Magnetic Resonance Direct Thrombus Imaging Research Articles

Acute pulmonary embolism with high-intensity signals on magnetic resonance direct thrombus imaging.

Acute pulmonary embolism with high-intensity signals on magnetic resonance direct thrombus imaging.

MRI- and CT-venography in the diagnosis of hemodynamic disorders in patients suffering from lower extremities chronic venous disorders. Part II. Possibilities of MRI in diagnostics of the deep vein thrombosis

In this literature review, the analysis of the studies of venous blood flow pathology in the inferior Vena cava system using magnetic resonance imaging (MRI) is carried out. Special attention is paid to the attempts made to use this method in the diagnosis of chronic lower limb vein disorders (CVD) through magnetic resonance venography (MRV). Historically and methodically, the gradual introduction of MRV methods in the diagnosis of lower limb vein thrombosis (LEDVT) and venous thromboembolism (VTE) has been shown.Methods of non-contrast MRV based on the effect of blood flow, as in the case of MR-Angiography, are divided into two principal groups: methods based on the amplitude effects of Time-of-Flight (TOF) and methods based on Phase Contrast effects (PC). Techniques for conducting contrast-free MRV are described in detail. Attention is paid to pulse sequences used in the world for visualization of veins in contrast-free MRV in TOF and PC mode (FR-FBI, SPADE, SSFP) and post-processing methods: 2D-TOF MRV FLASH, 2D-TOF MRV CRASS, FIPS, VED, VENS.Contrast-enhanced MRV (CE MRV) is based on the use of “blood pool” contrast agents, which feature the ability to form stable compounds with blood plasma proteins. Worldwidesubstances with magnetic and supermagnetic properties based on gadolinium or iron oxide are used as contrast agents for CE MRV. The result of using these contrast agents is an increase in the quality of visualization due to a better signal to noise ratio (SNR) using 3D image processing (3D CE MRV) using fast sequences: GRE, TFLAS, VESPA, CAT, in conditions of direct and indirect CE MRV.It is noted that in recent years, certain restrictions have been imposed on certain linear contrast agents containing gadolinium in their further use. Therefore, for the purpose of CE MRV, it is efficientl to use only cyclic contrast agents to avoid unnecessary risks.Contrast-free MRV has again received intensive development in recent years, due to the restrictions imposed, one of these methods is direct thrombus imaging (Direct Thrombus Imaging – DTI or Magnetic Resonance Direct Thrombus Imaging - MRDTI) using fast pulse sequences: bSSFP, BBTI, DANTE. The latest research on this LEDVT diagnostic method was published in 2019 and has shown high diagnostic value.For all the most commonly used methods of MRV, specificity and sensitivity are shown.Further MRV in patients with CVD and DVT is a promising diagnostic task in modern phlebology. MRV should be introduced into clinical practice more actively than it is today.

Cost-effectiveness of magnetic resonance imaging for diagnosing recurrent ipsilateral deep vein thrombosis

The diagnostic workup of recurrent ipsilateral deep vein thrombosis (DVT) using compression ultrasonography (CUS) can be complicated by persistent intravascular abnormalities after a previous DVT. We showed that magnetic resonance direct thrombus imaging (MRDTI) can exclude recurrent ipsilateral DVT. However, it is unknown whether the application of MRDTI in daily clinical practice is cost effective. The aim of this study was to evaluate the cost effectiveness of MRDTI-based diagnosis for suspected recurrent ipsilateral DVT during first year of treatment and follow-up in the Dutch health care setting. Patient-level data of the Theia study (NCT02262052) were analyzed in 10 diagnostic scenarios, including a clinical decision rule and D-dimer test and imaging with CUS and/or MRDTI. The total costs of diagnostic tests and treatment during 1-year follow-up, including costs of false-positive and false-negative diagnoses, were compared and related to the associated mortality. The 1-year health care costs with MRDTI (range, €1219-1296) were generally lower than strategies without MRDTI (range, €1278-1529). This was because of superior specificity, despite higher initial diagnostic costs. Diagnostic strategies including CUS alone and CUS followed by MRDTI in case of an inconclusive CUS were potential optimal cost-effective strategies, with estimated average costs of €1529 and €1263 per patient and predicted mortality of 1 per 737 patients and 1 per 609 patients, respectively. Our model shows that diagnostic strategies with MRDTI for suspected recurrent ipsilateral DVT have generally lower 1-year health care costs than strategies without MRDTI. Therefore, compared with CUS alone, applying MRDTI did not increase health care costs.

Time-efficient and contrast-free magnetic resonance imaging approach to the diagnosis of deep vein thrombosis on black-blood gradient-echo sequence: a pilot study.

Black-blood thrombus imaging (BTI) has shown to be advantageous for the diagnosis of deep vein thrombosis (DVT). However, previous techniques using fast spin echo have a high specific absorption rate. As DANTE (delay alternating with nutation for tailored excitation) black-blood preparation can suppress blood flows over a broad range of velocities, we hypothesized that a DANTE black-blood preparation combined with a fast low-angle shot (FLASH) gradient-echo readout-DANTE-FLASH could be used to diagnose DVT. Eleven healthy volunteers and 30 suspected DVT patients were recruited to undergo DANTE-FLASH and magnetic resonance direct thrombus imaging (MRDTI). The suspected DVT patients were also examined by ultrasound (US). For the segment level, a total of 1,066 venous vessel segments were analyzed. Using US and MRDTI as the references, the sensitivity (SE), specificity (SP), positive and negative predictive values (PPV and NPV), and accuracy (ACC) of DANTE-FLASH were calculated. To quantitatively compare image quality between DANTE-FLASH and MRDTI, image signal-to-noise ratio (SNR), apparent contrast-to-noise ratio (CNR) between muscle and the venous lumen, and the apparent CNR between the thrombus and venous lumen were measured. Additionally, diagnostic confidence, image quality, and clot burden were also evaluated. Using the consensus results of US and MRDTI as a standard reference, the diagnostic SE, SP, PPV, NPV, and ACC of DANTE-FLASH for the 2 readers were 97.0% and 93.2%, 99.0% and 98.2%, 93.4% and 87.9%, 99.6% and 99.0%, and 98.8% and 97.6%, respectively. According to the image quantitative analysis results, DANTE-FLASH demonstrated higher image SNR and CNR than MRDTI. The image quality and diagnostic confidence scores of DANTE-FLASH were higher than MRDTI (3.66±0.44 vs. 3.52±0.52, P<0.001, and 3.84±0.36 vs. 3.76±0.41, P<0.001). There was excellent agreement between DANTE-FLASH and MRDTI on clot burden evaluation. DANTE-FLASH provided better image quality than MRDTI and accurately detected thrombi. It may, therefore, serve as a safe and convenient alternative for the diagnosis of DVT.

Safety of using the combination of the Wells rule and D‐dimer test for excluding acute recurrent ipsilateral deep vein thrombosis

BackgroundThe diagnostic accuracy of clinical probability assessment and D‐dimer testing for clinically suspected recurrent deep vein thrombosis (DVT) is largely unknown. AimTo evaluate the safety of ruling out acute recurrent DVT based on an unlikely Wells score for DVT and a normal D‐dimer test. MethodsThis was a predefined endpoint of the Theia study in which the diagnostic accuracy of magnetic resonance direct thrombus imaging in acute recurrent ipsilateral DVT was validated. The Wells rule and D‐dimer test, performed as part of the study protocol, were not used for management decisions. The primary outcome of this analysis was the incidence of recurrent DVT at baseline or during 3‐month follow‐up for patients with an unlikely Wells score and a normal D‐dimer test. ResultsResults of both Wells score and D‐dimer tests were available in 231 patients without anticoagulant treatment. The recurrent DVT prevalence was 45% (103/231). Forty‐nine patients had an unlikely Wells score and normal D‐dimer test, of whom 3 (6.1%, 95% confidence interval [CI] 1.3%‐18%) had recurrent DVT at baseline/follow‐up, yielding a sensitivity of 97% (95% CI 92%‐99%) and specificity of 36% (95% CI 28%‐45%). Thus, if clinical probability scoring and D‐dimer testing would have been applied, radiological imaging could have been omitted in 21% of patients with a diagnostic failure rate of 6.1%. ConclusionBy applying clinical probability scoring and D‐dimer testing, radiological imaging could be spared in one fifth of patients with suspected recurrent ipsilateral DVT. However, the high failure rate does not support implementation of this strategy in daily practice.

Magnetic resonance imaging for diagnosis of recurrent ipsilateral deep vein thrombosis

AbstractThe diagnosis of recurrent ipsilateral deep vein thrombosis (DVT) is challenging, because persistent intravascular abnormalities after previous DVT often hinder a diagnosis by compression ultrasonography. Magnetic resonance direct thrombus imaging (MRDTI), a technique without intravenous contrast and with a 10-minute acquisition time, has been shown to accurately distinguish acute recurrent DVT from chronic thrombotic remains. We have evaluated the safety of MRDTI as the sole test for excluding recurrent ipsilateral DVT. The Theia Study was a prospective, international, multicenter, diagnostic management study involving patients with clinically suspected acute recurrent ipsilateral DVT. Treatment of the patients was managed according to the result of the MRDTI, performed within 24 hours of study inclusion. The primary outcome was the 3-month incidence of venous thromboembolism (VTE) after a MRDTI negative for DVT. The secondary outcome was the interobserver agreement on the MRDTI readings. An independent committee adjudicated all end points. Three hundred five patients were included. The baseline prevalence of recurrent DVT was 38%; superficial thrombophlebitis was diagnosed in 4.6%. The primary outcome occurred in 2 of 119 (1.7%; 95% confidence interval [CI], 0.20-5.9) patients with MRDTI negative for DVT and thrombophlebitis, who were not treated with any anticoagulant during follow-up; neither of these recurrences was fatal. The incidence of recurrent VTE in all patients with MRDTI negative for DVT was 1.1% (95% CI, 0.13%-3.8%). The agreement between initial local and post hoc central reading of the MRDTI images was excellent (κ statistic, 0.91). The incidence of VTE recurrence after negative MRDTI was low, and MRDTI proved to be a feasible and reproducible diagnostic test. This trial was registered at www.clinicaltrials.gov as #NCT02262052.

Magnetic Resonance Direct Thrombus Imaging (MRDTI) Can Distinguish Between Old and New Thrombosis in the Abdominal Aorta: a Case Report.

A 43-year-old man complaining of abdominal angina for several months showed a large suprarenal aneurysm of the abdominal aorta with extensive circumferential wall thrombosis, complete occlusion of the right renal artery and a critically stenosed left renal artery on CT angiography. He suffered from severe hypertension and renal failure. A percutaneous transluminal angioplasty (PTA) was planned. After the PTA procedure, which was complicated by the development of left renal artery occlusion, successful rescue revascularization surgery was performed. Since we were hesitant to start anticoagulant treatment because of a high bleeding risk, magnetic resonance direct thrombus imaging was performed to assess the age of the extensive arterial thrombosis. The aortic thrombus showed a low signal intensity, which is indicative of chronic rather than acute thrombosis. Therefore, oral anticoagulant treatment was not started. The patient recovered without major complications.LEARNING POINTSAccurate diagnosis and treatment of aortic intraluminal thrombosis are of the utmost importance to prevent serious complications such as (peripheral) arterial embolic occlusion with resultant ischemia.Current imaging modalities do not allow for accurate distinction between acute and chronic thrombosis in the abdominal aorta. Hence, differentiating between stable and unstable thrombosis is challenging.The non-invasive magnetic resonance direct thrombus imaging technique may be a valuable additional imaging test to establish a definitive diagnosis and treatment plan in patients with abdominal aortic thrombosis.

Diagnosing Recurrent DVT of the Leg by Two Different Non-Contrast-Enhanced Magnetic Resonance Direct Thrombus Imaging Techniques: A Pilot Study.

Introduction  Magnetic resonance direct thrombus imaging (MRDTI) is a promising technique to improve the diagnostic management of patients with a suspected ipsilateral recurrent deep vein thrombosis (DVT) by direct visualization of a thrombus. Another magnetic resonance imaging (MRI) technique, T1-weighted turbo spin-echo spectral attenuated inversion recovery (TSE-SPAIR), has the potential to image a thrombus directly with a high spatial resolution as well. The main aim of this pilot study was to investigate if adding the TSE-SPAIR sequence to an MRDTI sequence performed in patients with suspected recurrent DVT may increase the diagnostic confidence of expert MRDTI readers. Methods  Fifteen patients with suspected acute recurrent DVT were included in this study. The TSE-SPAIR sequence was scanned directly after the MRDTI scan but not used to guide clinical decision making, and both scans were adjudicated post hoc two times separately by three independent expert MRDTI readers. Diagnostic confidence was scored on a 4-point Likert scale: (1) poor (definite diagnosis impossible), (2) fair (evaluation of major findings possible), (3) good (definite diagnosis possible), and (4) excellent (exact diagnosis possible). Results  The diagnostic confidence of expert readers increased when adding the TSE-SPAIR sequence on top of the MRDTI sequence from “good” (median, 3.0; interquartile range [IQR], 2.66–3.0) to “excellent” (median, 3.67; IQR 3.33–3.67; p  = 0.001). Evaluation of the scans in the reversed order 5 months after initial reading showed similar results. Diagnostic accuracy for proximal DVT of both scan techniques was good. Conclusion  The extra TSE-SPAIR sequence may help increase diagnostic confidence of radiologists in cases of uncertain diagnosis in patients with suspected ipsilateral recurrent DVT.

Diagnosing upper extremity deep vein thrombosis with non-contrast-enhanced Magnetic Resonance Direct Thrombus Imaging: A pilot study

Diagnosing upper extremity deep vein thrombosis (UEDVT) can be challenging. Compression ultrasonography is often inconclusive because of overlying anatomic structures that hamper compressing veins. Contrast venography is invasive and has a risk of contrast allergy. Magnetic Resonance Direct Thrombus Imaging (MRDTI) and Three Dimensional Turbo Spin-echo Spectral Attenuated Inversion Recovery (3D TSE-SPAIR) are both non-contrast-enhanced Magnetic Resonance Imaging (MRI) sequences that can visualize a thrombus directly by the visualization of methemoglobin, which is formed in a fresh blood clot. MRDTI has been proven to be accurate in diagnosing deep venous thrombosis (DVT) of the leg. The primary aim of this pilot study was to test the feasibility of diagnosing UEDVT with these MRI techniques. MRDTI and 3D TSE-SPAIR were performed in 3 pilot patients who were already diagnosed with UEDVT by ultrasonography or contrast venography. In all patients, UEDVT diagnosis could be confirmed by MRDTI and 3D TSE-SPAIR in all vein segments. In conclusion, this study showed that non-contrast MRDTI and 3D TSE-SPAIR sequences may be feasible tests to diagnose UEDVT. However diagnostic accuracy and management studies have to be performed before these techniques can be routinely used in clinical practice.

Diagnosis of recurrent venous thromboembolism

The diagnostic management of suspected recurrent venous thromboembolism (VTE) is challenging for four main reasons. First, clinical decision rules are less useful to identity patients with a low pre-test probability. Second, the diagnostic performance of D-dimer tests is decreased. Together, these two point lead to a clearly lower proportion of patients in whom recurrent VTE can be ruled out without performing imaging tests. Third, recurrent thrombi may be difficult to differentiate from residual thrombi, which may be often identified in patients with a history of VTE. Fourth and lastly, the prevalence of VTE in patients with suspected recurrent disease is higher than in patients with suspected first VTE. As a consequence, the failure rates of the algorithms in patients with suspected recurrent VTE are higher as well, underling the relevance of accurate diagnostic management of this specific patient population. There is a lack of large well designed diagnostic studies that focus mainly on patients with prior VTE. Even so, available evidence suggests that diagnostic algorithms validated for first VTE are also largely applicable to suspected recurrent VTE. Emerging imaging techniques such as magnetic resonance direct thrombus imaging (MRDTI) are likely to improve the accuracy of the algorithms in the near future.

A Multicenter MRI Protocol for the Evaluation and Quantification of Deep Vein Thrombosis.

We evaluated a magnetic resonance venography (MRV) approach with gadofosveset to quantify total thrombus volume changes as the principal criterion for treatment efficacyin a multicenter randomized study comparing edoxaban monotherapy with a heparin/warfarin regimen for acute, symptomatic lower extremities deep vein thrombosis (DVT) treatment. We also used a direct thrombus imaging approach (DTHI, without the use of a contrast agent) to quantify fresh thrombus. We then sought to evaluate the reproducibility of the analysis methodology and applicability of using 3D magnetic resonance venography and direct thrombus imaging for the quantification of DVT in a multicenter trial setting. From 10 randomly selected subjects participating in the edoxaban Thrombus Reduction Imaging Study (eTRIS), total thrombus volume in the entire lower extremity deep venous system was quantified bilaterally. Subjects were imaged using 3D-T1W gradient echo sequences before (direct thrombus imaging, DTHI) and 5 min after injection of 0.03 mmol/kg of gadofosveset trisodium (magnetic resonance venography, MRV). The margins of the DVT on corresponding axial, curved multi-planar reformatted images were manually delineated by two observers to obtain volumetric measurements of the venous thrombi. MRV was used to compute total DVT volume, whereas DTHI was used to compute volume of fresh thrombus. Intra-class correlation (ICC) and Bland Altman analysis were performed to compare inter and intra-observer variability of the analysis. The ICC for inter and intra-observer variability was excellent (0.99 and 0.98, p <0.001, respectively) with no bias on Bland-Altman analysis for MRV images. For DTHI images, the results were slightly lower (ICC = 0.88 and 0.95 respectively, p <0.001), with bias for inter-observer results on Bland-Altman plots. This study showed feasibility of thrombus volume estimation in DVT using MRV with gadofosveset trisodium, with good intra- and inter-observer reproducibility in a multicenter setting.

Compression in acute stroke: nursing considerations

British Journal of Neuroscience NursingVol. 11, No. Sup2 CommentCompression in acute stroke: nursing considerationsEmma GeeEmma GeeSearch for more papers by this authorEmma GeePublished Online:27 Apr 2015https://doi.org/10.12968/bjnn.2015.11.Sup2.20AboutSectionsView articleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinked InEmail View article References CLOTS trial collaboration (2009) Effectiveness of thigh-length graduated compression stockings to reduce the risk of deep vein thrombosis after stroke (CLOTS Trial 1): a multicentre, randomised controlled trial. Lancet 373(9679): 1958–65 Crossref, Google ScholarCLOTS trials collaboration (2010) Thigh-length versus below-knee stockings for DVT prophylaxis after stroke: a randomised trial. Ann Intern Med 153(9): 553–62 Crossref, Google ScholarCLOTS (Clots in Legs Or sTockings after Stroke) Trials Collaboration et al. (2013) Effectiveness of intermittent pneumatic compression in reduction of risk of deep vein thrombosis in patients who have had a stroke (CLOTS3): a multicentre randomised controlled trial. Lancet 382(9891): 516–24 Crossref, Google ScholarCLOTS (Clots in Legs Or sTockings after Stroke) Trials Collaboration (2014) Effect of intermittent pneumatic compression on disability, living circumstances, quality of life, and hospital costs after stroke: secondary analyses from CLOTS 3, a randomised trial. Lancet Neurol 13(12): 1186–92 Crossref, Google ScholarKearon C (2003) Natural History of Venous Thromboembolism. Circulation 107(23): 122–30 Google ScholarKelly J, Rudd A, Lewis RR, Coshall C et al. (2004) Venous Thromboembolism after acute ischaemic stroke; a prospective study using magnetic resonance direct thrombus imaging. Stroke 35: 2320–25 Crossref, Google ScholarKohro S, Yamakage M, Sato K et al. (2005) Intermittent pneumatic foot compression can activate blood fibrinolysis without changes in blood coagulability and platelet activation. Acta Anaesthesiologica Scandinavica 49: 660–4 Crossref, Google ScholarLankeit M, Konstantinides S (2011) Mortality risk assessment and the role of thrombolysis in pulmonary embolism. Critical Care Clinics 27(4): 953–67 Crossref, Google ScholarNational Institute for Health and Care Excellence (2010) NICE clinical guidance 92. Venous thromboembolism: reducing the risk: Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital. https://www.nice.org.uk/guidance/cg92 (accessed 26 March 2015) Google ScholarNational Institute for Health and Care Excellence (2015) Addendum to NICE clinical guidance CG92. Reducing the risk of venous thromboembolism in patients admitted to hospital (Chapter 24-stroke patients). Draft for consultation. http://tinyurl.com/pdyk9xz (accessed 26 March 2015) Google ScholarStevens S, Woller S (2013) Intermittent pneumatic compression in patients with stroke. Lancet 382(9891): 484–6 Crossref, Google Scholar FiguresReferencesRelatedDetails 1 April 2015Volume 11Issue Sup2ISSN (print): 1747-0307ISSN (online): 2052-2800 Metrics History Published online 27 April 2015 Published in print 1 April 2015 Information© MA Healthcare LimitedPDF download

Magnetic resonance direct thrombus imaging differentiates acute recurrent ipsilateral deep vein thrombosis from residual thrombosis

AbstractAccurate diagnostic assessment of suspected ipsilateral recurrent deep vein thrombosis (DVT) is a major clinical challenge because differentiating between acute recurrent thrombosis and residual thrombosis is difficult with compression ultrasonography (CUS). We evaluated noninvasive magnetic resonance direct thrombus imaging (MRDTI) in a prospective study of 39 patients with symptomatic recurrent ipsilateral DVT (incompressibility of a different proximal venous segment than at the prior DVT) and 42 asymptomatic patients with at least 6-month-old chronic residual thrombi and normal D-dimer levels. All patients were subjected to MRDTI. MRDTI images were judged by 2 independent radiologists blinded for the presence of acute DVT and a third in case of disagreement. The sensitivity, specificity, and interobserver reliability of MRDTI were determined. MRDTI demonstrated acute recurrent ipsilateral DVT in 37 of 39 patients and was normal in all 42 patients without symptomatic recurrent disease for a sensitivity of 95% (95% CI, 83% to 99%) and a specificity of 100% (95% CI, 92% to 100%). Interobserver agreement was excellent (κ = 0.98). MRDTI images were adequate for interpretation in 95% of the cases. MRDTI is a sensitive and reproducible method for distinguishing acute ipsilateral recurrent DVT from 6-month-old chronic residual thrombi in the leg veins.

Accuracy of Magnetic Resonance Direct Thrombus Imaging (MRDTI) As a Novel Tool in the Diagnosis of Acute Ipsilateral Recurrent Deep Vein Thrombosis

AbstractAbstract 395 BackgroundAccurate diagnostic assessment of suspected acute ipsilateral recurrent deep vein thrombosis (DVT) is of high clinical importance, however discriminating residual thrombosis from acute recurrent DVT may be challenging. It is known that in 32% of the patients with a suspected acute ipsilateral recurrent DVT the ultrasound examination are non-conclusive. Despite this, patients were treated with indefinite anticoagulant therapy, indicating overtreatment in this group of patients (Tan M et al. J Thromb Haemost 2010). A non-invasive MR technique (Magnetic Resonance Direct Thrombus Imaging (MRDTI), without need for intravenous contrast agent, showed high sensitivity and specificity for diagnosing a first acute DVT (Fraser et al Ann Intern Med 2002). Furthermore the high signal associated with acute thrombosis was not detected 6 months after the initial acute thrombosis, making MRDTI potential relevant for distinguishing a recurrent DVT from a residual thrombosis (Westerbeek RE et al J Thromb Haemost 2008). This study evaluated the accuracy of MRDTI in patients with an acute ipsilateral recurrent DVT and patients with residual thrombosis. Patients/MethodsIn total 84 patients were enrolled. Of these, 42 consecutive patients had an acute ipsilateral recurrent DVT according to the current ultrasound examination standards in combination with a positive D-dimer test (≥ 500 μg/L); all patients were treated with anticoagulants. Furthermore, 42 patients were without acute signs and symptoms, however had a residual thrombosis on ultrasound examination in combination with a negative D-dimer test (< 500 μg/L). All patients received a MR examination within 48 hours of presentation. MR images were assessed in a blinded fashion by two radiologists. Sensitivity, specificity and interobserver variability were calculated. ResultsThe images of two patients with ipsilateral recurrent DVT were not interpretable, one patient had a knee prosthesis that gave artifacts and in the other patient not the venous system of interest was imaged. The images of 40 patients with an ipsilateral recurrent DVT and of 42 patients with residual thrombosis were fully interpretable. Sensitivity was 86% (95% CI, 71 –94%) and specificity was 100% (95% CI, 89–100%) for MRDTI by the first observer; sensitivity was 88% (95% CI, 74–96%) and specificity was 100% (89–100%) by the second observer. The interobserver agreement between both observers was excellent, with a kappa statistics of 0.97 (95% CI, 0.92 – 1.0). ConclusionOur study shows reasonable sensitivity and very good specificity figures with an excellent observer agreement for imaging an ipsilateral recurrent DVT and residual thrombosis with MRDTI. The sensitivity is somewhat lower than expected; a reason could be that patients with inconclusive ultrasounds were considered as acute recurrent thrombosis by the attending physician, while in fact they had a residual thrombosis. We conclude that MRDTI has good potential in distinguishing a residual thrombosis from an acute recurrent DVT and could therefore be of high value for the diagnosis of patients with suspected acute ipsilateral recurrent DVT. This should however be further evaluated in a management outcome study in which treatment decisions are based on the results of MR. AcknowledgmentThis study was supported by the Netherlands Heart Foundation (grant no. 2007B146) Disclosures:No relevant conflicts of interest to declare.

Finding the origin of pulmonary emboli with a total-body magnetic resonance direct thrombus imaging technique

Pulmonary embolism is considered to originate from embolization of a deep-vein thrombosis, resulting in two manifestations of one disease: venous thrombosis. However, in up to 50% of patients with pulmonary embolism no deep-vein thrombosis is found with ultrasonography. An explanation for this low proportion is currently lacking. Other imaging modalities may increase the yield of detection of deep-vein thrombosis in the calf or in the abdominal region. Alternatively, not all pulmonary emboli may originate from deep-vein thromboses in the extremities. We searched for the origin of pulmonary emboli, by performing total-body magnetic resonance imaging-scans to visualize thrombi. Ninety-nine patients with a first pulmonary embolism confirmed by computed tomography underwent a magnetic resonance direct thrombus imaging-scan, a validated technique using endogenous contrast. Additionally, acquired and genetic risk factors were assessed. No thrombus was found in 55 patients, whereas a thrombus was identified in 44 patients. The commonest thrombus location was the lower leg; 12 patients had isolated calf vein thrombosis and five had isolated superficial vein thrombosis. A peripheral thrombus was found by magnetic resonance imaging in less than half of patients with pulmonary embolism. We propose several hypotheses to explain the absence of thrombi, such as a cardiac thrombus origin or embolization of the whole deep-vein thrombus. The possibility that pulmonary embolism arises de novo in the lungs, due to local inflammation-driven coagulation, needs to be considered.

Intraplaque Hemorrhage in Symptomatic Intracranial Atherosclerotic Disease

Studies in patients with extracranial carotid disease have shown that high-resolution magnetic resonance direct thrombus imaging (MRDTI) can reliably identify intraplaque hemorrhage, which may be a better predictor of clinical events than traditional radiographic methods such as percent stenosis. We present the use of high-resolution magnetic resonance imaging for the detection of intraplaque hemorrhage in the intracranial arteries. High-resolution 3 Tesla MRDTI was performed using T1-weighted scans with an inversion pulse to null the signal from blood. Abnormal intraplaque T1 signal compatible with hemorrhage or blood products was defined as equal to or higher than 150% of T1 signal of adjacent muscle. The symptomatic middle cerebral artery demonstrated intraplaque signal higher than 150% of the muscle signal in two central slices, consistent with the imaging characteristics of intraplaque hemorrhage demonstrated in extracranial carotid arteries. High-resolution MRDTI of intracranial atherosclerotic lesions could provide a surrogate marker of plaque activity in vivo and could lead to improvements in risk stratification and treatment of this common disease.

Development of Carotid Intraplaque Hemorrhage Demonstrated by Serial Magnetic Resonance Imaging

HomeCirculationVol. 120, No. 16Development of Carotid Intraplaque Hemorrhage Demonstrated by Serial Magnetic Resonance Imaging Free AccessReview ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessReview ArticlePDF/EPUBDevelopment of Carotid Intraplaque Hemorrhage Demonstrated by Serial Magnetic Resonance Imaging R.M. Kwee, MD, F.H.B.M. Schreuder, MD, W.H. Mess, MD, PhD, R.J. van Oostenbrugge, MD, PhD, V.H.J.M. Triebels, MD, L.H. van den Akker, MD, PhD, S. Heeneman, PhD, P.A.M. Hofman, MD, PhD, J.M.A. van Engelshoven, MD, PhD, J.E. Wildberger, MD, PhD and M.E. Kooi, PhD R.M. KweeR.M. Kwee From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author , F.H.B.M. SchreuderF.H.B.M. Schreuder From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author , W.H. MessW.H. Mess From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author , R.J. van OostenbruggeR.J. van Oostenbrugge From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author , V.H.J.M. TriebelsV.H.J.M. Triebels From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author , L.H. van den AkkerL.H. van den Akker From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author , S. HeenemanS. Heeneman From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author , P.A.M. HofmanP.A.M. Hofman From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author , J.M.A. van EngelshovenJ.M.A. van Engelshoven From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author , J.E. WildbergerJ.E. Wildberger From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author and M.E. KooiM.E. Kooi From the Departments of Radiology (R.M.K., P.A.M.H., J.M.A.v.E., J.E.W., M.E.K.), Neurology (F.H.B.M.S., R.J.v.O.), Clinical Neurophysiology (W.H.M.), and Pathology (S.H.) and Cardiovascular Research Institute Maastricht (R.M.K., R.J.v.O., S.H., J.M.A.v.E., J.E.W., M.E.K.), Maastricht University Medical Center, Maastricht, Netherlands; and Departments of Neurology (V.H.J.M.T.) and Vascular Surgery (L.H.v.d.A.), Orbis Medical Center, Sittard, Netherlands. Search for more papers by this author Originally published20 Oct 2009https://doi.org/10.1161/CIRCULATIONAHA.109.873513Circulation. 2009;120:1637–1639A 68-year-old man presented with a sudden onset of weakness and paresthesia of the left arm. He had a history of myocardial infarction 4 years earlier and a known renal artery stenosis. A nonenhanced computed tomographic scan of the brain showed no signs of hemorrhage or infarction. The patient underwent intravenous thrombolysis with alteplase (0.9 mg/kg body wt, 10% initial bolus dose over 1 minute, followed by infusion of the remaining 90% of the dose over 60 minutes). Soon after, the symptoms completely disappeared except for the persistence of a slight paresthesia of the left arm. Doppler ultrasonography revealed a hypoechoic plaque proximally in the right internal carotid artery causing a 50% to 69% stenosis. ECG showed sinus rhythm with complete right bundle-branch block without ST-segment or T-wave abnormalities. Transcranial Doppler imaging revealed no stenosis of the right middle cerebral artery. Serum lipid profile was within normal limits. In addition to the aspirin (100 mg once per day) and atorvastatin (40 mg once per day) he was already using, the patient was prescribed dipyridamole (200 mg twice per day) for secondary stroke prevention.Fifteen days after the initial onset of symptoms, the patient was enrolled in a clinical study investigating the natural history of carotid artery plaques. Magnetic resonance imaging scans of the brain and right carotid artery plaque were obtained, which revealed a recent discrete infarction of the right sensory region (Figure 1A and 1B) and a plaque with a large lipid-rich necrotic core with no or little hemorrhage (Figure 2A through 2D), respectively. Download figureDownload PowerPointFigure 1. Cross-sectional magnetic resonance images of the brain. Baseline fluid-attenuated inversion recovery (A) and diffusion-weighted (B) images show a very small hyperintense area in the right sensory region (arrows), indicating recent discrete infarction. Compared with baseline magnetic resonance images, follow-up fluid-attenuated inversion recovery (C) and diffusion-weighted images (D) clearly show a new hyperintense area in the right motor region (arrows), indicating recent infarction.Download figureDownload PowerPointFigure 2. High-spatial-resolution magnetic resonance image, with cross-sectional coregistered images through plaque in the internal carotid artery. Baseline T2-weighted image (A) and precontrast (B) and postcontrast (C) T1-weighted images and plaque contours (D) (white: carotid artery lumen; light gray: vessel wall area) are shown. T2-weighted image (A) shows isointense plaque, precontrast T1-weighted image (B) shows hyperintense plaque, and postcontrast T1-weighted image (C) shows no enhancement of the plaque, which matches the criteria of a lipid-rich necrotic core with no or little hemorrhage. Follow-up T2-weighted (E) and precontrast (F) and postcontrast (G) T1-weighted images and plaque contours (F) (white: carotid artery lumen; light gray: vessel wall area; dark gray: hemorrhage) are shown. T2-weighted image (E) shows a striking hyperintense area within the plaque, adjacent to the lumen (dark gray area in H). This area is hyperintense at the precontrast T1-weighted image (F) and does not enhance at the postcontrast T1-weighted image (G). These findings indicate recent intraplaque hemorrhage.Three months after the initial event, the patient once more presented with sudden onset of weakness and a numb feeling of the left arm. The patient again underwent intravenous thrombolysis with alteplase. However, the symptoms persisted. A nonenhanced computed tomographic scan, performed 24 hours after thrombolysis, revealed a hypodense area in the right motor region. Repeated Doppler ultrasonography showed no change in carotid plaque echogenicity and degree of luminal narrowing of the right internal carotid artery. Ten days after the onset of the second event, the patient underwent repeated magnetic resonance imaging scans of the brain and right internal carotid artery plaque. These scans confirmed recent infarction in the right motor region (Figure 1C and 1D) and revealed recent intraplaque hemorrhage (Figure 2E through 2H).Because of recurrent symptoms, the patient underwent carotid endarterectomy 20 days after the onset of the second event. Histological analysis of the excised plaque demonstrated large intraplaque hemorrhage (Figure 3A and 3B), confirming the magnetic resonance imaging findings. According to the American Heart Association, it was a type VI plaque (complex plaque with possible surface defect, hemorrhage, or thrombus).1Download figureDownload PowerPointFigure 3. Cross section through the carotid endarterectomy specimen, corresponding to the level of the magnetic resonance images (Figure 2). Hematoxylin-eosin staining; magnification ×125 (A) and ×1000 (B). There are large areas of intraplaque hemorrhage (asterisks in A). At the right shoulder region, the fibrous cap is very thin and shows recent reendothelialization (arrows in A and B). Many erythrocytes are present within the fibrous cap (B).To our knowledge, this is the first report showing the in vivo development of carotid intraplaque hemorrhage and the coincidence of ipsilateral ischemic stroke. The findings of this case are in accordance with results of previous studies, which showed that carotid intraplaque hemorrhage on magnetic resonance imaging is associated with cerebral ischemic events.2–4Sources of FundingThis study was supported by a Dutch Heart Foundation grant (2006B061).DisclosuresNone.FootnotesReprint requests to Robert M. Kwee, MD, Department of Radiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, the Netherlands. E-mail [email protected]References1 Stary HC, Chandler AB, Dinsmore RE, Fuster V, Glagov S, Insull W Jr, Rosenfeld ME, Schwartz CJ, Wagner WD, Wissler RW. A definition of advanced types of atherosclerotic lesions and a histological classification of atherosclerosis: a report from the Committee on Vascular Lesions of the Council on Arteriosclerosis, American Heart Association. Arterioscler Thromb Vasc Biol. 1995; 15: 1512–1531.CrossrefMedlineGoogle Scholar2 Murphy RE, Moody AR, Morgan PS, Martel AL, Delay GS, Allder S, MacSweeney ST, Tennant WG, Gladman J, Lowe J, Hunt BJ. Prevalence of complicated carotid atheroma as detected by magnetic resonance direct thrombus imaging in patients with suspected carotid artery stenosis and previous acute cerebral ischemia. Circulation. 2003; 107: 3053–3058.LinkGoogle Scholar3 Altaf N, Daniels L, Morgan PS, Auer D, MacSweeney ST, Moody AR, Gladman JR. Detection of intraplaque hemorrhage by magnetic resonance imaging in symptomatic patients with mild to moderate carotid stenosis predicts recurrent neurological events. J Vasc Surg. 2008; 47: 337–342.CrossrefMedlineGoogle Scholar4 Takaya N, Yuan C, Chu B, Saam T, Underhill H, Cai J, Tran N, Polissar NL, Isaac C, Ferguson MS, Garden GA, Cramer SC, Maravilla KR, Hashimoto B, Hatsukami TS. Association between carotid plaque characteristics and subsequent ischemic cerebrovascular events: a prospective assessment with MRI—initial results. Stroke. 2006; 37: 818–823.LinkGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Appel A, Chou C, Larson J, Zhong Z, Schoen F, Johnston C, Brey E and Anastasio M (2013) An initial evaluation of analyser-based phase-contrast X-ray imaging of carotid plaque microstructure, The British Journal of Radiology, 10.1259/bjr.20120318, 86:1021, (20120318-20120318), Online publication date: 1-Jan-2013. Hoeks A and Kooi M (2011) Wear and Tear⁎⁎Editorials published in JACC: Cardiovascular Imaging reflect the views of the authors and do not necessarily represent the views of JACC: Cardiovascular Imaging or the American College of Cardiology., JACC: Cardiovascular Imaging, 10.1016/j.jcmg.2011.03.003, 4:5, (478-480), Online publication date: 1-May-2011. Kwee R, van Oostenbrugge R, Mess W, Prins M, van der Geest R, ter Berg J, Franke C, Korten A, Meems B, van Engelshoven J, Wildberger J and Kooi M (2010) Carotid Plaques in Transient Ischemic Attack and Stroke Patients, Investigative Radiology, 10.1097/RLI.0b013e3181ed15ff, 45:12, (803-809), Online publication date: 1-Dec-2010. October 20, 2009Vol 120, Issue 16 Advertisement Article InformationMetrics https://doi.org/10.1161/CIRCULATIONAHA.109.873513PMID: 19841310 Originally publishedOctober 20, 2009 PDF download Advertisement SubjectsComputerized Tomography (CT)ImagingStenosis

Intraplaque haemorrhage mimicking carotid pseudoaneurysm on magnetic resonance angiography

Contrast-enhanced magnetic resonance angiography (CE-MRA) is a commonly used technique to assess the extracranial carotid arteries. We describe two patients (investigated for carotid artery atherosclerotic disease) who underwent CE-MRA. Results suggested pseudoaneurysms of the extracranial carotid arteries. Magnetic resonance direct thrombus imaging (MRDTI) showed that the appearances were due to intraplaque haemorrhage adjacent to the vessel, with the T1-shortening effect of methaemoglobin within the intraplaque haemorrhage mimicking blood flow on the CE-MRA sequence. The cases presented demonstrate this diagnostic pitfall and illustrate the contribution of simple magnetic resonance plaque imaging to establishing the correct diagnosis.

Magnetic Resonance Direct Thrombus Imaging in Moderate Carotid Artery Stenosis

To the Editor: Wasserman et al1 present a proof-of-concept case elegantly demonstrating that high-resolution MRI of carotid plaque can identify a lesion that was highly likely to be causing cerebrovascular symptoms even though it was not causing significant stenosis of the carotid lumen. The authors also acknowledge that acquiring high-resolution MR images is time-consuming and requires the injection of contrast. We too are interested in using MR techniques to find features of carotid artery plaque related to its biological behavior, rather than simply the degree of stenosis caused by it. We …

Magnetic resonance direct thrombus imaging at 3 T field strength in patients with lower limb deep vein thrombosis: a feasibility study

To investigate the feasibility of imaging lower limb deep vein thrombosis using magnetic resonance imaging (MRI) at 3.0 T magnetic field strength with an optimized a T1 magnetization prepared rapid gradient echo technique (MP-RAGE) in patients with normal volunteers as controls. Patients with deep vein thrombosis (n = 4), thrombophlebitis (n = 2) and healthy volunteers (n = 9) were studied. MRI of the distal thigh and upper calf was performed at 3.0 T with MP-RAGE using two pre-pulses to suppress blood and fat (flip angle 15 degrees, echo time 5 ms, and repetition time 10 ms). A qualitative analysis was performed for detection of thrombi and image quality. Contrast-to-noise ratios were determined in thrombosed and patent veins. Thrombi were clearly visible as high-signal intensity structures with good suppression of the anatomical background. A blinded reader accurately diagnosed 15 out of 16 cases. The contrast-to-noise ratio measurements showed a positive contrast of thrombus over background muscle 16.9 (SD 4.3, 95% CI: 12.5-21.3) and a negative contrast of the lumen to muscle in patent veins of normal volunteers -7.8 (SD 4.3, 95% CI: -11.1 to -4.5), with p = 0.0015. Thrombi generate high signal intensity at 3.0 T allowing for their direct visualization if flowing blood, stationary blood and fat are sufficiently suppressed. This preliminary data supports the development of these techniques for other vascular applications.