Stress Magnetic Resonance Imaging Research Articles

Protocolo diagnóstico de la angina estable

Stable angina is one of the most frequent reasons for consultation in cardiology. It is essential that this disease is correctly diagnosed. The first diagnostic step is to take an accurate clinical history, electrocardiogram (ECG), blood tests and echocardiogram. Before we proceed further, we must rule out other causes of chest pain. Then we must calculate the patient's pre-test likelihood and, based on this, we will choose the most appropriate test. We can rule out ischaemic heart disease for likelihoods less than 5% and atypical symptoms. For intermediate likelihoods we can perform a CT scan of the coronary arteries, nuclear medicine tests, stress echocardiography or stress magnetic resonance imaging. Patients with high likelihood will undergo cardiac catheterisation if they present high-risk signs. If they do not present high-risk signs, we will perform one of the tests used for patients with intermediate likelihood (in this case CT of the coronary arteries is not recommended). It is essential to take a medical history, obtain an ECG, echocardiogram, and blood tests to assess patients with unstable angina correctly. We will then calculate the pre-test likelihood and choose the test that best suits our patient.

Position paper on stress cardiac magnetic resonance imaging in chronic coronary syndrome: Endorsed by the Société française de radiologie (SFR), the Société française d’imagerie cardiovasculaire (SFICV) and the Société française de cardiologie (SFC)

This paper is intended to update the former consensus between the French Societies of Radiology and Cardiology about the use of stress cardiac magnetic resonance imaging in chronic coronary syndrome, published in 2009. The Delphi method was used to build the present consensus. This expert panel consensus includes recommendations for indications, the procedure (with patient preparation), stress-inducing drugs, the acquisition protocol, interpretation and risk stratification by stress magnetic resonance imaging.

Quantitative Analysis of Deltoid Ligament Degradation in Patients With Chronic Ankle Instability Using Computed Tomographic Images.

Rotational ankle instability (RAI) is associated with the faster onset of severe ankle osteoarthritis via dysfunction of the anterior talofibular ligament, calcaneofibular ligament, and deltoid ligament. No specific clinical examination is available for RAI, and diagnostic imaging has limitations in evaluating ligament degradation. This study investigated the deltoid ligament degeneration using Hounsfield unit (HU) values on computed tomography (CT) images. Patients were enrolled in this retrospective analysis if they had undergone magnetic resonance imaging (MRI) and CT scans of the ankle. The chronic ankle instability (CAI) group comprised 20 ankles with CAI (9 men, 11 women; mean age, 28.7 years) and the control group comprised 28 ankles (16 men, 12 women, mean age, 41.3 years). The average HU values of the deep posterior tibiotalar ligament (dPTL) that constitutes the deltoid ligament were measured on coronal CT images, and MRI results were used as a reference. All patients were subdivided based on the MRI findings of dPTL injury such as fascicular disruption, irregularity, and the loss of striation. A strong negative correlation was identified between age and HU values for all patients (Spearman ρ = -0.63; P < .001). The mean HU values of the dPTL for participants aged <60 years were 81.0 HU for the control group (21 ankles) and 69.5 HU for the CAI group (P = .0075). No significant differences in the HU values were observed for the dPTL among the MRI subgroups. In addition to the conventional imaging examination such as stress radiographs and MRI, HU measurements of CT images could be useful for quantitatively and noninvasively evaluating degenerative changes in the deltoid ligament for CAI patients to assist the diagnosis of RAI. Level III. case-control study.

Computer-Assisted System in Stress Radiography for Anterior Cruciate Ligament Injury with Correspondent Evaluation of Relevant Diagnostic Factors.

We sought to design a computer-assisted system measuring the anterior tibial translation in stress radiography, evaluate its diagnostic performance for an anterior cruciate ligament (ACL) tear, and assess factors affecting the diagnostic accuracy. Retrospective research for patients with both knee stress radiography and magnetic resonance imaging (MRI) at our institution was performed. A complete ACL rupture was confirmed on an MRI. The anterior tibial translations with four different methods were measured in 249 patients by the designed algorithm. The diagnostic accuracy of each method in patients with all successful measurements was evaluated. Univariate logistic regression analysis for factors affecting diagnostic accuracy of method four was performed. In the inclusive 249 patients, 177 patients (129 with completely torn ACLs) were available for analysis. Mean anterior tibial translations were significantly increased in the patients with a completely torn ACL by all four methods, with diagnostic accuracies ranging from 66.7% to 75.1%. The diagnostic accuracy of method four was negatively associated with the time interval between stress radiography and MRI as well as force-joint distance on stress view, and not significantly associated with age, gender, flexion angle, intercondylar distance, and force-joint angle. A computer-assisted system measuring the anterior tibial translation in stress radiography showed acceptable diagnostic performance of complete ACL injury. A shorter time interval between stress radiography and MRI as well as shorter force-joint distance were associated with higher diagnostic accuracy.

Stress radiography findings in medial meniscus posterior root tears

BackgroundThe present study aimed to evaluate stress radiography and magnetic resonance imaging (MRI) findings in medial meniscus posterior root tears (MMPRTs). MethodsThe study included 27 patients (26 females, mean age, 53.52 years) who underwent high tibial osteotomy and in whom medial menisci were concurrently examined arthroscopically. Preoperative stress radiographs and MRI series in 14 cases with root tears (MMPRT group, detected arthroscopically) and in 13 cases without tears (control group) were evaluated. Joint spaces measured on the stress radiographs were compared between the operated and opposite knees in each group. ResultsOn the varus stress radiographs, the mean lateral joint space of the operated knees was significantly wider than that of the opposite knees in the MMPRT group (P = 0.007). Upon MRI studies, meniscal extrusion was significantly more common in the MMPRT group than in the control group. Moreover, the amount of meniscal extrusion was correlated with the tear size. ConclusionsWidening of the lateral joint space on the varus stress radiography was higher in the cases with root tears. Therefore, we propose that stress radiographs can be helpful in the diagnosis of MMPRT.

Magnetic resonance imaging of human knee joint functionality under variable compressive in-situ loading and axis alignment

Magnetic resonance imaging (MRI) under mechanical loading, commonly referred to as stress MRI, allows the evaluation of functional properties of intra- and periarticular tissues non-invasively beyond static assessment. Quantitative MRI can identify physiological and pathological responses to loading as indication of, potentially treatable, early degeneration and load transmission failure. Therefore, we have developed and validated an MRI-compatible pressure-controlled axial loading device to compress human knee specimens under variable loading intensity and axis deviation. Ten structurally intact human knee specimens (mean age 83.2 years) were studied on a 3.0T scanner (Achieva, Philips). Proton density-weighted fat-saturated turbo spin-echo and high-resolution 3D water selective 3D gradient-echo MRI scans were acquired sequentially at 10° joint flexion in seven configurations: unloaded and then at approximately half and full body weight loading in neutral, 10° varus and 10° valgus alignment, respectively. Following manual segmentation in both femorotibial compartments, cartilage thickness (ThC) was determined as well as meniscus extrusion (ExM). These measures were compared to computed tomography scans, histological grading (Mankin and Pauli scores), and biomechanical properties (Instantaneous Young's Modulus).Compartmental, regional and subregional changes in ThC and ExM were reflective of loading intensity and joint alignment, with the greatest changes observed in the medial compartment during varus and in the lateral compartment during valgus loading. These were not significantly associated with the histological tissue status or biomechanical properties.In conclusion, this study explores the physiological in-situ response of knee cartilage and meniscus, based on stress MRI, and as a function of loading intensity, joint alignment, histological tissue status, and biomechanical properties, as another step towards clinical implementation.

Angiography-based quantitative coronary contrast-flow ratio measurements correlate with myocardial ischemia assessed by stress MRI

Contrast-flow quantitative flow ratio (cQFR) is a new technology for quantitative evaluation of coronary stenosis using computational fluid dynamics based on angiograms. The aim of this study was to assess the sensitivity and specificity of cQFR to detect myocardial ischemia using stress magnetic resonance imaging (MRI) as a reference standard. Patients who received stress MRI and coronary angiography were selected from the hospital database. Relevant ischemia on stress MRI was defined as a perfusion deficit in ≥ 2 of 16 segments. cQFR was quantitated based on 3-dimensional quantitative coronary angiography using QAngio XA3D1.1 software by two blinded and independent investigators. A cQFR of ≤ 0.80 was considered abnormal. Among 87 patients 230 vessels met the criteria for full analysis by cQFR (88%). In vascular territories with a significant perfusion deficit, cQFR was significantly lower compared to areas with normal perfusion (0.72 (0.62–0.78) vs. 0.96 (0.89–0.99); p < 0.001). The sensitivity of cQFR in detecting significant epicardial stenoses of coronary vessels with documented ischemia in stress MRI was 81% (68–90%), the specificity was 88% (82–92%). Diameter stenoses (DS) and area stenoses (AS) in vessels with positive stress MRI were significantly higher than in vessels without ischemia (DS 59.1% (49.4–68.4%) vs. 34.8% (27.1–46.1%) p < 0.001; AS 75.6% (63.0–85.2%) vs. 45.0% (30.8–63.6%), p < 0.001). The analysis reveals a high correlation between coronary stenosis measured by cQFR and ischemic areas detected by stress MRI. The data set the stage to plan randomized studies assessing cQFR measurements with regard to clinical outcomes.

An MRI-compatible varus\u2013valgus loading device for whole-knee joint functionality assessment based on compartmental compression: a proof-of-concept study

ObjectiveBeyond static assessment, functional techniques are increasingly applied in magnetic resonance imaging (MRI) studies. Stress MRI techniques bring together MRI and mechanical loading to study knee joint and tissue functionality, yet prototypical axial compressive loading devices are bulky and complex to operate. This study aimed to design and validate an MRI-compatible pressure-controlled varus–valgus loading device that applies loading along the joint line.MethodsFollowing the device’s thorough validation, we demonstrated proof of concept by subjecting a structurally intact human cadaveric knee joint to serial imaging in unloaded and loaded configurations, i.e. to varus and valgus loading at 7.5 kPa (= 73.5 N), 15 kPa (= 147.1 N), and 22.5 kPa (= 220.6 N). Following clinical standard (PDw fs) and high-resolution 3D water-selective cartilage (WATSc) sequences, we performed manual segmentations and computations of morphometric cartilage measures. We used CT and radiography (to quantify joint space widths) and histology and biomechanics (to assess tissue quality) as references.ResultsWe found (sub)regional decreases in cartilage volume, thickness, and mean joint space widths reflective of areal pressurization of the medial and lateral femorotibial compartments.DiscussionOnce substantiated by larger sample sizes, varus–valgus loading may provide a powerful alternative stress MRI technique.

Clinical and functional outcome analysis of posterior decompression and spinal fusion surgery in the management of lumbar and sacral listhesis: A prospective cohort study

Introduction: Spondylolisthesis resulting in low backache, radiculopathy, and neurological involvement is a very common clinical entity. Conservative and surgical managements are available for the treatment of spondylolisthesis. Cases with severe instability and neurological deficits that cannot be managed conservatively may require surgical intervention. According to the SPORT trial, posterior decompression and spinal fusion was found to be an effective treatment modality. The present study was undertaken with an aim to understand the functional and clinical effects of posterior decompression and spinal fusion at lumbosacral region in patients with listhesis. Purpose: The purpose of this study is to evaluate the clinical and functional outcomes of listhesis at lumbar and sacral region managed by posterior decompression and spinal fusion. Methods: This was a prospective randomized study involving patients above 18 years, having low backache with or without sciatica, and having neurological deficits. Listhesis was diagnosed clinically and on stress radiograms and magnetic resonance imaging. All patients who fit the inclusion criteria underwent posterior decompression and if needed spinal fusion for symptomatic management. Results: A total of 30 patients participated in this study, with 73.33% women and the rest 26.67% men (mean age 51.37 ± 12.70 years). The most commonly affected level was L4–L5 along with L5–S1 right below it. Out of 30 patients, three underwent posterior decompression and fixation without fusion while one was managed with laminotomy and discectomy. The remaining patients were managed with posterior decompression and intervertebral fusion which was mainly at the L4–L5 level. At 6 months of follow-up, the mean preoperative visual analog scale score which was 8.70 ± 0.83 was reduced to 1.53 ± 1.38 along with appreciable reduction in Japan Orthopedic Association and Oswestry index scores. Three patients had surgical site infections while one patient had no pain relief. Conclusion: Posterior decompression and spinal fusion is an effective way in the management of lumbosacral listhesis.

Gender-specific reference values for high-sensitivity cardiac troponin T and I in well-phenotyped healthy individuals and validity of high-sensitivity assay designation

ObjectiveTo determine gender-specific reference limits of high-sensitivity (hs) cardiac troponins (cTn) and validity of hs assay designation for both genders. MethodsAfter screening with a questionnaire, 827 presumably healthy individuals were further selected based on clinical criteria (n = 740), clinical criteria plus cardiac imaging including stress magnetic resonance imaging or stress echocardiography (n = 726), and extended cardio-pulmonary parameters (n = 626). Blood samples were measured with hs-cTnT (Roche Diagnostics) on a cobas e602 analyzer as well as hs-cTnI (Abbott Diagnostics) on an ARCHITECTi2000SR. The impact of health definition, statistical methods, instrument selection and limit of detection (LoD) on overall and gender-specific 99th percentiles was assessed. ResultsMedian age was 56 years (50.9% female) for the total study cohort. 99th percentiles for females and males ranged between 13.1 and 13.3 ng/L and 16.8–19.9 ng/L for hs-cTnT as well as 10.3–12.5 ng/L and 27.4–29.7 ng/L for hs-cTnI depending on health definition. Utilization of stricter health definition criteria reduced the difference of the gender-specific 99th percentiles between males and females for hs-cTnT to 3.7 ng/L (males 16.8 ng/L, females 13.1 ng/L), whereas the difference rather increased for hs-cTnI to 19.4 ng/L (males 29.7 ng/L, females 10.3 ng/L). Values > LoD could be measured in the majority of males and females using hs-TnT (81.4–83.3% and 96.5–96.9%, respectively). In contrast, values > LoD could not be observed in the majority of females using hs-cTnI (38.4–41.1%). ConclusionsIn a well-phenotyped healthy cohort, reference values for hs-cTnT were slightly higher, whereas hs-cTnI cut-offs were considerably lower than previously observed. Gender differences were more pronounced in hs-cTnI than in hs-cTnT and were further reduced for hs-cTnT by application of stricter health definition criteria. Contrary to hs-cTnI, hs-cTnT fulfilled criteria for hs designation for both genders.

TL 18136 - Short-term results for acute instability of the syndesmosis treated with arthroscopic reduction and percutaneous fixation

Introduction: Acute syndesmotic sprain is rarely associated with instability in the absence of fracture. The surgical treatment of these injuries is usually performed as an open procedure with direct visualization of the anatomical reduction of the joint. However, direct visualization of the reduction can be achieved by arthroscopy with minor incisions avoiding damage to the soft tissues. The aim of this study is to present the short-term outcomes of a series of patients with acute unstable syndesmotic injuries who were surgically treated through an arthroscopic reduction and percutaneous fixation with a suture button. Methods: We report a series of 8 patients with a mean age of 25,62 years with acute instability of the syndesmosis without fracture who were treated through arthroscopic reduction of the syndesmosis followed by percutaneous fixation using a suture button, between October 2014 and May 2018. Medical records, the visual analogue scale (VAS) for pain, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, pre and postoperative radiological results (stress radiographs, computed tomography and magnetic resonance imaging) and complications were retrospectively reviewed. Results: After a mean follow-up of 13,4 months, the mean VAS was 0 and the mean AOFAS was 100. All patients were able to return to their preinjury activities and were completely satisfied with the treatment outcomes. Two patients had an associated deltoid ligament rupture and were treated by open repair at the same time. Two complications were observed. One patient developed an aseptic cyst over the distal knot, and one evolved with complex regional pain syndrome. The last one required a reoperation to remove the anterior button. Conclusion: Arthroscopic treatment represents an effective approach for acute syndesmotic instability. In the short-term, it provides satisfactory clinical and functional results, allowing patients to return to their previous activities. It is reliable regarding anatomic reduction of the syndesmotic joint and percutaneous fixation with a suture button without aggression toward the soft tissue of the ankle.

P2701Comparison of myocardial ischemia assessed by contrast-flow quantitative flow ratio (cQFR) and by stress MRI in patients with stable coronary artery disease

Abstract Background Contrast-flow quantitative flow ratio (cQFR) is a new technology for evaluation of coronary stenosis. cQFR allows to derive the fractional flow reserve (FFR) from coronary angiograms. Based on a three dimensional coronary model, FFR is calculated from computational fluid dynamics. Head to head comparisons with FFR showed an overall diagnostic accuracy of 85%. cQFR does not require coronary wires or hyperemia. However, the ability of cQFR to detect myocardial ischemia is unknown. Therefore, the aim of this study was to evaluate the relationship between cQFR and myocardial ischemia assessed by stress magnetic resonance imaging (stress MRI). Methods cQFR analysis was performed in patients selected from the hospital database who received stress MRI and coronary angiography. A relevant ischemia on stressMRI was defined as a perfusion deficit in ≥2 of 16 segments. The cQFR was based on 3-dimensional quantitative coronary angiography (3D-QCA) using the QAngio XA 3D 1.1, Medis Medical Imaging System, Leiden, The Netherlands. Two blinded investigators analysed all 3 main coronary vessels of each patient measuring diameter stenosis (DS), area stenosis (AS) and cQFR. A cQFR of ≤0.8 was considered abnormal. The primary endpoint was sensitivity and specificity of cQFR using stress MRI as a reference standard. Results 125 vessels of 53 patients could be fully analysed by cQFR (78.6%). The sensitivity of cQFR in detecting significant epicardial stenoses of coronary vessels with documented ischemia in stress MRI was 75%, the specificity was 87%. The 3D-QCA-derived diameter stenoses and area stenoses in vessels with positive stress MRI were significantly higher than in vessels without ischemia (see Table 1). Table 1. Means of diameter stenosis (DS) und area stenosis (AS) with interquartile range (IQR) Total (n=125) Ischemia (n=32) No Ischemia (n=93) p-value DS [%] 42.3 (28.3–53.1) 57.1 (47–68.5) 37.7 (27.6–45.1) &lt;0.0001 AS [%] 51.8 (32.4–69.7) 68.9 (56.8–85.9) 46.5 (29.7–62.7) &lt;0.0001 Conclusion The analysis reveals a high correlation between relevant coronary stenosis measured by cQFR and ischemic areas detected by stress MRI. Differences between the two methods are plausible because stress MRI detects ischemia due to other reasons than epicardial stenosis. Further randomized studies are mandatory to verify the prognostic significance of the cQFR measurements.

Non-invasive assessment prior to invasive coronary angiography in routine clinical practice in Switzerland - Is it according to the guidelines?

BackgroundNon-invasive testing is recommended as a basis to decide about the indication for invasive coronary angiography (ICA) in patients with suspected stenotic coronary artery disease (CAD). However, a recent study based on insurance claims data reported that one third of patients undergoing ICA in Switzerland did not have non-invasive testing beforehand. We aimed to re-evaluate the practice of testing prior to ICA in Switzerland by manual review of patient histories.MethodsRetrospective analysis of all 816 consecutive patients (age 67±9 years, 70% males) undergoing elective ICA solely for the evaluation of stenotic CAD during the year 2015 in a single center in Eastern Switzerland. The proportion of patients undergoing a non-invasive test was assessed, and predictors of the lack of such a test were determined.Results764/816 (94%) patients had a non-invasive test prior to ICA. The majority of patients (728/816; 89%) had an exercise stress test, one fifth (160/816; 20%) underwent a test other than an exercise stress test (6% scintigraphy, 4% stress echocardiography, 6% stress magnetic resonance imaging, 4% computed tomography coronary angiography), and 122/816 (15%) patients had two tests. The use of antianginal drugs other than beta-blockers [odds ratio 1.92 (95% confidence interval 1.01–3.66); p = 0.047] and a lower left ventricular ejection fraction [odds ratio 0.97 (95% confidence interval 0.94–0.99) per one % point increase; p = 0.005] were independent predictors of the lack of a non-invasive test. ICA revealed stenotic CAD in 72% of patients, and 54% of patients underwent revascularization. Patients with and without non-invasive tests did not differ with respect to ICA findings and management.ConclusionsThe present analysis suggests that patients are appropriately selected for ICA based on clinical judgement and non-invasive testing in Switzerland. There is no evidence for an overuse of ICA.

Posterior Malleolus Fracture Displacement Is Associated with Rotational Ankle Fracture Stability in Patients Without Medial Malleolar Fractures.

The optimal method for the determination of ankle stability remains controversial in rotational ankle fractures without medial bony injury. The purposes of this study were to (1) evaluate whether posterior malleolar (PM) fracture displacement is associated with deltoid ligament injury in supination-external rotation (SER) ankle fractures and (2) compare the diagnostic accuracy of PM displacement and magnetic resonance imaging (MRI) evaluation of the deep deltoid ligament in identifying fractures with deltoid ligament incompetence. Patients with rotational bimalleolar injuries containing lateral malleolar and PM fractures without bony medial injury were included. After operative lateral and PM fixation, an external rotation stress test was performed to evaluate deltoid ligament stability. Operative dictations were reviewed to confirm injury pattern, stability on stress test, and visual inspection of the deltoid ligament. Maximum PM displacement was assessed on lateral X-ray. Pre-operative MRI of the ankle was performed following closed reduction and splinting. The final cohort consisted of 13 trimalleolar equivalent fractures (torn deltoid ligament) and 20 bimalleolar fractures (medial malleolus and deltoid ligament intact). Average PM displacement was significantly higher for SER trimalleolar equivalent patterns when measured on lateral X-ray. The sensitivity of detecting trimalleolar equivalent fracture was higher on all reported X-ray findings than the sensitivity obtained by the reported MRI findings of deltoid ligament injury. PM displacement on X-ray is a useful adjuvant along with external rotation stress radiography and MRI evaluation of deep deltoid integrity to distinguish between stable and unstable fracture patterns and thus helps facilitate treatment decisions.

The Diagnostic Accuracy of Radiographs and Magnetic Resonance Imaging in Predicting Deltoid Ligament Ruptures in Ankle Fractures.

Operative indications for supination-external rotation (SER) ankle fractures depend on the integrity of the medial structures. Despite the importance of assessing deep deltoid ligament injuries, the accuracy of common diagnostic tests has not been established. The objective of this study was to compare the ability of injury (non-stress) and stress radiographs and magnetic resonance imaging (MRI) to diagnose deep deltoid ligament ruptures in operative SER ankle fractures. Patients were included who underwent surgical fixation of SER ankle fractures and had appropriate injury and manual stress test radiographs, pre-operative ankle MRI, and intra-operative assessment of deep deltoid integrity by direct visualization. The medial clear space (MCS) was considered positive for all values over 5mm on the injury or stress mortise radiographs. MRI analysis of the deep deltoid ligament injury was performed by blinded fellowship-trained musculoskeletal radiologists. Intra-operative direct visualization and assessment of the deltoid was performed using a direct medial ankle approach at the time of operative fracture fixation. Using intra-operative visualization as the gold standard, MCS measurements and MRI had differing abilities to diagnose a deep deltoid rupture. In cases where the MCS was less than 5mm on injury radiographs and stress tests were performed, MCS measurements were much less accurate than MRI in predicting deltoid ruptures (46% versus 79%, respectively) with a high false positive rate (80%). In contrast, an MCS measurement of greater than 5mm on injury radiographs was a strong predictor of deep deltoid rupture (accuracy of 95%). Compared with direct visualization of the deltoid ligament intra-operatively, these data support proceeding with surgery when the MCS on injury radiographs is greater than 5mm without any additional stress tests or advanced imaging. When the MCS is less than 5mm, we recommend MRI analysis because of its increased accuracy and decreased false positive rate. Improving our ability to diagnose deltoid ruptures will contribute to more effective management of patients with SER ankle fractures.

Could stress magnetic resonance imaging be useful in patients with a low probability of ischemic heart disease?

ObjectiveTo assess the usefulness of cardiac stress magnetic resonance imaging (MRI) with adenosine in the detection of ischemic heart disease in patients with a low pretest probability of disease. Material and methodsWe used the probability ratio to analyze the usefulness of cardiac stress MRI in a selection of patients with a low pretest probability of ischemic heart disease (low or moderate cardiovascular risk, atypical chest pain, or absence of prior ischemic heart disease). ResultsWe included 295 patients followed up for a median of 28 (19–36) months. A total of 60 patients had an event. Cardiac stress MRI was more useful in patients with a low pretest probability: atypical chest pain (probability ratio [PR] positive 8.56), absence of prior ischemic heart disease (PR positive 4.85), and low or moderate cardiovascular risk (PR positive 3.87). ConclusionsCardiac stress MRI can be useful in the diagnosis of ischemic heart disease in patients with a low pretest probability.

Assessment of Ankle Mortise Instability After Isolated Supination-External Rotation Lateral Malleolar Fractures.

The diagnosis of clinically important instability following isolated supination-external rotation (SER) distal fibular fractures is a challenge. The purpose of this study was to investigate the accuracy of clinical findings including medial tenderness, swelling, and ecchymosis, combined with the gravity stress test and magnetic resonance imaging (MRI), in the assessment of ankle mortise stability in association with isolated SER-type lateral malleolar fractures. The external rotation (ER) stress test was used as the reference with which the methods of assessment were compared. Thirty-seven patients were enrolled prospectively. Using the ER stress test as a reference, we evaluated the sensitivity, specificity, likelihood ratio (LR), and post-test probability of instability when using clinical examination, the gravity stress test, and MRI for diagnosing ankle mortise instability after an isolated SER lateral malleolar fracture. The positive LR for clinical findings ranged from 1.45 to 2.54, and the negative LR ranged from 0.25 to 0.70, shifting the pre-test probability to a rarely important degree. In contrast, the positive LR for the gravity stress test was 5.71 with a 95% confidence interval (CI) of 1.52 to 21.48, a moderate shift from the pre-test probability, and the negative LR was 0.33 (95% CI = 0.16 to 0.66), indicating a small shift. In cases with a deep deltoid ligament disruption identified on MRI, the positive LR was 3.05 (95% CI = 1.03 to 9.02) and the negative LR was 0.53 (95% CI = 0.31 to 0.91), demonstrating a small but sometimes important shift. The gravity stress test is a reliable method for diagnosing ankle mortise instability in patients with an isolated SER lateral malleolar fracture. Nevertheless, this test alone would not qualify as a replacement for the ER stress test. However, when the gravity stress test result is consistent with the clinical or MRI findings, its diagnostic value is almost equivalent to that of the ER stress test. Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

¿Podría ser útil la resonancia magnética de estrés en pacientes con baja probabilidad de cardiopatía isquémica?

ObjectiveTo assess the usefulness of cardiac stress magnetic resonance imaging (MRI) with adenosine in the detection of ischemic heart disease in patients with a low pretest probability of disease. Material and methodsWe used the probability ratio to analyze the usefulness of cardiac stress MRI in a selection of patients with a low pretest probability of ischemic heart disease (low or moderate cardiovascular risk, atypical chest pain, or absence of prior ischemic heart disease). ResultsWe included 295 patients followed up for a median of 28 (19-36) months. A total de 60 patients had an event. Cardiac stress MRI was more useful in patients with a low pretest probability: atypical chest pain (probability ratio [PR] positive 8.56), absence of prior ischemic heart disease (PR positive 4.85), and low or moderate cardiovascular risk (PR positive 3.87). ConclusionsCardiac stress MRI can be useful in the diagnosis of ischemic heart disease in patients with a low pretest probability.

Exercise cardiac magnetic resonance imaging: a feasibility study and meta-analysis.

Cardiac stress testing improves detection and risk assessment of heart disease. Magnetic resonance imaging (MRI) is the clinical gold-standard for assessing cardiac morphology and function at rest; however, exercise MRI has not been widely adapted for cardiac assessment because of imaging and device limitations. Commercially available magnetic resonance ergometers, together with improved imaging sequences, have overcome many previous limitations, making cardiac stress MRI more feasible. Here, we aimed to demonstrate clinical feasibility and establish the normative, healthy response to supine exercise MRI. Eight young, healthy subjects underwent rest and exercise cinematic imaging to measure left ventricular volumes and ejection fraction. To establish the normative, healthy response to exercise MRI we performed a comprehensive literature review and meta-analysis of existing exercise cardiac MRI studies. Results were pooled using a random effects model to define the left ventricular ejection fraction, end-diastolic, end-systolic, and stroke volume responses. Our proof-of-concept data showed a marked increase in cardiac index with exercise, secondary to an increase in both heart rate and stroke volume. The change in stroke volume was driven by a reduction in end-systolic volume, with no change in end-diastolic volume. These findings were entirely consistent with 17 previous exercise MRI studies (226 individual records), despite differences in imaging approach, ergometer, or exercise type. Taken together, the data herein demonstrate that exercise cardiac MRI is clinically feasible, using commercially available exercise equipment and vendor-provided product sequences and establish the normative, healthy response to exercise MRI.

Increased Accuracy of Varus Stress Radiographs Versus Magnetic Resonance Imaging in Diagnosing Fibular Collateral Ligament Grade III Tears

To evaluate the diagnostic accuracy of magnetic resonance imaging and varus stress radiographs for fibular collateral ligament (FCL) tears, and compare these modalities to intraoperative findings. All patients who underwent an isolated FCL or combined anterior cruciate ligament (ACL)/FCL reconstruction by a single surgeon between 2010 and 2017 with preoperative varus stress radiographs and magnetic resonance imaging (MRI) were included in this study. A control group was composed of patients with an MRI and intact ACL and FCL. Sensitivity and specificity of diagnosing FCL injuries on MRI were determined based on review by a fellowship-trained musculoskeletal radiologist, blinded to the pathology associated with each patient (FCL injury vs control), and compared with the gold standard of examination under anesthesia, followed by surgical confirmation of an FCL tear at the time of FCL reconstruction. The sensitivity of diagnosing an FCL injury based on varus stress radiographs was also determined. Furthermore, the ability of both imaging modalities to identify an FCL injury was stratified based on acute versus chronic etiology. A total of 232 patients were included: 98 patients in the FCL tear group (mean age: 33.6 ± 12.2years) and 134 patients in the control group (mean age: 44.0 ± 17.2years). Varus stress radiographs were determined to be more sensitive in diagnosing FCL injuries compared with MRI, with an overall sensitivity of 70% compared with 66%, respectively. Based on MRI, overall specificity was 68%. Based on chronicity of the injuries, MRI was more accurate for detecting acute FCL injuries than chronic injuries (P= .002), and varus stress radiographs were more accurate for detecting chronic FCL injuries than acute injuries (P= .041). The results support the use of both varus stress radiographs and MRI in diagnosing FCL injuries, because MRI is more sensitive in diagnosing an acute FCL tear, and varus stress radiographs are more sensitive in diagnosing a chronic FCL tear. Both imaging modalities are recommended to diagnose both acute and chronic FCL injuries. Level II, case-control study.