Prognostic value of pulmonary transit time by cardiac magnetic resonance imaging in ST-elevation myocardial infarction

OBJECTIVES

To investigate the prognostic value of pulmonary transit time (pTT) determined by cardiac magnetic resonance (CMR) after acute ST-segment-elevation myocardial infarction (STEMI).

METHODS

Comprehensive CMR examinations were performed in 207 patients 3 days and 4 months after reperfused STEMI. Functional parameters and infarct characteristics were assessed. PTT was defined as the interval between peaks of gadolinium contrast time-intensity curves in the right and left ventricles in first-pass perfusion imaging. Cox regression models were calculated to assess the association between pTT and the occurrence of major adverse cardiac events (MACE), defined as a composite of death, re-infarction, and congestive heart failure.

RESULTS

PTT was 8.6 s at baseline and 7.8 s at the 4-month CMR. In Cox regression, baseline pTT (hazard ratio [HR]: 1.58; 95% CI: 1.12 to 2.22; p = 0.009) remained significantly associated with MACE occurrence after adjustment for left ventricular ejection fraction (LVEF) and cardiac index. The association of pTT and MACE remained significant also after adjusting for infarct size and microvascular obstruction size. In Kaplan-Meier analysis, pTT ≥ 9.6 s was associated with MACE (p < 0.001). Addition of pTT to LVEF resulted in a categorical net reclassification improvement of 0.73 (95% CI: 0.27 to 1.20; p = 0.002) and integrated discrimination improvement of 0.07 (95% CI: 0.02 to 0.13; p = 0.007).

CONCLUSIONS

After reperfused STEMI, CMR-derived pTT was associated with hard clinical events with prognostic information independent of and incremental to infarct size and LV systolic function.

KEY POINTS

• Pulmonary transit time is the duration it takes the heart to pump blood from the right chambers across lung vessels to the left chambers. • This prospective single-centre study showed inferior outcome in patients with prolonged pulmonary transit time after myocardial infarction. • Pulmonary transit time assessed by magnetic resonance imaging added incremental information to established prognostic markers.

Diagnosis of acute heart failure in CT pulmonary angiography: feasibility and accuracy

OBJECTIVES

To evaluate the feasibility and accuracy of diagnosing acute heart failure (HF) with CT pulmonary angiography (CTPA) in emergency department patients.

METHODS

In this retrospective single-center study, we evaluated 150 emergency department patients (mean age 65 ± 17 years) undergoing CTPA with a fixed scan (100 kVp) and contrast media protocol (60 mL, 4 mL/s) who had no pulmonary embolism (PE). Patients were subdivided into training cohort (n = 100) and test cohort (n = 50). Three independent, blinded readers measured the attenuation in the right ventricle (RV) and left ventricle (LV) on axial images. The ratio (HU_ratio) and difference (HU_diff) between RV and LV attenuation were calculated. Diagnosis of acute HF was made on the basis of clinical, laboratory, and echocardiography data. Optimal thresholds, sensitivity, and specificity were calculated using the area under the curve (AUC) from receiver operating characteristics analysis.

RESULTS

Fifty-nine of the 150 patients (40%) were diagnosed with acute HF. Attenuation measurements showed an almost perfect interobserver agreement (intraclass correlation coefficient: 0.986, 95%CI: 0.980-0.991). NT-pro BNP exhibited moderate correlations with HU_ratio (r = 0.50, p < 0.001) and HU_diff (r = 0.50, p < 0.001). In the training cohort, HU_ratio (AUC: 0.89, 95%CI: 0.82-0.95) and HU_diff (AUC: 0.88, 95%CI: 0.81-0.95) showed a very good performance to diagnose HF. Optimal cutoff values were 1.42 for HU_ratio (sensitivity 93%; specificity 75%) and 113 for HU_diff (sensitivity 93%; specificity 73%). Applying these thresholds to the test cohort yielded a sensitivity of 89% and 89% and a specificity of 69% and 63% for HU_ratio and HU_diff, respectively.

CONCLUSION

In emergency department patients undergoing CTPA and showing no PE, both HU_ratio and HU_diff have a high sensitivity for diagnosing acute HF.

KEY POINTS

• Heart failure is a common differential diagnosis in patients undergoing CT pulmonary angiography. • In emergency department patients undergoing CT pulmonary angiography and showing no pulmonary embolism, attenuation differences of the left and right ventricle have a high sensitivity for diagnosing acute heart failure.

A practical biphasic contrast media injection protocol strongly enhances the aorta and pulmonary artery simultaneously using a single CT angiography scan

Background

Enhancement profiles of the pulmonary artery (PA) and aorta differ when using computed tomography (CT) angiography. Our aim was to determine the optimal CT protocol for a one-time CT scan that assesses both blood vessels.

Methods

We prospectively enrolled 101 cases of CT angiography in patients with suspected pulmonary embolism or aortic dissection from our center between 2018 and 2020. We also retrospectively collected the data of 40 patients who underwent traditional two-time CT scans between 2015 and 2018. Patients were divided into four groups: test bolus (TB) I, TB II, bolus-tracking (BT) I, and BT II. The enhancement of the PA and aorta, and the radiation doses used in the four groups were collected. Those who underwent two-time scans were classified into the traditional PA or aorta scan groups. Data were compared between the BT and traditional groups.

Results

The aortic enhancement was highest in BT II (294.78 ± 64.48 HU) followed BT I (285.18 ± 64.99 HU), TB II (186.58 ± 57.53 HU), and TB I (173.62 ± 69.70 HU). The radiation dose used was lowest in BT I (11.85 ± 5.55 mSv) and BT II (9.07 ± 3.44 mSv) compared with that used in the traditional groups (20.07 ± 7.78 mSv) and accounted for half of the traditional group (45.17–59.02%). The aortic enhancement was also highest in BT II (294.78 ± 64.48 HU) followed by BT I (285.18 ± 64.99 HU) when compared with that in the traditional aorta scan group (234.95 ± 94.18 HU).

Conclusion

Our CT protocol with a BT technique allows for a lower radiation dose and better image quality of the PA and aorta than those obtained using traditional CT scans.

Trial registration: NCT04832633, retrospectively registered in April 2021 to the clinical trial registry.

Identification of Patients With Heart Failure From Test Bolus of Computed Tomography Angiography in Patients Undergoing Preoperative Evaluation for Transcatheter Aortic Valve Replacement

PURPOSE

Identify a measurable parameter from test bolus of computed tomography angiography that can differentiate aortic stenosis patients with normal systolic function from those with heart failure and reduced ejection fraction (HFrEF).

MATERIALS AND METHODS

This retrospective study included patients (undergoing evaluation for transcatheter aortic valve replacement) who had retrospective electrocardiogram-gated cardiac computed tomography angiography using test bolus. The measured variables were time to peak contrast enhancement in the pulmonary artery (PAtime), in the ascending (AsAotime) and descending aorta (DsAotime). From these, the pulmonary transit time (PTT: difference between time to peak enhancement in the ascending aorta to peak enhancement in the main pulmonary artery), aortic transit time (ATT: difference between time to peak enhancement in the descending aorta to time to peak enhancement in the ascending aorta) and DsAotime-PAtime were also calculated. Biventricular volumes and function were calculated.The subjects were classified on the basis of ventricular ejection fractions: normal (EF>50%), midrange (EF 40% to 50%), and HF patients with reduced EF (EF<40%). Continuous variables were compared between all groups using ordinary 1-way analysis of variance, while sex was compared using the Fisher exact test. The unpaired t tests were used to compare between the normal and HF groups. Receiver operating characteristic analysis was used in predicting decreased cardiac function (EF<40% vs. EF>50%).

RESULTS

AsAotime and PTT were significant predictors of low biventricular EF when controlling for sex and body mass index (AsAotime: odds ratio=0.74 [95% confidence interval=0.61-0.91], P=0.005; PTT: odds ratio=0.64 95% confidence interval=0.46-0.88], P=0.006). A threshold of 23 seconds for AsAotime resulted in 72.1% sensitivity and 71.4% specificity, and 79.1% sensitivity and 64.3% specificity for DsAotime.

CONCLUSIONS

The time to peak contrast enhancement from the test bolus images correlates with cardiac function. Decreased biventricular systolic dysfunction can be predicted if the time to peak contrast enhancement is >23 seconds in the ascending or descending aorta.

Pulmonary transit time derived from pulmonary angiography for the diagnosis of hepatopulmonary syndrome

BACKGROUND & AIMS

Pulmonary transit time (PTT) is the transit time of blood from the right side of the heart to the left side of the heart. The aim of the present study was to evaluate the role of the PTT derived from pulmonary angiography in the diagnosis of hepatopulmonary syndrome (HPS).

METHODS

From December 2014 to September 2015, all patients with chronic liver disease and/or portal hypertension undergoing a venous interventional radiologic procedure at our institution were eligible for inclusion in this prospective study. Pulmonary angiography was performed in all patients, and the PTT, which was defined as the time between opacification of the pulmonary trunk and the right border of the left atrium, was determined.

RESULTS

A total of 53 patients were included, 20 of whom had a positive contrast-enhanced echocardiography result and an elevated alveolar-arterial oxygen gradient were considered to have HPS. PTT was significantly shorter in patients with HPS than in those without [median, 3.34 (interquartile range, 3.01-3.67) seconds vs 4.0 (interquartile range, 3.67-4.17) seconds; P < .001]. The area under the receiver operating characteristic curve of PTT for diagnosing HPS was 0.83 (95% confidence interval, 0.70-0.92). The optimal cut-off value of PTT for diagnosing HPS, based on Youden's index, was 3.55 seconds. The sensitivity, specificity and accuracy of PTT < 3.55 seconds for diagnosing HPS were 70%, 85% and 79% respectively.

CONCLUSIONS

Pulmonary transit time derived from pulmonary angiography is useful for diagnosing HPS, especially for patients with intracardiac shunts and inadequate echocardiographic windows.

Diagnostic and Prognostic Implications of Exercise Treadmill and Rest First-Pass Radionuclide Angiography in Patients With Pulmonary Hypertension

PURPOSE

Pulmonary hypertension (PH) is characterized by abnormally increased pulmonary vascular pressure, leading to deteriorated right ventricular function and premature death. Pulmonary mean transit time (PMTT) and biventricular function response to exercise in first-pass radionuclide angiography (FP-RNA) may provide early detection and timely disease monitoring of PH. This study aimed to investigate the diagnostic and prognostic values of this imaging modality in PH patients.

METHODS

Left and right ventricular ejection fraction (LVEF/RVEF) and PMTT at rest and immediately after exercise treadmill test were measured by FP-RNA in 77 consecutive patients with clinical presentations suggestive of PH (aged 46 ± 15 years, 33 men), mostly with symptoms of unexplained progressive dyspnea. These parameters, along with other clinical variables, were correlated with right-sided heart catheterization data and clinical outcomes.

RESULTS

Fifty patients (64.9%) were diagnosed as having definite PH. Besides higher N-terminal pro-B-type natriuretic peptide levels, right atrial pressure, and pulmonary vascular resistance, PH patients had significantly longer PMTT, lower LVEF after exercise and rest, and lower poststress RVEF (all P < 0.05), compared with non-PH subjects. Moreover, PH patients exhibited stress-induced right ventricular dysfunction and stationary poststress PMTT. Poststress PMTT and echocardiography had comparable diagnostic utility (area under the curve, 0.80 vs 0.84, respectively). Eighteen patients died during a median follow-up period of 380 days. Failure of exercise treadmill test, lower peak heart rate response, and stress/rest LVEF ratio of less than 90% using exercise treadmill FP-RNA were independent predictors of mortality in PH patients.

CONCLUSIONS

Exercise treadmill and rest FP-RNA provided diagnostic value and had prognostic implications in patients with PH.

Effect of pulmonary hyperinflation on central blood volume: An MRI study

Pulmonary hyperinflation attained by glossopharyngeal insufflation (GPI) challenges the circulation by compressing the heart and pulmonary vasculature. Our aim was to determine the amount of blood translocated from the central blood volume during GPI. Cardiac output and cardiac chamber volumes were assessed by magnetic resonance imaging in twelve breath-hold divers at rest and during apnea with GPI. Pulmonary blood volume was determined from pulmonary blood flow and transit times for gadolinium during first-pass perfusion after intravenous injection. During GPI, the lung volume increased by 0.8±0.6L (11±7%) above the total lung capacity. All cardiac chambers decreased in volume and despite a heart rate increase of 24±29 bpm (39±50%), pulmonary blood flow decreased by 2783±1820mL (43±20%). The pulmonary transit time remained unchanged at 7.5±2.2s and pulmonary blood volume decreased by 354±176mL (47±15%). In total, central blood volume decreased by 532±248mL (46±14%). Voluntary pulmonary hyperinflation leads to ∼50% decrease in pulmonary and central blood volume.

Identification of Left Ventricle Failure on Pulmonary Artery CTA: Diagnostic Significance of Decreased Aortic & Left Ventricle Enhancement

PURPOSE

This study aimed to identify findings on non-ECG-gated CT pulmonary angiography (CTPA) indicating decreased left ventricle (LV) systolic function, later confirmed by echocardiogram.

METHODS

After obtaining institutional review board approval, review was performed of emergency department (ED) patients who had CTPA and follow-up echocardiogram within 48 h, over 18 months. Patients with pulmonary embolus, suboptimal CTPA, arrhythmias or pericardial tamponade were excluded. One hundred thirty-seven patients were identified and divided into cases (LVEF <40%, n = 52) and controls (LVEF >50%, n = 85). Two reviewers performed these analyses: measurement of enhancement in main pulmonary artery (MPA), LV, and aorta; subjective enhancement of LV and aorta (Ao) relative to MPA using a four-point Likert scale; contrast transit time (TD) to trigger CTPA and LV short & long axis dimensions. When available, the most recent N-terminal pro-B-type natriuretic peptide (NT-proBNP) level was recorded.

RESULTS

Decreased aortic and LV subjective enhancement were the best predictors of LV systolic dysfunction. For Ao/MPA ratio, an optimal cutoff value of 0.20 resulted in a sensitivity of 0.54 and specificity of 0.93 (AUC = 0.83, 0.78-0.88 95% CI). A threshold of 86.7 HU for Ao enhancement resulted in a sensitivity of 0.68 and specificity of 0.90 (AUC = 0.82, 0.77-0.88 95% CI). A LV short axis diameter of more than 54.3 mm had a sensitivity of 0.62 and specificity of 0.98 (AUC = 0.88, 0.83-0.92 95% CI). For the LV long axis diameter, a cutoff of 87.5 mm resulted in a sensitivity of 0.66 and specificity of 0.84 (AUC = 0.78, 0.72-0.84 95% CI). With bolus timing, cases had a longer TD (13.4 vs. 10.4 s, p < 0.0001).

CONCLUSION

Unsuspected LV systolic dysfunction can be recognized on a CTPA by identification of decreased aortic enhancement, LV enlargement and increased TD. This has important diagnostic implications for the patient presenting with shortness of breath, chest pain, or dyspnea.

Contrast opacification on thoracic CT angiography: challenges and solutions

Contrast flow and enhancement patterns seen on thoracic CT angiography (CTA) can often be challenging and may often reveal more than is immediately apparent. A non-diagnostic CTA following the initial contrast injection can be secondary to many causes; these include both extrinsic factors, such as injection technique/equipment failure (iv cannula, power injector), and intrinsic, patient-related factors. Contrast pressure and flow graphs often contain useful information regarding the etiology of a non-diagnostic scan. Understanding these graphs will help the radiologist plan a repeat contrast injection to overcome the deficiencies of the first injection and thus obtain a diagnostic scan. The current review article outlines normal and abnormal intravenous contrast dynamics, discusses how to recognize etiologies of non-diagnostic scans, and ultimately addresses techniques to overcome obstacles towards obtaining normal contrast opacification of the target vessel. In addition, there are some life-threatening findings, which unless sought for, may remain hidden in plain sight.

Key Points

• Using contrast enhancement and flow patterns to identify the cause of a non-diagnostic CTA.

• Recognize life threatening causes of altered contrast dynamics such as cardiac asystole.

• Non-target vessel opacification may hold key to underlying pathophysiology.

Dynamic contrast-enhanced magnetic resonance imaging in patients with pulmonary arterial hypertension

Dynamic contrast-enhanced (DCE) time-resolved magnetic resonance (MR) imaging is a technique whereby the passage of an intravenous contrast bolus can be tracked through the pulmonary vascular system. The aim of this study was to investigate the prognostic significance of DCE-MR pulmonary blood transit times in patients with pulmonary arterial hypertension (PAH). Seventy-nine patients diagnosed with PAH underwent pulmonary DCE imaging at 1.5 T using a time-resolved three-dimensional spoiled gradient echo sequence. The prognostic significance of two DCE parameters, full width at half maximum (FWHM) of the first-pass clearance curve and pulmonary transit time (PTT), along with demographic and invasive catheter measurements, was evaluated by univariate and bivariate Cox proportional hazards regression and Kaplan-Meier analysis. DCE-MR transit times were most closely correlated with cardiac index (CI) and pulmonary vascular resistance index (PVRI) and were both found to be accurate for detecting reduced CI (FWHM area under the curve [AUC] at receiver operating characteristic analysis = 0.91 and PTT AUC = 0.92, respectively) and for detecting elevated PVRI (FWHM AUC = 0.88 and PTT AUC = 0.84, respectively). During the follow-up period, 25 patients died. Patients with longer measurements of FWHM (P = 0.0014) and PTT (P = 0.004) were associated with poor outcome at Kaplan-Meier analysis, and both parameters were strong predictors of adverse outcome from Cox proportional hazards analysis (P = 0.013 and 0.010, respectively). At bivariate analysis, DCE measurements predicted mortality independent of age, gender, and World Health Organization functional class; however, invasive hemodynamic indexes CI, PVRI, and DCE measurements were not independent of one another. In conclusion, DCE-MR transit times predict mortality in patients with PAH and are closely associated with clinical gold standards CI and PVRI.

Cardiac imaging in adults with congenital heart disease: unknowns and issues related to diagnosis

OPINION STATEMENT

Many adults with simple and complex congenital heart disease (CHD) survive to adulthood. The goal of imaging is to diagnose the underlying anomalies and to detect late complications of their CHD and past surgical repair, in order to assess the need for further intervention and better prepare for endovascular or open-heart surgery. Cardiac magnetic resonance imaging (MRI) and computerized tomography (CT) are increasingly utilized in this patient population, due to the technical advances made to these modalities in the past decade regarding image acquisition and reconstruction, spatial and temporal resolution, and radiation dose reduction. Here, we aim to review the role of cardiac MR in initial diagnosis, pre-treatment planning and post-surgical follow-up of adults with CHD, and to discuss the ancillary role of cardiac CT in these patients.

Right ventricular plasticity and functional imaging

Right ventricular (RV) function is a strong independent predictor of outcome in a number of distinct cardiopulmonary diseases. The RV has a remarkable ability to sustain damage and recover function which may be related to unique anatomic, physiologic, and genetic factors that differentiate it from the left ventricle. This capacity has been described in patients with RV myocardial infarction, pulmonary arterial hypertension, and chronic thromboembolic disease as well as post-lung transplant and post-left ventricular assist device implantation. Various echocardiographic and magnetic resonance imaging parameters of RV function contribute to the clinical assessment and predict outcomes in these patients; however, limitations remain with these techniques. Early diagnosis of RV function and better insight into the mechanisms of RV recovery could improve patient outcomes. Further refinement of established and emerging imaging techniques is necessary to aid subclinical diagnosis and inform treatment decisions.

Pulmonary arterial hypertension: MR imaging-derived first-pass bolus kinetic parameters are biomarkers for pulmonary hemodynamics, cardiac function, and ventricular remodeling

PURPOSE

To prospectively compare contrast material-enhanced (CE) magnetic resonance (MR) imaging-derived right-to-left ventricle pulmonary transit time (PTT), left ventricular (LV) full width at half maximum (FWHM), and LV time to peak (TTP) between patients with pulmonary arterial hypertension (PAH) and healthy volunteers and to correlate these measurements with survival markers in patients with PAH.

MATERIALS AND METHODS

This HIPAA-compliant study received institutional review board approval. Written informed consent was obtained from all participants. Forty-three patients (32 with PAH [29 women; median age, 55.4 years], 11 with scleroderma but not PAH [seven women; median age, 58.9 years]) underwent right-sided heart catheterization and 3-T CE cardiac MR imaging. Eighteen age- and sex-matched healthy control subjects (12 women; median age, 51.7 years) underwent only CE MR imaging. A short-axis saturation-recovery gradient-echo section was acquired in the basal third of both ventricles, and right-to-left-ventricle PTT, LV FWHM, and LV TTP were calculated. Statistical analysis included Kruskal-Wallis test, Wilcoxon rank sum test, Spearman correlation coefficient, multiple linear regression analysis, and Lin correlation coefficient analysis.

RESULTS

Patients had significantly longer PTT (median, 8.2 seconds; 25th-75th percentile, 6.9-9.9 seconds), FWHM (median, 8.2 seconds; 25th-75th percentile, 5.7-11.4 seconds), and TTP (median, 4.8 seconds; 25th-75th percentile, 3.9-6.5 seconds) than did control subjects (median, 6.4 seconds; 25th-75th percentile, 5.7-7.1 seconds; median, 5.2 seconds; 25th-75th percentile, 4.1-6.1 seconds; median, 3.2 seconds; 25th-75th percentile, 2.8-3.8 seconds, respectively; P < .01 for each) and subjects with scleroderma but not PAH (median, 6.5 seconds; 25th-75th percentile, 5.6-7.0 seconds; median, 5.0 seconds; 25th-75th percentile, 4.0-7.3 seconds; median, 3.6 seconds; 25th-75th percentile, 2.7-4.0 seconds, respectively; P < .02 for each). PTT, LV FWHM, and LV TTP correlated with pulmonary vascular resistance index (P < .01), right ventricular stroke volume index (P ≤ .01), and pulmonary artery capacitance (P ≤ .02). In multiple linear regression models, PTT, FWHM, and TTP were associated with mean pulmonary arterial pressure and cardiac index.

CONCLUSION

CE MR-derived PTT, LV FWHM, and LV TTP are noninvasive compound markers of pulmonary hemodynamics and cardiac function in patients with PAH. Their predictive value for patient outcome warrants further investigation.

Time-resolved magnetic resonance angiography: evaluation of intrapulmonary circulation parameters in pulmonary arterial hypertension

PURPOSE

To determine whether pulmonary arterial and venous transit times measured by time-resolved magnetic resonance angiography (MRA) can be used as a diagnostic tool for pulmonary arterial hypertension (PAH).

MATERIALS AND METHODS

Twelve patients with confirmed PAH and 10 healthy volunteers were scanned with Institutional Review Board (IRB) approval. Time-resolved MRA and 2D phase contrast flow images of the pulmonary vasculature were acquired. Pulmonary arterial and venous transit times (PaTT and PvTT) and pulmonary valve flow (PVF) were obtained. Pulmonary arterial and pulmonary venous blood volumes (PaBV and PvBV) were calculated as the product of flow and transit time.

RESULTS

Patients with PAH showed statistically significant increases in PaTT and PvTT (P < 0.0004, P < 0.05, respectively) compared to controls. PaBV (165.2 ± 92.0 mL) was significantly higher in PAH subjects than controls (97.0 ± 47.1 mL) (P < 0.04), whereas PvBV (127.9 ± 148.9 mL) of PAH subjects had no significant increase from those of healthy controls (142.5 ± 104.1 mL) (P < 0.38).

CONCLUSION

Pulmonary arterial transit times measured using time-resolved MRA can be used as a simple, noninvasive metric for detection of altered hemodynamics in PAH.

Four-dimensional phase contrast magnetic resonance angiography: potential clinical applications

Unlike other magnetic resonance angiographic techniques, phase contrast imaging (PC-MRI) offers co-registered morphologic images and velocity data within a single acquisition. While the basic principle of PC-MRI dates back almost 3 decades, novel time-resolved three-dimensional PC-MRI (4D PC-MRI) approaches have become increasingly researched over the past years. So-called 4D PC-MRI includes three-directional velocity encoding in a three-dimensional imaging volume over time, thereby providing the opportunity to comprehensively analyze human hemodynamics in vivo. Moreover, its large volume coverage offers the option to study systemic hemodynamic effects. Additionally, this offers the possibility to re-visit flow in any location of interest without being limited to predetermined two-dimensional slices. The attention received for hemodynamic research is partially based on flow-based theories of atherogenesis and arterial remodeling. 4D PC-MRI can be used to calculate flow-related vessel wall parameters and may hence serve as a diagnostic tool in preemptive medicine. Furthermore, technical improvements including the availability of sufficient computing power, data storage capabilities, and optimized acceleration schemes for data acquisition as well as comprehensive image processing algorithms have largely facilitated recent research progresses. We will present an overview of the potential of this relatively young imaging paradigm. After acquisition and processing the data in morphological and phase difference images, various visualization strategies permit the qualitative analysis of hemodynamics. A multitude of quantitative parameters such as pulse wave velocities and estimates of wall shear stress which might serve as future biomarkers can be extracted. Thereby, exciting new opportunities for vascular imaging and diagnosis are available.