.

Common fetal measurements: a comparison between ultrasound and magnetic resonance imaging.

BACKGROUND: Ultrasound has been the method of choice for antenatal fetal assessment for the past three decades; however, problems may arise in cases of oligohydramnion, unfavorable position of the fetus, and maternal obesity. PURPOSE: To compare ultrasound (US) and magnetic resonance imaging (MRI) for common fetal measurements at 19-30 weeks' gestation, and to assess the effect of high maternal body-mass index (BMI). MATERIAL AND METHODS: 59 low-risk singleton pregnancies were enrolled in a prospective blinded cross-sectional study. In a first session, an experienced obstetrician used a high-resolution US technique and in a second session on the same day MRI was used to measure biparietal diameter (BPD), head circumference (HC), mean abdominal diameter (MAD), abdominal circumference (AC), and femur length (FL). Inter- and intraobserver and intermodality variability was determined using Bland-Altman plots. The effect of maternal BMI was assessed using Spearman's statistics. RESULTS: A total of 45 women aged 19-43 years (median 29 years) attended both US and MRI at median 22 weeks' gestation. The mean differences between US and MRI were 1.6 mm for HC (95% confidence interval [CI] -1.0, 4.3 mm), 1 mm for AC (95% CI -0.2, 4.0 mm), 0.2 mm for MAD (95% CI -0.7, 1.2 mm), 2.2 mm for BPD (95% CI 1.7, 2.7 mm), and 4.6 mm for FL (95% CI 2.9, 6.4 mm). Maternal BMI did not affect the results (Spearman' rho 0.054-0.277; P=NS). The intraobserver agreement for all MRI measurements was acceptable, except for FL, while the interobserver agreement was poor. CONCLUSION: There was good agreement between US and MRI for common fetal measurements, but not for all (i.e., BPD and particularly FL). MRI had a poor interobserver agreement, underscoring the need for technical refinement and reference ranges specifically established for MRI.

Incidence and Prognostic Significance of the Segond Fracture in Patients Undergoing Anterior Cruciate Ligament Reconstruction.

BACKGROUND: The Segond fracture is an avulsion of the anterolateral tibia that can be found in patients with an anterior cruciate ligament (ACL) tear. It is currently unclear if the Segond fracture needs treatment or if it heals spontaneously and if it is associated with an increased risk of failure after ACL reconstruction. PURPOSE: To identify the incidence and spontaneous healing rate of Segond fractures in a consecutive cohort of patients undergoing ACL reconstruction and to examine the predictive value of the Segond fracture on the risk of undergoing revision surgery. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective review of a cohort undergoing isolated ACL reconstruction between 2002 and 2016 was performed. Radiographs from the time of injury and preoperative radiographs were evaluated for Segond fractures and healed Segond fractures. Descriptive data were extracted from an internal quality database. Statistical analyses were performed to investigate risk of revision surgery and to compare across subgroups of patients. RESULTS: A total of 1364 patients were included in the study. The incidence of Segond fractures was 7.4%. In addition, 10.4% of patients displayed signs of healed Segond fractures. In total, 15.2% of patients had either 1 or both findings. The overall healing response of the fracture was 35.6%. Those with Segond fractures were older (P = .014) and had a shorter interval from injury to surgery (P = .003) as compared with the rest of the cohort. The incidence of Segond fractures was significantly higher in those injured during downhill skiing as compared with other injury mechanisms (P = .04). The Segond fracture did not represent an increased risk of undergoing revision when compared with the control group (not significant). CONCLUSION: The incidence of conventional Segond fractures in patients with ACL injury was found to be in accordance with former studies. Accounting for the high incidence of healed Segond fractures, a much higher incidence (15%) was seen. Although the spontaneous healing rate from initial radiographs to preoperative imaging was only 36%, the presence of Segond fractures did not represent a higher risk of undergoing revision surgery.

Computed Tomography Assessment of Anatomic Graft Placement After ACL Reconstruction: A Comparative Study of Grid and Angle Measurements.

BACKGROUND: The anatomic placement of anterior cruciate ligament (ACL) grafts is often assessed with postoperative imaging. In clinical practice, graft angles are measured to indicate anatomic placement on magnetic resonance imaging, whereas grid measurements are performed on computed tomography (CT). Recently, a study indicated that graft angle measurements could also be assessed on CT. No consensus has yet been reached on which measurement method is best suited to assess anatomic graft placement. PURPOSE: To compare the ability of grid measurements and angle measurements to identify anatomic versus nonanatomic tunnel placement on CT performed in patients undergoing ACL reconstruction. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 100 knees undergoing primary reconstruction with a hamstring graft (HAM group), 91 undergoing reconstruction with a bone-patellar tendon-bone graft (BPTB group), and 117 undergoing revision ACL reconstruction (REV group) were assessed with CT. Grid measurements of the femoral and tibial tunnels and angle measurements of grafts were performed. Graft placement, rated as anatomic or nonanatomic, was assessed with both methods. Pearson chi-square, analysis of variance, Kruskal-Wallis, and weighted kappa tests were performed as appropriate. RESULTS: The grid assessment classified 10% of the HAM group, 4% of the BPTB group, and 17% of the REV group as nonanatomic (P < .001). The angle assessment classified 37% of the HAM group, 54% of the BPTB group, and 47% of the REV group as nonanatomic. The weighted kappa between angle measurements and grid measurements was low in all groups (HAM: 0.009; BPTB: 0.065; REV: 0.041). CONCLUSION: The agreement between grid measurements and angle measurements was very low. The angle measurements seemed to overestimate nonanatomic tunnel placement. Grid measurements were better in identifying malpositioned grafts.

Protruding anterior medial meniscus-An indirect sign of posterior cruciate ligament deficiency.

BACKGROUND: to examine if PROTruding of the Anterior Medial Meniscus (PROTAMM) could be an indirect sign of PCL deficiency by comparing PROTAMM to passive posterior tibial sagging (PSS) for chronic PCL rupture on routine MRI. METHODS: Patients with PCL reconstruction between 2011 and 2016 were included in a case control study. Primarily cases with combined ACL/PCL injury were excluded. Secondary exclusion criteria were bony fractures, medial meniscus pathology and poor quality MRIs. Three (blinded) observers reviewed the pre-operative MRIs according to a pre-defined protocol. RESULTS: After applying the inclusion and primary exclusion criteria 16 patients were identified in the PCL rupture group. The control group consisted of 15 patients. After reviewing the MRIs, 6 were excluded due to secondary exclusion criteria. Mean PPS measured 4.8 mm (±â€¯4.4 mm) in the PCL rupture group and 1.8 mm (±2.9 mm) in the control group, p = 0.05. Mean PROTAMM was 3.6 mm (±0.6 mm) in the PCL rupture group and 0.7 mm (±0.9 mm) in the control group, p = 0.004. CONCLUSION: We found a mean PROTAMM of 3.6 mm in patients with PCL rupture. We suggest that this sign, after knee injury in an otherwise normal medial meniscus, is a promising indirect sign of PCL deficiency compared to PPS. Implementation of this sign in clinical practice may improve the sensitivity of routine non-weight bearing MRI in identifying PCL deficient knees.

Reduced glucose transporter-1 in brain derived circulating endothelial cells in mild Alzheimer's disease patients.

Patients with Alzheimer's disease (AD) have blood-brain barrier (BBB) dysfunction. Methods to study cells of the BBB in vivo would facilitate analyses of neurovascular damage in early AD. Thus, we conducted a pilot study to investigate if brain-derived endothelial cells (BDCECs) could be identified from a cell population of circulating endothelial cells (CECs). Peripheral blood was sampled from early AD patients (n = 9), patients with vascular diseases (myocardial infarction (n = 8) and ischemic stroke (n = 8)), and healthy controls (n = 8). We enumerated CD34+/CD146+/CD45- cells (CECs) and Glucose transporter-1 (Glut1+ CECs (BDCECs)) by flow cytometry. We found that BDCECs formed a separate, aggregate cell population. Glut1 expression on BDCECs, measured by the median fluorescence intensity, was significantly decreased in patients with AD compared to both the healthy controls and patients with myocardial infarction ((p < .05, Kruskal-Wallis, Dunn's post hoc test). We found no significant differences in cell numbers. Our study shows that isolation of BDCECs offers a promising non-invasive tool to investigate cells derived from the BBB. Downregulation of Glut1 at the mild stages of AD suggests that agents that increase Glut1 levels may be therapeutic candidates to improve energy availability to the brain.