Cost-Effectiveness of Performing Reference Ultrasonography in Patients with Deep Vein Thrombosis.

BACKGROUND: The diagnosis of recurrent ipsilateral deep vein thrombosis (DVT) with compression ultrasonography (CUS) may be hindered by residual intravascular obstruction after previous DVT. A reference CUS, an additional ultrasound performed at anticoagulant discontinuation, may improve the diagnostic work-up of suspected recurrent ipsilateral DVT by providing baseline images for future comparison. OBJECTIVES: To evaluate the cost-effectiveness of routinely performing reference CUS in DVT patients. METHODS: Patient-level data (n = 96) from a prospective management study (Theia study; NCT02262052) and claims data were used in a decision analytic model to compare 12 scenarios for diagnostic management of suspected recurrent ipsilateral DVT. Estimated health care costs and mortality due to misdiagnosis, recurrent venous thromboembolism, and bleeding during the first year of follow-up after presentation with suspected recurrence were compared. RESULTS: All six scenarios including reference CUS had higher estimated 1-year costs (€1,763-€1,913) than the six without reference CUS (€1,192-€1,474). Costs were higher because reference CUS results often remained unused, as 20% of patients (according to claims data) would return with suspected recurrent DVT. Estimated mortality was comparable in scenarios with (14.8-17.9 per 10,000 patients) and without reference CUS (14.0-18.5 per 10,000). None of the four potentially most desirable scenarios included reference CUS. CONCLUSION: One-year health care costs of diagnostic strategies for suspected recurrent ipsilateral DVT including reference CUS are higher compared to strategies without reference CUS, without mortality benefit. These results can inform policy-makers regarding use of health care resources during follow-up after DVT. From a cost-effectiveness perspective, the findings do not support the routine application of reference CUS.

Automated quantification of the pulmonary vasculature in pulmonary embolism and chronic thromboembolic pulmonary hypertension.

The shape and distribution of vascular lesions in pulmonary embolism (PE) and chronic thromboembolic pulmonary hypertension (CTEPH) are different. We investigated whether automated quantification of pulmonary vascular morphology and densitometry in arteries and veins imaged by computed tomographic pulmonary angiography (CTPA) could distinguish PE from CTEPH. We analyzed CTPA images from a cohort of 16 PE patients, 6 CTEPH patients, and 15 controls. Pulmonary vessels were extracted with a graph-cut method, and separated into arteries and veins using deep-learning classification. Vascular morphology was quantified by the slope (α) and intercept (ß) of the vessel radii distribution. To quantify lung perfusion defects, the median pulmonary vascular density was calculated. By combining these measurements with densities measured in parenchymal areas, pulmonary trunk, and descending aorta, a static perfusion curve was constructed. All separate quantifications were compared between the three groups. No vascular morphology differences were detected in contrast to vascular density values. The median vascular density (interquartile range) was -567 (113), -452 (95), and -470 (323) HU, for the control, PE, and CTEPH group. The static perfusion curves showed different patterns between groups, with a statistically significant difference in aorta-pulmonary trunk gradient between the PE and CTEPH groups (p = 0.008). In this proof of concept study, not vasculature morphology but densities differentiated between patients of three groups. Further technical improvements are needed to allow for accurate differentiation between PE and CTEPH, which in this study was only possible statistically by measuring the density gradient between aorta and pulmonary trunk.

Detection of upper extremity deep vein thrombosis by magnetic resonance non-contrast thrombus imaging.

BACKGROUND: Compression ultrasonography (CUS) is the first-line imaging test for diagnosing upper extremity deep vein thrombosis (UEDVT), but often yields inconclusive test results. Contrast venography is still considered the diagnostic standard but is an invasive technique. OBJECTIVES: We aimed to determine the diagnostic accuracy of magnetic resonance noncontrast thrombus imaging (MR-NCTI) for the diagnosis of UEDVT. METHODS: In this international multicenter diagnostic study, we prospectively included patients with clinically suspected UEDVT who were managed according to a diagnostic algorithm that included a clinical decision rule (CDR), D-dimer test, and diagnostic imaging. UEDVT was confirmed by CUS or (computed tomography [CT]) venography. UEDVT was excluded by (1) an unlikely CDR and normal D-dimer, (2) a normal serial CUS or (3) a normal (CT) venography. Within 48 h after the final diagnosis was established, patients underwent MR-NCTI. MR-NCTI images were assessed post hoc by two independent radiologists unaware of the presence or absence of UEDVT. The sensitivity, specificity, and interobserver agreement of MR-NCTI for UEDVT were determined. RESULTS: Magnetic resonance noncontrast thrombus imaging demonstrated UEDVT in 28 of 30 patients with UEDVT and was normal in all 30 patients where UEDVT was ruled out, yielding a sensitivity of 93% (95% CI 78-99) and specificity of 100% (95% CI 88-100). The interobserver agreement of MR-NCTI had a kappa value of 0.83 (95% CI 0.69-0.97). CONCLUSIONS: Magnetic resonance noncontrast thrombus imaging is an accurate and reproducible method for diagnosing UEDVT. Clinical outcome studies should determine whether MR-NCTI can replace venography as the second-line imaging test in case of inconclusive CUS.

[Diagnosis of recurrent venous thromboembolism]. / Diagnostiek van een recidief veneuze trombo-embolie.

A correct diagnosis of recurrent venous thromboembolism (VTE) is essential as patients diagnosed with a recurrence are mostly treated with lifelong anticoagulant treatment. However, the diagnosis of recurrent VTE is complex as routine diagnostic tests for suspected VTE are less accurate in patients without a prior VTE. Clinical decision rules (CDR) and D-dimer tests have a lower specificity in suspected recurrent VTE, leading to an increase in required diagnostic imaging tests. In contrast to suspected recurrent pulmonary embolism (PE), the safety of a CDR and D-dimer test in excluding recurrent deep vein thrombosis (DVT) is debated. A CDR in combination with D-dimer testing followed by computed tomography pulmonary angiography is the preferred diagnostic management for suspected recurrent PE. In suspected recurrent DVT, compression ultrasonography is the imaging technique of choice and in case of a suspected recurrent ipsilateral DVT and an inconclusive ultrasonography, magnetic resonance direct thrombus imaging is decisive.

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.

Computed Tomography Pulmonary Perfusion for Prediction of Short-Term Clinical Outcome in Acute Pulmonary Embolism.

Background Computed tomography pulmonary angiography (CTPA) is the imaging modality of choice for the diagnosis of acute pulmonary embolism (PE). With computed tomography pulmonary perfusion (CTPP) additional information on lung perfusion can be assessed, but its value in PE risk stratification is unknown. We aimed to evaluate the correlation between CTPP-assessed perfusion defect score (PDS) and clinical presentation and its predictive value for adverse short-term outcome of acute PE. Patients and Methods This was an exploratory, observational study in 100 hemodynamically stable patients with CTPA-confirmed acute PE in whom CTPP was performed as part of routine clinical practice. We calculated the difference between the mean PDS in patients with versus without chest pain, dyspnea, and hemoptysis and 7-day adverse outcome. Multivariable logistic regression analysis and likelihood-ratio test were used to assess the added predictive value of PDS to CTPA parameters of right ventricle dysfunction and total thrombus load, for intensive care unit admission, reperfusion therapy and PE-related death. Results We found no correlation between PDS and clinical symptoms. PDS was correlated to reperfusion therapy ( n = 4 with 16% higher PDS, 95% confidence interval [CI]: 3.5-28%) and PE-related mortality ( n = 2 with 22% higher PDS, 95% CI: 4.9-38). Moreover, PDS had an added predictive value to CTPA assessment for PE-related mortality (from Chi-square 14 to 19, p = 0.02). Conclusion CTPP-assessed PDS was not correlated to clinical presentation of acute PE. However, PDS was correlated to reperfusion therapy and PE-related mortality and had an added predictive value to CTPA-reading for PE-related mortality; this added value needs to be demonstrated in larger studies.

Magnetic Resonance Thrombus Imaging to Differentiate Acute from Chronic Portal Vein Thrombosis.

Introduction Timely diagnosis and treatment of portal vein thrombosis (PVT) is crucial to prevent morbidity and mortality. However, current imaging tests cannot always accurately differentiate acute from chronic (nonocclusive) PVT. Magnetic resonance noncontrast thrombus imaging (MR-NCTI) has been shown to accurately differentiate acute from chronic venous thrombosis at other locations and may also be of value in the diagnostic management of PVT. This study describes the first phase of the Rhea study (NTR 7061). Our aim was to select and optimize MR-NCTI sequences that would be accurate for differentiation of acute from chronic PVT. Study Design The literature was searched for different MRI sequences for portal vein and acute thrombosis imaging. The most promising sequences were tested in a healthy volunteer followed by one patient with acute PVT and two patients with chronic PVT, all diagnosed on (repetitive) contrast-enhanced computed tomography (CT) venography to optimize the MR-NCTI sequences. All images were evaluated by an expert panel. Results Several MR-NCTI sequences were identified and tested. Differentiation of acute from chronic PVT was achieved with 3D T1 TFE (three-dimensional T1 turbo field echo) and 3D T1 Dixon FFE (three-dimensional T1 fast field echo) sequences with best image quality. The expert panel was able to confirm the diagnosis of acute PVT on the combined two MR-NCTI sequences and to exclude acute PVT in the two patients with chronic PVT. Conclusion Using 3D T1 TFE and 3D T1 Dixon FFE sequences, we were able to distinguish acute from chronic PVT. This clinical relevant finding will be elucidated in clinical studies to establish their test performance.

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

BACKGROUND: The diagnostic accuracy of clinical probability assessment and D-dimer testing for clinically suspected recurrent deep vein thrombosis (DVT) is largely unknown. AIM: To evaluate the safety of ruling out acute recurrent DVT based on an unlikely Wells score for DVT and a normal D-dimer test. METHODS: This 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. RESULTS: Results 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%. CONCLUSION: By 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.

Current imaging modalities for diagnosing cerebral vein thrombosis - A critical review.

Cerebral vein thrombosis (CVT) is a rare presentation of venous thromboembolism. Prompt and accurate diagnosis is essential as delayed recognition and treatment may lead to permanent disability or even death. Since no validated diagnostic algorithms exist, the diagnosis of CVT mainly relies on neuroimaging. Digital subtraction angiography (DSA) is the historical diagnostic standard for CVT, but is rarely used nowadays and replaced by computed tomography (CT) and magnetic resonance imaging (MRI). High quality studies to evaluate the diagnostic test characteristics of state of the art imaging modalities are however unavailable to date. This review provides an overview of the best available evidence regarding the diagnostic performance of CT and MRI for the diagnosis of CVT. Notably, available studies are observational, mostly small, outdated, and with a high risk of bias. Therefore, direct comparison between studies is difficult due to large diversity in study design, imaging method, reference standard, patient selection and sample size. In general, contrast-enhanced techniques are more accurate for the diagnosis of CVT then non-contrast-enhanced techniques. CT venography and MRI have been both reported to be adequate for establishing a final diagnosis of CVT, but choice of modality as used in clinical practice depends on availability, local preference and experience, as well as patient characteristics. Our review underlines the need for high-quality diagnostic studies comparing CT venography and MRI in specific settings, to improve clinical care and standardize clinical trials.

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 POINTS: Accurate 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.

Magnetic resonance imaging for diagnosis of recurrent ipsilateral deep vein thrombosis.

The 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.

Isolated fat pad sign in acute elbow injury: is it clinically relevant?

An isolated fat pad sign (i.e. joint effusion without a visible fracture), commonly seen in acute elbow injury, is associated with occult fracture and treated as such. However, the clinical relevance of an isolated fat pad is unclear, thereby questioning the need for specialized follow-up. In this study, 111 patients (median age 15 years, interquartile range 9-27 years) with an isolated fat pad sign after acute elbow injury were included. The clinical relevance of an isolated fat pad sign was derived from descriptives on pain, elbow function, treatment change, number of revisits and recovery time after 1 week follow-up and long-term follow-up. Treatment alterations were rarely made and none of the patients needed an operative intervention; also, none of the patients had persistent symptoms. The median recovery time was 3 weeks (interquartile range 2-12 weeks). This study shows that, unless symptoms persist or worsen, regular follow-up at a specialized outpatient clinic is not needed.

Extension test and ossal point tenderness cannot accurately exclude significant injury in acute elbow trauma.

STUDY OBJECTIVE: Elbow injury is a common presentation at the emergency department (ED). There are no guidelines indicating which of these patients require radiography, whereas clinical decision rules for other limb injuries are widely accepted and resulted in less radiography and reduced waiting times. We aim to identify clinical signs that can be used to predict the need for radiography in elbow injury. METHODS: A prospective observational study at 2 ED locations in the Netherlands was performed. For every eligible patient with acute elbow injury, elbow extension and addition of point tenderness at the olecranon, epicondyles, and radial head were evaluated for predicting the need for radiography (primary endpoint). A subgroup of patients was assessed by a blinded second investigator to analyze interobserver variability (secondary endpoint). All patients received anterior-posterior and lateral elbow radiographs. Fractures were treated according to current guidelines and patients were followed at outpatient clinics. RESULTS: In total, 587 patients were included. Normal extension was observed in 174 patients (30%). Normal extension predicted absence of a fracture or isolated fat pad with 88% sensitivity and 55% specificity. Five patients with normal extension had a fracture that required surgery. Absence of point tenderness in patients with normal extension was observed in only 24 patients, of whom 3 showed a fracture and 1 required surgery. Addition of point tenderness to the extension test to predict absence of a fracture or isolated fat pad resulted in 98% sensitivity and 11% specificity. Interobserver analysis for extension and palpation of olecranon, epicondyles, and radial head resulted in κ values between 0.6 and 0.7. CONCLUSION: In contrast with previous studies, ours shows that in acute elbow injury, the extension test alone or in combination with point tenderness assessment does not safely rule out clinically significant injury. Interobserver variability was substantial. We would not recommend the use of the extension test (+/- point tenderness assessment) as a clinical decision rule to guide radiologic diagnostics in acute elbow trauma.